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Sample records for cannulated screw fixation

  1. Latarjet Fixation: A Cadaveric Biomechanical Study Evaluating Cortical and Cannulated Screw Fixation.

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    Alvi, Hasham M; Monroe, Emily J; Muriuki, Muturi; Verma, Rajat N; Marra, Guido; Saltzman, Matthew D

    2016-04-01

    Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure. To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure. Controlled laboratory study. Ten fresh-frozen matched-pair shoulder specimens were randomized into 2 separate fixation groups: (1) 3.5-mm stainless steel cortical screws and (2) 4.0-mm stainless steel partially threaded cannulated cancellous screws. Shoulder specimens were dissected free of all soft tissue and a 25% glenoid defect was created. The coracoid process was osteomized, placed at the site of the glenoid defect, and fixed in place with 2 parallel screws. All 10 specimens failed by screw cutout. Nine of 10 specimens failed by progressive displacement with an increased number of cycles. One specimen in the 4.0-mm screw group failed by catastrophic failure on initiation of the testing protocol. The 3.5-mm screws had a mean of 274 cycles (SD, ±171 cycles; range, 10-443 cycles) to failure. The 4.0-mm screws had a mean of 135 cycles (SD, ±141 cycles; range, 0-284 cycles) to failure. There was no statistically significant difference between the 2 types of screws for cycles required to cause failure (P = .144). There was no statistically significant difference in energy or cycles to failure when comparing the stainless steel cortical screws versus partially threaded cannulated cancellous screws. Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option.

  2. Transpedicular screw fixation in the thoracic and lumbar spine with a novel cannulated polyaxial screw system

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    Lutz Weise

    2008-10-01

    Full Text Available Lutz Weise, Olaf Suess, Thomas Picht, Theodoros KombosNeurochirurgische Klinik, Charité – Universitätsmedizin Berlin, Berlin, GermanyObjective: Transpedicular screws are commonly and successfully used for posterior fixation in spinal instability, but their insertion remains challenging. Even using navigation techniques, there is a misplacement rate of up to 11%. The aim of this study was to assess the accuracy of a novel pedicle screw system.Methods: Thoracic and lumbar fusions were performed on 67 consecutive patients for tumor, trauma, degenerative disease or infection. A total of 326 pedicular screws were placed using a novel wire-guided, cannulated, polyaxial screw system (XIA Precision®, Stryker. The accuracy of placement was assessed post operatively by CT scan, and the patients were followed-up clinically for a mean of 16 months.Results: The total medio-caudal pedicle wall perforation rate was 9.2% (30/326. In 19 of these 30 cases a cortical breakthrough of less than 2 mm occurred. The misplacement rate (defined as a perforation of 2 mm or more was 3.37% (11/326. Three of these 11 screws needed surgical revision due to neurological symptoms or CSF leakage. There have been no screw breakages or dislocations over the follow up-period.Conclusion: We conclude that the use of this cannulated screw system for the placement of pedicle screws in the thoracic and lumbar spine is accurate and safe. The advantages of this technique include easy handling without a time-consuming set up. Considering the incidence of long-term screw breakage, further investigation with a longer follow-up period is necessary.Keywords: spinal instrumentation, pedicle screws, misplacement, pedicle wall perforation

  3. Biomechanical testing of bioabsorbable cannulated screws for slipped capital femoral epiphysis fixation.

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    Kroeber, Markus W; Rovinsky, David; Haskell, Andrew; Heilmann, Moira; Llotz, Jeff; Otsuka, Norman

    2002-06-01

    This study compared cannulated 4.5-mm bioabsorbable screws made of self-reinforced poly-levolactic acid to cannulated 4.5-mm steel and titanium screws for resistance to shear stress and ability to generate compression in a polyurethane foam model of slipped capital femoral epiphysis fixation. The maximum shear stress resisted by the three screw types was similar (self-reinforced poly-levolactic acid 371 +/- 146 MPa, steel 442 +/- 43 MPa, and titanium 470 +/- 91 MPa). The maximum compression generated by both the self-reinforced poly-levolactic acid screw (68.5 +/- 3.3 N) and the steel screw (63.3 +/- 5.9 N) was greater than that for the titanium screw (3 +/- 1.4 N, P <.05). These data suggest cannulated self-reinforced poly-levolactic acid screws can be used in the treatment of slipped capital femoral epiphysis because of their sufficient biomechanical strength.

  4. Fibular grafting with cannulated hip screw fixation in late femoral neck fracture in young adults

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    Goyal R

    2006-01-01

    Full Text Available Background: We reviewed the operative results of fibular bone graft with cannulated hip screw fixation in femoral neck fracture in young adults. Method: Sixteen young adults with femoral neck fracture were treated by fibular bone graft with cannulated hip screw fixation. All the fractures were more than 3 weeks old. Results: Results were assessed in 15 patients while one patient died due to complications not related to surgery. Union occurred in all 15 patients. One patient had intra-operative complication in the form of screw cut out with graft in the joint space. The average fallow up was 24.4 months. Out of 15 patients assessed clinico-radiologically 11 showed good results, 3 had fair while 1 had poor result. Conclusion: We conclude that this is a simple and cost effective procedure for late femoral fleck fracture in young adults with good results.

  5. Comparison of cannulated screws versus compression staples for subtalar arthrodesis fixation.

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    Herrera-Pérez, Mario; Andarcia-Bañuelos, Cesar; Barg, Alexej; Wiewiorski, Martin; Valderrabano, Victor; Kapron, Ashley L; De Bergua-Domingo, Josep Maria; Pais-Brito, Jose Luis

    2015-02-01

    Different fixation techniques have been described in the literature for isolated subtalar arthrodesis (ISA). The purpose of this study was to compare the fusion rate and clinical outcome of ISA using cannulated compression screws or compression staples. Thirty-three patients (33 feet) underwent ISA using screw (17 feet) or staples (16 feet) fixation. Patients were followed for 42.7 ± 16.4 months (range, 24.5-84.3 months). The subtalar fusion was assessed radiographically and clinically. Clinical outcome measures included the visual analog scale (VAS) for pain and American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score. The average pain score decreased significantly from 6.4 ± 1.1 (range, 5-9) to 0.8 ± 1.3 (range, 0-4) (P < .001). In the screws group, the average AOFAS hindfoot score increased significantly from 54.6 ± 8.8 (range, 37-67) preoperatively to 86.1 ± 7.1 (range, 71-91) postoperatively (P < .001). In the staples group, the average AOFAS hindfoot score increased significantly from 53.4 ± 11.1 (range, 33-69) preoperatively to 83.4 ± 6.9 (range, 71-91) postoperatively (P < .001). The AOFAS hindfoot score was comparable in both groups (P = .149). Only the AOFAS hindfoot score function subgroup in the screw fixation was significantly higher than in the staples fixation group (P = .005). There were 4 cases of nonunion at the site of subtalar arthrodesis (2 from screws group, 2 from staples group). The complication rate was comparable in both groups. The fusion rate was comparable in both groups, while the postoperative functional outcome was significantly better in the screw fixation group. Level III, retrospective comparative cohort study. © The Author(s) 2014.

  6. Internal Fixation of Transverse Patella Fractures Using Cannulated Cancellous Screws with Anterior Tension Band Wiring

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    Khan I

    2016-07-01

    Full Text Available Aims: To evaluate the effectiveness and safety of anterior tension band wiring technique using two cannulated cancellous screws in patients with transverse (AO34-C1 or transverse with mildly comminuted (AO34-C2 patellar fractures. Materials and Methods: This is a prospective study of 25 patients with transverse fracture or transverse fracture with mildly comminuted patella fractures. All the patients were treated with open reduction and internal fixation using two parallel cannulated screws and 18G stainless steel wire as per the tension band principle. Results: There were eighteen males (72% and seven females (28%. The age group ranged from 24 to 58 years, with mean age of 38 years. The most common mode of injury was fall (72% followed by road traffic accident (20% and violent quadriceps contraction (8%. Transverse fracture was present in 60% and transverse fracture with mild comminution in 40% of patients. Mean time to achieve union was 10.7 weeks (range 8-12 weeks. Mean ROM at three months was 113.8 degree (90-130 and at final follow up this improved to 125.4 degrees (range 100-140. There was one case of knee stiffness and no case of implant failure was observed. Patients were evaluated using Bostman scoring, the mean score at three months being 26.04 which improved to 27.36 at the end of final follow up at one year. Conclusion: Cannulated cancellous screws with anterior tension band wiring is a safe, reliable and reproducible method in management of transverse patellar fractures, with less chances of implant failure and soft tissue irritation.

  7. Correlation Between Residual Displacement and Osteonecrosis of the Femoral Head Following Cannulated Screw Fixation of Femoral Neck Fractures.

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    Wang, Chen; Xu, Gui-Jun; Han, Zhe; Jiang, Xuan; Zhang, Cheng-Bao; Dong, Qiang; Ma, Jian-Xiong; Ma, Xin-Long

    2015-11-01

    The aim of the study was to introduce a new method for measuring the residual displacement of the femoral head after internal fixation and explore the relationship between residual displacement and osteonecrosis with femoral head, and to evaluate the risk factors associated with osteonecrosis of the femoral head in patients with femoral neck fractures treated by closed reduction and percutaneous cannulated screw fixation.One hundred and fifty patients who sustained intracapsular femoral neck fractures between January 2011 and April 2013 were enrolled in the study. All were treated with closed reduction and percutaneous cannulated screw internal fixation. The residual displacement of the femoral head after surgery was measured by 3-dimensional reconstruction that evaluated the quality of the reduction. Other data that might affect prognosis were also obtained from outpatient follow-up, telephone calls, or case reviews. Multivariate logistic regression analysis was applied to assess the intrinsic relationship between the risk factors and the osteonecrosis of the femoral head.Osteonecrosis of the femoral head occurred in 27 patients (18%). Significant differences were observed regarding the residual displacement of the femoral head and the preoperative Garden classification. Moreover, we found more or less residual displacement of femoral head in all patients with high quality of reduction based on x-ray by the new technique. There was a close relationship between residual displacement and ONFH.There exists limitation to evaluate the quality of reduction by x-ray. Three-dimensional reconstruction and digital measurement, as a new method, is a more accurate method to assess the quality of reduction. Residual displacement of the femoral head and the preoperative Garden classification were risk factors for osteonecrosis of the femoral head. High-quality reduction was necessary to avoid complications.

  8. Percutaneous cannulated screw fixation of sacral fractures and sacroiliac joint disruptions with CT-controlled guidewires performed by interventionalists: Single center experience in treating posterior pelvic instability

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    Fischer, Sebastian, E-mail: sebastian.fischer@kgu.de [Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Vogl, Thomas J. [Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Marzi, Ingo [Department of Trauma, Hand and Reconstructive Surgery, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Zangos, Stephan; Wichmann, Julian L.; Scholtz, Jan-Erik; Mack, Martin G. [Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Schmidt, Sven [Orthopaedic University Hospital Friedrichsheim, Marienburgstraße, 260528 Frankfurt (Germany); Eichler, Katrin [Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany)

    2015-02-15

    Highlights: • Minimally invasive sacroiliac screw fixation can be performed under CT-imaging. • Guidewires help in precise placement of cannulated sacroiliac screw. • Only a diminishing rate of misplacements can be seen. • The method appears to be a safe and very accurate procedure. - Abstract: Objective: The purpose of our study was to evaluate minimally invasive sacroiliac screw fixation for treatment of posterior pelvic instability with the help of CT controlled guidewires, assess its accuracy, safety and effectiveness, and discuss potential pitfalls. Methods: 100 guidewires and hollow titan screws were inserted in 38 patients (49.6 ± 19.5 years) suffering from 35 sacral fractures and/or 16 sacroiliac joint disruptions due to 33 (poly-)traumatic, 2 osteoporotic and 1 post-infectious conditions. The guidewire and screw positions were analyzed in multiplanar reconstructions. Results: The mean minimal distance between guidewire and adjacent neural foramina was 4.5 ± 2.01 mm, with a distinctly higher precision in S1 than S2. Eight guidewires showed cortical contacts, resulting in a total of 2% mismatched screws with subsequent wall violation. The fracture gaps were reduced from 3.6 ± 0.53 mm to 1.2 ± 0.54 mm. During follow-up 3 cases of minor iatrogenic sacral impaction (<5 mm) due to the bolting and 2 cases of screw loosening were observed. Interventional time was 84.0 min with a mean of 2.63 screws per patient whilst acquiring a mean of 93.7 interventional CT-images (DLP 336.7 mGy cm). Conclusions: The treatment of posterior pelvic instability with a guidewire-based screw insertion technique under CT-imaging results in a very high accuracy and efficacy with a low complication rate. Careful attention should be drawn to radiation levels.

  9. Biomechanical Analysis of Latarjet Screw Fixation: Comparison of Screw Types and Fixation Methods.

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    Shin, Jason J; Hamamoto, Jason T; Leroux, Timothy S; Saccomanno, Maristella F; Jain, Akshay; Khair, Mahmoud M; Mellano, Christen R; Shewman, Elizabeth F; Nicholson, Gregory P; Romeo, Anthony A; Cole, Brian J; Verma, Nikhil N

    2017-09-01

    To compare the initial fixation stability, failure strength, and mode of failure of 5 different screw types and fixation methods commonly used for the classic Latarjet procedure. Thirty-five fresh-frozen cadaveric shoulder specimens were allocated into 5 groups. A 25% anteroinferior glenoid defect was created, and a classic Latarjet coracoid transfer procedure was performed. All grafts were fixed with 2 screws, differing by screw type and/or fixation method. The groups included partially threaded solid 4.0-mm cancellous screws with bicortical fixation, partially threaded solid 4.0-mm cancellous screws with unicortical fixation, fully threaded solid 3.5-mm cortical screws with bicortical fixation, partially threaded cannulated 4.0-mm cancellous screws with bicortical fixation, and partially threaded cannulated 4.0-mm captured screws with bicortical fixation. All screws were stainless steel. Outcomes included cyclic creep and secant stiffness during cyclic loading, as well as load and work to failure during the failure test. Intergroup comparisons were made by a 1-way analysis of variance. There were no significant differences among different screw types or fixation methods in cyclic creep or secant stiffness after cyclic loading or in load to failure or work to failure during the failure test. Post-failure radiographs showed evidence of screw bending in only 1 specimen that underwent the Latarjet procedure with partially threaded solid cancellous screws with bicortical fixation. The mode of failure for all specimens analyzed was screw cutout. In this biomechanical study, screw type and fixation method did not significantly influence biomechanical performance in a classic Latarjet procedure. When performing this procedure, surgeons may continue to select the screw type and method of fixation (unicortical or bicortical) based on preference; however, further studies are required to determine the optimal method of treatment. Surgeons may choose the screw type and

  10. Surgical treatment of the osteoporotic spine with bone cement-injectable cannulated pedicle screw fixation: technical description and preliminary application in 43 patients

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    Fei Dai

    2015-02-01

    Full Text Available OBJECTIVES: To describe a new approach for the application of polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws. METHODS: Between June 2010 and February 2013, 43 patients with degenerative spinal disease and osteoporosis (T-score <-2.5 underwent lumbar fusion using cement-injectable cannulated pedicle screws. Clinical outcomes were evaluated using a Visual Analog Scale and the Oswestry Disability Index. Patients were given radiographic follow-up examinations after 3, 6, and 12 months and once per year thereafter. RESULTS: All patients were followed for a mean of 15.7±5.6 months (range, 6 to 35 months. The Visual Analog Scale and Oswestry Disability Index scores showed a significant reduction in back pain (p = 0.018 and an improvement in lower extremity function (p = 0.025 in patients who underwent lumbar fusion using the novel screw. Intraoperative cement leakage occurred in four patients, but no neurological complications were observed. Radiological observation indicated no loosening or pulling out of the novel screw, and bone fusion was excellent. CONCLUSIONS: The described polymethylmethacrylate augmentation technique using bone cement-injectable cannulated pedicle screws can reduce pain and improve spinal dysfunction in osteoporotic patients undergoing osteoporotic spine surgery.

  11. Mechanical Comparison of Headless Screw Fixation and Locking Plate Fixation for Talar Neck Fractures.

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    Karakasli, Ahmet; Hapa, Onur; Erduran, Mehmet; Dincer, Cemal; Cecen, Berivan; Havitcioglu, Hasan

    2015-01-01

    For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A reproducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p = .655), yield load (p = .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues.

  12. Pullout strength of pedicle screws with cement augmentation in severe osteoporosis: A comparative study between cannulated screws with cement injection and solid screws with cement pre-filling

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    Lee Yen-Chen

    2011-02-01

    Full Text Available Abstract Background Pedicle screws with PMMA cement augmentation have been shown to significantly improve the fixation strength in a severely osteoporotic spine. However, the efficacy of screw fixation for different cement augmentation techniques, namely solid screws with retrograde cement pre-filling versus cannulated screws with cement injection through perforation, remains unknown. This study aimed to determine the difference in pullout strength between conical and cylindrical screws based on the aforementioned cement augmentation techniques. The potential loss of fixation upon partial screw removal after screw insertion was also examined. Method The Taguchi method with an L8 array was employed to determine the significance of design factors. Conical and cylindrical pedicle screws with solid or cannulated designs were installed using two different screw augmentation techniques: solid screws with retrograde cement pre-filling and cannulated screws with cement injection through perforation. Uniform synthetic bones (test block simulating severe osteoporosis were used to provide a platform for each screw design and cement augmentation technique. Pedicle screws at full insertion and after a 360-degree back-out from full insertion were then tested for axial pullout failure using a mechanical testing machine. Results The results revealed the following 1 Regardless of the screw outer geometry (conical or cylindrical, solid screws with retrograde cement pre-filling exhibited significantly higher pullout strength than did cannulated screws with cement injection through perforation (p = 0.0129 for conical screws; p = 0.005 for cylindrical screws. 2 For a given cement augmentation technique (screws without cement augmentation, cannulated screws with cement injection or solid screws with cement pre-filling, no significant difference in pullout strength was found between conical and cylindrical screws (p >0.05. 3 Cement infiltration into the open cell of

  13. Odontoid cannulated screw fixation using digital navigation based on three-dimensional printing technique%基于3D打印齿状突空心钉置入的数字化导航

    Institute of Scientific and Technical Information of China (English)

    陈宣煌; 张国栋; 吴长福; 林海滨; 陈旭; 余正希; 孙宇庆

    2015-01-01

    BACKGROUND:Odontoid fracture is very common in cervical spine injuries, the special position of odontoid process, which is adjacent to important anatomic structure, makes screw placement difficult, and a slight discrepancy in position and orientation of the inserted screw leads to a decrease in intensity of internal fixation, even invalid internal fixation. Therefore, it is very necessary to develop an individualized treatment protocol by which screws can be precisely and safely placed and which is worthy of clinical popularization. OBJECTIVE:To study the navigation of Mimics software and three dimensional (3D)-printed module in anterior odontoid cannulated screw fixation and to investigate its feasibility and accuracy. METHODS:Sixteen human cadaveric cervical spines were scanned by a continuous thin-slice CT scanner. Original DICOM CT images were three-dimensional y reconstructed using Mimics software. The screw channel and support column were designed for C2 vertebra odontoid cannulated screw fixation for odontoid fracture. Segmentation of bone surface was performed. Navigation modules with screw channel were built using 3D printing technique. Navigation modules were used to aid screw placement. Screw fitting and placement were evaluated using X-ray and CT scan. RESULTS AND CONCLUSION:Total y 16 navigation modules were built and 22 screws were implanted. During and after screw placement, the cortical bone along screw channel and surrounding the vertebral body was not cracked. Postoperative X-ray and CT scans showed that some factors regarding screw placement such as entry point, orientation and depth of placement were consistent with those ideal factors simulated by Mimics software. The navigation modules were closely attached to the corresponding bony structure in front of the vertebral body, with a satisfactory gomphosis. Screw fitting and stability were good during application. These results verify that with the aid of navigation module, anterior odontoid

  14. Comparison of percutaneous cannulated screw fixation and calcium sulfate cement grafting versus minimally invasive sinus tarsi approach and plate fixation for displaced intra-articular calcaneal fractures: a prospective randomized controlled trial.

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    Feng, Yongzeng; Shui, Xiaolong; Wang, Jianshun; Cai, Leyi; Yu, Yang; Ying, Xiaozhou; Kong, Jianzhong; Hong, Jianjun

    2016-07-15

    The management of displaced intra-articular calcaneal fractures (DIACFs) remains challenging and controversial. A prospective randomized controlled trial was conducted to compare percutaneous reduction, cannulated screw fixation and calcium sulfate cement (PR+CSC) grafting with minimally invasive sinus tarsi approach and plate fixation (MISTA) for treatment of DIACFs. Ultimately, 80 patients with a DIACFs were randomly allocated to receive either PR+CSC (N = 42) or MISTA (N = 38). Functional outcomes were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scores. Radiological results were assessed using plain radiographs and computed tomography (CT) scans, and postoperative wound-related complications were also recorded. The average time from initial injury to operation and the average operation time in the PR+CSC group were both significantly shorter than those in the MISTA group (p < 0.05). There were significantly fewer complications in the PR+CSC group than those in the MISTA group (7.1 % vs 28.9 %, p < 0.001). The calcaneal width immediate postoperatively and at the final follow-up in the MISTA group were obviously improved compared to those in the PR+CSC group (p < 0.001). The variables of sagittal motion and hindfoot motion of the AOFAS scoring system in the PR+CSC group were significantly higher than those in the MISTA group (p < 0.05). The good and excellent results in the two groups were comparable for Sanders Type-II calcaneal fractures, but the good to excellent rate in the MISTA group was significantly higher for Sanders Type-III fractures (p < 0.05). The clinical outcomes are comparable between the two minimally invasive techniques in the treatment of Sanders Type-II DIACFs. The PR+CSC grafting is superior to the MISTA in terms of the average time between initial injury and operation, operation time, wound-related complications and subtalar joint activity. However, the MISTA has its own

  15. Optimum Configuration of Cannulated Lag Screws for the Fixation of Femoral Neck Fractures:A Biomechanical Study%空心钉在股骨颈中构型的生物力学研究

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    王世坤; 王志义; 刘振宇

    2011-01-01

    Objective To determine which of configurations,a inverse triangular configuration and an upright triangular configuration,provide significantly improved fixation strength for fixation of femoral neck fractures with three cannulated lag screws. Methods Eight pairs of femurs were selected. A osteotomy was made. One femur of each pair was randomly selected for stabilization using cannulated lag screws in either an inverse triangular configuration or an upright triangular configuration. An Universal Material Testing Machine was used to apply vertical loads directly onto the femoral head. At each applied load, the inferior femoral head displacement reading and shearing displacement of the osteotomy were recorded. Results The inverse triangular configuration group sustained a higher (P<0. 05) average ultimate load to failure (3375 N) than did specimens in the upright triangular configuration (2725 N). At a load of 8 0 0 N , the average shearing displacement was less for specimens stabilized in the inverse triangular configuration (39. 1 μm) than for those stabilized in the upright triangular configuration (93. 1 μm;P<0. 05). Conclusion Three cannulated lag screws placed in the inverse triangular configuration provide significantly improved fixation strength compared with three screws placed in the upright triangular configuration for fixation of femoral neck fractures without posterior comminution.%目的 通过生物力学实验探讨空心钉固定股骨颈骨折时,3枚螺钉的构型对固定强度和稳定性的影响.方法 选取25~70岁尸体股骨8对,左右股骨随机分成两组.倾角50°截骨,3枚空心钉分别呈正三角和倒三角构型固定股骨颈骨折.生物力学实验机对股骨-螺钉复合体进行线性递增的加载,同时测量股骨头的位移和沿截骨面的剪切化移.结果 倒三角形构型的空心固定组较正三角形组具有更高的极限负荷和抗剪切能力,差异有统计学意义(P<0.05).结论 对于无

  16. Four quadrant parallel peripheral screw fixation for displaced femoral neck fractures in elderly patients

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    Bhava RJ Satish

    2013-01-01

    Conclusion: Closed reduction and cannulated cancellous screw fixation gives satisfactory functional results in large group of elderly patients. The four quadrant parallel peripheral (FQPP screw fixation technique gives good stability, allows controlled collapse, avoids fixation failure and achieves predictable bone healing in displaced femoral neck fracture in patients ≥50 years of age.

  17. CT引导经皮置钉治疗病理性骶髂关节疼痛%Percutaneous CT-guided fixation of sacroiliac joint with cannulated lag screw for treating pathologic pain of sacroiliac joint

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    胡勇; Ebraheim NA; 徐荣明; 薛波

    2005-01-01

    BACKGROUND: Most patients with posterior pelvic and sacroiliac metastasis are terminally ill. Their treatment is usually palliative and directed toward relieving pain and improving the quality of life with the least possible intervention.OBJECTIVE: To investigate the possibility of percutaneous CT-guided fixation of sacroiliac joint with cannulated lag screw treatment for pathologic pain of sacroiliac joint.DESIGN: Preoperative and postoperative auto-control clinical trial was conducted.SETTING and PARTICIPANTS: The study was completed in Ningbo Sixth Hospital. Eight patients(4 males and 4 females, aged 12 years to 83 years)with metastatic tumor of sacroiliac joint were selected for our study.METHODS: After treatment with percutaneous CT-guided fixation of sacroiliac joint with cannulated lag screw, the sacroiliac joint of the 8 patients became pathologically unstable. Enneking pain scale was obtained preoperatively and postoperatively.MAIN OUTCOME MEASURES: Pain recovery was assessed preoperatively and postoperatively.RESULTS: After 2. 5 years' follow-up, pain of the patients was relieved with a range of 0 to 5(mean 3.2).CONCLUSION: Percutaneous cannulated lag screws with CT guidance help alleviate the patients' pain due to pathologically unstable sacroiliac joint.%背景:大多数后路骨盆和骶髂关节转移肿瘤患者为临终患者,其治疗目的主要是姑息治疗和减轻疼痛,提高患者生活质量.目的:探讨在CT引导下经皮微创技术置入空心拉力螺钉治疗病理性骶髂关节疼痛.设计:前后对照的临床试验.地点和对象:在浙江省宁波市第六医院完成.8例骶髂关节转移肿瘤患者,男4例,女4例;年龄12~83岁.方法:对8例骶髂关节转移肿瘤患者试行在CT引导下经皮微创技术置入空心拉力螺钉稳定病理性骶髂关节不稳.术前和术后进行Enneking疼痛评分.主要观察指标:手术前后疼痛恢复情况.结果:经2年5个月随访,患者疼痛减轻,平均3.2

  18. Management of Cannulated Screw Failure and Recurrent SCFE Displacement – Case Report

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    Nathan A Jacobson

    2014-01-01

    Full Text Available Introduction: SCFE occurs in 10 per 100,000 in some regions of the United States with the incidence continuing to increase. Percutaneous screw fixation is a well-accepted treatment for this disorder for over 20 years but management of complications is not well elucidated in the literature. Case Report: We describe a case where a traumatic unstable SCFE that was initially treated with closed reduction and fixation with a single transphyseal screw went on to hardware failure with recurrence of the deformity. The complication was successfully treated with closed reduction and re- cannulating the fractured screw within the epiphysis and extracting it using a conical extraction screw commonly referred to as an “easy out.” Three trans physeal screws were then placed for improved fixation strength. Follow-up at 9 months demonstrates a fused physis and no signs of avascular necrosis of the femoral head. Conclusion: Percutaneous management of SCFE screw breakage is possible utilizing specialized instruments and a precise and gentle manipulation preventing the need for more invasive treatments with their obligatory potential complications profile. Keywords: Hardware Failure, Slip Recurrence, SCFE, Complication, Conical Extraction Screw, Easy Out.

  19. Management of Cannulated Screw Failure and Recurrent SCFE Displacement – Case Report

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    Jacobson, Nathan A; Feierabend, Siegfried P; Lee, Christopher L

    2014-01-01

    Introduction: SCFE occurs in 10 per 100,000 in some regions of the United States with the incidence continuing to increase. Percutaneous screw fixation is a well-accepted treatment for this disorder for over 20 years but management of complications is not well elucidated in the literature. Case Report: We describe a case where a traumatic unstable SCFE that was initially treated with closed reduction and fixation with a single transphyseal screw went on to hardware failure with recurrence of the deformity. The complication was successfully treated with closed reduction and re-cannulating the fractured screw within the epiphysis and extracting it using a conical extraction screw commonly referred to as an “easy out.” Three trans physeal screws were then placed for improved fixation strength. Follow-up at 9 months demonstrates a fused physis and no signs of avascular necrosis of the femoral head. Conclusion: Percutaneous management of SCFE screw breakage is possible utilizing specialized instruments and a precise and gentle manipulation preventing the need for more invasive treatments with their obligatory potential complications profile. PMID:27298941

  20. The role of Esmarch bandage and percutaneous cannulated cancellous screws in tibial condylar fracture

    Directory of Open Access Journals (Sweden)

    Shete Kiran

    2006-01-01

    Full Text Available Background : Proximal tibial fractures involving the condyles are often a matter of debate with regards to surgical management. The purpose of this study was to evaluate the efficacy of using closed reduction with an eschmarch bandage, gentle hammering, and use of percutaneous cannulated cancellous screws for fixation and buttressing the fracture, as a treatment modality for specific tibial condyle fractures. Methods : We evaluated 90 closed upper end tibia fractures, Schatzker types I, III, and IV, treated with closed reduction using an esmarch bandage and minimally invasive percutaneus fixation with cannulated cancellous screws. Results : We achieved excellent results in 33.3% of the cases, good result in 50%, a fair result in 13.3 %, and a poor result in 3.3 % cases. Conclusion : This minimally invasive modality of treatment of upper end tibia fractures gives satisfactory results. The use of esmarch bandage and gentle hammering to help achieve acceptable reduction has the advantage of being relatively simple and easily reproducible, without the use of any expensive extra medical equipment. The percutaneous fixation with cancellous screws has minimal morbidity. Thus, this is a good modality of treatment of tibial condlyle fractures of Schatzker types I, III and IV.

  1. 石膏固定和空心螺钉内固定修复腕部舟状骨新鲜骨折:功能恢复比较%Plaster fixationversus cannulated screw internal fixation for the wrist scaphoid bone fresh fracture:comparison of functional recovery

    Institute of Scientific and Technical Information of China (English)

    卡依沙尔•买买提明; 赵岩

    2015-01-01

      结果与结论:随访3-6个月对比分析石膏组和空心螺钉组患者腕关节功能Cooney评分,空心螺钉组优9例,良1例,可1例,差0例;石膏组优1例,良5例,可3例,差2例,空心螺钉组患者治疗后优良率为91%,石膏组患者治疗后优良率为55%,空心螺钉组显著高于石膏组(t=4.817,P OBJECTIVE:To compare and analyze functional recovery of the wrist scaphoid bone fresh fracture after plaster fixation and internal fixation. METHODS: Twenty-two patients with wrist scaphoid bone fresh fracture were recruited from the First Affiliated Hospital of Xinjiang Medical University from March 2012 to March 2014, and the injury time was 2 hours to 12 days. Preoperative X-ray films revealed that, the involved patients had no wrist scaphoid bone colapses, lunate bone dislocation, ischemic necrosis of bone and osseous changes. Al the cases showed shift, unstable fractures. According to the patient’s wiling and the surgical method, the involved patients were divided into two groups, receiving plaster fixation and cannulated screw internal fixation respectively. Each group contained 11 cases. Wrist joint function was evaluated using Cooney score system. There was no significant difference in the age distribution and gender between the two groups (P > 0.05). RESULTS AND CONCLUSION: At 3-6 months of folow-up, wrist joint function of patients in the two groups was compared and analyzed with Cooney scores. According to the Cooney scores, nine cases in internal fixation group were excelent, 1 good, 1 fair and none poor; one case in plaster fixation group was excelent, 5 good, 3 fair, and 2 poor. The excelent and good rate in the internal fixation group was significantly higher than that in the plaster fixation group (91%, 55%,t=4.817,P < 0.05). Although plaster fixation has certain effects on wrist scaphoid bone fresh fracture, open reduction and canulated screw fixation has obvious effect and promotes the

  2. Tissue reaction to implants of different metals: a study using guide wires in cannulated screws

    National Research Council Canada - National Science Library

    Devine, D M; Leitner, M; Perren, S M; Boure, L P; Pearce, S G

    2009-01-01

    ... (316L stainless steel) cannulated screws. However the possibility of galvanic or crevice corrosion and adverse tissue reaction, exists when using dissimilar materials, particularly in the event that a guide wire breaks, and remains in situ...

  3. Application of individualization percutaneous cannulated screws fixation with the help of com-puter-assisted design in carpal scaphoid fracture%计算机辅助设计个体化经皮空心螺钉内固定治疗腕舟骨骨折的应用

    Institute of Scientific and Technical Information of China (English)

    曾俊; 林旭; 郭勇; 钟泽莅; 曹林虎; 谭伦

    2014-01-01

    目的:利用Mimics软件设计一种腕舟骨骨折个体化掌侧经皮空心螺钉置钉技术。方法将24例成人腕舟骨骨折腕关节CT扫描数据导入Mimics软件,在Mimics软件中进行腕关节三维重建,模拟舟骨手术,制定舟骨个体化置钉参数并模拟置钉,据此参数在腕舟骨上经皮置钉。术后行腕关节CT扫描,验证置钉准确性。结果 Mimics重建图像和CT扫描的腕舟骨参数差异无统计学意义,能准确反映舟骨三维立体结构。用该方法对24例成人腕舟骨骨折行经皮空心螺钉固定,术后CT显示螺钉位置良好,随访腕关节功能良好。结论用Mimics软件对腕关节进行三维重建,模拟手术,测量、制订详细合理的个体化置钉参数,可优化手术方案与方式,减少并发症,降低手术风险,提高临床治疗效果。%Objective To provide a individualization volar percutaneous cannulated screws fixation with the help of Mimics-assisted design in carpal scaphoid fracture surgery. Methods Three-dimensional reconstruction of 24 CT scanned adult carpal scaphoid fractures were performed by using Mimics software. The operations were analogued in Mimics software and then individual fixation parameters were designed. Based on which percutaneous cannulated screws fixation of carpal scaphoid fracture were performed under Mimics individual fixation parameters. The accuracy of postoperation was assessed by CT scanning. Results There was no statistical difference in parameters of the CT scan and Mimics reconstruction images, which could reflect carpal scaphoid accurate three dimensional structure. Postoperation CT scanning showed that the cannulated screws were fixed successfully in 24 adult carpal scaphoid frac-tures. The function of wrists were well in follow-up. Conclusions Three-dimensional reconstruction of the carpal scaphoid by using mimics software, sham operated,measurement and design individual screw fixation parameters

  4. Effect of different inner core diameters on structural strength of cannulated pedicle screws under various lumbar spine movements.

    Science.gov (United States)

    Chang, Chia-Ming; Lai, Yu-Shu; Cheng, Cheng-Kung

    2017-08-15

    Currently, cannulated pedicle screws have been widely used in minimal invasive or navigation techniques. However, the stress distribution and the strength of different core diameters of cannulated screw are not clear. This study aimed to investigate the mechanical strength of cannulated screws with different inner core diameter under various lumbar spine movements using finite element analysis. The results showed that the von-Mises stress of a cannulated screw was larger than that of a solid screw in all loading conditions, especially above 2 mm in cannulated core diameter. In lateral bending, extension, and flexion, the maximum von-Mises stress was found approximate to the proximal thread for all types of screws. In rotation condition, the maximum von-Mises stress was located at the middle of the screw. Additionally, the difference in stiffness of instrumented levels was not significant among four screws under the same loading condition. Cannulated screws could provide enough stability for the vertebral body fusion comparing to solid screws. The diameter of cannulated core is suggested not to exceed 2.0 mm.

  5. 21 CFR 872.4880 - Intraosseous fixation screw or wire.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraosseous fixation screw or wire. 872.4880... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4880 Intraosseous fixation screw or wire. (a) Identification. An intraosseous fixation screw or wire is a metal device intended to be...

  6. Anterior transarticular screw fixation as a conventional operation for rigid stabilization

    Directory of Open Access Journals (Sweden)

    Manabu Sasaki

    2014-01-01

    Full Text Available Background: Anterior transarticular screw (ATS fixation is a useful surgical option for atlantoaxial (AA stabilization. This report presents a revised ATS method for AA fusion. Methods: A 79-year-old male presented with AA instability attributed both to an old odontoid fracture and severe degeneration of the lateral atlantoaxial joints (LAAJs. ATS fixation was performed through the conventional anterior cervical approach. The longest screw trajectories were planned preoperatively using multiplanar reconstruction computed tomography (CT scans, with entry points of the screws situated at the midpoint on the inferior border of the axial body. The surgical exposure was limited to opening at the entry points alone. Our retractor of choice was the Cusco speculum; it sufficiently secured space for utilizing the required instruments for screw placement while offering sufficient protection of soft tissues. Cannulated full-threaded bicortical screws stabilized the LAAJs. Screw insertion required a significant amount of coronal angulation up to the superior articular process of the atlas under open-mouth and lateral fluoroscopy image guidance. After ATS fixation, bone grafting was performed between the posterior laminae of the axis and the atlas through a conventional posterior approach. Results: Bony fusion between the atlas and the axis was confirmed radiographically. Arthrodesis of the LAAJs occurred despite no bone grafting. Conclusions: Rigid fixation of the LAAJs was obtained by our ATS technique, indicating that it is an alternative method for AA fixation when posterior rigid internal fixation is not applicable.

  7. Anterior transarticular screw fixation as a conventional operation for rigid stabilization.

    Science.gov (United States)

    Sasaki, Manabu; Matsumoto, Katsumi; Tsuruzono, Koichiro; Yoshimura, Kazuhiro; Shibano, Katsuhiko; Yonenobu, Kazuo

    2014-01-01

    Anterior transarticular screw (ATS) fixation is a useful surgical option for atlantoaxial (AA) stabilization. This report presents a revised ATS method for AA fusion. A 79-year-old male presented with AA instability attributed both to an old odontoid fracture and severe degeneration of the lateral atlantoaxial joints (LAAJs). ATS fixation was performed through the conventional anterior cervical approach. The longest screw trajectories were planned preoperatively using multiplanar reconstruction computed tomography (CT) scans, with entry points of the screws situated at the midpoint on the inferior border of the axial body. The surgical exposure was limited to opening at the entry points alone. Our retractor of choice was the Cusco speculum; it sufficiently secured space for utilizing the required instruments for screw placement while offering sufficient protection of soft tissues. Cannulated full-threaded bicortical screws stabilized the LAAJs. Screw insertion required a significant amount of coronal angulation up to the superior articular process of the atlas under open-mouth and lateral fluoroscopy image guidance. After ATS fixation, bone grafting was performed between the posterior laminae of the axis and the atlas through a conventional posterior approach. Bony fusion between the atlas and the axis was confirmed radiographically. Arthrodesis of the LAAJs occurred despite no bone grafting. Rigid fixation of the LAAJs was obtained by our ATS technique, indicating that it is an alternative method for AA fixation when posterior rigid internal fixation is not applicable.

  8. Fixation with percutaneous cannulated screws assisted by robot navigation for femoral neck fractures%机器人导航定位系统辅助下经皮空心螺钉内固定治疗股骨颈骨折

    Institute of Scientific and Technical Information of China (English)

    刘建全; 刘黎军; 黄俊锋; 尤微; 王大平

    2015-01-01

    目的 探讨机器人导航定位系统辅助下经皮空心螺钉内固定治疗股骨颈骨折的疗效.方法 回顾性分析2012年10月至2014年6月采用机器人导航定位系统辅助下经皮空心螺钉内固定治疗的21例股骨颈骨折患者资料(导航组),男8例,女13例;年龄为20 ~ 85岁,平均(65.2±4.2)岁;骨折按Garden分型:Ⅰ型2例,Ⅱ型5例,Ⅲ型9例,Ⅳ型5例.选择同期采用传统徒手定位方法手术治疗的25例股骨颈骨折患者作为对照组.比较两组患者的手术时间、术中透视次数、术中出血量、总钻孔次数、骨折愈合时间及末次随访时髋关节Harris评分等. 结果 导航组患者的手术时间[(75.2±10.6) min]和骨折愈合时间[(5.3±2.5)个月]短于对照组[(85.1±11.3) min、(6.1±3.0)个月],但差异均无统计学意义(P>0.05).导航组患者的术中透视次数[(28.5±9.8)次]、术中出血量[(9.4±7.6)mL]及总钻孔次数[(9.2±4.5)次]显著少于对照组[(48.6±8.1)次、(40.2±10.3)mL、(17.5±8.5)次],差异均有统计学意义(P<0.05).导航组患者末次随访时髋关节Harris评分平均为(87.6±3.1)分,对照组患者平均为(86.9±4.7)分,差异无统计学意义(P>0.05).随访期间导航组无一例患者发生伤口感染、内固定物松动、骨折再移位及股骨头缺血性坏死等并发症. 结论 与传统徒手定位方法相比,机器人导航定位系统辅助下经皮空心螺钉内固定治疗股骨颈骨折具有设备操作相对简单、术中螺钉置入更加精准和规范等优点,实现了手术的微创化,减少了放射线的接触时间.%Objective To discuss clinical efficacy of fixation with percutaneous cannulated screws assisted by robot navigation for femoral neck fractures.Methods From October 2012 to June 2014,21 patients with femoral neck fracture were treated by internal fixation with percutaneous cannulated screws assisted by robot navigation.They were 8 men and 13 women,20 to 85 years of age

  9. Translaminar facetal screw (magerl′s fixation

    Directory of Open Access Journals (Sweden)

    Rajasekaran S

    2005-01-01

    Full Text Available Translaminar facet screw fixation (TLFS achieves stabilization of the vertebral motion segment by screws inserted at the base of the spinous process, through the opposite lamina, traversing the facet joint, and ending in the base of the transverse process. It is simple, does not require any specialized equipment, and has the advantages of being a procedure of lesser magnitude, lesser operative time, less cost and few complication rate. Recently there is growing interest in this technique to augment the anterior lumbar fusions to achieve global fusion less invasively. In this review article, we discuss the clinical and biomechanical considerations, surgical technique, indications, contraindications and recent developments of TLFS fixation in lumbar spine fusion.

  10. Two I.CO.S.s and general cannulated compression screw in femoral neck fracture fixation: a biomechanical comparison of 2 different configurations%2种构型2枚I.CO.S.固定股骨颈骨折的生物力学比较

    Institute of Scientific and Technical Information of China (English)

    陆慧; 吴元勇; 朱明; 倪卫东

    2011-01-01

    目的:探讨双重空心加压螺钉(Ideal compression screw,I.CO.S.)在治疗股骨颈骨折中的生物力学作用,并为临床上选择合适空间构型的2枚此类螺钉治疗股骨颈骨折提供一定的理论依据.方法:采集20具尸体股骨标本,模拟股骨颈头下型骨折,随机分为I.CO.S.组(实验组)和普通空心加压螺钉组(对照组),每组各10个标本,分别随机采用2枚水平位(2枚螺钉前后平行位于股骨颈轴心上方)和垂直位(2枚螺钉上下平行位于股骨颈轴心上下方)固定各5个.测定各组载荷下的应变值、股骨头的水平和垂直位移、并进行屈服力学性能测试.结果:在生物力学稳定性方面,I.CO.S.在水平位移和屈服载荷方面较普通空心加压螺钉好,螺钉水平位固定在应变、水平位移和屈服载荷方面较垂直位好.结论:I.C0.S.固定股骨颈骨折的稳定性较好,且2枚I.CO.S.水平位固定有较高的稳定性可应用于临床.%Objective : To explore the hiomechanical stability for treatment of femoral neck fracture with ideal compression screw ( I.CO. s. ) and to provide theoretical basis for choosing appropriate geometric configurations of two I.CO.S.s in clinical application. Methods : 20 cadaveric human femurs were selected and divided randomly into two groups : experiment group and control group, 10 in each one which was then divided equally into two sub-groups. The model of subcapital femoral neck fracture was made , then given anatomical reduction and fixed with I.CO.S. ( experiment group ) and general cannulated compression screw ( control group)separately with two different configurations : horizontal one ( parallel screws in superior aspect of femoral neck ) and vertical one( parallel screws in sagittal plane of femoral neck ) . The different biomechanical performances were evaluated through experimental stress analysis. Results : In hiomechanical stahility aspect,I.CO.S.was better than general screw in the horizontal

  11. 空心钉克氏针内固定治疗儿童陈旧性肱骨外髁骨折近期疗效观察%Short-term effect of cannulated screw with K-wires used as internal fixation in management of pediatric neglected humeral lateral condylar fractures

    Institute of Scientific and Technical Information of China (English)

    易新成; 鲍琨; 陈博昌

    2014-01-01

    目的:探讨空心钉克氏针内固定手术治疗儿童陈旧性肱骨外髁骨折的临床疗效。方法回顾性分析2009年10月至2012年12月我们收治并获完整随访的的11例肱骨外髁陈旧性骨折患儿临床资料,其中男9例,女2例,年龄2岁1个月至6岁4个月,平均4岁5个月。患儿受伤至手术时间为30~90 d,平均52 d。受伤初期按Milch分型,MilchⅠ型4例,MilchⅡ型7例,肘关节功能有不同程度受限。患儿均切开复位后用1枚空心钉外加2枚交叉克氏针内固定治疗。术后随访观察骨折愈合时间及并发症情况,术后1年采用Dhillon评分值和Baumann角评定疗效。结果所有患儿术后均获12~34个月(平均22.7个月)随访。均在术后6~8周获骨性愈合。术后1年按照Dhillon评分标准,10例为优,1例为良,优良率100%,术前患侧肘关节活动弧度平均为90.5°±27.3°,术后1年时平均为129.1°±11.8°,二者差异有统计学意义(t=6.527,P=0.000)。术后1年所有患儿Baumann角均在正常范围(68°~80°),平均74.3°±4.2°。无一例发生术后感染、骨折延迟愈合、畸形愈合、骨不连、肘内外翻、肱骨小头缺血坏死、医源性血管神经损伤等并发症。结论切开复位后采用1枚空心钉外加2枚交叉克氏针内固定治疗儿童陈旧性肱骨外髁骨折可达到复位满意、内固定稳定和良好的近期疗效,并发症少。%Objetive To discuss the short-term effect of cannulated screw with K-wires used as internal fixation in management of pediatric neglected humeral lateral condylar fractures. Methods The clinical data of 1 1 cases with neglected humeral lateral condylar fracture were analyzed retrospectively.from October 2009 to December 2012.There were 9 boys and 2 girls,aged from 2 years and 1month to 6 year and 4 months old (aver-age,4 years and 5 months).The duration of initially trauma to surgery ranged

  12. Hemiarthroplasty compared to internal fixation with percutaneous cannulated screws as treatment of displaced femoral neck fractures in the elderly: cost-utility analysis performed alongside a randomized, controlled trial.

    Science.gov (United States)

    Waaler Bjørnelv, G M; Frihagen, F; Madsen, J E; Nordsletten, L; Aas, E

    2012-06-01

    We estimated the cost-effectiveness of hemiarthroplasty compared to internal fixation for elderly patients with displaced femoral neck fractures. Over 2 years, patients treated with hemiarthroplasty gained more quality-adjusted life years than patients treated with internal fixation. In addition, costs for hemiarthroplasty were lower. Hemiarthroplasty was thus cost effective. Estimating the cost utility of hemiarthroplasty compared to internal fixation in the treatment of displaced femoral neck fractures in the elderly. A cost-utility analysis (CUA) was conducted alongside a clinical randomized controlled trial at a university hospital in Norway; 166 patients, 124 (75%) women with a mean age of 82 years were randomized to either internal fixation (n = 86) or hemiarthroplasty (n = 80). Patients were followed up at 4, 12, and 24 months. Health-related quality of life was assessed with the EQ-5D, and in combination with time used to calculate patients' quality-adjusted life years (QALYs). Resource use was identified, quantified, and valued for direct and indirect hospital costs and for societal costs. Results were expressed in incremental cost-effectiveness ratios. Over the 2-year period, patients treated with hemiarthroplasty gained 0.15-0.20 more QALYs than patients treated with internal fixation. For the hemiarthroplasty group, the direct hospital costs, total hospital costs, and total costs were non-significantly less costly compared with the internal fixation group, with an incremental cost of €2,731 (p = 0.81), €2,474 (p = 0.80), and €14,160 (p = 0.07), respectively. Thus, hemiarthroplasty was the dominant treatment. Sensitivity analyses by bootstrapping supported these findings. Hemiarthroplasty was a cost-effective treatment. Trial registration, NCT00464230.

  13. Closed reduction and Kirschner wire and cannulated screws fixation for grade Ⅳ supination-external rotation ankle fractures%闭合复位克氏针及空心钉内固定治疗旋后外旋型Ⅳ度踝关节骨折

    Institute of Scientific and Technical Information of China (English)

    孔祥标; 李铭雄; 张细祥

    2011-01-01

    Objective To investigate the less damage surgical methods and efficacy in treating grade Ⅳ supinationextenal rotation ankle fractures.Methods 22 patients of grade Ⅳ supination-external rotation ankle fractures were treated by closed reduction and Kirschner wire and cannulated screws fixation.Results 18 cases were followed up ranged from 4 to 10 months.The wound got primary healing without infection.All fracture were healed without obvious aching.According to the ankle-hindfoot scale of AOFAS: the results were excellent in 12 cases, good in 7 , and fair in 3.Conclusions This method is effective for grade Ⅳ supination-external rotation ankle fractures with small incision, less infection rate and good result.%目的 探讨旋后外旋型Ⅳ度踝关节骨折的微创治疗方法及疗效.方法 对22例旋后外旋型Ⅳ度踝关节骨折患者采用闭合复位克氏针及空心钉内固定治疗.结果 18例患者获得随访,时间4~10个月.伤口均一期愈合,无感染.骨折均愈合,无明显疼痛不适.采用 AOFAS踝关节-后足评分标准:优 12例,良7例,一般3例.结论 闭合复位经皮克氏针及空心钉固定治疗旋后外旋型Ⅳ度踝关节骨折,切口小,感染率低,疗效良好.

  14. Tissue reaction to implants of different metals: A study using guide wires in cannulated screws

    Directory of Open Access Journals (Sweden)

    DM Devine

    2009-10-01

    Full Text Available Cannulated screws, along with guide wires, are typically used for surgical fracture treatment in cancellous bone. Breakage or bending deformation of the guide wire is a clinical concern. Mechanically superior guide wires made of Co-Cr alloys such as MP35N and L605 may reduce the occurrence of mechanical failures when used in combination with conventional (316L stainless steel cannulated screws. However the possibility of galvanic or crevice corrosion and adverse tissue reaction, exists when using dissimilar materials, particularly in the event that a guide wire breaks, and remains in situ. Therefore, we designed an experiment to determine the tissue reaction to such an in vivo environment. Implant devices were designed to replicate a clinical situation where dissimilar metals can form a galvanic couple. Histological and SEM analyses were used to evaluate tissue response and corrosion of the implants. In this experiment, no adverse in vivo effects were detected from the use of dissimilar materials in a model of a broken guide wire in a cannulated screw.

  15. 经皮撬拨复位轴向结合横向多枚中空钉内固定治疗SandersⅡ、Ⅲ型跟骨骨折的临床疗效%An analysis of the clinical effects of percutaneous fracture reduction followed by internal fixation with multiple axial and horizontal cannulated screws in the treatment of Sanders type II and III calcaneal fracture

    Institute of Scientific and Technical Information of China (English)

    林文琛; 许耀明; 颜峻; 李超颖; 郑烽礼

    2014-01-01

    ObjectiveTo explore and compare the curative effects of percutaneous fracture reduction followed by internal fixation with cannulated screws and open reduction followed by internal fixation with titanium plate in the treatment of Sanders typeⅡ andⅢ calcaneal fracture at early stage.Methods 60 patients with calcaneal fracture from February 2010 to September 2013 were selected. They all belonged to Sanders typeⅡ andⅢ fracture, in which 34 patients were typeⅡ and 26 typeⅢ. All patients were randomly assigned to two groups and received surgeries of percutaneous fracture reduction followed by internal fixation with cannulated screws and open reduction followed by internal fixation with titanium plate. They were observed in the follow-ups, and functional evaluation was carried out via Marryland evaluation system. Excellent and good rate of the two methods was calculated, and differences between the two groups were analyzed through statistics. Results Follow-ups were carried out for 60 patients, and the follow-up time was 4-38 months (average 18 months). Clinical effects: among 31 patients who received percutaneous fracture reduction followed by internal fixation with cannulated screws, 18 patients showed excellent foot functions, 6 good, 3 average and 2 unsatisfactory. The excellent and good rate was 83.8%; among 29 patients who received open reduction followed by internal fixation with titanium plate, 18 patients showed excellent foot functions, 6 good, 3 average and 2 unsatisfactory. The excellent and good rate was 82.8%. The differences of the excellent and good rate between the two methods were not statistically significant (x2=0.617,P =0.971>0.05).Conclusion Percutaneous fracture reduction followed by internal fixation with cannulated screws and open reduction followed by internal fixation with titanium plate in the treatment of calcaneal fracture can both achieve favorable effects. Percutaneous fracture reduction followed by internal fixation with

  16. Biomechanical characteristics of two geometric configurations of cannulated compression screws in the fixation of femoral neck fracture%两种构型空心加压螺钉固定头颈型股骨颈骨折的生物力学特征

    Institute of Scientific and Technical Information of China (English)

    史威; 范婕; 张英泽; 杨搏贵; 贾卫斗; 李素红

    2007-01-01

    BACKGROUND : After femoral neck fracture, incidences of ischemic necrosis and bone non-healing are closely related to biomechanical characteristics of internal fixation devices. Compression stress can improve fracture healing, tension force can delay fracture healing, and shear stress can inhibit fracture healing. How to relieve shear stress and expand compression stress is of significance for theories and clinical applications.OBJECTIVE: To compare the biomechanical characteristics of the two geometric configurations of three cannulated compression screws in the fixation for femoral neck fracture and to provide a theoretical foundation in the treatment of femoral neck fracture.DESIGN : Observational contrast study.SETTING: Department of Orthopaedics, the 251 Hospital of Chinese PLA; Department of Orthopaedics, the Third Hospital, Hebei Medical University.PARTICIPANTS: The experiment was carried out in the Hebei Orthopaedic Institute from November 2002 to March 2003. Five cadavers including 4 males and 1 female with similar bone mineral density (BMD) were provided by Department of Anatomy, Hebei Medical University. X-ray photographs proved that all the cadavers did not have rheumatism, tuberculosis, tumor, fracture or deformity.METHODS: Ten femurs were randomly divided into inverted and upright isosceles triangle with 5 in each group. Femur samples with femoral neck fracture were fixed with three cannulated screws and measured with the biomechanical machine (CSS-44020, made in Changchun Experimental Researching Institute, provided by Hebei Orthopaedics Institute). The compression strength, torsibility and the maximal vertical loading were compared between the two configurations of screws.MAIN OUTCOME MEASURES:①Displacement of femoral head at 600 N and 750 N during torsibility test; ②torque-moment at 2°and 4°during torsibility test;③load during maximal vertical loading test.CONCLUSION: The effect of three cannulated compression screws configured as an

  17. Preliminary experimental results of radiofrequency-cement-augmented and cannulated pedicle screws

    Directory of Open Access Journals (Sweden)

    Goost H

    2011-01-01

    Full Text Available The risk of cut-out of a pedicle screw is high in the presence of osteoporotic bone. In cadaver studies it was found that cement augmentation of pedicle screws markedly increases pullout forces. However, the use of conventional low viscosity vertebroplasty or kyphoplasty cement is associated with the risk of cement extravasation. The risk might be reduced by using high viscosity, radiofrequency-activated bone cement. After performing DEXA scans, six fresh-frozen vertebral bodies of different bone densities were obtained from cadavers. Two pedicle screws (WSI Expertise-Inject, Peter Brehm, Germany were placed in the pedicles. About 3 ml of radiofrequency-activated, ultra-high viscosity cement (ER2 Bone Cement, DFine Europe GmbH, Germany was injected through the right pedicle. The left pedicle screw was left uncemented and served as control. Axial pullout tests were performed using a material testing device (Zwick/Roell Zmartpro, Ulm, Germany. The tests revealed that cementaugmented pedicle screws were able to withstand markedly higher pullout forces. Extravasation of cement did not occur. The value of the study is limited by the fact that only six samples were investigated. Further cadaver studies and clinical evaluation will be needed in the future. However, this pilot study showed that combining cannulated pedicle screws with ultra-high viscosity bone cement is a successful approach. Revision due to cut-out and complications secondary to cement extravasation can be reduced by this method.

  18. Torsional stiffness after subtalar arthrodesis using second generation headless compression screws: Biomechanical comparison of 2-screw and 3-screw fixation.

    Science.gov (United States)

    Riedl, Markus; Glisson, Richard R; Matsumoto, Takumi; Hofstaetter, Stefan G; Easley, Mark E

    2017-06-01

    Subtalar joint arthrodesis is a common operative treatment for symptomatic subtalar arthrosis. Because excessive relative motion between the talus and calcaneus can delay or prohibit fusion, fixation should be optimized, particularly in patients at risk for subtalar arthrodesis nonunion. Tapered, fully-threaded, variable pitch screws are gaining popularity for this application, but the mechanical properties of joints fixed with these screws have not been characterized completely. We quantified the torsion resistance of 2-screw and 3-screw subtalar joint fixation using this type of screw. Ten pairs of cadaveric subtalar joints were prepared for arthrodesis and fixed using Acutrak 2-7.5 screws. One specimen from each pair was fixed with two diverging posterior screws, and the contralateral joint was fixed using two posterior screws and a third screw directed through the anterior calcaneus into the talar neck. Internal and external torsional loads were applied and joint rotation and torsional stiffness were measured at two torque levels. Internal rotation was significantly less in specimens fixed with three screws. No difference was detectable between 2-screw and 3-screw fixation in external rotation or torsional stiffness in either rotation direction. Both 2-screw and 3-screw fixation exhibited torsion resistance surpassing that reported previously for subtalar joints fixed with two diverging conventional lag screws. Performance of the tapered, fully threaded, variable pitch screws exceeded that of conventional lag screws regardless of whether two or three screws were used. Additional resistance to internal rotation afforded by a third screw placed anteriorly may offer some advantage in patients at risk for nonunion. Copyright © 2017. Published by Elsevier Ltd.

  19. Biomechanical performance of subpectoral biceps tenodesis: a comparison of interference screw fixation, cortical button fixation, and interference screw diameter.

    Science.gov (United States)

    Sethi, Paul M; Rajaram, Arun; Beitzel, Knut; Hackett, Thomas R; Chowaniec, David M; Mazzocca, Augustus D

    2013-04-01

    Subpectoral biceps tenodesis with interference screw fixation allows reproducible positioning of the tendon to help maintain the length-tension relationship. The aim of our study was to evaluate the role of cortical button fixation in isolation or as an augment to interference screw fixation and to determine if the diameter of the interference screw affected fixation strength. Thirty-two cadaveric shoulders were dissected and randomized to 1 of 4 groups: (1) 7-mm interference screw and cortical button, (2) cortical button alone, (3) 7-mm interference screw, or (4) 8-mm interference screw. Testing was performed on a materials testing system with a 100-N load cycled at 1 Hz for 5000 cycles, followed by an axial load to failure test. Cyclic displacement, ultimate load to failure, and site of failure were recorded for each specimen. The mean ultimate failure loads were 7-mm interference screw with cortical button augmentation, 237.8 ± 120.4 N; cortical button alone, 99.4 ± 16.9 N; 7-mm interference screw, 275.5 ± 56 N; 8-mm interference screw, 277.1 ± 42.1 N. All specimens failed through tendon failure at the screw-tendon-bone interface. The biomechanical performance of subpectoral biceps tenodesis with interference screw fixation was not improved with cortical button augmentation. In addition, cortical button fixation alone yielded a significantly lower ultimate load to failure compared with interference screws. Finally, the biomechanical performance of smaller-diameter interference screws with matching bone tunnels was not affected by interference screw diameter. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  20. 4 mm cannulatedcancellous screws fixation in extra articular distal 1/3 radius fracture - A study

    Directory of Open Access Journals (Sweden)

    M.S. Patil

    2017-01-01

    Full Text Available Background: Distal radius fracture are extremely common and represents 16% of fractures treated by orthopaedic surgeons. Near anatomical reduction with restoration of radial length, radial tilt and ulnar variances are important for good functional results. Cannulated 4 mm long threaded using minimally invasive osteosynthesis technique are less aggressive towards soft tissue covering. It allows immediate range of motion of the wrist while maintaining alignment resulting in rapid and comfortable functional recovery. The objective of this study was to evaluate the clinical, radiological and functional efficacy of 4 mm cannulated screws in the management of extra articular distal radius fracture using the criteria of Gartland and Werley point system. Material & Method: 40 Patients with extra articular distal radius fracture were treated by minimally invasive osteosynthesis technique using 4 mm cannulatedcancellous screws in AL-Ameen Medical College Hospital, Bijapur between Nov 2013 to Oct 2015 which included 19 males and 21 female patients. The duration of follow-up was ranged from 12-18 months. Results: Using Demerit scoring system of Gartland and Werley, we had 45% excellent, 50% good, 0% fair and 5% poor results. As per our results, excellent to good results were found in 95% of patients. Conclusion: Cannulatedcancellous screws fixation is an effective means of fixation in distal 1/3 radius fracture, allowing immediate range of motion of the wrist, resulting in a rapid and comfortable functional recovery while maintaining alignment and bone healing. It has higher degree of purchase when treating extra articular distal radius fracture with poor bone quality. Being minimally invasive with minimal soft tissue dissection, less operative time, cost effective, cannulated screws is a good option for both young and elderly patients with extra articular distal radius fracture.

  1. [Clinical efficacy of subtalar joint arthrodesis with percutaneous opposite parallel cannulated screws].

    Science.gov (United States)

    Yuan, Cheng-song; Tang, Kang-lai; Chen, Cheng; Hu, Chao; Zhou, Bing-hua; Xu, Jian-zhong

    2013-06-04

    To explore the clinical efficacy of subtalar joint arthrodesis with percutaneous opposite parallel cannulated screws for severe subtalar joint arthritis. A total of 88 patients with 90 feet underwent subtalar joint fusion under four different incisions from April 2008 to April 2012. There were 56 males and 32 females with a mean age of 43.7 (15-74) years. All of them were evaluated by radiography or computed tomography (CT) scan and assessed by the rating scores of visual analog scale (VAS) and American Orthopedic Foot and Ankle Society (AOFAS). Among them, 68 cases were followed up for an average of 18.5 (6-48) months. Fusion was confirmed on radiography or CT in 67 cases with a fusion rate of 98.5%. The mean duration of fusion was 13.8 (6-28) weeks, the mean VAS score decreased from 6.00 to 1.03 points (P < 0.05) and the mean AOFAS score improved from 57.0 to 80.6 points (P < 0.05) with a good-and-excellent rate of 80.8%. Subtalar joint arthrodesis with percutaneous opposite parallel cannulated screws is recommend for severe subtalar joint arthritis. Such a procedure has a high fusion rate, excellent clinical outcomes and fewer complications.

  2. Subtrochanteric fracture: a rare but severe complication after screw fixation of femoral neck fractures in the elderly.

    Science.gov (United States)

    Jansen, Hendrik; Frey, Soenke P; Meffert, Rainer H

    2010-12-01

    Cannulated screw fixation is a minimal invasive technique to treat undisplaced femoral neck fractures. It is the preferred method in elderly patients who often suffer co-morbidities. There is scarce literature on subtrochanteric femoral fracture as a complication of cannulated screw fixation of a femoral neck fracture. This complication occurred, without an adequate trauma, in two of 35 patients (5.7%) in this retrospective study of patients older than 65 years (mean age: 77 years) who were treated with cannulated screws for an undisplaced femoral neck fracture between 2004 and 2009. We reviewed the literature for the incidence of this complication and possible predisposing factors. The overall incidence reported in literature is 2.4-4.4% (mean: 2.97%). Despite a broad use of this type of osteosynthesis, the literature does not provide clear biomechanical or clinical indications for optimal screw placement to avoid this complication. Considering the literature and our personal results, surgeons should be aware of this severe complication; they may opt for a different implant in the very old, osteoporotic patient with an undisplaced femoral neck fracture.

  3. Salvage of failed osteosynthesis of an intracapsular fracture of the femoral neck using two cannulated compression screws and a vascularised iliac crest bone graft.

    Science.gov (United States)

    Xiaobing, Y; Dewei, Z

    2015-07-01

    We evaluated the outcome of treatment of nonunion of an intracapsular fracture of the femoral neck in young patients using two cannulated screws and a vascularised bone graft. A total of 32 patients (15 women and 17 men, with a mean age of 36.5 years; 20 to 50) with failed internal fixation of an intracapsular fracture were included in the study. Following removal of the primary fixation, two cannulated compression screws were inserted with a vascularised iliac crest bone graft based on the ascending branch of the lateral femoral circumflex artery. At a mean follow-up of 6.8 years (4 to 10), union was achieved in 27 hips (84%). A total of five patients with a mean age of 40.5 years (35 to 50) had a persistent nonunion and underwent total hip arthroplasty as also did two patients whose fracture united but who developed osteonecrosis of the femoral head two years post-operatively. Statistical analysis showed that younger patients achieved earlier and more reliable union (p 45 years (p osteosynthesis of a displaced intracapsular fractures of the femoral neck has failed.

  4. Biomechanical analysis of titanium fixation plates and screws in ...

    African Journals Online (AJOL)

    Key words: Bone plates, bone screws, finite element analysis, jaw fixation techniques, mandible, mandibular .... model is built up, in similar way to building block construction, .... shows advantages, such as granting intraoral route, minimal.

  5. Sacroiliac screw fixation: A mini review of surgical technique

    Directory of Open Access Journals (Sweden)

    Hernando Raphael Alvis-Miranda

    2014-01-01

    Full Text Available The sacral percutaneous fixation has many advantages but can be associated with a significant exposure to X-ray radiation. Currently, sacroiliac screw fixation represents the only minimally invasive technique to stabilize the posterior pelvic ring. It is a technique that should be used by experienced surgeons. We present a practical review of important aspects of this technique.

  6. Sacroiliac screw fixation: A mini review of surgical technique

    Science.gov (United States)

    Alvis-Miranda, Hernando Raphael; Farid-Escorcia, Hector; Alcalá-Cerra, Gabriel; Castellar-Leones, Sandra Milena; Moscote-Salazar, Luis Rafael

    2014-01-01

    The sacral percutaneous fixation has many advantages but can be associated with a significant exposure to X-ray radiation. Currently, sacroiliac screw fixation represents the only minimally invasive technique to stabilize the posterior pelvic ring. It is a technique that should be used by experienced surgeons. We present a practical review of important aspects of this technique. PMID:25336831

  7. Triple arthrodesis stabilization: a quantitative analysis of screw versus staple fixation in fresh cadaveric matched-pair specimens.

    Science.gov (United States)

    Payette, C R; Sage, R A; Gonzalez, J V; Sartori, M; Patwardhan, A; Vrbos, L

    1998-01-01

    Qualitative analyses of midfoot stabilization in triple arthrodeses utilizing bone staple versus 4.5-mm cannulated cancellous screw fixation, with and without washers, were performed in fresh cadaveric specimens. Twenty-two trials (11 matched-pair feet) were used for direct comparison. Stiffness, defined as force/displacement, was determined at each talonavicular and calcaneocuboid joint. Ultimate load failure points of each specimen were also calculated. Trial results showed no statistically significant difference in stiffness or ultimate failure between these two forms of midfoot fixation for triple arthrodeses.

  8. Computed tomography- and fluoroscopy-guided percutaneous screw fixation of low-grade isthmic spondylolisthesis in adults: a new technique

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Huwart, Laurent; Browaeys, Patrick; Nouri, Yasir; Ibba, Caroline [Hopital Archet 2, Centre Hospitalo-Universitaire de Nice, Department of Radiology, Nice (France); Hauger, Olivier [Hopital Pellegrin, Centre Hospitalo-Universitaire de Bordeaux, Department of Radiology, Bordeaux (France); Marcy, Pierre-Yves [Antoine Lacassagne Cancer Research Institute, Department of Radiology, Nice (France); Boileau, Pascal [Hopital Archet 2, Centre Hospitalo-Universitaire de Nice, Department of Orthopedic Surgery, Nice (France)

    2012-12-15

    To evaluate the feasibility of computed tomography (CT)- and fluoroscopy-guided percutaneous screw fixation for the treatment of low-grade isthmic spondylolisthesis in adults. Ten consecutive adult patients (four men and six women; mean age: 57.1 [range, 44-78 years]) were prospectively treated by percutaneous screw fixation for low-grade (six grade 1 and four grade 2) isthmic spondylolisthesis of L5. For each patient, two 4.0-mm Asnis III cannulated screws were placed to fix the pars interarticularis defects. All procedures were performed under local anaesthesia by using CT and fluoroscopy guidance. Post-operative outcome was assessed using the visual analogue scale and Oswestry Disability Index (ODI) scores. The procedure time ranged from 45 to 60 min. The mean screw length was 27 mm (range, 24-32 mm). The VAS and ODI measurements {+-} SD decreased from 7.8 {+-} 0.9 preoperatively to 1.5 {+-} 1.1 at the last 2-year follow-up, and from 62.3 {+-} 17.2 to 15.1 {+-} 6.0, respectively (P < 0.001 in both cases). Neither slip progression nor screw failure was noted. This feasibility study showed that CT- and fluoroscopy-guided percutaneous screw fixation could be a rapid, safe and effective method of treating low-grade isthmic spondylolisthesis. (orig.)

  9. Robot-assisted Anterior Odontoid Screw Fixation: A Case Report.

    Science.gov (United States)

    Tian, Wei; Wang, Han; Liu, Ya-Jun

    2016-08-01

    Anterior odontoid screw fixation has been proved to be effective but technically challenging because the difficult approach is associated with high risks of screw malposition and damage to surrounding vital structures. Navigation techniques are therefore increasingly being used to improve safety and accuracy. However, no robot-assisted odontoid screw fixation has yet been reported. We here report a 61-year-old woman with a type II dens fracture on whom anterior odontoid screw fixation was performed under the guidance of a newly developed robotic system (TiRobot, co-designed by Beijing Jishuitan Hospital and TINAVI Medical Technologies). One odontoid screw was safely and accurately placed, the calculated deviation between the planned and actual positions being 0.9 mm. No intraoperative complications were identified and the patient was discharged on Day 5. Follow-up studies after 2 weeks showed good clinical and radiological results. We believe this is the first reported case of robot-assisted anterior odontoid screw fixation. We consider that complicated procedures can become feasible, safe and accurate using TiRobot systems.

  10. A multiple correlation factors analysis of avascular necrosis after closed reduction and cannulated compression screws fixation of intra-capsular femoral neck fracture.A multi-center retrospective study%股骨颈骨折闭合复位加压螺纹钉内固定术后股骨头坏死多中心多因素相关分析

    Institute of Scientific and Technical Information of China (English)

    周锦春; 郭敦明; 王青; 陈哲峰; 崔维顶; 范卫民; 刘锋

    2013-01-01

    Objective To determine the incidence of avascular necrosis after closed reduction and cannulated compression screws fixation of intra-capsular femoral neck fracture and to investigate the multiple factors correlated to avascular femoral head necrosis.Methods All the patients of intra-capsular femoral neck fracture who accepted closed reduction and cannulated compression screws fixation between 2001 and 2010 in Jiangsu Province were reviewed in multi-centers retrospectively.The multiple factors were analyzed including age,gender,affected side,mechanism of injury,fracture classification,procedure delay,quality of reduction,time of full-weight-bearing,configuration of the screws and removal of the screws.Multiple correlation factors were analyzed with SPSS 13.0 statistic system.Results Complete case records were documented in 1849 cases who were followed up for an average 6.5±2.7 years (range,2-10 years).Avascular necrosis occurred in 246 cases (13.3%).The average time of diagnosis of avascular necrosis was 17±4.6months (range,8-72 months) after injury.The average Harris score of the hips which didn't develop to avascular necrosis was 93.8±8.9 (range,78~100) at the last follow up.Multiple correlation factors analysis indicated that displacement degrees of fracture and the quality of reduction were significantly correlated to the incidence of avascular necrosis (OR=2.078,3.423).Conclusion Closed reduction and cannulated compression screws fixation after the intra-capsular femoral neck fracture can get satisfactory results.Displacement degrees of fracture and the quality of reduction are significantly correlated to the incidence of avascular femoral head necrosis.%目的 调查股骨颈骨折闭合复位加压螺纹钉内固定术后股骨头坏死的发生率,探讨各影响因素与股骨头坏死的相关性.方法 对江苏地区2001至2010年期间接受闭合复位加压螺纹钉内固定治疗的股骨颈骨折患者进行回顾性调查.以股骨头坏

  11. Osteosynthesis ­of ­femoral ­neck ­fracture ­with­ cannulated ­screws. Prognostic ­factors ­and­ results ­in ­93 ­cases

    Directory of Open Access Journals (Sweden)

    Sebastián Pereira

    2014-03-01

    Full Text Available Abstract Background: Reduction and osteosynthesis with cannulated screws in femoral neck fracture is a valid therapeutic option. Our objective is to identify prognostic factors and risk groups. Methods: We studied retrospectively 93 femoral neck fractures treated with internal fixation with cannulated screw between June 1995 and March 2011 (71 non-displaced and 22 displaced. Results: In 82 of the 93 cases we observed bone consolidation of the fracture. Eleven patients presented complications (5 non-union and 6 avascular necrosis. Consolidation rates were 95.8% and 63.6% in the non-displaced group and the displaced group of fractures. If the displaced fractures presented conminution, consolidation rate was 50% and 71.4% in the group without conminution. The consolidation index was 46.1% with closed reduction and 88% with open reduction. Conclusion: Closed reduction and internal fixation with cannulated screws in non-displaced femoral neck fractures, regardless of the patient’s age, is a successful method. In displaced fractures, on the other hand, necrosis free consolidation is less predictable, so its indication must be evaluated carefully.

  12. Odontoid screw fixation for fresh and remote fractures

    Directory of Open Access Journals (Sweden)

    Rao Ganesh

    2005-01-01

    Full Text Available Fractures of the odontoid process are common, accounting for 10% to 20% of all cervical spine fractures. Odontoid process fractures are classified into three types depending on the location of the fracture line. Various treatment options are available for each of these fracture types and include application of a cervical orthosis, direct anterior screw fixation, and posterior cervical fusion. If a patient requires surgical treatment of an odontoid process fracture, the timing of treatment may affect fusion rates, particularly if direct anterior odontoid screw fixation is selected as the treatment method. For example, type II odontoid fractures treated within the first 6 months of injury with direct anterior odontoid screw fixation have an 88% fusion rate, whereas fractures treated after 18 months have only a 25% fusion rate. In this review, we discuss the etiology, biomechanics, diagnosis, and treatment (including factors affecting fusion such as timing and fracture orientation options available for odontoid process fractures.

  13. Migration of polyethylene fixation screw after total knee arthroplasty.

    Science.gov (United States)

    Cho, Woo-Shin; Youm, Yoon-Seok

    2009-08-01

    Duracon (Howmedica, Rutherford, NJ) posterior stabilized total knee system has a snap fit locking mechanism of a tibial polyethylene, including an additional locking screw for further fixation of polyethylene. We report 13 cases of locking screw migration from tibial component after Duracon posterior stabilized primary total knee arthroplasty. Among 13 knees, screw migration in 10 asymptomatic cases was incidentally detected during regular follow-up, and they were just observed in the outpatient clinic. Only 3 knees had moderate pain, swelling, and instability, and revision was done on 2 of 3 knees.

  14. Are two retrograde 3.5 mm screws superior to one 7.3 mm screw for anterior pelvic ring fixation in bones with low bone mineral density?

    Science.gov (United States)

    Zderic, I.; Grechenig, S.; Richards, R. G.; Schmitz, P.; Gueorguiev, B.

    2017-01-01

    Objectives Osteosynthesis of anterior pubic ramus fractures using one large-diameter screw can be challenging in terms of both surgical procedure and fixation stability. Small-fragment screws have the advantage of following the pelvic cortex and being more flexible. The aim of the present study was to biomechanically compare retrograde intramedullary fixation of the superior pubic ramus using either one large- or two small-diameter screws. Materials and Methods A total of 12 human cadaveric hemipelvises were analysed in a matched pair study design. Bone mineral density of the specimens was 68 mgHA/cm3 (standard deviation (sd) 52). The anterior pelvic ring fracture was fixed with either one 7.3 mm cannulated screw (Group 1) or two 3.5 mm pelvic cortex screws (Group 2). Progressively increasing cyclic axial loading was applied through the acetabulum. Relative movements in terms of interfragmentary displacement and gap angle at the fracture site were evaluated by means of optical movement tracking. The Wilcoxon signed-rank test was applied to identify significant differences between the groups Results Initial axial construct stiffness was not significantly different between the groups (p = 0.463). Interfragmentary displacement and gap angle at the fracture site were also not statistically significantly different between the groups throughout the evaluated cycles (p ⩾ 0.249). Similarly, cycles to failure were not statistically different between Group 1 (8438, sd 6968) and Group 2 (10 213, sd 10 334), p = 0.379. Failure mode in both groups was characterised by screw cutting through the cancellous bone. Conclusion From a biomechanical point of view, pubic ramus stabilisation with either one large or two small fragment screw osteosynthesis is comparable in osteoporotic bone. However, the two-screw fixation technique is less demanding as the smaller screws deflect at the cortical margins. Cite this article: Y. P. Acklin, I. Zderic, S. Grechenig, R. G. Richards, P

  15. Closed reduction with CT-guided screw fixation for unstable sacroiliac joint fracture-dislocation

    Energy Technology Data Exchange (ETDEWEB)

    Baskin, Kevin M.; Cahill, Ann Marie; Kaye, Robin D. [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Born, Christopher T. [Temple University Hospital/Temple Children' s Hospital, Temple Sports Medicine, Marlton, NJ (United States); Grudziak, Jan S. [Children' s Hospital of Pittsburgh, Department of Orthopedic Surgery, Pittsburgh, PA (United States); Towbin, Richard B.

    2004-12-01

    Unstable posterior pelvic ring fractures and dislocations are uncommon but potentially life-threatening injuries in children. Early definitive management reduces risk of immediate complications as well as chronic pain and gait dysfunction. Conventional operative therapy carries substantial risk of extensive blood loss and iatrogenic neurological and vascular injury. Minimally invasive image-guided intervention may further reduce immediate risk and improve long-term outcome. To describe CT-guided closed reduction and internal fixation (CRIF) and review outcomes of unstable fracture-dislocation of the sacroiliac (SI) joint in children. Between 2000 and 2003, three children (two girls, one boy) age 8-14 years were referred to interventional radiology for treatment of unstable SI joint fracture-dislocation not adequately treated with anterior external fixation alone. The three affected SI joints (two left, one right) were treated in a combined approach by pediatric interventional radiologists and orthopedic surgeons, using a percutaneous approach under CT guidance. Over a threaded guiding pin, 7.3 mm cannulated screws were used to achieve stable reduction of the affected SI joints. One screw was removed after slight (2 mm) migration. No neurovascular or other complications occurred. All patients had satisfactory healing with near-anatomic reduction, although recovery of the youngest was delayed by associated spinal injury. Compared to open surgical alternatives, CRIF under CT guidance reduces operating time, decreases blood loss, and allows early definitive fixation and immediate non-weight-bearing mobilization with a low rate of complication for unstable posterior pelvic ring fractures. In addition, CT-guided placement of the guide pin may allow safer screw positioning and may minimize the total number of screws needed to achieve pelvic stability. (orig.)

  16. Percutaneous hemi-epiphysiodesis using transphyseal cannulated screws for genu valgum in adolescents.

    Science.gov (United States)

    Mesa, Pedro Antonio Sánchez; Yamhure, Fernando Helo

    2009-10-01

    The purpose of this study was to assess percutaneous femoral distal hemi-epiphysiodesis using transphyseal cannulated screws in order to correct valgus angular deformities of the knee in pediatric and adolescent patients. This is a prospective longitudinal study in which our experience with 52 patients is described. We evaluated 100 knees surgically managed for pathologic genu valgum over a 68-month period. The average age at surgery for boys and girls was 14 years and 7 months (range 12.7-15.1 years) and 13 years and 6 months (range 12.9-14.8 years), respectively. The pre-surgical tibiofemoral (T-F) angle was measured at between 14.17° and 35.3°, and the postoperative T-F was measured at between 6.2° and 15.8° (7.2° ± 0.65°, mean ± standard deviation), for an average correction of 0.73° ± 0.45° per month). The mean follow-up after surgery was 3.2 years (range 2.3-5.3 years). We demonstrate a simple, fast and reproducible surgical technique for percutaneous epiphysiodesis with low morbidity, rapid rehabilitation and a rapid return to school and sports activities. We experienced no complications, such as overcorrection, undercorrection, postoperative hematoma or infection. We conclude that percutaneous screw epiphysiodesis is an excellent option for the treatment of genu valgum in adolescents.

  17. Pedicle screw fixation against burst fracture of thoracolumbar vertebrae

    Institute of Scientific and Technical Information of China (English)

    L(U) Fu-xin; HUANG Yong; ZHANG Qiang; SHI Feng-lei; ZHAO Dong-sheng; HU Qiao

    2007-01-01

    Objective: To analyze the application of vertebral pedicle screw fixation in the treatment of burst fracture of thoracolumbar vertebrae.Methods: A total of 48 cases (31 males and 17 females, aged from 18-72 years, mean: 41.3 years) with thoracolumbar vertebrae burst fracture were treated by pedicle screw system since January 2004. According to the AO classification of thoracolumbar vertebrae fracture,there are 36 cases of Type A, 9 of Type B and 3 of Type C.Results: All patients were followed up for 6-25 months (average 12 months ), no secondary nerve root injury, spinal cord injury, loosening or breakage of pedicle screw were observed. The nerve function of 29 patients with cauda equina nerve injury was restored to different degrees. The vertebral body height returned to normal level and posterior process angle was rectified after operation.Conclusions: The vertebral pedicle screw internal fixation was technologically applicable, which can efficiently reposition and stablize the bursting fractured vertabrae,indirectly decompress canalis spinalis, maintain spine stablity, scatter stress of screw system, reduce the risk of loosening or breakage of screw and loss of vertebral height,and prevent the formation of posterior convex after operation.

  18. Percutaneous Facet Screw Fixation in the Treatment of Symptomatic Recurrent Lumbar Facet Joint Cyst: A New Technique

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas, E-mail: amorettinicolas@yahoo.fr; Gallo, Giacomo, E-mail: giacomo.gallo83@gmail.com; Bertrand, Anne-Sophie, E-mail: asbertrand3@hotmail.com [Centre Hospitalier Universitaire de Nice (France); Bard, Robert L., E-mail: rbard@cancerscan.com [New York Medical College (United States); Kelekis, Alexis, E-mail: akelekis@med.uoa.gr [University General Hospital “ATTIKON” (Greece)

    2016-01-15

    We present a case of percutaneous treatment of symptomatic recurrent lumbar facet joint cyst resistant to all medical treatments including facet joint steroid injection. Percutaneous transfacet fixation was then performed at L4–L5 level with a cannulated screw using CT and fluoroscopy guidance. The procedure time was 30 min. Using the visual analog scale (VAS), pain decreased from 9.5, preoperatively, to 0 after the procedure. At 6-month follow-up, an asymptomatic cystic recurrence was observed, which further reduced at the 1-year follow-up. Pain remained stable (VAS at 0) during all follow-ups. CT- and fluoroscopy-guided percutaneous cyst rupture associated with facet screw fixation could be an alternative to surgery in patients suffering from a symptomatic recurrent lumbar facet joint cyst.

  19. Percutaneous Facet Screw Fixation in the Treatment of Symptomatic Recurrent Lumbar Facet Joint Cyst: A New Technique.

    Science.gov (United States)

    Amoretti, Nicolas; Gallo, Giacomo; Bertrand, Anne-Sophie; Bard, Robert L; Kelekis, Alexis

    2016-01-01

    We present a case of percutaneous treatment of symptomatic recurrent lumbar facet joint cyst resistant to all medical treatments including facet joint steroid injection. Percutaneous transfacet fixation was then performed at L4-L5 level with a cannulated screw using CT and fluoroscopy guidance. The procedure time was 30 min. Using the visual analog scale (VAS), pain decreased from 9.5, preoperatively, to 0 after the procedure. At 6-month follow-up, an asymptomatic cystic recurrence was observed, which further reduced at the 1-year follow-up. Pain remained stable (VAS at 0) during all follow-ups. CT- and fluoroscopy-guided percutaneous cyst rupture associated with facet screw fixation could be an alternative to surgery in patients suffering from a symptomatic recurrent lumbar facet joint cyst.

  20. Augmentation of Pedicle Screw Fixation with Calcium Phosphate Cement

    Institute of Scientific and Technical Information of China (English)

    YANG Shu-hua; FU De-hao; LI Jin; XU Wei-hua; YANG Cao; YE Zhe-wei; ZUO Xiao-yan

    2004-01-01

    To determine whether a biodegradable calcium phosphate cement(CPC) provides significant augmentation of pedicle screw fixation or not,an in vitro biomechanical study was carried out to evaluate the biomechanical effect of CPC in the restoration and augmentation of pedicle screw fixation.Axial pullout test and cyclic bending resistance test were employed in the experiment,and polymethylmethacrylate (PMMA) was chosen as control.The results demonstrate that the pullout strengths following CPC restoration and augmentation are 74% greater on an average than those of the control group,but less than those of PMMA restoration group and augmentation group respectively (increased by 126% versus control).In cyclic bending resistance test,the CPC augmented screws are found to withstand a greater number of cycles or greater loading with less displacement before loosening,but the augmentation effect of PMMA is greater than that of CPC.

  1. Posterior atlantoaxial transpedicle screw fixation for traumatic atlatoaxial instability

    Directory of Open Access Journals (Sweden)

    Zheng-lei WANG

    2015-10-01

    Full Text Available Objective To explore the clinical efficacy of posterior atlantoaxial pedicle screw fixation for traumatic atlantoaxial instability. Methods From September 2009 to March 2013, 17 patients with atlantoaxial instability received posterior atlantoaxial pedicle screw fixation. There were 12 males and 5 females, with a mean age of 42 years old (ranged from 19 to 63 years old. Transpedicle screw fixation was employed in 8 patients with atlantoaxial fracture and dislocation, in 2 with traumatic disruption of transverse atlantal ligament, and in 7 with odontoid fracture. The Japanese Orthopaedic Association (JOA score before operation was from 5 to 14, with a mean of 11.2. Preoperative CT, MRI and radiographs, as well as intraoperative screw placement and bone graft were administered in all the patients. Results In all the patients, complete reduction was achieved without injury to the vertebral artery, spinal cord or never root, and they started to be ambulatory on the first day after the operation. The patients were followed up for 6-36 months (mean 21 months, and clinical symptoms were seen to be improved significantly. Imaging reexamination 6 months after the surgery showed satisfactory healing of implanted bone and position of all the screws without loosening of the implant. The mean JOA scores was 15.5(11.0-17.0 twelve months after the operation. Conclusion Atlantoaxial pedicle screw fixation for traumatic atlantoaxial instability is safe and reliable with a favorable clinical result. DOI: 10.11855/j.issn.0577-7402.2015.09.14

  2. Clinical Analysis of Tension Band Internal Fixation Screw Combined with Cannulated Titanium Wire Treatment of Patella Fracture%空心加压螺纹钉结合钛丝张力带法内固定治疗髌骨骨折临床探讨

    Institute of Scientific and Technical Information of China (English)

    陈哲

    2015-01-01

    Objective To hol ow compression screw nail combining with titanium wire internal fixation treatment of patel a fracture with tension band method shal be discussed in this paper.Methods Selected from October 2011to October 2014 were 31 cases of patel ar fracture patients,using hol ow compression screw nails with internal fixation with titanium wire tension band method to treatment, the treatment ef ect analysis.Results Al patients were successful y completed surgery,no looseness or breakage implants,knee function and basic returned to normal.Conclusion The treatment in patients with patel ar fracture,hol ow compression screw nails in combination with the use of internal fixation with titanium wire tension band method,fixed ef ect is good,can be as early as possible for knee joint function in patients with postoperative exercise,is a bet er treatment method.%目的对空心加压螺纹钉结合钛丝张力带法内固定治疗髌骨骨折予以探讨。方法选取我院2011年10月~2014年10月收治的31例髌骨骨折患者,采用空心加压螺纹钉结合钛丝张力带法内固定予以治疗,对治疗效果予以分析。结果所有患者均顺利完成手术,植入物无松动或断裂,膝关节功能也基本恢复正常。结论对髌骨骨折患者予以治疗时,空心加压螺纹钉结合钛丝张力带法内固定的运用,固定效果较好,术后患者可以尽早进行膝关节功能锻炼,是一种较好的治疗方法。

  3. Intermaxillary Fixation Screw Morbidity in Treatment of Mandibular Fractures

    DEFF Research Database (Denmark)

    Florescu, Vlad-Andrei; Kofod, Thomas; Pinholt, Else Marie

    2016-01-01

    Surgery, Rigshospitalet, University Hospital of Copenhagen, Copenhagen, Denmark). The fracture type, radiographic findings, treatment modality, screw type and number, and root damage were recorded. For the outcome comparison, a review of the published data regarding iatrogenic dental root damage caused......Purpose The aim of the present retrospective study was to investigate the morbidity of screws used for intermaxillary fixation (IMF) in the treatment of mandibular fractures. A review of the published data was also performed for a comparison of outcomes. Our hypothesis was that the use of screws...... for IMF of mandibular fractures would result in minimal morbidity. Materials and Methods Patients treated for mandibular fractures from 2007 to 2013, using screws for IMF, using the international diagnosis code for mandibular fracture, DS026, were anonymously selected (Department of Oral and Maxillofacial...

  4. Biomechanical Evaluation of the Fixation Methods for Transcondylar Fracture of the Humerus:ONI Plate Versus Conventional Plates and Screws

    Directory of Open Access Journals (Sweden)

    Shimamura,Yasunori

    2010-04-01

    Full Text Available

    We biomechanically evaluated the bone fixation rigidity of an ONI plate (Group I during fixation of experimentally created transcondylar humerus fractures in cadaveric elbows, which are the most frequently observed humeral fractures in the elderly, and compared it with the rigidity achieved by 3 conventional fixation methods:an LCP reconstruction plate 3.5 using a locking mechanism (Group II, a conventional reconstruction plate 3.5 (CRP with a cannulated cancellous screw (Group III, and a CRP with 2 cannulated cancellous screws (CS in a crisscross orientation (Group IV. In the axial loading test, the mean failure loads were:Group I, 98.9+/-32.6;Group II, 108.5+/-27.2;Group III, 50.0+/-7.5;and Group IV, 34.5+/-12.2 (N. Group I fixations failed at a significantly higher load than those of Groups III and IV (p0.05. In the extension loading test, the mean failure loads were:Group I, 34.0+/-12.4;Group II, 51.0+/-14.8;Group III, 19.3+/-6.0;and Group IV, 14.7+/-3.1 (N. Group IV fixations showed a significantly lower failure load than those of Group I (p0.05. The fixation rigidities against mechanical loading by the ONI plate and LCP plate were comparable. These results suggested that an ONI system might be superior to the CRP and CS method, and comparable to the LCP method in terms of fixation rigidity for distal humerus fractures.

  5. Arthroscopic Bony Bankart Repair Using Double-Threaded Headless Screw: A Case Report

    Directory of Open Access Journals (Sweden)

    Takeshi Kokubu

    2012-01-01

    Full Text Available We present a case of arthroscopic fixation for bony Bankart lesion using a double-threaded cannulated screw. A 39-year-old man sustained a left shoulder injury from a motorcycle accident. Radiographs showed bony Bankart lesion and CT revealed 40% defect of glenoid articular surface. Arthroscopic fixation was performed using double-threaded cannulated screw after the bony fragment was reduced by suturing the labrum at the edge with a suture anchor. Arthroscopic bony Bankart repair using double-threaded cannulated screw fixation is effective because compression force could be applied between bony fragments and the screw head is not exposed in the glenohumeral joint.

  6. [Posterior atlantoaxial fixation using vertex multiaxial screw system].

    Science.gov (United States)

    Zhong, Dejun; Song, Yueming

    2007-06-01

    This study aims to assess the effectiveness and advantages of Vertex multiaxial screw system in use for stabilizing the atlanto-axial junction. The entry point of the atlas was located 18-20 mm lateral to the midline and 2.0 mm superior to the inferior border of posterior arch, and the direction of screw was chosen to be about 10 degrees medial to the sagittal plane and about 5 degrees cephalad to the transverse plane. In odontoid vertebra (C2), the direction of the drill bit was guided directly by the medial and superior aspect of the individual C2 pedicle. All screws were placed properly without incidence of nerve or blood vessel injury, and no complication appeared in operation and after surgery. All cases were followed up for an average of 9 months, all cases achieved well reposition and fixation of atlantoaxial joint, average JOA grade was 9.6 before preoperation and 15.9 after operation. Fixation of the atlantoaxial complex using Vertex multiaxial screw system seemed to be a reliable technique and should be considered a good alternative in atlantoaxial fusion. The technique could be used in young patiens.

  7. InterTan钉板系统与空心钉固定Pauwels Ⅲ型股骨颈骨折的有限元分析%InterTan compression hip screw versus three parallel cannulated screws for Pauwels Ⅲ femoral neck fractures: a finite element analysis

    Institute of Scientific and Technical Information of China (English)

    张晟; 王一民; 王博炜; 佟矿; 余斌

    2013-01-01

    目的 用有限元分析的方法研究InterTan钉板系统与3枚互相平行的空心钉固定PauwelsⅢ型股骨颈骨折的生物力学特点. 方法选取1名男性健康志愿者,28岁,体质量为75 kg,通过16排螺旋CT扫描,取右侧近端股骨数据作为样本.通过逆向工程软件分别重建PauwelsⅢ型股骨颈骨折三维可视化模型、InterTan钉板系统固定模型及3枚互相平行空心钉固定模型,并于Ansys软件中建立2种内固定模型的三维有限元模型,予以轴向700 N应力,研究不同内固定的von Mises应力分布和位移分布、股骨的yon Mises应力分布和位移分布,并比较内固定和股骨模型的应力峰值和位移峰值. 结果 内固定物的应力主要集中于骨折线附近,其中InterTan钉板系统钉板系统固定模型的应力峰值(65.7 MPa)低于空心钉固定模型(116.4 MPa);骨端的应力分布集中于股骨近端内侧,InterTan钉板系统固定模型的应力峰值(13.2 MPa)小于空心钉固定模型(27.6 MPa).lnterTan钉板系统固定模型中,内固定物位移方向为垂直向下,内固定物和骨端的位移峰值分别为0.84和0.76 mm;空心钉固定模型中,位移方向沿着股骨颈方向,内固定物和骨端的位移峰值分别为1.49和1.61 mm. 结论 使用InterTan钉板系统固定PauwelsⅢ型股骨颈骨折时,应力分布均匀,固定稳定性优于3枚互相平行空心钉固定.InterTan钉板系统固定时,位移方向垂直向下,髋内翻是需要预防的并发症;后者位移方向沿着股骨颈向外侧,股骨颈短缩为需要预防的并发症.%Objective To explore the biomechanical properties of InterTan compression hip screw versus versus three parallel cannulated screws in the fixation of Pauwels Ⅲ femoral neck fracture and their clinical implications.Methods A healthy male volunteer,28 years of age and 75 kg in weight,was enrolled in the present study.The spiral CT scans of his right proximal femur were used for reconstruction

  8. Fixation of displaced subcapital femoral fractures. Compression screw fixation versus double divergent pins.

    Science.gov (United States)

    Christie, J; Howie, C R; Armour, P C

    1988-03-01

    One hundred and twenty-seven consecutive patients with displaced subcapital fractures of the femoral neck (Garden Grade III or IV) all under 80 years of age and independently mobile, were randomly allocated to fixation with either double divergent pins or a single sliding screw-plate device. The incidence of non-union and infection in the sliding screw-plate group was significantly higher, and we believe that when internal fixation is considered appropriate multiple pinning should be used. Mobility after treatment was disappointing in about half of the patients, and we feel that internal fixation can only be justified in patients who are physiologically well preserved and who maintain a high level of activity.

  9. A retrospective comparison of the modified tension band technique and the parallel titanium cannulated lag screw technique in transverse patella fracture

    Directory of Open Access Journals (Sweden)

    Wang Chengxue

    2014-07-01

    Full Text Available 【Abstract】Objective: To compare efficacy between the modified tension band technique and the parallel titanium cannulated lag screw technique for the transverse patella fracture. Methods:Seventy-two patients were retrospectively analyzed aged 22 to 79 years (mean, 55.6 years with transverse patella fractures, among whom 37 patients underwent the modified tension band and 35 patients received the titanium cannulated lag screw. Patients were followed up for 1-3 years. We analyzed the difference of operation time, complications, fracture reduction, fracture healing time, and the Iowa score for knee function between both groups. Results:In modified tension band group, five patients had skin irritation and seven suffered wire migration, two of whom required a second operation. In comparison, there were no complications in the titanium cannulated lag screw group, which also had a higher fracture reduction rate and less operation time. Conclusion:The parallel titanium cannulated lag screw technique has superior results and should be considered as an alternative method to treat transverse patella fracture. Key words: Fractures, bone; Patella; Titanium; Bone screws

  10. Pseudoaneurysm of profunda femoris artery following dynamic hip screw fixation for intertrochanteric femoral fracture

    Institute of Scientific and Technical Information of China (English)

    Shailendra Singh; Sumit Arora; Ankit Thora; Ram Mohan; Sumit Sural; Anil Dhal

    2013-01-01

    Dynamic hip screw fixation is a commonly performed procedure for internal fixation of intertrochanteric femoral fractures.Arterial injury following the operative fixation is a rare but serious event.We present a patient who developed pseudoaneurysm of profunda femoris artery after internal fixation of intertrochanteric fracture with a dynamic hip screw.The diagnosis was confirmed by angiographic study and it was successfully treated by coil embolization.

  11. Biomechanical Evaluation of Plate Versus Lag Screw Only Fixation of Distal Fibula Fractures.

    Science.gov (United States)

    Misaghi, Amirhossein; Doan, Josh; Bastrom, Tracey; Pennock, Andrew T

    2015-01-01

    Traditional fixation of unstable Orthopaedic Trauma Association type B/C ankle fractures consists of a lag screw and a lateral or posterolateral neutralization plate. Several studies have demonstrated the clinical success of lag screw only fixation; however, to date no biomechanical comparison of the different constructs has been performed. The purpose of the present study was to evaluate the biomechanical strength of these different constructs. Osteotomies were created in 40 Sawbones(®) distal fibulas and reduced using 1 bicortical 3.5-mm stainless steel lag screw, 2 bicortical 3.5-mm lag screws, 3 bicortical 3.5-mm lag screws, or a single 3.5-mm lag screw coupled with a stainless steel neutralization plate with 3 proximal cortical and 3 distal cancellous screws. The constructs were tested to determine the stiffness in lateral bending and rotation and failure torque. No significant differences in lateral bending or rotational stiffness were detected between the osteotomies fixed with 3 lag screws and a plate. Constructs fixed with 1 lag screw were weaker for both lateral bending and rotational stiffness. Osteotomies fixed with 2 lag screws were weaker in lateral bending only. No significant differences were found in the failure torque. Compared with lag screw only fixation, plate fixation requires larger incisions and increased costs and is more likely to require follow-up surgery. Despite the published clinical success of treating simple Orthopaedic Trauma Association B/C fractures with lag screw only fixation, many surgeons still have concerns about stability. For noncomminuted, long oblique distal fibula fractures, lag screw only fixation techniques offer construct stiffness similar to that of traditional plate and lag screw fixation.

  12. Intramedullary Screw and Kirschner Wire Fixation for Unstable Scaphoid Nonunion.

    Science.gov (United States)

    Allon, Raviv; Kramer, Aviv; Wollstein, Ronit

    2016-12-01

    Surgical treatment of scaphoid nonunion is not always successful, often requiring stabilization and bone grafting to achieve healing. Even after intramedullary screw fixation, residual instability may still hinder union. The purpose of this study was to describe the addition of Kirschner wires (KWs) through the capitate and the lunate to supplement an intramedullary screw for temporary enhanced stability, possibly improving healing of unstable fractures. A case-control study reviewing 25 cases with addition of KWs and 19 controls was performed. Demographic and fracture information, time to diagnosis, and healing time were documented. We found no differences in population characteristics, fracture characteristics, or outcome measures between patients treated with this method and those treated with a screw alone. We had no complications related to the addition of KWs. Preoperative lunate type and scapholunate gapping was suggestive but not significantly associated with KW insertion. Addition of KWs is safe and may be considered in scaphoid nonunion in the presence of intraoperative suboptimal stability. Intraoperative stability may possibly be inferred by reviewing preoperative radiographs for signs of instability.

  13. SURVEY SUBAXIAL CERVICAL VERTEBRAE FOR TRANSPEDICULAR SCREW FIXATION

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective In this study, the pedicles of subaxial vertebrae from C3 to C7 were measured to provide some morphometric data for cervical transpedicular screw fixation. Methods 20 dried bone cervical spinal columns (C3-C7), pedicle dimensions (pedicle height, width, length), and transverse and sagittal angles of the pedicles were performed with vernier in linear and angular measurements. Results The obtained data revealed that the mean values were approximately ranging from 6.7 to 7.2 mm for pedicle height, 4.4 to 4.9 mm for pedicle width, 22.2 to 27.7 mm for pedicle axis length, 42.3° to 51.5° for transverse angle, and 5.2° to 14.1° for sagittal angle. Conclusion Linear measurements of pedicle dimensions and also axial angles from horizontal and vertical planes may provide some anatomic limitations for subaxial cervical transpedicular screw fixation, and also contribute to the safety of the surgical procedure.

  14. Morphological character of cervical spine for anterior transpedicular screw fixation

    Directory of Open Access Journals (Sweden)

    Rong-Ping Zhou

    2013-01-01

    Full Text Available Background: Anterior cervical interbody grafts/cages combined with a plate were frequently used in multilevel discectomies/corpectomies. In order to avoid additional posterior stabilization in patients who undergo anterior reconstructive surgery, an anterior cervical transpedicular screw fixation, which offers higher stability is desirable. We investigated in this study the anatomical (morphologic characters for cervical anterior transpedicular screw fixation. Materials and Methods: Left pedicle parameters were measured on computed tomography (CT images based on 36 cervical spine CT scans from healthy subjects. The parameters included outer pedicle width (Distance from lateral to medial pedicle surface in the coronal plane, outer pedicle height (OPH (Distance from upper to lower pedicle surface in the sagittal plane, maximal pedicle axis length (MPAL, distance transverse insertion point (DIP, distance of the insertion point to the upper end plate (DIUP, pedicle sagittal transverse angle (PSTA and pedicle transverse angle (PTA at C3 to C7. Results: The values of outer pedicle width and MPAL in males were larger than in females from C3 to C7. The OPH in males was larger than in females at C3 to C6, but there was no difference at C7. The DIP and PTA were significantly greater in males than in females at C3, but there was no difference in the angle at C4-7. The PSTA was not statistically different between genders at C3, 4, 7, but this value in males was larger than females at C5, 6. The DIUP was significantly greater in males at C3, 4, 6, 7 but was non significant at C5. Conclusions: The placement of cervical anterior transpedicular screws should be individualized for each patient and based on a detailed preoperative planning.

  15. Study of Bone-screw Surface Fixation in Lumbar Dynamic Stabilization

    Directory of Open Access Journals (Sweden)

    Yun-Gang Luo

    2015-01-01

    Full Text Available Background: We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with surrounding bone, and determine whether pedicle screws achieve good mechanical stability in the vertebrae. Methods: Twenty-four goats aged 2-3 years had Cosmic ® pedicle screws implanted into both sides of the L2-L5 pedicles. Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5. Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine. The side that was not implanted with fixation rods was used as a static control group. Results: In the static control group, new bone was formed around the pedicle screw and on the screw surface. In the unilateral and bilateral dynamic fixation groups, large amounts of connective tissue formed between and around the screw threads, with no new bone formation on the screw surface; the pedicle screws were loose after the fixed rods were removed. The bone mineral density and morphological parameters of the region of interest (ROI in the unilateral and bilateral dynamic fixation group were not significantly different (P > 0.05, but were lower in the fixed groups than the static control group (P 0.05; however the maximum pull force of the fixation groups was significantly less than the static control group (P < 0.01. Conclusions: Fibrous connective tissue formed at the bone-screw interface under unilateral and bilateral pedicle dynamic fixation, and the pedicle screws lost mechanical stability in the vertebrae.

  16. Biomechanical comparison of cervical fixation via transarticular facet screws without rods versus lateral mass screws with rods.

    Science.gov (United States)

    Yi, Seong; Rim, Dae-Cheol; Nam, Ki-Se; Keem, Sang-Hyun; Murovic, Judith A; Lim, Jesse; Park, Jon

    2015-04-01

    Transarticular facet screws restore biomechanical stability to the cervical spine when posterior cervical anatomy has been compromised. This study compares the more recent, less invasive, and briefer transarticular facet screw system without rods with the lateral mass screw system with rods. For this study, 6 human cervical spines were obtained from cadavers. Transarticular facet screws without rods were inserted bilaterally into the inferior articular facets at the C5-C6 and C5-C6-C7 levels. Lateral mass screws with rods were inserted bilaterally at the same levels using Magerl's technique. All specimens underwent range of motion (ROM) testing by a material testing machine for flexion, extension, lateral bending, and axial rotation. Both fixation methods, transarticular facet screws without rods and lateral mass screws with rods, reduced all ROM measurements and increased spinal stiffness. No statistically significant differences between the 2 stabilization methods were found in ROM measurements for 1-level insertions. However, in 2-level insertions, ROM for the nonrod transarticular facet screw group was significantly increased for flexion-extension and lateral bending. Transarticular facet screws without rods and lateral mass screws with rods had similar biomechanical stability in single-level insertions. For 2-level insertions, transarticular facet screws without rods are a valid option in cervical spine repair. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Latarjet Fixation

    Science.gov (United States)

    Alvi, Hasham M.; Monroe, Emily J.; Muriuki, Muturi; Verma, Rajat N.; Marra, Guido; Saltzman, Matthew D.

    2016-01-01

    Background: Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure. Purpose: To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen matched-pair shoulder specimens were randomized into 2 separate fixation groups: (1) 3.5-mm stainless steel cortical screws and (2) 4.0-mm stainless steel partially threaded cannulated cancellous screws. Shoulder specimens were dissected free of all soft tissue and a 25% glenoid defect was created. The coracoid process was osteomized, placed at the site of the glenoid defect, and fixed in place with 2 parallel screws. Results: All 10 specimens failed by screw cutout. Nine of 10 specimens failed by progressive displacement with an increased number of cycles. One specimen in the 4.0-mm screw group failed by catastrophic failure on initiation of the testing protocol. The 3.5-mm screws had a mean of 274 cycles (SD, ±171 cycles; range, 10-443 cycles) to failure. The 4.0-mm screws had a mean of 135 cycles (SD, ±141 cycles; range, 0-284 cycles) to failure. There was no statistically significant difference between the 2 types of screws for cycles required to cause failure (P = .144). Conclusion: There was no statistically significant difference in energy or cycles to failure when comparing the stainless steel cortical screws versus partially threaded cannulated cancellous screws. Clinical Relevance: Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option. PMID:27158630

  18. Comparison between Bilateral C2 Pedicle Screwing and Unilateral C2 Pedicle Screwing, Combined with Contralateral C2 Laminar Screwing, for Atlantoaxial Posterior Fixation

    OpenAIRE

    Miyakoshi, Naohisa; HONGO, MICHIO; Kobayashi, Takashi; Suzuki, Tetsuya; Abe, Eiji; Shimada, Yoichi

    2014-01-01

    Study Design A retrospective study. Purpose To compare clinical and radiological outcomes between bilateral C2 pedicle screwing (C2PS) and unilateral C2PS, combined with contralateral C2 laminar screwing (LS), for posterior atlantoaxial fixation. Overview of Literature Posterior fixation with C1 lateral mass screwing (C1LMS) and C2PS (C1LMS-C2PS method) is an accepted procedure for rigid atlantoaxial stabilization. However, conventional bilateral C2PS is not always allowed in this method due ...

  19. Navigated percutaneous screw fixation of a periprosthetic acetabular fracture.

    Science.gov (United States)

    Gras, Florian; Marintschev, Ivan; Klos, Kajetan; Fujak, Albert; Mückley, Thomas; Hofmann, Gunther O

    2010-10-01

    Periprosthetic fractures are severe complications of total hip arthroplasty with increasing incidence. Most fractures are localized around the femoral component of prosthesis, whereas periacetabular fractures are rare and their management is difficult. In most cases, an operative procedure with revision and exchange of the acetabular cup is necessary. The approaches are demanding and an increased risk of complications is reported. We present the case of a female patient with a cementless total hip arthroplasty due to severe arthritis, suffering of an infratectal transverse periprosthetic fracture. After an initial conservative treatment attempt, we performed a minimally invasive screw fixation using navigated 2-dimensional fluoroscopic guidance. In this report, the literature for treatment recommendations is reviewed and the chosen navigation technique discussed. Copyright © 2010. Published by Elsevier Inc.

  20. Open reduction and internal fixation: Screw injury - Retrospective study

    Directory of Open Access Journals (Sweden)

    Preetha Balaji

    2017-01-01

    Full Text Available Background/Aims: Open reduction and internal fixation (ORIF is a standard surgical procedure in jaw trauma and in orthognathic surgery. Insertion of screws is a significant risk for accidental tooth root injury with varying outcomes. Contrary evidences are found in literature due to a variety of study designs. This study was undertaken to address the lacunae and possibly estimate the difference in occurrence of tooth damage during or after ORIF between trauma and planned osteotomies. Materials and Methods: In this retrospective study, the data of ORIF in either trauma or orthognathic surgery fulfilling inclusion and exclusion criteria were collected and analyzed. Results: There were 1632 patients fulfilling the inclusion and exclusion criteria and formed the study group, of which 663 were in orthognathic surgery, of whom 210 had bimaxillary orthognathic surgery. In the trauma group, 358 patients had fractures involving both jaws whereas 272 had maxilla alone and 339 had mandibular fractures alone. On comparing the outcome, of the 9073 screws studied, 93.40% were not involved in any contact with the teeth, 6.3% were in category of potential hits (near apices or the root surfaces, and only 0.28% had evidence of root damage with the screws. It is observed that molar and premolar had a significant difference in terms of the type of surgery (P ≤ 0.05 whereas canine (P = 0.75 and incisor (P = 0.67 showed no statistical difference. Conclusion: ORIF when used as mentioned is a safe way for the management of fractures. The incidence of root injury is not uncommon but can be avoided with careful planning and execution.

  1. Interference Screw vs. Suture Anchor Fixation for Open Subpectoral Biceps Tenodesis: Does it Matter?

    Directory of Open Access Journals (Sweden)

    Gobezie Reuben

    2008-09-01

    Full Text Available Abstract Background Bioabsorbable interference screw fixation has superior biomechanical properties compared to suture anchor fixation for biceps tenodesis. However, it is unknown whether fixation technique influences clinical results. Hypothesis We hypothesize that subpectoral interference screw fixation offers relevant clinical advantages over suture anchor fixation for biceps tenodesis. Study Design Case Series. Methods We performed a retrospective review of a consecutive series of 88 patients receiving open subpectoral biceps tenodesis with either interference screw fixation (34 patients or suture anchor fixation (54 patients. Average follow up was 13 months. Outcomes included Visual Analogue Pain Scale (0–10, ASES score, modified Constant score, pain at the tenodesis site, failure of fixation, cosmesis, deformity (popeye and complications. Results There were no failures of fixation in this study. All patients showed significant improvement between their preoperative and postoperative status with regard to pain, ASES score, and abbreviated modified Constant scores. When comparing IF screw versus anchor outcomes, there was no statistical significance difference for VAS (p = 0.4, ASES score (p = 0.2, and modified Constant score (P = 0.09. One patient (3% treated with IF screw complained of persistent bicipital groove tenderness, versus four patients (7% in the SA group (nonsignificant. Conclusion Subpectoral biceps tenodesis reliably relieves pain and improves function. There was no statistically significant difference in the outcomes studied between the two fixation techniques. Residual pain at the site of tenodesis may be an issue when suture anchors are used in the subpectoral location.

  2. [Finite element analysis of the initial stability of subtalar arthrodesis with double-screw fixation].

    Science.gov (United States)

    Cui, Zhuang; Yu, Bin; Li, Xue; Xu, Changpeng; Song, Jinqi; Ouyang, Hanbin; Diao, Xicai; Chen, Liguang

    2012-11-01

    To assess the optimal configuration of double-screw fixation for subtalar arthrodesis using finite element analysis. Three-dimensional finite element double-screw models of subtalar arthrodesis were reconstructed using Mimics 13.0, Geomagic 10.0 and solid works software based on the 3-D images of the volunteer's right foot. The external and internal rotation torques of 4 N·m were applied, and the micromotion at the bone-to-bone interface were measured to evaluate the initial stability of subtalar arthrodesis. A neck screw plus an anterolateral dome screw was the most stable model. The peak micromotion at the fusion site of this fixation configuration were 41.67mnplus;0.49 and 42.64mnplus;0.75 µm in response to the respectively. A neck screw plus a posteromedial dome screw was the least stable model, with peak micromotion at the bone-to-bone interface of 61.76mnplus;1.00 and 62.32mnplus;0.90 µm, respectively. A neck screw plus an anterolateral dome screw is the best fixation configuration while a neck screw plus a posteromedial screw provides the least stability of subtalar arthrodesis. Three-dimensional finite element models allow effective preoperative planning of the screw number and placement.

  3. 股骨颈断端愈合去除空心钉后的有限元分析%The finite element analysis of the femoral head after repair of the femoral neck fracture and removal of the inserted cannulated screws

    Institute of Scientific and Technical Information of China (English)

    吴伟; 喻爱喜; 漆白文; 肖卫东

    2015-01-01

    Objective To discuss the biomechanics factors which caused osteonecrosis of the femoral head (ONFH) after removal of the cannulated screws inserted in the healing operation of femoral neck fracture.Methods Using the finite element analysis,finite element models with three or two cannulated screws inserted in the healing operation were established respectively.In the models,the directions of inserted cannulated screws and the femoral neck were parallel.The distribution of inserted cannulated screws was the most centralized,the most dispersive and between them.The far-end depth of inserted cannulated screws was 10,5,and 2 mm.Under the same load and constraint,the stresses of the femeral head in different models were compared by the finite element analysis.Results The stress of the femeral head reached to a maximum value of 46.1 mPa when the distribution of three inserted cannulated screws was the most dispersive and their far-end depth was 2 mm.And it reached to a mimimum value of 10.3 mPa when the distribution of two inserted cannulated screws was the most centralized and their far-end depth was 10 mm.Conclusion The distribution,the far-end depth and number of inserted cannulated screws were the biomechanics factors which caused ONFH.This experiment indirectly proved the cannulated screws insert method recommended by international institute for internal fixation (AO) foundation made the least effect to the stress of femeral head after the inserted cannulated screws were removed.%目的 探讨股骨颈骨折断端骨性愈合去除空心钉后股骨头坏死的生物力学因素.方法 利用有限元分析技术分别建立3枚或2枚空心钉固定股骨颈骨折的有限元模型,空心钉平行于股骨颈方向,排列分布处于最集中、最分散及介于两者之间,空心钉远端分别位于股骨头下10、5、2 mm.在相同的加载和约束情况下,通过有限元分析计算比较各模型中内固定去除以后股骨头的受力情况.结果 当3

  4. Three-dimensional comparison of alternative screw positions versus actual fixation of scaphoid fractures.

    Science.gov (United States)

    Volk, Ido; Gal, Jonathan; Peleg, Eran; Almog, Gil; Luria, Shai

    2017-06-01

    The recommended technique for the fixation of a scaphoid waist fracture involves a headless compression screw placed in the proximal fragment center. This is usually accomplished by placing a longitudinal axis screw as visualized by fluoroscopy. The screw length has been shown to have a biomechanical advantage. An alternative to these options, which has been debated in the literature, is a screw placed perpendicular to the fracture plane and in its center. The perpendicular screw may have a biomechanical advantage despite the fact that it may be shorter. This study examined the differences in location and length in actual patients between a screw in the center of the proximal fragment with a longitudinal axis screw, and the actual fixating screw. These were then compared to a perpendicular axis screw. Pre- and post-operative CT scans of 10 patients with scaphoid waist fractures were evaluated using a 3D computer model. Comparisons were made between the length, location and angle of actual and virtual screw alternatives; namely, a screw along the central third of the proximal fragment (central screw axis) where the scaphoid longitudinal axis was calculated mathematically (longitudinal screw axis) and a screw placed at 90° to the fracture plane and in its center (perpendicular screw axis). The longitudinal axis screw was found to be significantly longer than the other axes (28.3mm). There was a significant difference between the perpendicular axis screw and the location and angle of the other screw axis, but it was only shorter than the longitudinal screw (23.6mm versus 25.5mm for the actual screw; ns.). A computed longitudinal axis screw is longer than a central or actual screw placed longitudinally by visual inspection by the surgeon. Although it needs to be placed using computer assisted (CAS) techniques, it may have the biomechanical advantages of a longer screw in a similar trajectory. The perpendicular screw was found to be significantly different in position

  5. Comparison of two-transsacral-screw fixation versus triangular osteosynthesis for transforaminal sacral fractures.

    Science.gov (United States)

    Min, Kyong S; Zamorano, David P; Wahba, George M; Garcia, Ivan; Bhatia, Nitin; Lee, Thay Q

    2014-09-01

    Transforaminal pelvic fractures are high-energy injuries that are translationally and rotationally unstable. This study compared the biomechanical stability of triangular osteosynthesis vs 2-transsacral-screw fixation in the repair of a transforaminal pelvic fracture model. A transforaminal fracture model was created in 10 cadaveric lumbopelvic specimens. Five of the specimens were stabilized with triangular osteosynthesis, which consisted of unilateral L5-to-ilium lumbopelvic fixation and ipsilateral iliosacral screw fixation. The remaining 5 were stabilized with a 2-transsacral-screw fixation technique that consisted of 2 transsacral screws inserted across S1. All specimens were loaded cyclically and then loaded to failure. Translation and rotation were measured using the MicroScribe 3D digitizing system (Revware Inc, Raleigh, North Carolina). The 2-transsacral-screw group showed significantly greater stiffness than the triangular osteosynthesis group (2-transsacral-screw group, 248.7 N/mm [standard deviation, 73.9]; triangular osteosynthesis group, 125.0 N/mm [standard deviation, 66.9]; P=.02); however, ultimate load and rotational stiffness were not statistically significant. Compared with triangular osteosynthesis fixation, the use of 2 transsacral screws provides a comparable biomechanical stability profile in both translation and rotation. This newly revised 2-transsacral-screw construct offers the traumatologist an alternative method of repair for vertical shear fractures that provides biplanar stability. It also offers the advantage of percutaneous placement in either the prone or supine position.

  6. Study of Bone-screw Surface Fixation in Lumbar Dynamic Stabilization

    Institute of Scientific and Technical Information of China (English)

    Yun-Gang Luo; Tao Yu; Guo-Min Liu; Nan Yang

    2015-01-01

    Background:We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with surrounding bone,and determine whether pedicle screws achieve good mechanical stability in the vertebrae.Methods:Twenty-four goats aged 2-3 years had Cosmic(R) pedicle screws implanted into both sides of the L2-L5 pedicles.Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5.Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine.The side that was not implanted with fixation rods was used as a static control group.Results:In the static control group,new bone was formed around the pedicle screw and on the screw surface.In the unilateral and bilateral dynamic fixation groups,large amounts of connective tissue formed between and around the screw threads,with no new bone formation on the screw surface; the pedicle screws were loose after the fixed rods were removed.The bone mineral density and morphological parameters of the region of interest (ROI) in the unilateral and bilateral dynamic fixation group were not significantly different (P > 0.05),but were lower in the fixed groups than the static control group (P < 0.05).This showed the description bone of the ROI in the static control group was greater than in the fixation groups.Under loading conditions,the pedicle screw maximum pull force was not significantly different between the bilateral and unilateral dynamic fixation groups (P > 0.05); however the maximum pull force of the fixation groups was significantly less than the static control group (P < 0.01).Conclusions:Fibrous connective tissue formed at the bone-screw interface under unilateral and bilateral pedicle dynamic fixation,and the pedicle screws lost mechanical stability in the vertebrae.

  7. Progressive slip after removal of screw fixation in slipped capital femoral epiphysis: two case reports

    Directory of Open Access Journals (Sweden)

    Engelsma Yde

    2012-11-01

    Full Text Available Abstract Introduction In slipped capital femoral epiphysis the femoral neck displaces relative to the head due to weakening of the epiphysis. Early recognition and adequate surgical fixation is essential for a good functional outcome. The fixation should be secured until the closure of the epiphysis to prevent further slippage. A slipped capital femoral epiphysis should not be confused with a femoral neck fracture. Case presentation Case 1 concerns a 15-year-old boy with an adequate initial screw fixation of his slipped capital femoral epiphysis. Unfortunately, it was thought that the epiphysis had healed and the screw was removed after 11 weeks. This caused new instability with a progressive slip of the femoral epiphysis and subsequently re-fixation and a subtrochanteric correction osteotomy was obligatory. Case 2 concerns a 13-year-old girl with persistent hip pain after screw fixation for slipped capital femoral epiphysis. The screw was removed as lysis was seen around the screw on the hip X-ray. This operation created a new unstable situation and the slip progressed resulting in poor hip function. A correction osteotomy with re-screw fixation was performed with a good functional result. Conclusion A slipped epiphysis of the hip is not considered ‘healed’ after a few months. Given the risk of progression of the slip the fixation material cannot be removed before closure of the growth plate.

  8. Bilateral osteochondritis dissecans of the elbow treated by Herbert screw fixation.

    Science.gov (United States)

    Inoue, G

    1991-09-01

    The case of a 15-year-old boy, a high-performance motocross rider, who developed bilateral osteochondritis dissecans of the elbow is described. Both lesions were successfully treated by Herbert screw internal fixation.

  9. Arthroscopic Bony Bankart Repair Using Double-Threaded Headless Screw: A Case Report

    OpenAIRE

    Takeshi Kokubu; Issei Nagura; Yutaka Mifune; Masahiro Kurosaka

    2012-01-01

    We present a case of arthroscopic fixation for bony Bankart lesion using a double-threaded cannulated screw. A 39-year-old man sustained a left shoulder injury from a motorcycle accident. Radiographs showed bony Bankart lesion and CT revealed 40% defect of glenoid articular surface. Arthroscopic fixation was performed using double-threaded cannulated screw after the bony fragment was reduced by suturing the labrum at the edge with a suture anchor. Arthroscopic bony Bankart repair using double...

  10. Is there enough evidence to regularly apply bone screws for intermaxillary fixation in mandibular fractures?

    NARCIS (Netherlands)

    A. Bins; M.A.E. Oomens; P. Boffano; T. Forouzanfar

    2015-01-01

    Purpose Intermaxillary fixation (IMF) is traditionally achieved with arch bars; however, this method has several well-known disadvantages and other techniques, such as bone screws, are available. This study evaluated current evidence regarding these IMF screws (IMFSs) for mandibular trauma and to as

  11. A biomechanical study of two different pedicle screw methods for fixation in osteoporotic and nonosteoporotic vertebrae.

    Science.gov (United States)

    Higashino, Kosaku; Kim, Jin Hwan; Horton, William C; Hutton, William C

    2012-01-01

    In reconstruction of the osteoporotic spine, patients often show poor outcome because of pedicle screw failure. This study used osteoporotic and nonosteoporotic vertebrae to determine the difference in fixation strength between pedicle screws inserted straight forward and pedicle screws inserted in an upward trajectory toward the superior end plate (i.e., end-plate screws). There is some evidence to suggest that end-plate screws have a strength advantage. The particular focus was on osteoporotic vertebrae. Thirty-three vertebrae (T10-L2) were harvested. The bone mineral density (BMD) was measured: 15 vertebrae were greater than 0.8 g/cm(2) and designated as nonosteoporotic (average BMD 1.146 ± 0.186 g/cm(2)) and 18 vertebrae were designated as osteoporotic (average BMD 0.643 ± 0.088 g/cm(2)). On one pedicle the screw was inserted straight forward and on the other pedicle the screw was inserted as an end-plate screw. The torque of insertion was measured (Proto 6106 torque screwdriver). Using an MTS Mini Bionix, two types of mechanical testing were carried out on each pedicle: (a) cephalocaudad toggling was first carried out to simulate some physiological type loading: 500 cycles at 0.3 Hz, at ±50 N; and (b) then each pedicle screw was pulled out at a displacement rate of 12.5 cm/min.There was no difference in pullout force between the pedicle screws inserted straight forward and the pedicle screws inserted as end-plate screws. This result applies whether the vertebrae were osteoporotic or nonosteoporotic. For both the straight-forward screws and the end-plate screws, a statistically significant correlation was observed between torque of insertion and pullout force. The results of this experiment indicate that pedicle screws inserted as end-plate screws do not provide a strength advantage over pedicle screws inserted straight forward, whether the vertebrae are osteoporotic or not.

  12. Sextant percutaneous pedicle screw fixation for correcting single-segment thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    Ming Jiang-hua; Zheng Hui-feng; Zhao Qi; Chen Qing; Wang Gang

    2014-01-01

    BACKGROUND:Though the effects of conservative or traditional open reduction and internal fixation in the treatment of thoracolumbar fractures are reliable and satisfactory for most cases, two methods also have shortages. Minimal-invasive percutaneous pedicle screw system provides a new available method. OBJECTIVE:To investigate the clinical effect of Sextant percutaneous pedicle screw system in the treatment of thoracolumbar fractures. METHODS:A total of 55 patients, who had undergone percutaneous pedicle screw fixation using Sextant system (25 patients) or traditional open internal fixation (30 patients) for single-level vertebral body compression fractures in Department of Orthopedics of Renmin Hospital of Wuhan University from February 2011 to January 2013, were enrol ed in this study. RESULTS AND CONCLUSION:Except two patients in traditional open internal fixation group were lost after discharge, al other patients were fol owed up for 8-14 months. Operative time, intraoperative blood loss, postoperative drainage amount and hospital day were better in percutaneous pedicle screw fixation group than in the traditional open internal fixation group (P0.05). The results show that percutaneous pedicle screw fixation using Sextant system has a satisfactory outcome in the treatment of thoracolumbar fractures. However, obeying indication strictly is very important for clinical application.

  13. Anatomic Study of Anterior Transdiscal Axial Screw Fixation for Subaxial Cervical Spine Injuries.

    Science.gov (United States)

    Ji, Wei; Zheng, Minghui; Qu, Dongbin; Zou, Lin; Chen, Yongquan; Chen, Jianting; Zhu, Qingan

    2016-08-01

    Anterior transdiscal axial screw (ATAS) fixation is an alternative or supplement to the plate and screw constructs for the upper cervical spine injury. However, no existing literatures clarified the anatomic feasibility of this technique for subaxial cervical spine. Therefore, the objective of this study was to evaluate the anatomical feasibility and to establish guidelines for the use of the ATAS fixation for the subaxial cervical spine injury.Fifty normal cervical spines had radiographs to determine the proposed screw trajectory (the screw length and insertion angle) and the interbody graft-related parameters (the disc height and depth, and the distance between anterior vertebral margin and the screw) for all levels of the subaxial cervical spine. Following screw insertion in 8 preserved human cadaver specimens, surgical simulation and dissection verified the feasibility and safety of the ATAS fixation.Radiographic measurements showed the mean axial screw length and cephalic incline angle of all levels were 41.2 mm and 25.2°, respectively. The suitable depth of the interbody graft was >11.7 mm (the distance between anterior vertebral margin and the screw), but C2-C3, C3-C4, C4-C5, and C5-C6 levels, but impossible at C6-C7 due to the obstacle of the sternum. All screws were placed accurately. None of the screws penetrated into the spinal canal and caused fractures determined by dissecting the specimens.The anterior transdiscal axial screw fixation, as an alternative or supplementary instrumentation for subaxial cervical spine injuries, is feasible and safe with meticulous surgical planning.

  14. Individualized 3D printing navigation template for pedicle screw fixation in upper cervical spine

    Science.gov (United States)

    Guo, Fei; Dai, Jianhao; Zhang, Junxiang; Ma, Yichuan; Zhu, Guanghui; Shen, Junjie; Niu, Guoqi

    2017-01-01

    Purpose Pedicle screw fixation in the upper cervical spine is a difficult and high-risk procedure. The screw is difficult to place rapidly and accurately, and can lead to serious injury of spinal cord or vertebral artery. The aim of this study was to design an individualized 3D printing navigation template for pedicle screw fixation in the upper cervical spine. Methods Using CT thin slices data, we employed computer software to design the navigation template for pedicle screw fixation in the upper cervical spine (atlas and axis). The upper cervical spine models and navigation templates were produced by 3D printer with equal proportion, two sets for each case. In one set (Test group), pedicle screws fixation were guided by the navigation template; in the second set (Control group), the screws were fixed under fluoroscopy. According to the degree of pedicle cortex perforation and whether the screw needed to be refitted, the fixation effects were divided into 3 types: Type I, screw is fully located within the vertebral pedicle; Type II, degree of pedicle cortex perforation is 1 mm or with the poor internal fixation stability and in need of renovation. Type I and Type II were acceptable placements; Type III placements were unacceptable. Results A total of 19 upper cervical spine and 19 navigation templates were printed, and 37 pedicle screws were fixed in each group. Type I screw-placements in the test group totaled 32; Type II totaled 3; and Type III totaled 2; with an acceptable rate of 94.60%. Type I screw placements in the control group totaled 23; Type II totaled 3; and Type III totaled 11, with an acceptable rate of 70.27%. The acceptability rate in test group was higher than the rate in control group. The operation time and fluoroscopic frequency for each screw were decreased, compared with control group. Conclusion The individualized 3D printing navigation template for pedicle screw fixation is easy and safe, with a high success rate in the upper cervical spine

  15. Calcium phosphate cement augmentation of cancellous bone screws can compensate for the absence of cortical fixation.

    Science.gov (United States)

    Stadelmann, Vincent A; Bretton, Elise; Terrier, Alexandre; Procter, Philip; Pioletti, Dominique P

    2010-11-16

    An obvious means to improve the fixation of a cancellous bone screw is to augment the surrounding bone with cement. Previous studies have shown that bone augmentation with Calcium Phosphate (CaP) cement significantly improves screw fixation. Nevertheless, quantitative data about the optimal distribution of CaP cement is not available. The present study aims to show the effect of cement distribution on the screw fixation strength for various cortical thicknesses and to determine the conditions at which cement augmentation can compensate for the absence of cortical fixation in osteoporotic bone. In this study, artificial bone materials were used to mimic osteoporotic cancellous bone and cortical bone of varying thickness. These bone constructs were used to test the fixation strength of cancellous bone screws in different cortical thicknesses and different cement augmentation depths. The cement distribution was measured with microCT. The maximum pullout force was measured experimentally. The microCT analysis revealed a pseudo-conic shape distribution of the cement around the screws. While the maximum pullout strength of the screws in the artificial bone only was 30±7N, it could increase up to approximately 1000N under optimal conditions. Cement augmentation significantly increased pullout force in all cases. The effect of cortical thickness on pullout force was reduced with increased cement augmentation depth. Indeed, cement augmentation without cortical fixation increased pullout forces over that of screws without cement augmentation but with cortical fixation. Since cement augmentation significantly increased pullout force in all cases, we conclude that the loss of cortical fixation can be compensated by cement augmentation.

  16. A 3-D CT Analysis of Screw and Suture-Button Fixation of the Syndesmosis.

    Science.gov (United States)

    Schon, Jason M; Williams, Brady T; Venderley, Melanie B; Dornan, Grant J; Backus, Jonathon D; Turnbull, Travis Lee; LaPrade, Robert F; Clanton, Thomas O

    2017-02-01

    Historically, syndesmosis injuries have been repaired with screw fixation; however, some suggest that suture-button constructs may provide a more accurate anatomic and physiologic reduction. The purpose of this study was to compare changes in the volume of the syndesmotic space following screw or suture-button fixation using a preinjury and postoperative 3-D computed tomography (CT) model. The null hypothesis was that no difference would be observed among repair techniques. Twelve pairs of cadaveric specimens were dissected to identify the syndesmotic ligaments. Specimens were imaged with CT prior to the creation of a complete syndesmosis injury and were subsequently repaired using 1 of 3 randomly assigned techniques: (a) one 3.5-mm cortical screw, (b) 1 suture-button, and (c) 2 suture-buttons. Specimens were imaged postoperatively with CT. 3-D models of all scans and tibiofibular joint space volumes were calculated to assess restoration of the native syndesmosis. Analysis of variance and Tukey's method were used to compare least squares mean differences from the intact syndesmosis among repair techniques. For each of the 3 fixation methods, the total postoperative syndesmosis volume was significantly decreased relative to the intact state. The total mean decreases in volume compared with the intact state for the 1-suture-button construct, 2-suture-button construct, and syndesmotic screw were -561 mm(3) (95% CI, -878 to -244), -964 mm(3) (95% CI, -1281 to -647) and -377 mm(3) (95% CI, -694 to -60), respectively. All repairs notably reduced the volume of the syndesmosis beyond the intact state. Fixation with 1 suture-button was not significantly different from screw or 2-suture-button fixation; however, fixation with 2 suture-buttons resulted in significantly decreased volume compared with screw fixation. The results of this study suggest that the 1-suture-button repair technique and the screw fixation repair technique were comparable for reduction of syndesmosis

  17. Posterior lumbar interbody fusion with cortical bone trajectory screw fixation versus posterior lumbar interbody fusion using traditional pedicle screw fixation for degenerative lumbar spondylolisthesis: a comparative study.

    Science.gov (United States)

    Sakaura, Hironobu; Miwa, Toshitada; Yamashita, Tomoya; Kuroda, Yusuke; Ohwada, Tetsuo

    2016-11-01

    OBJECTIVE Several biomechanical studies have demonstrated the favorable mechanical properties of the cortical bone trajectory (CBT) screw. However, no reports have examined surgical outcomes of posterior lumbar interbody fusion (PLIF) with CBT screw fixation for degenerative spondylolisthesis (DS) compared with those after PLIF using traditional pedicle screw (PS) fixation. The purposes of this study were thus to elucidate surgical outcomes after PLIF with CBT screw fixation for DS and to compare these results with those after PLIF using traditional PS fixation. METHODS Ninety-five consecutive patients underwent PLIF with CBT screw fixation for DS (CBT group; mean followup 35 months). A historical control group consisted of 82 consecutive patients who underwent PLIF with traditional PS fixation (PS group; mean follow-up 40 months). Clinical status was assessed using the Japanese Orthopaedic Association (JOA) scale score. Fusion status was assessed by dynamic plain radiographs and CT. The need for additional surgery and surgery-related complications was also evaluated. RESULTS The mean JOA score improved significantly from 13.7 points before surgery to 23.3 points at the latest follow-up in the CBT group (mean recovery rate 64.4%), compared with 14.4 points preoperatively to 22.7 points at final follow-up in the PS group (mean recovery rate 55.8%; p fusion was achieved in 84 patients from the CBT group (88.4%) and in 79 patients from the PS group (96.3%, p > 0.05). Symptomatic adjacent-segment disease developed in 3 patients from the CBT group (3.2%) compared with 9 patients from the PS group (11.0%, p fusion rate tended to be lower in the CBT group than in the PS group, although the difference was not statistically significant between the 2 groups.

  18. Monoaxial Pedicle Screws Are Superior to Polyaxial Pedicle Screws and the Two Pin External Fixator for Subcutaneous Anterior Pelvic Fixation in a Biomechanical Analysis

    Directory of Open Access Journals (Sweden)

    Rahul Vaidya

    2013-01-01

    Full Text Available Purpose. Comparison of monoaxial and polyaxial screws with the use of subcutaneous anterior pelvic fixation. Methods. Four different groups each having 5 constructs were tested in distraction within the elastic range. Once that was completed, 3 components were tested in torsion within the elastic range, 2 to torsional failure and 3 in distraction until failure. Results. The pedicle screw systems showed higher stiffness (4.008 ± 0.113 Nmm monoaxial, 3.638 ± 0.108 Nmm Click-x; 3.634 ± 0.147 Nmm Pangea than the exfix system (2.882 ± 0.054 Nmm in distraction. In failure testing, monoaxial pedicle screw system was stronger (360 N than exfixes (160 N and polyaxial devices which failed if distracted greater than 4 cm (157 N Click-x or 138 N Pangea. The exfix had higher peak torque and torsional stiffness than all pedicle systems. In torsion, the yield strengths were the same for all constructs. Conclusion. The infix device constructed with polyaxial or monoaxial pedicle screws is stiffer than the 2 pin external fixator in distraction testing. In extreme cases, the use of reinforcement or monoaxial systems which do not fail even at 360 N is a better option. In torsional testing, the 2 pin external fixator is stiffer than the pedicle screw systems.

  19. Extracapsular hip fractures: fixation with a twin hook or a lag screw?

    Science.gov (United States)

    Olsson, O; Ceder, L; Lunsjö, K; Hauggaard, A

    2000-01-01

    The twin hook, which has 2 oppositely directed apical hooks, is an alternative to the lag screw for use with a 'dynamic plate' in the fixation of trochanteric hip fractures. In this prospective study lasting 1 year, 102 consecutive patients with trochanteric hip fractures were treated by 19 surgeons with either a twin hook or a lag screw combined with a conventional sliding hip screw plate or a Medoff sliding plate. Seven intraoperative errors were made with the twin hook but postoperative migration did not differ significantly between the 2 groups. Postoperative fixation failures were equally distributed between the 2 groups. The twin hook provides adequate fixation, which is comparable to that produced by a lag screw.

  20. Fixation strength of biocomposite wedge interference screw in ACL reconstruction: effect of screw length and tunnel/screw ratio. A controlled laboratory study

    Directory of Open Access Journals (Sweden)

    Herrera Antonio

    2010-06-01

    Full Text Available Abstract Background Primary stability of the graft is essential in anterior cruciate ligament surgery. An optimal method of fixation should be easy to insert and provide great resistance against pull-out forces. A controlled laboratory study was designed to test the primary stability of ACL tendinous grafts in the tibial tunnel. The correlation between resistance to traction forces and the cross-section and length of the screw was studied. Methods The tibial phase of ACL reconstruction was performed in forty porcine tibias using digital flexor tendons of the same animal. An 8 mm tunnel was drilled in each specimen and two looped tendons placed as graft. Specimens were divided in five groups according to the diameter and length of the screw used for fixation. Wedge interference screws were used. Longitudinal traction was applied to the graft with a Servohydraulic Fatigue System. Load and displacement were controlled and analyzed. Results The mean loads to failure for each group were 295,44 N (Group 1; 9 × 23 screw, 564,05 N (Group 2; 9 × 28, 614,95 N (Group 3; 9 × 35, 651,14 N (Group 4; 10 × 28 and 664,99 (Group 5; 10 × 35. No slippage of the graft was observed in groups 3, 4 and 5. There were significant differences in the load to failure among groups (ANOVA/P Conclusions Longer and wider interference screws provide better fixation in tibial ACL graft fixation. Short screws (23 mm do not achieve optimal fixation and should be implanted only with special requirements.

  1. Suture-button versus screw fixation of the syndesmosis: a biomechanical analysis.

    Science.gov (United States)

    Klitzman, Robert; Zhao, Heng; Zhang, Li-Qun; Strohmeyer, Greg; Vora, Anand

    2010-01-01

    The treatment of ankle fractures with syndesmotic injuries associated with disruption of the deltoid ligament complex is controversial. The purpose of this study was to compare both the biomechanical and physiologic properties of suture-button fixation to the intact syndesmosis and screw fixation. Eight fresh frozen human cadaveric ankles were used in three different groups. One group had an intact syndesmosis and deltoid ligamentous complex and two groups had fixation of the syndesmosis after its disruption along with disruption of the deltoid ligaments. One fixation group used a suture-button and the other used a 3.5-mm tricortical syndesmotic screw. The syndesmotic gap after cycling at submaximal loads, laxity due to cycling, and fibular movement allowed in the sagittal plane were all measured and analyzed for statistical significance. The syndesmotic gap after cycling was not significantly different between the intact group (9.1 mm) and the suture-button group (8.8 mm) (p = 0.1509). The screw fixation group had a significantly smaller gap (7.9 mm) as compared to the other two groups (screw versus intact, p = 0.00004; screw versus suture-button, p = 0.0004). The intact group did not demonstrate a significant difference in laxity before (9.0 mm) and after (9.1 mm) cycling (p = 0.0670), whereas the suture-button group did have a significant difference (before, 8.01 mm; after, 8.28 mm) (p = 0.000251). The movement of the fibula in the sagittal plane was significantly greater in the suture-button group (3.17 mm) as compared to the intact group (2.77 mm) (p = 0.00554). Screw fixation allowed significantly less fibular movement in the sagittal plane (1.16 mm) as compared to the intact (p = 0.00014) and suture-button (p = 0.0000012) groups. Suture-button fixation maintained reduction after cycling with submaximal loads that compared favorably to the intact syndesmosis. It also allowed more physiologic movement of the fibula in the sagittal plane when compared to

  2. A finite element modeling of posterior atlantoaxial fixation and biomechanical analysis of C2 intralaminar screw fixation

    Institute of Scientific and Technical Information of China (English)

    Ma Xuexiao; Peng Xianbo; Xiang Hongfei; Zhang Yan; Zhang Guoqing; Chen Bohua

    2014-01-01

    Background The objective of this study was to use three-dimensional finite element (FE) models to analyze the stability and the biomechanics of two upper cervical fixation methods:the C2 intralaminar screw method and the C2 pedicle screw method.Methods From computed tomography images,a nonlinear three-dimensional FE model from C0 (occiput) to C3 was developed with anatomic detail.The C2 intralaminar screw and the C2 pedicle screw systems were added to the model,in parallel to establish the interlaminar model and the pedicle model.The two models were operated with all possible states of motion and physiological loads to simulate normal movement.Results Both the C2 intralaminar screw method and the C2 pedicle screw method significantly reduced motion compared with the intact model.There were no statistically significant differences between the two methods.The Von Mises stresses of the internal and external laminar walls were similar between the two methods.Stability was also similar.Conclusions The C2 intralaminar screw method can complement but cannot completely replace the C2 pedicle screw method.Clinicians would need to assess and decide which approach to adopt for the best therapeutic effect.

  3. An in vitro biomechanical evaluation of an expansive double-threaded bi-directional compression screw for fixation of type II odontoid process fractures: A SQUIRE-compliant article.

    Science.gov (United States)

    Liu, Ning; Tian, Li; Jiang, Rong-Xian; Xu, Chao; Shi, Lei; Lei, Wei; Zhang, Yang

    2017-04-01

    Odontoid process fracture accounts for 5% to 15% of all cervical spine injuries, and the rate is higher among elderly people. The anterior cannulated screw fixation has been widely used in odontoid process fracture, but the fixation strength may still be limited under some circumstances. This study aims to investigate the biomechanical fixation strength of expansive double-threaded bi-directional compression screw (EDBCS) compared with cannulated lag screw (CLS) and improved Herbert screw (IHS) for fixation of type II odontoid process fracture.Thirty fresh cadaveric C2 vertebrae specimens were harvested and randomly divided into groups A, B, and C. A type II fracture model was simulated by osteotomy. Then the specimens of the 3 groups were stabilized with a single CLS, IHS, or EDBCS, respectively. Each specimen was tested in torsion from 0° to 1.25° for 75 s in each of 5 cycles clockwise and 5 cycles anticlockwise. Shear and tensile forces were applied at the anterior-to-posterior and proximal-to-distal directions, respectively, both to a maximum load of 45 N and at a speed of 1 mm/min.The mean torsional stiffness was 0.309 N m/deg for IHS and 0.389 N m/deg for EDBCS, which were significantly greater compared with CLS, respectively (0.169 N m/deg) (P < .05 and P < .05). The mean shear stiffness for the EDBCS was 238 N/mm, which was significantly greater than CLS (150 N/mm) and IHS (132 N/mm) (P < .05 and P < .05). All 3 screws only partly restored tensile stiffness, but not significantly.Fixation with the EDBCS can improve the biomechanical strength for odontoid process fracture compared with CLS and IHS, especially in terms of torsional and shear stiffness.

  4. Accuracy and safety of free-hand pedicle screw fixation in age less than 10 years

    Directory of Open Access Journals (Sweden)

    Hyoung Yeon Seo

    2013-01-01

    Full Text Available Background: Pedicle screws are being used commonly in the treatment of various spinal disorders. However, use of pedicle screws in the pediatric population is not routinely recommended because of the risk of complications. The present study was to evaluate the safety of pedicle screws placed in children aged less than 10 years with spinal deformities and to determine the accuracy and complication (early and late of pedicle screw placement using the postoperative computed tomography (CT scans. Materials and Methods: Thirty one patients (11 males and 20 females who underwent 261 pedicle screw fixations (177 in thoracic vertebrae and 84 in lumbar vertebrae for a variety of pediatric spinal deformities at a single institution were included in the study. The average age of patients was 7 years and 10 months. These patients underwent postoperative CT scan which was assessed by two independent observers (spine surgeons not involved in the treatment. Results: Breach rate was 5.4% (14/261 screws for all pedicles. Of the 177 screws placed in the thoracic spine, 13 (7.3% had breached the pedicle, that is 92.7% of the screws were accurately placed within pedicles. Seven screws (4% had breached the medial pedicle wall, 4 screws (2.3% had breached the lateral pedicle wall and 2 screws (1.1% had breached the superior or inferior pedicle wall respectively. Of the 84 screws placed in the lumbar spine, 83 (98.8% screws were accurately placed within the pedicle. Only 1 screw (1.2% was found to be laterally displaced. In addition, the breach rate was found to be 4.2% (11/261 screws with respect to the vertebral bodies. No neurological, vascular or visceral complications were encountered. Conclusions: The accuracy of pedicle screw placement in pedicles and vertebral bodies were 94.6% and 95.8% respectively and there was no complication related to screw placement noted until the last followup. These results suggest that free-hand pedicle screw fixation can be safely

  5. Biomechanical comparison of intramedullary cortical button fixation and interference screw technique for subpectoral biceps tenodesis.

    Science.gov (United States)

    Buchholz, Arne; Martetschläger, Frank; Siebenlist, Sebastian; Sandmann, Gunther H; Hapfelmeier, Alexander; Lenich, Andreas; Millett, Peter J; Stöckle, Ulrich; Elser, Florian

    2013-05-01

    The purpose of this study was to biomechanically evaluate a new technique of intramedullary cortical button fixation for subpectoral biceps tenodesis and to compare it with the interference screw technique. We compared intramedullary unicortical button fixation (BicepsButton; Arthrex, Naples, FL) with interference screw fixation (Bio-Tenodesis screw; Arthrex) for subpectoral biceps tenodesis using 10 pairs of human cadaveric shoulders and ovine superficial digital flexor tendons. After computed tomography analysis, the specimens were mounted in a testing machine. Cyclic loading was performed (preload, 5 N; 5 to 70 N at 1.5 Hz for 500 cycles), recording the displacement of the tendon. Load to failure and stiffness were subsequently evaluated with a load-to-failure test (1 mm/s). Cyclic loading showed a displacement of 11.3 ± 2.8 mm for intramedullary cortical button fixation and 9 ± 1.7 mm for interference screw fixation (P = .112). All specimens within the cortical button group passed the cyclic loading test, whereas 3 of 10 specimens within the interference screw group failed by tendon slippage at the screw-tendon-bone interface after a mean of 252 cycles (P = .221). Load-to-failure testing showed a mean load to failure of 218.8 ± 40 N and stiffness of 27.2 ± 7.2 N/mm for the intramedullary cortical button technique. For the interference screw, the mean load to failure was 212.1 ± 28.3 N (P = .625) and stiffness was 40.4 ± 13 N/mm (P = .056). We could not find any major differences in load to failure when comparing the tested techniques for subpectoral biceps tenodesis. Intramedullary cortical button fixation showed no failure during cyclic testing. However, we found a 30% failure rate (3 of 10) for the interference screw fixation. Intramedullary cortical button fixation provides an alternative technique for subpectoral biceps tenodesis with comparable and, during cyclic loading, even superior biomechanical properties to interference screw fixation

  6. Supra-acetabular fixation and sacroiliac screws for treating unstable pelvic ring injuries: preliminary results from 20 patients☆

    Science.gov (United States)

    Guimarães, Rodrigo Pereira; de Góes Ribeiro, Arthur; Ulson, Oliver; de Ávila, Ricardo Bertozzi; Ono, Nelson Keiske; Polesello, Giancarlo Cavalli

    2016-01-01

    Objective To analyze the treatment results from 20 patients who underwent an alternative osteosynthesis method as definitive treatment for pelvic ring fractures. Methods A retrospective analysis was conducted on a series of 20 patients with pelvic ring fractures (Tile type C) and a high risk of postoperative infection, who were treated at Santa Casa de Misericórdia de São Paulo between August 2004 and December 2012. The patients underwent percutaneous supra-acetabular external fixation in association with cannulated 7.0 mm iliosacral screws. Results The patients’ mean age was 40 years (range 22–77 years) and the mean length of follow-up was 18.5 months (range 3–69 months). At the end of the treatment, ten patients (50%) were classified as having good results, nine patients (45%) had fair results and one patient (5%) did not have any improvement. Six patients presented complications, and paresthesia of the lateral femoral cutaneous nerve was the most frequent of these (two patients). Conclusion Supra-acetabular external fixation in association with iliosacral percutaneous osteosynthesis is a good definitive treatment method for patients with a high risk of postoperative infection. PMID:27069879

  7. Prevention of arthrofibrosis after arthroscopic screw fixation of tibial spine fracture in children and adolescents.

    Science.gov (United States)

    Parikh, Shital N; Myer, David; Eismann, Emily A

    2014-01-01

    Arthrofibrosis is a major complication of tibial spine fracture treatment in children, potentially resulting in knee pain, quadriceps weakness, altered gait, decreased function, inability to return to sports, and long-term osteoarthritis. Thus, prevention rather than treatment of arthrofibrosis is desirable. The purpose of this study was to evaluate an aggressive postoperative rehabilitation and early intervention approach to prevent permanent arthrofibrosis after tibial spine fracture treatment and to compare epiphyseal and transphyseal screws for fixation. A consecutive series of 24 patients younger than age 18 with displaced type II and III tibial spine fractures who underwent arthroscopic reduction and screw fixation between 2006 and 2011 were retrospectively reviewed. Final range of motion was compared between patients with epiphyseal (n=12) and transphyseal (n=9) screws. One-third (4 of 12) of patients with epiphyseal screws underwent arthroscopic debridement and screw removal approximately 3 months postoperatively; 3 patients lacked 5° to 15° of extension, 1 experienced pain with extension, and 1 had radiographic evidence of screw pullout, loss of reduction, and resultant malunion. In the transphyseal screw group, 3 patients had 10° loss of extension, and all corrected after arthroscopic debridement and screw removal. The two groups did not significantly differ in time to hardware removal or return to sports or final range of motion. No growth disturbances were identified in patients after transphyseal screw removal. An aggressive approach of postoperative rehabilitation and early intervention after arthroscopic reduction and screw fixation of tibial spine fractures in children was successful in preventing permanent arthrofibrosis.

  8. A Comparison of Screw Fixation and Suture-Button Fixation in a Syndesmosis Injury in an Ankle Fracture.

    Science.gov (United States)

    Kim, Jung-Han; Gwak, Heui-Chul; Lee, Chang-Rack; Choo, Hye-Jeung; Kim, Jeon-Gyo; Kim, Dae-Yoo

    2016-01-01

    The present study compared the quality of reduction and the clinical assessment between screw fixation and suture-button fixation with an ankle fracture accompanied by syndesmosis injury. We studied the clinical and radiologic findings 1 year postoperatively through retrospective examination of 24 patients who had undergone screw fixation from January 2011 to December 2012 and prospective examination of 20 patients who had undergone suture button fixation from January 2013 to May 2014. Regarding the tibiofibular clear space, tibiofibular overlap, and medial clear space, the screw fixation group had improvement from a preoperative mean of 6.97 (range 2.79 to 15.81) mm, 4.43 (range 0 to 7.87) mm, 7.90 (range 4.24 to 19.50) mm to a postoperative mean of 4.95 (range 2.72 to 9.08) mm, 6.29 (range 0 to 10.37) mm, and 4.32 (range 1.98 to 6.57) mm, respectively. The corresponding improvement for the suture-button fixation group was from a preoperative mean of 6.65 (range 3.94 to 13.73) mm, 5.39 (range 0 to 9.44) mm, 7.27 (range 4.04 to 16.00) mm to a postoperative mean of 5.15 (range 2.93 to 7.30) mm, 7.21 (range 2.15 to 10.30) mm, and 4.25 (range 2.97 to 5.71) mm. No statistically significant difference was found between the 2 techniques. Both suture-button and metal screw fixation are effective treatment methods for an ankle fracture accompanied by syndesmosis injury. However, a long-term and prospective analysis is needed. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Bicortical screw fixation of distal fibula fractures with a lateral plate: an anatomic and biomechanical study of a new technique.

    Science.gov (United States)

    Milner, Brenton F; Mercer, Deana; Firoozbakhsh, Keikhosrow; Larsen, Kenna; Decoster, Thomas A; Miller, Richard A

    2007-01-01

    One of the potential drawbacks of lateral plating of distal fibula fractures is less than satisfactory fixation of unicortical screws commonly placed in the distal fragment to avoid implant penetration of the ankle joint. This study examines the anatomy of the distal fibula, proposes new techniques for bicortical screw fixation and radiographic evaluation of screw placement, and compares pullout strength of unicortical versus bicortical screws in this area. Sixteen pairs of human cadaver feet were used in this study. It was found that a large percentage of the surface area of the distal fibula is nonarticular and that the distal fibula could be divided into 3 zones with distinct anatomic features. Zone I is defined as the distal most 1.5 cm of the fibula, zone II is the next 1 cm of fibula proximal to zone I, and zone III is defined as the fibula above the ankle joint, starting at just over 2.5 cm proximal to the tip of the fibula. We determined a safe corridor for bicortical screw placement by means of a lateral plate in each zone. An improved radiographic view is described for confirmation of extraarticular screw placement. Screw pullout testing was performed on 8 pairs of fresh-frozen human cadaver fibulas. In both zone I and zone II, the bicortical screw fixation was significantly stronger than the unicortical screw fixation. In zone I, the average pullout strength for the bicortical screw fixation was 2.3 times higher than the unicortical screw fixation. In zone II, the average pullout strength for the bicortical screw fixation was 3.3 times higher than the unicortical screw fixation. This study shows that not only is bicortical screw placement in the distal fibula technically feasible, but it is also biomechanically stronger than unicortical placement in this area.

  10. Biomechanical and clinical study on screw hook fixation after direct repair of lumbar spondylolysis

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jian; LIU Fan; SHI Hong-guang; FAN Jian; ZHAO Wei-dong; WANG You-hua; CAI Yu-hui

    2006-01-01

    Objective: To evaluate the biomechanical effect and clinical results of hook screw fixation after direct repair of lumbar spondylous defects in the pars interarticularis.Methods: L2-L6 spines of 8 fresh-frozen and thawed calf cadavers were used for mechanical testing. Bilateral spondylous defects were created in the L4 vertebra. The intervertebral rotation ranges between L4 and Ls were scanned and computerized in various states of motion, such as flexion/extension, lateral bending and torsional loadings applied on the intact spine and the spondylous spine when the spondylous spine was fixed with modified Scott's fixation, hook screw fixation and Buck's fixation sequentially and respectively. Between July 2002 and February 2004, 14 young male patients (aged 15-31 years)suffering from symptomatic lumbar spondylolysis were treated with TSRH hook screw fixation after direct repair of the defects. MacNab criteria1 were used to assess their preand post-operative status.Results: Each fixation technique could significantly increase the intervertebral rotational stiffness and made the stiffness return to nearly the intact level. Hook screw technique provided more rotational stability than the others. Hook screw and Buck's techniques provided more flexion/extension stability than modified Scott's technique.Neither complication nor instrumental failure was observed in this study. The mean follow-up period was 21 months.All the patients except one acquired union during the follow-up period. Thirteen patients had a "good" or "excellent" result according to MacNab criteria.Conclusions: Hook screw fixation shows biomechanical advantages and is safe and effective for young patients with lumbar spondylolysis.

  11. Outcomes of C1 and C2 posterior screw fixation for upper cervical spine fusion.

    Science.gov (United States)

    De Iure, F; Donthineni, R; Boriani, S

    2009-06-01

    To achieve stable fixation of the upper cervical spine in posterior fusions, the occiput is often included. With the newer techniques, excluding fixation to the occiput will retain the occiput-cervical motion, while still allowing a stable fixation. Harms's technique has been adapted at our institution and its effectiveness for indications such as C2 complex fractures and tumors using C1 or C2 as endpoints of a posterior fixation are reviewed. Fourteen cases were identified, consisting of one os odontoideum; four acute fractures and four non-unions of the odontoid; three tumors and two complex fractures of C2 vertebral body, and one C2-C3 post-traumatic instability. One misplaced screw without clinical consequences was the only complication recorded. Screw loosening or migration was not observed at follow-up, showing a stable fixation.

  12. Screw fixation for atlantoaxial dislocation related to Down syndrome in children younger than 5 years.

    Science.gov (United States)

    Ito, Kenyu; Imagama, Shiro; Ito, Zenya; Ando, Kei; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ishikawa, Yoshimoto; Ishiguro, Naoki

    2017-01-01

    The aim of this study was to present cases of upper cervical fixation in Down syndrome patients younger than 5 years. In two cases, C1 lateral mass screws were installed. However, owing to the irreducible atlantoaxial dislocation, the screw backed out and fractured. Therefore, O-C2 fusion was performed. Furthermore, C2 bilateral lamina screws were added to the C2 pedicle screw for reinforcement. C1-C2 fusion is an option for Down syndrome patients younger than 5 years with atlantoaxial dislocation, when the dislocation is reducible. If the dislocation is irreducible, or the implant cannot be firmly secured, the fixation range should be expanded to O-C2 or below.

  13. Posterior fixation and fusion with atlas pedicle screw system for upper cervical diseases

    Institute of Scientific and Technical Information of China (English)

    LI Lei; ZHOU Feng-hua; WANG Huan; CUI Shao-qian

    2008-01-01

    Objective: To evaluate the feasibility, safety and efficacy of atlas pedicle screws system fixation and fusion for the treatment of upper cervical diseases. Methods: Twenty-three consecutive patients with up-per cervical disorders requiring stabilization, including 19 cases of atlantoaxial dislocation (4 congenital odontoid disconnections, 6 old odontoid fractures, 4 fresh odontoid fractures of Aderson Ⅱ C, 3 ruptures of the C1 transverse ligament, and 2 fractures ofC1), 2 cases ofC2 tumor (instability after the resection of the tumors), and 2 giant neurilemomas of C2-C3(instability after resection of the tumors), were treated by posterior fixation and fusion with the atlas pedicle screw system, in which the screws were inserted through the posterior arch of Cr The operative time, bleeding volume and complications were reported. All patients were immobilized without external fixation or with rigid cervical collars for 1-3 months. All patients were followed up and evaluated with radiographs and CT. Results: In the 23 patients, 46 C1 pedicle screws, 42 C2 pedicle screws and 6 lower cervical lateral mass screws and 2 lower cervical pedicle screws were placed. The mean operative time and bleeding volume was 2.7 hours and 490 ml respectively. No intraoperative complications were directly related to surgical technique. No neurological, vascular or infective complications were encountered. All patients were followed up for 3-36 months (average 15 months). Firm bony fusion was documented in all patients after 3-6 months. One patient with atlas fracture showed anterior occipitocervical fusion. There was no implant failure. Conclusions: Posterior fixation and fusion of the atlas pedicle screw system is feasible and safe for the treatment of upper cervical diseases, and may be applicable to a larger number of patients.

  14. Comparison of crossed screw versus plate fixation for radial neck fractures.

    Science.gov (United States)

    Gutowski, Christina J; Darvish, Kurosh; Ilyas, Asif M; Jones, Christopher M

    2015-11-01

    Fixation of radial neck fractures can be achieved with a plate and screw construct or, in absence of comminution, with two obliquely-oriented screws. This study investigated the mechanical properties, specifically the stiffness and load to failure, of these two fixation strategies in a cadaver model. Ten matched-pair radii were removed from fresh cadaver arms. A transverse osteotomy was created at the neck of each radius. Right-sided radii were fixed with two oblique headless compression screws; left-sided radii were fixed with a radial neck plate. The distal aspect of each radius was potted in urethane casting resin. The radial head was loaded in shear in 4 different planes (medial to lateral, lateral to medial, posterior to anterior, and anterior to posterior) using an Instron machine. Stiffness and load to failure were recorded. The stiffness of both constructs was similar in all planes except for loading from medial to lateral where the screw construct was 1.8 times stiffer. Average ultimate failure occurred at 229N for the screws and 206N for the plate. Failure strength was not statistically different. However, mode of failure differed for both fixation constructs, the plate failed in bending while the screws failed by pullout and fracture. The two strategies provide similar strength and stiffness for the fixation of transverse, non-comminuted radial neck fractures. While plate and screw constructs are more appropriate for axially unstable or comminuted fractures, two oblique screws might be preferred for simple transverse neck fractures since this strategy requires less exposure and the implant is buried. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Cervical pedicle screw fixation at C6 and C7 A cadaveric study

    Directory of Open Access Journals (Sweden)

    Ye Li

    2015-01-01

    Conclusion: The intersection of the horizontal line through the midpoint of the transverse process root and vertical line through the intersection of the posterolateral and posterior planes of the isthmus can be used as an entry point for C6 and C7 pedicle screw fixation. The screws should be inserted at 60 or 90° with the posterolateral isthmus in the horizontal plane and at 75° with the posterior isthmus in the sagittal plane. The LSC should not exceed 30 mm.

  16. Treatment of neuromuscular scoliosis with posterior-only pedicle screw fixation

    OpenAIRE

    Fernandez Harry M; Song Hae-Ryong; Suh Seung-Woo; Modi Hitesh N; Yang Jae-Hyuk

    2008-01-01

    Abstract Background To determine whether posterior-only approach using pedicle screws in neuromuscular scoliosis population adequately addresses the correction of scoliosis and maintains the correction over time. Methods Between 2003 and 2006, 26 consecutive patients (7 cerebral palsy, 10 Duchenne muscular dystrophy, 5 spinal muscular atrophy and 4 others) with neuromuscular scoliosis underwent posterior pedicle screw fixation for the deformity. Preoperative, immediate postoperative and final...

  17. Evaluation of different screw fixation techniques and screw diameters in sagittal split ramus osteotomy: finite element analysis method.

    Science.gov (United States)

    Sindel, A; Demiralp, S; Colok, G

    2014-09-01

    Sagittal split ramus osteotomy (SSRO) is used for correction of numerous congenital or acquired deformities in facial region. Several techniques have been developed and used to maintain fixation and stabilisation following SSRO application. In this study, the effects of the insertion formations of the bicortical different sized screws to the stresses generated by forces were studied. Three-dimensional finite elements analysis (FEA) and static linear analysis methods were used to investigate difference which would occur in terms of forces effecting onto the screws and transmitted to bone between different application areas. No significant difference was found between 1·5- and 2-mm screws used in SSRO fixation. Besides, it was found that 'inverted L' application was more successful compared to the others and that was followed by 'L' and 'linear' formations which showed close rates to each other. Few studies have investigated the effect of thickness and application areas of bicortical screws. This study was performed on both advanced and regressed jaws positions.

  18. Comparison of migration behavior between single and dual lag screw implants for intertrochanteric fracture fixation

    Directory of Open Access Journals (Sweden)

    Katonis Pavlos G

    2009-05-01

    Full Text Available Abstract Background Lag screw cut-out failure following fixation of unstable intertrochanteric fractures in osteoporotic bone remains an unsolved challenge. This study tested if resistance to cut-out failure can be improved by using a dual lag screw implant in place of a single lag screw implant. Migration behavior and cut-out resistance of a single and a dual lag screw implant were comparatively evaluated in surrogate specimens using an established laboratory model of hip screw cut-out failure. Methods Five dual lag screw implants (Endovis, Citieffe and five single lag screw implants (DHS, Synthes were tested in the Hip Implant Performance Simulator (HIPS of the Legacy Biomechanics Laboratory. This model simulated osteoporotic bone, an unstable fracture, and biaxial rocking motion representative of hip loading during normal gait. All constructs were loaded up to 20,000 cycles of 1.45 kN peak magnitude under biaxial rocking motion. The migration kinematics was continuously monitored with 6-degrees of freedom motion tracking system and the number of cycles to implant cut-out was recorded. Results The dual lag screw implant exhibited significantly less migration and sustained more loading cycles in comparison to the DHS single lag screw. All DHS constructs failed before 20,000 cycles, on average at 6,638 ± 2,837 cycles either by cut-out or permanent screw bending. At failure, DHS constructs exhibited 10.8 ± 2.3° varus collapse and 15.5 ± 9.5° rotation around the lag screw axis. Four out of five dual screws constructs sustained 20,000 loading cycles. One dual screw specimens sustained cut-out by medial migration of the distal screw after 10,054 cycles. At test end, varus collapse and neck rotation in dual screws implants advanced to 3.7 ± 1.7° and 1.6 ± 1.0°, respectively. Conclusion The single and double lag screw implants demonstrated a significantly different migration resistance in surrogate specimens under gait loading simulation with

  19. Evaluation of Reduction Accuracy of Suture-Button and Screw Fixation Techniques for Syndesmotic Injuries.

    Science.gov (United States)

    Kocadal, Onur; Yucel, Mehmet; Pepe, Murad; Aksahin, Ertugrul; Aktekin, Cem Nuri

    2016-12-01

    Among the most important predictors of functional results of treatment of syndesmotic injuries is the accurate restoration of the syndesmotic space. The purpose of this study was to investigate the reduction performance of screw fixation and suture-button techniques using images obtained from computed tomography (CT) scans. Patients at or below 65 years who were treated with screw or suture-button fixation for syndesmotic injuries accompanying ankle fractures between January 2012 and March 2015 were retrospectively reviewed in our regional trauma unit. A total of 52 patients were included in the present study. Fixation was performed with syndesmotic screws in 26 patients and suture-button fixation in 26 patients. The patients were divided into 2 groups according to the fixation methods. Postoperative CT scans were used for radiologic evaluation. Four parameters (anteroposterior reduction, rotational reduction, the cross-sectional syndesmotic area, and the distal tibiofibular volumes) were taken into consideration for the radiologic assessment. Functional evaluation of patients was done using the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale at the final follow-up. The mean follow-up period was 16.7 ± 11.0 months, and the mean age was 44.1 ± 13.2. There was a statistically significant decrease in the degree of fibular rotation (P = .03) and an increase in the upper syndesmotic area (P = .006) compared with the contralateral limb in the screw fixation group. In the suture-button fixation group, there was a statistically significant increase in the lower syndesmotic area (P = .02) and distal tibiofibular volumes (P = .04) compared with the contralateral limbs. The mean AOFAS scores were 88.4 ± 9.2 and 86.1 ± 14.0 in the suture-button fixation and screw fixation group, respectively. There was no statistically significant difference in the functional ankle joint scores between the groups. Although the functional outcomes were similar, the

  20. Use of self-tapping metal screws for temporary fixation of a resorbable plate system in maxillofacial surgery.

    Science.gov (United States)

    Iwai, Toshinori; Omura, Susumu; Aoki, Noriaki; Tohnai, Iwai

    2015-05-01

    Resorbable plate systems have been used in maxillofacial surgery to obviate the need for plate removal. However, resorbable plates and screws are very costly, and refixation with additional screws may be necessary when reduction or repositioning of the bone segment is inaccurate. Here we report the use of self-tapping metal screws for temporary fixation of a resorbable plating system in maxillofacial surgery to avoid the use of additional screws following inaccurate fixation or the reuse of resorbable screws, which may result in loosening.

  1. Augmentation of screw fixation with injectable calcium sulfate bone cement in ovariectomized rats.

    Science.gov (United States)

    Yu, Xiao-Wei; Xie, Xin-Hui; Yu, Zhi-Feng; Tang, Ting-Ting

    2009-04-01

    The objective of this study was to determine the effect of augmenting screw fixation with an injectable calcium sulfate cement (CSC) in the osteoporotic bone of ovariectomized rats. The influence of the calcium sulfate (CS) on bone remodeling and screw anchorage in osteoporotic cancellous bone was systematically investigated using histomorphometric and biomechanical analyses. The femoral condyles of 55 Sprague-Dawley ovariectomized rats were implanted with screw augmented with CS, while the contralateral limb received a nonaugmented screw. At time intervals of 2, 4, 8, 12, and 16 weeks, 11 rats were euthanized. Six pair-matched samples were used for histological analysis, while five pair-matched samples were preserved for biomechanical testing. Histomorphometric data showed that CS augmented screws activated cancellous bone formation, evidenced by a statistically higher (p < 0.05) percentage of osteoid surface at 2, 4, and 8 weeks and a higher rate of bone mineral apposition at 12 weeks compared with nonaugmented screws. The amount of the bone-screw contact at 2, 8, and 12 weeks and of bone ingrowth on the threads at 4 and 8 weeks was greater in the CS group than in the nonaugmented group (p < 0.05), although these parameters increased concomitantly with time for both groups. The CS was resorbed completely at 8 weeks without stimulating fibrous encapsulation on the screw surface. Also, the cement significantly increased the screw pull-out force and the energy to failure at 2, 4, 8, and 12 weeks after implantation, when compared with the control group (p < 0.05). These results imply that augmentation of screw fixation with CS may have the potential to decrease the risk of implant failure in osteoporotic bone.

  2. Combining of small fragment screws and large fragment plates for open reduction and internal fixation of periprosthetic humeral fractures.

    Science.gov (United States)

    Seybold, Dominik; Citak, Mustafa; Königshausen, Matthias; Gessmann, Jan; Schildhauer, Thomas A

    2011-10-01

    Operative treatment of periprosthetic humeral fractures in elderly patients with osteoporotic bone requires a stable fixations technique. The combination of 3.5 cortical screws with washers in a 4.5 Arbeitsgemeinschaft für Osteosynthesefragen, Limited-contact dynamic compression plate or Locking plate, allows a stable periprosthetic fixation with the small 3.5 screws and 4.5 screws above and below the prosthesis, respectively. This combination is a cost-effective technique to treat periprosthetic humeral fractures.

  3. Design of three-dimensional visualization based on the posterior lumbar pedicle screw fixation

    Directory of Open Access Journals (Sweden)

    Kai XU

    2011-09-01

    Full Text Available Objective To establish a three-dimensional visualization model of posterior lumbar pedicle screw fixation.Methods A patient with lumbar intervertebral disc hernia and another patient with compression fracture of lumbar vertebra were involved in the present study.Both patients underwent multi-slice spiral CT scan before and after lumbar pedicle screw fixation.The degree of preoperative vertebral compression,vertebral morphology before and after surgery,postoperative pedicle screw position,and decompression effects were observed.The original data of the multi-slice spiral CT were inputted into the computer.The three-dimensional reconstructed images of the lumbar and implanted screws were obtained using the software Amira 4.1 to show the three-dimensional shape of the lumbar vertebrae before and after surgery and the location of the implanted screws.Results The morphology and structure of the lumbar vertebrae before and after surgery and of the implanted screws were reconstructed using the digital navigation platform.The reconstructed 3D images could be displayed in multicolor,transparent,or arbitrary combinations.In the 3D surface reconstruction images,the location and structure of the implanted screws could be clearly observed,and the decompression of the spinal cord or nerve roots and the severity of the fracture and the compression of lumbar vertebrae could be fully evaluated.The reconstructed images before operation revealed the position of the vertebral pedicles and provided reference for intraoperative localization.Conclusions The three-dimensional computerized reconstructions of lumbar pedicle screw fixation may be valuable in basic research,clinical experiment,and surgical planning.The software Amira is one of the bases of three-dimensional reconstruction.

  4. A biomechanical study on fixation stability with twin hook or lag screw in artificial cancellous bone.

    Science.gov (United States)

    Olsson, O; Tanner, K E; Ceder, L; Ryd, L

    2002-01-01

    The twin hook has been developed as an alternative to the conventional lag screw to be combined with a barrelled side-plate in the treatment of trochanteric hip fractures. With two oppositely directed apical hooks introduced into the subchondral bone of the femoral head, the twin hook provides different stabilising properties to the lag screw. The femoral head purchase of the twin hook and the lag screw were compared in a biomechanical study using artificial cancellous bone, and responses to axial and torsional loading was determined. A distinct yield point in load and torque was noted for the lag screw, representing failure of the laminas supporting the threads. For the twin hook, gradual increase of load and torque occurred during impaction of the bone supporting the hooks. The peak loads and torques were higher for the lag screw, but were similar for both devices after 8 mm deformation. The stiffness was higher for the lag screw, but in counter-clockwise rotation the stiffness for the lag screw was negligible. The twin hook appeared to provide fixation stability comparable to that offered by the lag screw, but with conceivable advantages in terms of a deformation response involving bone impaction and gradually increasing stability.

  5. Double Threaded Screw Fixation for Bilateral Stress Fracture of the Medial Malleolus

    Directory of Open Access Journals (Sweden)

    Ryo Kanto

    2014-01-01

    Full Text Available An 18-year-old college basketball player presented with continued ankle pain. A radiographic examination showed bilateral medial malleolus stress fractures. Considering the prolonged history and refractory nature of this injury, surgery was adopted as a treatment option. At surgery, the fracture site was percutaneously fixed using two cannulated double threaded screws. Surgery for each side was sequentially performed two months apart. Prompt bony healing was attained after surgery, and the patient could return to his previous sports level six months after the first surgery without subsequent recurrence.

  6. Collateral ligament reconstruction of the chronic thumb injury with bio-tenodesis screw fixation

    DEFF Research Database (Denmark)

    Gvozdenovic, Robert; Boeckstyns, Michel

    2014-01-01

    We describe a new technique for the reconstruction of chronic lesions of the collateral ligaments of the metacarpophalangeal ligaments of the thumb, using a Bio-Tenodesis screw for the fixation of a tendon graft in a triangular manner with proximal apex and allowing early mobilization, starting 2...

  7. Short Segment Fixation Versus Short Segment Fixation With Pedicle Screws at the Fracture Level for Thoracolumbar Burst Fracture

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    Anghel S

    2014-04-01

    Full Text Available Objective: The most prevailing surgical procedure in the treatment of thoracolumbar burst fractures, Short Segment Fixation (SSF, is often followed by loss of correction or hardware failure which may be significant enough to require another surgical intervention. In order to take advantage of its benefits but to avoid or diminish the risk and impact of associated drawbacks, some other alternatives have been lately developed among which we refer to short segment fixation with intermediate screws (SSF+IS. This article provides a comparative picture over the effectiveness of the two above-mentioned surgical treatments, focusing on their potential to prevent the loss of correction.

  8. IMF Screw: An Ideal Intermaxillary Fixation Device During Open Reduction of Mandibular Fracture.

    Science.gov (United States)

    Sahoo, N K; Mohan, Ritu

    2010-06-01

    Intermaxillary fixation (IMF) is conventionally used for treatment of fractures involving maxillomandibular complex both for closed reduction and as an adjuvant to open reduction. To overcome the cumbersome procedure of tooth borne appliances cortical bone screws were introduced in the year of 1989 to achieve IMF which is essentially a bone borne appliance. In our institution we treated 45 cases of mandibular fracture both single and multiple fractures by open reduction over a period of 24 months. IMF screws were used to achieve dental occlusion in all the cases. Various advantages, disadvantages and complications are discussed. In our institutional experience we found that the IMF screws are an ideal device for temporary intermaxillary fixation for the cases having only mandibular fracture.

  9. Ergotropic effect of bone cement on pedicle screw fixation in treatment of osteoporotic thoracolumbar fracture

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    Da LIU

    2017-02-01

    Full Text Available Objective To evaluate the ergotropic effect of bone cement on pedicle screw fixation in treatment of osteopo¬rotic thoracolumbar fracture. Methods Fifty-three patients with osteoporotic thoracolumbar fracture, admitted from Jun. 2013 to Dec. 2014, were included for treatment by augmentation of pedicle screw fixation with bone cement. All patients underwent pre-operative examination of bone mineral density with T-score ≤-2.5 and augmentation of pedicle screw fixation with injection of 1.5 ml bone cement in adjacent to fractured vertebra. All patients were treated with anti-osteoporosis therapy pre- and post-operation, ob¬served and recorded with basic conditions and complications. At pre-operation, one-week post-operation and last follow-up, pain vi¬sual analogue scale (VAS and neurological function score (ASIA of all patients were recorded, and the compression rats of anterior and posterior edge of fractured vertebra, and compression rats of spinal canal and Cobb angel of all patients were measured. Results All the 53 patients were successfully undergone operation in about 90-140 min with blood loss of about 150-350 ml. No spinal cord or nerve injury, dural tear and obvious leakage of bone cement and screw loosening occurred during operation. All patients were followed up for 12 to 36 months and the neurological function obviously recovered contrasted with pre-operation. X-ray and CT examination at last follow-up showed good fractures healing, good position and non-loosening of internal fixation device and non-leakage of bone cement. At one week post-operation and last follow-up, VAS, compression rats of anterior edge and posterior edge of fractured vertebra, compression rats of spinal canal and Cobb angel were significantly lower than those at pre-operation (P0.05. Conclusions Augmentation of pedicle screw fixation with bone cement can effectively strengthen the initial stability of pedicle screw in osteo¬porosis, restore the

  10. Root contact with maxillomandibular fixation screws in orthognathic surgery: incidence and consequences.

    Science.gov (United States)

    Camargo, I B; Van Sickels, J E; Laureano Filho, J R; Cunningham, L L

    2016-08-01

    The use of maxillomandibular fixation (MMF) screws in orthognathic surgery has become common in recent years. The risk of injury to adjacent roots with their placement in this population has not been studied extensively. The aim of this study was to review the incidence and consequences of root contact/injury in patients undergoing orthognathic surgery. A retrospective analysis of the treatment and radiographic records of patients who underwent orthognathic surgery between January 2013 and September 2014 at a university in Kentucky, USA was performed. The mean number of screws used was correlated to the mean number of roots affected using Spearman's test, set to a level of significance of 5%. Of 125 patients who underwent orthognathic surgery, 15 (12%) had evidence of root contact. Subsequent radiographs showed resolution of the bone defects. There was no clinical evidence of pulpal necrosis or pain during follow-up. The average number of screws used was 3.14±0.35 per patient, with an average of 0.17±0.52 root contacts per patient. There was no correlation between the number of screws used and the number of roots injured (P=0.279). Based on these results, MMF screws can safely be used to establish interim fixation during orthognathic surgery. Caution should be taken during placement to avoid direct injury to the roots of teeth.

  11. The calcar screw in angular stable plate fixation of proximal humeral fractures - a case study

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    Simmen Hans-Peter

    2011-09-01

    Full Text Available Abstract Background With new minimally-invasive approaches for angular stable plate fixation of proximal humeral fractures, the need for the placement of oblique inferomedial screws ('calcar screw' has increasingly been discussed. The purpose of this study was to investigate the influence of calcar screws on secondary loss of reduction and on the occurrence of complications. Methods Patients with a proximal humeral fracture who underwent angular stable plate fixation between 01/2007 and 07/2009 were included. On AP views of the shoulder, the difference in height between humeral head and the proximal end of the plate were determined postoperatively and at follow-up. Additionally, the occurrence of complications was documented. Patients with calcar screws were assigned to group C+, patients without to group C-. Results Follow-up was possible in 60 patients (C+ 6.7 ± 5.6 M/C- 5.0 ± 2.8 M. Humeral head necrosis occurred in 6 (C+, 15.4% and 3 (C-, 14.3% cases. Cut-out of the proximal screws was observed in 3 (C+, 7.7% and 1 (C-, 4.8% cases. In each group, 1 patient showed delayed union. Implant failure or lesions of the axillary nerve were not observed. In 44 patients, true AP and Neer views were available to measure the head-plate distance. There was a significant loss of reduction in group C- (2.56 ± 2.65 mm compared to C+ (0.77 ± 1.44 mm; p = 0.01. Conclusions The placement of calcar screws in the angular stable plate fixation of proximal humeral fractures is associated with less secondary loss of reduction by providing inferomedial support. An increased risk for complications could not be shown.

  12. Sol-gel derived titania coating with immobilized bisphosphonate enhances screw fixation in rat tibia.

    Science.gov (United States)

    Linderbäck, Paula; Areva, Sami; Aspenberg, Per; Tengvall, Pentti

    2010-08-01

    A variety of surface modifications have been tested for the enhancement of screw fixation in bone, and locally delivered anti-osteoporosis drugs such as bisphosphonates (BP) are then of interest. In this in vivo study, the impact of surface immobilized BP was compared with systemic BP delivery and screws with no BP. After due in vitro characterization, differently treated stainless steel (SS) screws were divided into four groups with 10 rats each. Three of the groups received screws coated with sol-gel derived TiO(2) and calcium phosphate (SS+TiO(2)+CaP). One of these had no further treatment, one had alendronate (BP) adsorbed to calcium phosphate mineral, and one received systemic BP treatment. The fourth group received uncoated SS screws and no BP (control). The screw pullout force was measured after 4 weeks of implantation in rat tibiae. The immobilized amount and release rate of alendronate could be controlled by different immersion times. The SS+TiO(2)+CaP coating did not increase the pullout force compared to SS alone. Surface delivered alendronate enhanced the pullout force by 93% [p = 0.000; 95% Confidence Interval (CI): 67-118%] compared to SS, and by 39% (p = 0.044; 95% CI: 7-71%) compared to systemic alendronate delivery. Both surface immobilized and systemically delivered alendronate improved implant fixation. Also, locally delivered, that is, surface immobilized alendronate showed a better fixation than systemically delivered. Using sol-gel derived TiO(2) as a platform, it is possible to administer controllable amounts of a variety of BPs.

  13. Transarticular screw fixation for atlantoaxial instability - modified Magerl's technique in 38 patients

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    Dhatt Saravdeep S

    2010-11-01

    Full Text Available Abstract Background Symptomatic atlantoaxial instability needs stabilization of the atlantoaxial joint. Among the various techniques described in literature for the fixation of atlantoaxial joint, Magerl's technique of transarticular screw fixation remains the gold standard. Traditionally this technique combines placement of transarticular screws and posterior wiring construct. The aim of this study is to evaluate clinical and radiological outcomes in subjects of atlantoaxial instability who were operated using transarticular screws and iliac crest bone graft, without the use of sublaminar wiring (a modification of Magerl's technique. Methods We evaluated retrospectively 38 subjects with atlantoaxial instability who were operated at our institute using transarticular screw fixation. The subjects were followed up for pain, fusion rates, neurological status and radiographic outcomes. Final outcome was graded both subjectively and objectively, using the scoring system given by Grob et al. Results Instability in 34 subjects was secondary to trauma, in 3 due to rheumatoid arthritis and 1 had tuberculosis. Neurological deficit was present in 17 subjects. Most common presenting symptom was neck pain, present in 35 of the 38 subjects. Postoperatively residual neck and occipital pain was present in 8 subjects. Neurological deficit persisted in only 7 subjects. Vertebral artery injury was seen in 3 subjects. None of these subjects had any sign of neurological deficit or vertebral insufficiency. Three cases had nonunion. At the latest follow up, subjectively, 24 subjects had good result, 6 had fair and 8 had bad result. On objective grading, 24 had good result, 11 had fair and 3 had bad result. The mean follow up duration was 41 months. Conclusions Transarticular screw fixation is an excellent technique for fusion of the atlantoaxial complex. It provides highest fusion rates, and is particularly important in subjects at risk for nonunion. Omitting the

  14. Acromioclavicular Joint Fixation Using an Acroplate Combined With a Coracoclavicular Screw

    Science.gov (United States)

    Tavakoli Darestani, Reza; Ghaffari, Arash; Hosseinpour, Mehrdad

    2013-01-01

    Background Appropriate treatment of acromioclavicular joint dislocation is controversial. Acroplate fixation is one of the most common treatment methods of acromioclavicular joint (ACJ) dislocation. Based on the risk of re-dislocation after Acroplate fixation, we assumed that combined fixation with an Acroplate and a coracoclavicular screw helps improve the outcome. Objectives The main purpose of the current study was to compare the outcome of ACJ dislocation treated with an Acroplate alone and in combination with coracoclavicular screw. Patients and Methods This study was carried out on 40 patients with ACJ dislocation types III to VI who were divided randomly into two equal groups: Acroplate group (P) and Acroplate in combination with coracoclavicular screw group (P + S). The screws were extracted 3-6 months postoperatively. The patients were followed for 1 year and Imatani’s score was calculated. Finally, the data were compared between the groups. Results The mean Imatani’s score was significantly higher in P + S group (83.4 ± 14.1) than P group (81.2 ± 10.3) (P < 0.001). The mean duration of surgery was the same in the two groups (59.8 ± 9.4 minutes in group P V.s 64.3 ± 10.9 minutes in group P + S; P = 0.169). There were no cases of re-dislocation, degenerative changes and ossification and all patients returned to their previous jobs or sporting activities. Conclusions Using a coracoclavicular screw combined with an Acroplate can improve the patients’ function after ACJ disruption without any significant increase in surgical duration. Authors recommend this technique in the fixation of ACJ dislocation. PMID:24396788

  15. [Odontoid bending stiffness after anterior fixation with a single lag screw: biomechanical study].

    Science.gov (United States)

    Buchvald, P; Čapek, L; Barsa, P

    2015-01-01

    PURPOSE OF THE STUDY The aim of the experiment was to compare the bending stiffness of an intact odontoid process with bending stiffness after its simulated type II fracture was fixed with a single lag screw. The experiment was done with a desire to answer the question of whether a single osteosynthetic screw is sufficient for good fixation of a type II odontoid fracture. MATERIAL AND METHODS The C2 vertebrae of six cadavers were used. With simultaneous measurement of odontoid bending stiffness, the occurrence of a fracture (type IIA, Grauer's modification of the Anderson- D'Alonzo classification) was simulated using action exerted by a tearing machine in the direction perpendicular to the odontoid axis. Each odontoid fracture was subsequently treated by direct osteosynthesis with a single lag screw inserted in the axial direction by a standard surgical procedure in order to provide conditions similar to those achieved by routine surgical management. The treated odontoid process was subsequently subjected to the same tearing machine loading as applied to it at the start of the experiment. The bending stiffness measured was then compared with that found before the fracture occurred. The results were statistically evaluated by the t-test for paired samples at the level of significance α = 0.05. RESULTS The average value of bending stiffness for odontoid processes of intact vertebrae at the moment of fracture occurrence was 318.3 N/mm. After single axial lag screw fixation of the fracture, the average bending stiffness for the odontoid processes treated was 331.3 N/mm. DISCUSSION Higher values of bending stiffness after screw fixation were found in all specimens and, in comparison with the values recorded before simulated fractures, the increase was statistically significant. CONCLUSIONS The results of our measurements suggest that the single lag screw fixation of a type IIA odontoid fracture will provide better stability for the fracture fragment-C2 body complex on

  16. Short segmental pedicle screw fixation combined with percutaneous vertebroplasty in treatment of nonadjacent thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    HE Qing-yi; XU Jian-zhong

    2009-01-01

    To evaluate the short-term outcomes of short segmental pedicle screw fixation combined with per-cutaneous vertebroplasty in treatment of nonadjacent tho-racolumbar fractures. Methods: Twenty patients who suffered from nonadja-cent thoracolumbar fractures were treated by short segmental pedicle screw fixation for burst fracture and by percutane-ous vertebroplasty for compression fracture. X-rays, CT and MRI scans were conducted using the same protocol before and after surgery and during follow-up. Pre- and post-operative American Spinal Injury Association (ASIA) grades, fusion of fracture sites, visual analog scale (VAS) of back pain, and Oswestry disability index (ODI) were accessed. Results: All patients were followed up for an average period of 12 months. The sagittal profile of the thoracolum-bar spine was restored satisfactorily. No patient had neuro-logic deterioration after surgery, and 9 patients with incom-plete lesions improved postoperatively by at least one ASIA grade. The fusion rate was 100%. The average VAS of back pain was 7.6 preoperatively and 3.2 postoperatively. The average ODI was 72.5 preoperatively and 35.5 postoperatively. Conclusions: Short segmental pedicle screw fixation combined with percutaneous vertebroplasty in treatment of nonadjacent thoracolumbar fractures exhibits such advan-tages as preserving functional segment units, reliable fixation, good neurologic recovery and early mobilization and, therefore, is suitable for treating nonadjacent thora-columbar fractures.

  17. Posterior interbody fusion using a diagonal cage with unilateral transpedicular screw fixation for lumbar stenosis.

    Science.gov (United States)

    Zhao, Jian; Zhang, Feng; Chen, Xiaoqing; Yao, Yu

    2011-03-01

    Few reports have described the combined use of unilateral pedicle screw fixation and interbody fusion for lumbar stenosis. We retrospectively reviewed 79 patients with lumbar stenosis. The rationale and effectiveness of unilateral pedicle screw fixation were studied from biomechanical and clinical perspectives, aiming to reduce stiffness of the implant. All patients were operated with posterior interbody fusion using a diagonal cage in combination with unilateral transpedicular screw fixation and had reached the 3-year follow-up interval after operation. The mean operating time was 115 minutes (range=95-150 min) and the mean estimated blood loss was 150 mL (range=100-200 mL). The mean duration of hospital stay was 10 days (range=7-15 days). Clinical outcomes were assessed prior to surgery and reassessed at intervals using Denis' pain and work scales. Fusion status was determined from X-rays and CT scans. At the final follow-up, the clinical results were satisfactory and patients showed significantly improved scores (pdiagonal cage with unilateral transpedicular fixation is an effective treatment for decompressive surgery for lumbar stenosis.

  18. Tunnel widening after ACL reconstruction with aperture screw fixation or all-inside reconstruction with suspensory cortical button fixation: Volumetric measurements on CT and MRI scans.

    Science.gov (United States)

    Mayr, Raul; Smekal, Vinzenz; Koidl, Christian; Coppola, Christian; Fritz, Josef; Rudisch, Ansgar; Kranewitter, Christof; Attal, René

    2017-10-01

    Tunnel widening after anterior cruciate ligament reconstruction (ACLR) is influenced by the surgical and fixation techniques used. Computed tomography (CT) is the most accurate image modality for assessing tunnel widening, but magnetic resonance imaging (MRI) might also be reliable for tunnel volume measurements. In the present study tunnel widening after ACLR using biodegradable interference screw fixation was compared with all-inside ACLR using button fixation, with tunnel volume changes being measured on CT and MRI scans. Randomized controlled trial; Level of evidence, 2. Thirty-three patients were randomly assigned to hamstring ACLR using a biodegradable interference screw or all-inside cortical button fixation. CT and MRI scanning were done at the time of surgery and six months after. Tunnel volume changes were calculated and compared. On CT, femoral tunnel volumes changed from the postoperative state (100%) to 119.8% with screw fixation and 143.2% with button fixation (P=0.023). The changes in tibial tunnel volumes were not significant (113.9% vs. 117.7%). The changes in bone tunnel volume measured on MRI were comparable with those on CT only for tunnels with interference screws. Tibial tunnels with button fixation were significantly underestimated on MRI scanning (P=0.018). All-inside ACLR using cortical button fixation results in increased femoral tunnel widening in comparison with ACLR with biodegradable interference screw fixation. MRI represents a reliable imaging modality for future studies investigating tunnel widening with interference screw fixation. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Suture Button Fixation Versus Syndesmotic Screws in Supination-External Rotation Type 4 Injuries: A Cost-Effectiveness Analysis.

    Science.gov (United States)

    Neary, Kaitlin C; Mormino, Matthew A; Wang, Hongmei

    2017-01-01

    In stress-positive, unstable supination-external rotation type 4 (SER IV) ankle fractures, implant selection for syndesmotic fixation is a debated topic. Among the available syndesmotic fixation methods, the metallic screw and the suture button have been routinely compared in the literature. In addition to strength of fixation and ability to anatomically restore the syndesmosis, costs associated with implant use have recently been called into question. This study aimed to examine the cost-effectiveness of the suture button and determine whether suture button fixation is more cost-effective than two 3.5-mm syndesmotic screws not removed on a routine postoperative basis. Economic and decision analysis; Level of evidence, 2. Studies with the highest evidence levels in the available literature were used to estimate the hardware removal and failure rates for syndesmotic screws and suture button fixation. Costs were determined by examining the average costs for patients who underwent surgery for unstable SER IV ankle fractures at a single level-1 trauma institution. A decision analysis model that allowed comparison of the 2 fixation methods was developed. Using a 20% screw hardware removal rate and a 4% suture button hardware removal rate, the total cost for 2 syndesmotic screws was US$20,836 and the total effectiveness was 5.846. This yielded a total cost of $3564 per quality-adjusted life-year (QALY) over an 8-year time period. The total cost for suture button fixation was $19,354 and the total effectiveness was 5.904, resulting in a total cost of $3294 per QALY over the same time period. A sensitivity analysis was then conducted to assess suture button fixation costs as well as screw and suture button hardware removal rates. Other possible treatment scenarios were also examined, including 1 screw and 2 suture buttons for operative fixation of the syndesmosis. To become more cost-effective, the screw hardware removal rate would have to be reduced to less than 10

  20. Analysis of Therapeutic Effect of the Treatment of Cannulated Screws on Displaced Medial Humeral Epicondyle Fractures%空心螺钉治疗移位肱骨内上髁骨折的疗效分析

    Institute of Scientific and Technical Information of China (English)

    朱仲伦; 谢德; 谭鸿; 高博

    2015-01-01

    Objective To explore the effect and clinic value of appplying cannulated screws on medial humeral epicon-dyle fractures. Methods From August 2005 to March 2012,15 consecutive patients(male 13,female 2;right elbow 11,left elbow 4;mean age 16 years;range 11 to 23 years) suffered from medial epicondylar fractures were treated with cannulated screws in open reduction and internal fixation(ORIF). All patients had medial humeral epicondyle fractures with displacement >1cm or had epi-condyle fractures accompanying elbow dislocations and with entrapment of the fragments in the elbow joint after manipulative reduc-tion of elbow dislocation. Of the 15 patients, 7 complicated with elbow dislocation and 1 had ulnar nerve disfunction syndrome. The duration time between the injury and operation ranged from 3 to 6 days. All the patients were followed up and evaluated. The outcome was evaluated by bone union and elbow function. Results All cases were followed up for 13-24 months with an average of 15 months. All the incisions were healed primarily and there were neither failures of the implantation divices nor early physeal growth cessations. All patients had union of the medial epicondyle with the mean healing time of 10 weeks and there were no avas-cular necroses ( AVN) of bone. According to Mayo Elbow Performance Score ( MEPS) for the function of elbow joint, among these 14 cases was excellent, 1 was good. Conclusion ORIF with cannulated screws is an ideal surgical method for treatment of medial humeral epicondyle fractures with larger than 1cm of displacement or with fragment being entrapped in the joint.%目的 探讨空心螺钉治疗肱骨内上髁骨折的临床疗效及应用价值. 方法 回顾性分析我院收治的采用空心螺钉治疗的15例肱骨内上髁骨折患者资料. 所有患者均骨折块移位大于1cm或伴有肘关节脱位并且复位后骨折块嵌顿在关节间隙中,即Ⅱ度~Ⅳ度肱骨内上髁骨折. 其中男13例,女2例;右侧11

  1. 不同角度植骨和空心钉固定股骨颈骨折的生物力学研究%Biomechanical study of femoral neck fracture fixed by cannulated screws and iliac bone graft at different angles

    Institute of Scientific and Technical Information of China (English)

    李智勇; 张奇; 张英泽; 王娟; 田帅; 秦士吉; 刘跃驹; 许斌

    2015-01-01

    Objective To investigate the biomechanical stability of iliac bone grafts at different angles with three cannulated screws for fixation of femoral neck fractures in order to provide scientific basis for clinical application.Methods The nine pairs of proximal femora and ipsilateral iliac bone grafts with lateral and upper surface retaining cortex were harvested from nine cadavers fixed in formalin,which were randomly divided into two groups: cannulated screw with medial bone graft fixation group ( CMB group) ,cannulated screw with cross bone graft fixation group ( CCB group) .The specimens were cut with power saw to create a standardized midcervical osteotomy perpendicular to the cervical neck.The fracture was then reduced and fixed with three parallel 7.3mm cannulated screws and an iliac bone graft.The cannulated screws were placed triangularly with one screw superior and two inferior.In the CMB group,the bone graft was in the middle of three cannulated screws and parallel with it,however,in the CCB group,the bone graft was made an angle of 30°with the screws on postero-anterior position.All the bone grafts were passed across the fracture line about 1.5cm.Every specimen was detected by Electroforce 3520-AT biomechanical machine.Results When femoral head was rotated to 3°and 5°, the torque values in CCB group were significantly higher than those in CMB group ( P <0.05) ,however,during axial displacement at the load of 700N and 1000N, the displacement values in CCB group were significantly lower than those in CMB group ( P <0.05).All the specimens underwent cycling compression test at 700N compression force successfully,without fatigue fracture or screw failure.The mean ultimate load in CMB group and CCB group was (2112.689 ±186.913)N and (2360.811 ±204.340)N,respectively,there was a significant difference between two groups ( P <0.05).Conclusion The biomechanical stability of fixation of femoral neck fracture with three cannulated screws in CCB group is

  2. "NIMS technique" for minimally invasive spinal fixation using non-fenestrated pedicle screws: A technical note

    Directory of Open Access Journals (Sweden)

    Alugolu Rajesh

    2015-01-01

    Full Text Available Study Design: Case series. Objective: To reduce the cost of minimally invasive spinal fixation. Background: Minimally invasive spine (MIS surgery is an upcoming modality of managing a multitude of spinal pathologies. However, in a resource-limited situations, using fenestrated screws (FSs may prove very costly for patients with poor affordability. We here in describe the Nizam′s Institute of Medical Sciences (NIMS experience of using routine non-FSs (NFSs for transpedicular fixation by the minimally invasive way to bridge the economic gap. Materials and Methods: A total of 7 patients underwent NFS-minimally invasive spine (MIS surgery. Male to female distribution was 6:1. The average blood loss was 50 ml and the mean operating time was 2 and 1/2 h. All patients were mobilized the very next day after confirming the position of implants on X-ray/computed tomography. Results: All 7 patients are doing well in follow-up with no complaints of a backache or fresh neurological deficits. There was no case with pedicle breach or screw pullout. The average cost of a single level fixation by FS and NFS was `1, 30,000/patient and `32,000/patient respectively ($2166 and $530, respectively. At the end of 1-year follow-up, we had two cases of screw cap loosening and with a displacement of the rod cranio-caudally in one case which was revised through the same incisions. Conclusions: Transpedicular fixation by using NFS for thoracolumbar spinal pathologies is a cost-effective extension of MIS surgery. This may extend the benefits to a lower socioeconomic group who cannot afford the cost of fenestrated screw (FS.

  3. Surgical complications in neuromuscular scoliosis operated with posterior- only approach using pedicle screw fixation

    Directory of Open Access Journals (Sweden)

    Singh Surya Udai

    2009-05-01

    Full Text Available Abstract Background There are no reports describing complications with posterior spinal fusion (PSF with segmental spinal instrumentation (SSI using pedicle screw fixation in patients with neuromuscular scoliosis. Methods Fifty neuromuscular patients (18 cerebral palsy, 18 Duchenne muscular dystrophy, 8 spinal muscular atrophy and 6 others were divided in two groups according to severity of curves; group I ( 90°. All underwent PSF and SSI with pedicle screw fixation. There were no anterior procedures. Perioperative (within three months of surgery and postoperative (after three months of surgery complications were retrospectively reviewed. Results There were fifty (37 perioperative, 13 postoperative complications. Hemo/pneumothorax, pleural effusion, pulmonary edema requiring ICU care, complete spinal cord injury, deep wound infection and death were major complications; while atelectesis, pneumonia, mild pleural effusion, UTI, ileus, vomiting, gastritis, tingling sensation or radiating pain in lower limb, superficial infection and wound dehiscence were minor complications. Regarding perioperative complications, 34(68% patients had at least one major or one minor complication. There were 16 patients with pulmonary, 14 with abdominal, 3 with wound related, 2 with neurological and 1 cardiovascular complications, respectively. There were two deaths, one due to cardiac arrest and other due to hypovolemic shock. Regarding postoperative complications 7 patients had coccygodynia, 3 had screw head prominence, 2 had bed sore and 1 had implant loosening, respectively. There was a significant relationship between age and increased intraoperative blood loss (p = 0.024. However it did not increased complications or need for ICU care. Similarly intraoperative blood loss > 3500 ml, severity of curve or need of pelvic fixation did not increase the complication rate or need for ICU. DMD patients had higher chances of coccygodynia postoperatively. Conclusion

  4. Self-tapping Intermaxillary Fixation Screw: An Alternative to Arch Bar.

    Science.gov (United States)

    Barodiya, Animesh; Thukral, Rishi; Agrawal, S M; Chouhan, Anil S; Singh, Sidharth; Loksh, Yogesh

    2017-02-01

    The use of intermaxillary fixation (IMF) in the treatment of faciomaxillary fractures is the key factor for reduction and immobilization. Various techniques of IMF have been described in the past and recently IMF screws have been introduced. This technique has various advantages, including ease of use, less time consumption, less trauma to the surrounding soft tissues, and relatively reduced risk of needle stick injury. This study evaluates the efficacy of IMF screws over arch bar IMF before definitive fixation of facial fractures. This study is a randomized clinical study. Study population consists of 20 patients with mandibu-lar fractures requiring IMF with open reduction and reported to Department of Oral Surgery, Modern Dental College and Research Centre, Indore, Madhya Pradesh, India between September 2012 and April 2015. Two groups were formed with 10 patients in each group. In the first group, IMF was achieved using the Erich's arch bar and wires. In the second group, IMF was achieved using self-tapping IMF screw. The patients were assessed for various parameters, such as the time required in minutes for the IMF stability of fixation, postoperative occlusion, postoperative pain, periodontal health, oral hygiene, and incidence of needle stick injury. All the cases had stable IMF in both groups. At the end of 14th day, overall oral hygiene was poor in group I and good in group II, significant statistically (p = 0.031). Iatrogenic injury to tooth was absent in group I and present in 1 case in group II, not significant statistically (p = 0.305). Average time taken for the IMF in group I was 74.9 minutes, with the range of 58 to 88 minutes, and in group II was 16.1 minutes, with the range of 11 to 22 minutes, which is highly significant statistically (p = 0.001). Needle stick injuries were taken as positive if glove perforation was present and these were reported in four cases in group I, whereas in group II, no case had incidence of needle stick injuries, which

  5. Combining of small fragment screws and large fragment plates for open reduction and internal fixation of periprosthetic humeral fractures

    Directory of Open Access Journals (Sweden)

    Dominik Seybold

    2011-01-01

    Full Text Available Operative treatment of periprosthetic humeral fractures in elderly patients with osteoporotic bone requires a stable fixations technique. The combination of 3.5 cortical screws with washers in a 4.5 Arbeitsgemeinschaft fόr Osteosynthesefragen, Limited-contact dynamic compression plate or Locking plate, allows a stable periprosthetic fixation with the small 3.5 screws and 4.5 screws above and below the prosthesis, respectively. This combination is a cost-effective technique to treat periprosthetic humeral fractures.

  6. Management of closed tibial plateau fractures with percutaneous cancellous screw fixation

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    Tushar Agarwal

    2013-01-01

    Full Text Available Background: Tibial plateau fractures, intra-articular in nature and caused by high-velocity trauma, constitute approximately 1% of all fractures. Primary goal in the management of proximal tibial articular fracture aims for a stable, congruous, pain-free, mobile joint. Objective: To study the technique, results, and complications of percutaneous cancellous screw fixation for tibial plateau fractures. Materials and Methods: Twenty-three men and seven women aged 18-65 years (mean = 36.8 years underwent closed reduction and percutaneous screw fixation for closed tibial plateau fractures with <5 mm depression. According to the Schatzker classification, patients were grouped as type I (n = 18, type II (n = 4, type III (n = 0, type IV (n = 8, type V (n = 2, and type VI (n = 1. Closed reduction was achieved by manual ligamentotaxis technique under image intensifier control and fixed percutaneously with two cancellous screws (6.5 mm with or without washers in a parallel fashion. Results: Functional outcome was evaluated using the Mason Hohl evaluation system. A total score of 19-24 was considered as excellent, 13-18 as good, 7-12 as fair, and <6 as poor. Outcomes were excellent in 10 patients, good in 15, fair in 4, and poor in 1 patient. Patients were allowed partial weight bearing with walker after 1 month and full weight bearing after radiological union in approximately 3-4 months. The mean period of hospital stay was 5 (range 2-15 days. All the fractures united radiologically after a mean of 3 (range 2.5- 5 months. Patients were evaluated at a mean of 3 years after injury. No patient had any complication like infection, wound dehiscence, or hardware problem. Conclusion: Percutaneous cancellous screw fixation for closed tibial plateau fractures is minimally invasive. It reduces hospital stay and cost, enables early mobilization with minimal instrumentation, and achieves satisfactory outcomes.

  7. Application of IMF screws to assist internal rigid fixation of jaw fractures: our experiences of 168 cases.

    Science.gov (United States)

    Bai, Zhenxi; Gao, Zhibiao; Xiao, Xia; Zhang, Wenjuan; Fan, Xing; Wang, Zhaoling

    2015-01-01

    Intermaxillary fixation (IMF) screws were first introduced to achieve IMF as a kind of bone borne appliance for jaw fractures in 1989. Because this method can overcome many disadvantages associated with tooth borne appliance, IMF screws have been popularly used for jaw fractures since then. From March 2011 to February 2014, we treated 168 cases with single or multiple jaw fractures by open reduction and a total of 705 IMF screws were intraoperatively applied in all the cases to achieve IMF and maintain dental occlusion as an adjuvant to open reduction. The numbers, implantation sites and complications of IMF screws were retrospectively analyzed. In our experience, we found that IMF screws were important to assist open reduction of jaw fractures but their roles should be objectively assessed and the reliability of open reduction and internal rigid fixation must be emphasized. Much attention should be paid when implanting.

  8. A Novel Nonpedicular Screw-Based Fixation in Lumbar Spondylolisthesis

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    Ming-Hong Chen

    2017-01-01

    Full Text Available Objective. The authors present the clinical results obtained in patients who underwent interspinous fusion device (IFD implantation following posterior lumbar interbody fusion (PLIF. The purpose of this study is investigating the feasibility of IFD with PLIF in the treatment of lumbar spondylolisthesis. Methods. Between September 2013 and November 2014, 39 patients underwent PLIF and subsequent IFD (Romeo®2 PAD, Spineart, Geneva, Switzerland implantation. Medical records of these patients were retrospectively reviewed to collect relevant data such as blood loss, operative time, and length of hospital stay. Radiographs and clinical outcome were evaluated 6 weeks and 12 months after surgery. Results. All 39 patients were followed up for more than one year. There were no major complications such as dura tear, nerve injuries, cerebrospinal fluid leakage, or deep infection. Both interbody and interspinous fusion could be observed on radiographs one year after surgery. However, there were 5 patients having early retropulsion of interbody fusion devices. Conclusion. The interspinous fusion device appears to achieve posterior fixation and facilitate lumbar fusion in selected patients. However, further study is mandatory for proposing a novel anatomic and radiological scoring system to identify patients suitable for this treatment modality and prevent postoperative complications.

  9. A Novel Nonpedicular Screw-Based Fixation in Lumbar Spondylolisthesis

    Science.gov (United States)

    2017-01-01

    Objective. The authors present the clinical results obtained in patients who underwent interspinous fusion device (IFD) implantation following posterior lumbar interbody fusion (PLIF). The purpose of this study is investigating the feasibility of IFD with PLIF in the treatment of lumbar spondylolisthesis. Methods. Between September 2013 and November 2014, 39 patients underwent PLIF and subsequent IFD (Romeo®2 PAD, Spineart, Geneva, Switzerland) implantation. Medical records of these patients were retrospectively reviewed to collect relevant data such as blood loss, operative time, and length of hospital stay. Radiographs and clinical outcome were evaluated 6 weeks and 12 months after surgery. Results. All 39 patients were followed up for more than one year. There were no major complications such as dura tear, nerve injuries, cerebrospinal fluid leakage, or deep infection. Both interbody and interspinous fusion could be observed on radiographs one year after surgery. However, there were 5 patients having early retropulsion of interbody fusion devices. Conclusion. The interspinous fusion device appears to achieve posterior fixation and facilitate lumbar fusion in selected patients. However, further study is mandatory for proposing a novel anatomic and radiological scoring system to identify patients suitable for this treatment modality and prevent postoperative complications. PMID:28164125

  10. The application of atlantoaxial screw and rod fixation in revision operations for postoperative re-dislocation in children.

    Science.gov (United States)

    Ma, XiangYang; Yin, QingShui; Xia, Hong; Wu, ZengHui; Yang, JinCheng; Liu, JingFa; Xu, JunJie; Qiu, Feng

    2015-03-01

    We evaluate the feasibility, safety, and efficacy of atlantoaxial screw and rod fixation for revision operations in the treatment of re-dislocation after atlantoaxial operations in children. Eight consecutive children with atlantoaxial instability required a revision operation due to atlantoaxial re-dislocation caused by the failure of the initial posterior wire fixation. The children were 5-11 years of age with an average age of 8.5 years. The posterior atlantoaxial screw and rod fixation and fusion operation was then performed. Autograft bones harvested from rib (in 3 patients), local bone (2 patients), and the iliac crest bone (3 patients) were used. There were no complications such as vertebral artery or spinal cord injury during the operations or loosening or fracture of the fixations after the operations. Stability and reduction of the atlantoaxial segments were achieved in all patients postoperatively. Follow-up time was 24-55 months, with an average of 35 months. All patients achieved solid osseous fusion demonstrated on plain radiographs or CT scanning. Atlantoaxial screw and rod fixation is feasible in children and may be considered for use during the initial operation in the treatment of atlantoaxial dislocation in children to minimize the need for a revision operation. If a revision operation is required, atlantoaxial screw-rod fixation is a safe and effective method. Because the anatomical structure is complicated in revision operation patients, CAD-RP technology could guide the the procedures of exposure and screw placement.

  11. Effects of Lateral Mass Screw Rod Fixation to the Stability of Cervical Spine after Laminectomy

    Science.gov (United States)

    Rosli, Ruwaida; Kashani, Jamal; Kadir, Mohammed Rafiq Abdul

    There are many cases of injury in the cervical spine due to degenerative disorder, trauma or instability. This condition may produce pressure on the spinal cord or on the nerve coming from the spine. The aim of this study was, to analyze the stabilization of the cervical spine after undergoing laminectomy via computational simulation. For that purpose, a three-dimensional finite element (FE) model for the multilevel cervical spine segment (C1-C7) was developed using computed tomography (CT) data. There are various decompression techniques that can be applied to overcome the injury. Usually, decompression procedures will create an unstable spine. Therefore, in these situations, the spine is often surgically restabilized by using fusion and instrumentation. In this study, a lateral mass screw-rod fixation was created to stabilize the cervical spine after laminectomy. Material properties of the titanium alloy were assigned on the implants. The requirements moments and boundary conditions were applied on simulated implanted bone. Result showed that the bone without implant has a higher flexion and extension angle in comparison to the bone with implant under applied 1Nm moment. The bone without implant has maximum stress distribution at the vertebrae and ligaments. However, the bone with implant has maximum stress distribution at the screws and rods. Overall, the lateral mass screw-rod fixation provides stability to the cervical spine after undergoing laminectomy.

  12. Single-screw Fixation of Adolescent Salter-II Proximal Humeral Fractures: Biomechanical Analysis of the "One Pass Door Lock" Technique.

    Science.gov (United States)

    Miller, Mark Carl; Redman, Christopher N; Mistovich, R Justin; Muriuki, Muturi; Sangimino, Mark J

    2017-09-01

    Pin fixation of Salter-II proximal humeral fractures in adolescents approaching skeletal maturity has potential complications that can be avoided with single-screw fixation. However, the strength of screw fixation relative to parallel and diverging pin fixation is unknown. To compare the biomechanical fixation strength between these fixation modalities, we used synthetic composite humeri, and then compared these results in composite bone with cadaveric humeri specimens. Parallel pinning, divergent pinning, and single-screw fixation repairs were performed on synthetic composite humeri with simulated fractures. Six specimens of each type were tested in axial loading and other 6 were tested in torsion. Five pair of cadaveric humeri were tested with diverging pins and single screws for comparison. Single-screw fixation was statistically stronger than pin fixation in axial and torsional loading in both composite and actual bone. There was no statistical difference between composite and cadaveric bone specimens. Single-screw fixation can offer greater stability to adolescent Salter-II fractures than traditional pinning. Single-screw fixation should be considered as a viable alternative to percutaneous pin fixation in transitional patients with little expected remaining growth.

  13. Percutaneous Screw Fixation of Crescent Fracture-Dislocation of the Sacroiliac Joint.

    Science.gov (United States)

    Shui, Xiaolong; Ying, Xiaozhou; Mao, Chuanwan; Feng, Yongzeng; Chen, Linwei; Kong, Jianzhong; Guo, Xiaoshan; Wang, Gang

    2015-11-01

    Crescent fracture-dislocation of the sacroiliac joint (CFDSIJ) is a type of lateral compression pelvic injury associated with instability. Open reduction and internal fixation is a traditional treatment of CFDSIJ. However, a minimally invasive method has never been reported. The purpose of this study was to assess the outcome of closed reduction and percutaneous fixation for different types of CFDSIJ and present their clinical outcome. The authors reviewed 117 patients diagnosed with CFDSIJ between July 2003 and July 2013. Closed reduction and percutaneous fixation was performed in 73 patients. Treatment selection was based on Day's fracture classification. For type I fractures, fixation perpendicular to the fracture line were performed. For type II fractures, crossed fixation was performed. For type III fractures, fixation was performed with iliosacral screws. Forty-four patients were treated by open reduction and plate fixation. Demographics, fracture pattern distribution, blood loss, incision lengths, revision surgeries, radiological results, and functional scores were compared. All 117 patients were followed for more than 6 months (mean, 14 months [range, 6-24 months]). Blood loss, extensive exposure, duration of posterior ring surgery, duration of hospital stay, and infection rates were lower in the closed group (P<.01). Patients in the closed group achieved better functional performance (P<.01). There were no significant differences in reduction quality (P=.32), revision surgery rates (P=.27), and iatrogenic neurologic injuries (P=.2) between the 2 groups. The authors' results indicate that closed reduction and percutaneous fixation is a safe and effective surgical method for CFDSIJ. Copyright 2015, SLACK Incorporated.

  14. C1-c2 pedicle screw fixation for treatment of old odontoid fractures.

    Science.gov (United States)

    Qi, Lei; Li, Mu; Zhang, Shuai; Si, Haipeng; Xue, Jingsong

    2015-02-01

    Nonunion and C1-C2 instability of odontoid fractures usually result from delayed diagnosis and inappropriate treatment. However, the available treatment options for odontoid fractures remain controversial. The authors evaluated the effectiveness of internal screw fixation via the C1 and C2 pedicle in cases of old odontoid fractures. This retrospective study included 21 patients with old odontoid fractures (13 men and 8 women; mean age, 46.5 years; range, 24-69 years). Internal screw fixation via the C1 and C2 pedicle was performed in all patients. Fracture reduction and C1-C2 fusion were assessed with imaging. The neck pain visual analog scale score and cervical spinal cord functional Japanese Orthopaedic Association score (for those who had cervical spinal cord injury) were used to evaluate the effectiveness of treatment. Postoperative complications were recorded. Postoperative imaging showed that the C1-C2 dislocation was satisfactorily repositioned in all patients. Bone fusion was observed 1 year after surgery in all patients. No loosening or breaking of internal fixation occurred. The preoperative neck pain visual analog scale score was 5.9±1.5 and improved significantly to 1.8±0.8 after surgery (PC2 pedicle was found to be an effective and safe surgical approach for the treatment of old odontoid fractures with C1-C2 dislocation or instability.

  15. Risks to the Superior Gluteal Neurovascular Bundle During Iliosacral and Transsacral Screw Fixation: A Computed Tomogram Arteriography (CTA) Study.

    Science.gov (United States)

    Collinge, Cory; Maslow, Jed

    2017-07-31

    Iliosacral (IS) and transsacral (TS) screws are popular techniques to repair complicated injuries to the pelvis. The anatomy of the superior gluteal neurovasculature (SG NV bundle) is well described as running along the posterior ilium, providing innervation and perfusion to important abductor muscles. The method of pelvis fixation least likely to injure the SG NV bundle is unknown. Twenty uninjured patients with a contrasted computed tomogram of the pelvis and lower extremities (CTA) were evaluated. Starting points for an S1 IS screw, and S1 and S2 TS screws were estimated on the "ghost" lateral CTA image for those pelvi with safe corridors (>9mm diameter). The distance from the projected screw to the SG artery was measured. A distance of <3.65mm (half of a 7.3mm screw's diameter) was considered likely for NV bundle injury. Of forty pelvi CTA's (single sides), 10 pelvi (25%) were determined to be inappropriate for a S1 TS screw. The average distances from the screw starting point and the artery were 25.3mm (±9.2) for S1 IS, 12.4mm (±9.0) for S1 TS, and 23.5mm (±10.7) for S2 TS screws, respectively. Ten S1 TS screws (25%) and no S1 IS or S2 TS screws were projected to have caused injury to the SG NV bundle (P<0.001). Inserting S1 IS and S2 TS screws put the SG NV anatomy at significantly less risk than S1 TS screws. This information may aid in choosing the "best" fixation option for patients with pelvic ring trauma requiring surgery. Therapeutic level III.

  16. Magnetic resonance imaging analysis of the bioabsorbable Milagro interference screw for graft fixation in anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Frosch, K-H; Sawallich, T; Schütze, G; Losch, A; Walde, T; Balcarek, P; Konietschke, F; Stürmer, K M

    2009-10-01

    Ligament graft fixation with bioabsorbable interference screws is a standard procedure in cruciate ligament replacement. Previous screw designs may resorb incompletely, and can cause osteolysis and sterile cysts despite being implanted for several years. The aim of this study was to examine the in vivo degradation and biocompatibility of the new Milagro interference screw (Mitek, Norderstedt, Germany). The Milagro interference screw is made of 30% ss-TCP (TriCalcium phosphate) and 70% PLGA (Poly-lactic-co-glycolic acid). In the period between June 2005 and February 2006, 38 patients underwent graft fixation with Milagro screws in our hospital. Arthroscopic ACL reconstruction was performed using hamstring tendon grafts in all the patients. MR imaging was performed on 12 randomly selected patients out of the total of 38 at 3, 6 and 12 months after surgery. During the examination, the volume loss of the screw, tunnel enlargement, presence of osteolysis, fluid lines, edema and postoperative screw replacement by bone tissue were evaluated. There was no edema or signs of inflammation around the bone tunnels. At 3, 6 and 12 months, the tibial screws showed an average volume loss of 0, 8.1% (+/-7.9%) and 82.6% (+/-17.2%, P Milagro screw is closely linked to the graft healing process. The screws were rapidly resorbed after 6 months and, at 12 months, only the screw remnants were detectable. Moreover, the Milagro screw is biocompatible and osteoconductive, promoting bone ingrowth during resorption. Tunnel enlargement is not prevented in the first months but is reduced by bone ingrowth after 12 months.

  17. Magnesium-Based Absorbable Metal Screws for Intra-Articular Fracture Fixation

    Directory of Open Access Journals (Sweden)

    Roland Biber

    2016-01-01

    Full Text Available MAGNEZIX® (Syntellix AG, Hanover, Germany is a biodegradable magnesium-based alloy (MgYREZr which is currently used to manufacture bioabsorbable compression screws. To date, there are very few studies reporting on a limited number of elective foot surgeries using this innovative implant. This case report describes the application of this screw for osteochondral fracture fixation at the humeral capitulum next to a loose radial head prosthesis, which was revised at the same time. The clinical course was uneventful. Degradation of the magnesium alloy did not interfere with fracture healing. Showing an excellent clinical result and free range-of-motion, the contour of the implant was still visible in a one-year follow-up.

  18. Polymethylmethacrylate augmentation of a cannulated and fenestrated pedicle screw for lumbar degenerative disease accompanied with osteoporosis:strengthening technical points%骨水泥注入中空侧孔椎弓根螺钉内固定骨质疏松性腰椎退变:强化技术要点

    Institute of Scientific and Technical Information of China (English)

    荆丹峰; 许艺荠; 孙太存; 田进; 鲁彪; 崔学文

    2014-01-01

    BACKGROUND:Once lumbar degenerative diseases merge with lumbar spinal stenosis, lumbar instability and degenerative scoliosis, surgical therapy is required for corresponding clinical symptoms, and the usage of internal fixators cannot be inevitable. Osteoporosis is rather common in the elderly. Therefore, how to implant stable pedicle screw fixation system in serious osteoporosis patients wil be a big difficulty. In recent years, some studies have proven the biomechanical stability of polymethylmethacrylate augmentation of a cannulated and fenestrated pedicle screw in the vertebral body, so it becomes very hot in the spine surgery. OBJECTIVE: To explore the clinical efficacy of the use of polymethylmethacrylate augmentation of a cannulated and fenestrated pedicle screw fixation for the treatment of lumbar degenerative disease accompanied with osteoporosis. METHODS:Thirty-one patients with lumbar degenerative disease accompanied with osteoporosis from Jun 2008 to Jan 2013 were selected, including 11 males and 20 females with an average age of 73.5 years (range, 65-86 years). There were 14 cases of lumbar degenerative stenosis, 9 of lumbar intervertebral disc herniation combined with segmental instability, 6 of lumbar degenerative spondylolisthesis, and 2 of lumbar degenerative scoliosis. The patients were treated with lumbar canal decompression, fusion and polymethylmethacrylate augmentation of a cannulated and fenestrated pedicle screw fixation according to their clinical features and imaging data. Visual analog scale for pain evaluation was used before and after fixation, the Japanese Orthopaedic Association (JOA) scale was used for assessment of neurological function and life skils before internal fixation and during folow-up. RESULTS AND CONCLUSION:Al cases were folowed up for 40 months (range, 36-48months). No screw breakage, rod breakage, screw extraction, loosening, pseudoarticulation formation, or incision infection was found. The postoperative visual

  19. Experimental and Numerical Analysis of Screw Fixation in Anterior Cruciate Ligament Reconstruction

    Science.gov (United States)

    Chizari, Mahmoud; Wang, Bin; Snow, Martyn; Barrett, Mel

    2008-09-01

    This paper reports the results of an experimental and finite element analysis of tibial screw fixation in anterior cruciate ligament (ACL) reconstruction. The mechanical properties of the bone and tendon graft are obtained from experiments using porcine bone and bovine tendon. The results of the numerical study are compared with those from mechanical testing. Analysis shows that the model may be used to establish the optimum placement of the tunnel in anterior cruciate ligament reconstruction by predicting mechanical parameters such as stress, strain and displacement at regions in the tunnel wall.

  20. 三枚与四枚螺钉置入治疗Pauwels Ⅲ型股骨颈骨折的有限元分析%Finite element analysis of the three and four cannulated screws for Pauwels III femoral neck fractures

    Institute of Scientific and Technical Information of China (English)

    张浩; 史雪峰; 杨春宝; 吕继宏; 项毅; 孙振军; 官敬涛; 唐勇; 续力民

    2016-01-01

    背景:股骨颈骨折的内固定方式主要采用3枚空心螺钉倒三角固定,有学者提出Pauwels Ⅲ型的股骨颈骨折在应用3枚空心拉力螺钉固定的基础上增加1枚抗螺钉,以增强固定效果,但稳定性未得到验证。目的:研究3枚与4枚螺钉置入治疗Pauwels Ⅲ型股骨颈骨折中的生物力学稳定性及螺钉应力分布。方法:将第4代人工骨sawbones的CT数据导入Mimics软件中,进行三维重建,将模型导入3-matic软件中,创建股骨颈中段PauwelsⅢ型骨折模型,应用UG 8.0软件制作空心螺钉模型,导入到骨折模型中,创建3枚螺钉与4枚螺钉置入治疗Pauwels Ⅲ型股骨颈骨折的有限元模型。在相同条件下,应用abaqus软件中对两模型股骨头顶端施加轴向载荷411 N,比较两模型骨折断端两标志点的位移变化及内固定系统Von Mises应力分布情况。结果与结论:①3枚钉模型两点间位移为0.42 mm,4枚钉模型两点间位移为0.17 mm,4枚螺钉模型骨折断端移位小于3枚螺钉模型;②两模型Von Mises应力峰值分别为547 MPa、27.8 MPa,4枚螺钉模型的Von Mises峰值小于3枚螺钉模型,两模型的应力集中部位为均为骨折断端处,但4枚螺钉模型的应力范围更广、应力更加分散;③从有限元分析的结果来看,4枚螺钉置入治疗Pauwels Ⅲ型股骨颈骨折具有更强的抗剪切力效果,具有更强的生物力学稳定性,其临床优势尚需进一步的临床对比研究证实。%BACKGROUND:Femoral neck fracture is mainly fixed by three inverted triangle cannulated screws. Scholars have proposed to add a cannulated screw to enhance the fixation strength of femoral neck fracture of Pauwels III type based on three cannulated screw fixation, but the stability is not verified. OBJECTIVE:To analyze the biomechanical stability and stress of the three and four cannulated screws for the treatment of the Pauwels III femoral neck

  1. Optimal fixation of oblique scaphoid fractures: a cadaver model.

    Science.gov (United States)

    Luria, Shai; Lenart, Lado; Lenart, Borut; Peleg, Eran; Kastelec, Matej

    2012-07-01

    Acute scaphoid fractures are commonly fixed with headless cannulated screws positioned in the center of the proximal fragment. Central placement of the screw may be difficult and may violate the scaphotrapezial joint. We hypothesize that placement of the screw through the scaphoid tuberosity will achieve perpendicular fixation of an oblique waist fracture and result in more stable fixation than a screw in the center of the proximal fragment. We designed oblique osteotomies for 8 matched pairs of cadaver scaphoids and fixed each specimen with a headless cannulated screw. In 1 specimen, we positioned the screw at the center of the proximal fragment; we placed its matched pair perpendicular to the fracture. The perpendicular screw was directed through the scaphoid tuberosity. We placed the specimen under the increasing load of a pneumatically driven plunger. We compared stiffness, load, distance at failure, and mechanism of failure between the central and perpendicular screw groups. We found no difference between groups. Stiffness was identical in both groups (131 N/mm) and load to failure was similar (central screw, 137 N vs perpendicular screw, 148 N). In this biomechanical model of an unstable scaphoid fracture, we found that similar stability of fixation had been achieved with a screw perpendicular to the fracture plane with entry through the tuberosity, compared with a screw in a central position in the proximal fragment. This study suggests that placing the screw through the tuberosity, perpendicular to a short oblique fracture, will not impair fixation stability. Percutaneous fixation of scaphoid fractures has become popular although it is technically challenging. An easier distal approach through the tuberosity, without violating the scaphotrapezial joint, may not impair the fixation stability of an oblique fracture. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  2. Improving fixation strength of pedicle screw by microarc oxidation treatment: an experimental study of osteoporotic spine in sheep.

    Science.gov (United States)

    Shi, Lei; Wang, Ling; Zhang, Yang; Guo, Zheng; Wu, Zi-xiang; Liu, Da; Gao, Ming-xuan; Chen, Huan; Fu, Suo-chao; Lei, Wei

    2012-08-01

    Failure of fixation caused by loosening of pedicle screws in osteoporosis is a problem in spinal surgery. We compared the in vivo fixation strength between pedicle screws treated with microarc oxidation (MAO) and untreated screws in an osteoporotic model of ovariectomized sheep. The MAO treated and untreated screws were placed in lumbar vertebral bodies. After 3 months of implantation, biomechanical tests, micro-CT analysis, and histological observations were conducted to examine the performance of the two groups. At time 0, no significant difference was found between the two groups in biomechanical tests (p > 0.05); 3 months later, higher pull-out strength and load with less displacement were detected in the MAO-treated group (p sheep.

  3. Arthroscopically measured syndesmotic stability after screw vs. suture button fixation in a cadaveric model.

    Science.gov (United States)

    Lubberts, Bart; Vopat, Bryan G; Wolf, Jonathon C; Longo, Umile Giuseppe; DiGiovanni, Christopher W; Guss, Daniel

    2017-08-31

    Appropriate management of ankle syndesmotic instability is needed to prevent the development of complications. Previous biomechanical studies have evaluated movement of the fibula after screw or suture button fixations with different results, most likely being caused by variations in experimental setups that did not mirror the in vivo clinical setting. This study aimed to arthroscopically compare in a cadaveric model the stability of syndesmotic fixation with either a suture button or syndesmotic screw. Eight fresh matched pairs of human ankle cadaver specimens (above knee) underwent arthroscopic assessment with (1) intact ligaments, (2) after complete disruption, and (3) after repair with either a quadracortical syndesmotic screw or suture button construct. In every stage, four loading conditions were considered under 100N of direct force: 1) unstressed, 2) lateral hook test, 3) anterior to posterior (AP) translation test, and 4) posterior to anterior (PA) translation test. Coronal plane tibiofibular diastasis, as well as sagittal plane tibiofibular translation, were arthroscopically measured. Coronal plane anterior and posterior tibiofibular diastasis and sagittal plane tibiofibular translation were measured using probes of increasing diameters. Following screw fixation, syndesmotic stability was similar to the uninjured syndesmosis in the coronal plane (anterior, median 0.0mm [IQR 0.0-0.3] vs. 0.3mm [IQR 0.2-0.3]; p=0.57; posterior, median 0.1mm [IQR 0.0-0.4] vs. 0.2mm [IQR 0.1-0.3]; p=1.0) but more rigid in the sagittal plane (median 0.0mm [IQR 0.0-0.1] vs. 1.0mm [IQR 0.4-1.5]; p=0.012). Repairing the unstable syndesmosis with a suture button construct resulted in coronal plane stability similar to the uninjured syndesmosis (anterior, median 0.2mm [IQR 0.1-0.3] vs. 0.2mm [IQR 0.1-0.3]; p=0.48; posterior, median 0.2mm [IQR 0.1-0.3] vs. 0.3mm [IQR 0.1-0.5]; p=0.44). However, sagittal plane fibular motion remained unstable as compared to the uninjured syndesmosis

  4. Tibial inlay press-fit fixation versus interference screw in posterior cruciate ligament reconstruction

    Directory of Open Access Journals (Sweden)

    Max Ettinger

    2013-11-01

    Full Text Available Reconstruction of the posterior cruciate ligament (PCL by a tibial press-fit fixation of the patellar tendon with an accessory bone plug is a promising approach because no foreign materials are required. Until today, there is no data about the biomechanical properties of such press-fit fixations. The aim of this study was to compare the biomechanical qualities of a bone plug tibial inlay technique with the commonly applied interference screw of patellar tendon PCL grafts. Twenty patellar tendons including a bone block were harvested from ten human cadavers. The grafts were implanted into twenty legs of adult German country pigs. In group P, the grafts were attached in a press-fit technique with accessory bone plug. In group S, the grafts were fixed with an interference screw. Each group consisted of 10 specimens. The constructs were biomechanically analyzed in cyclic loading between 60 and 250 N for 500 cycles recording elongation. Finally, ultimate failure load and failure mode were analyzed. Ultimate failure load was 598.6±36.3 N in group P and 653.7±39.8 N in group S (not significant, P>0.05. Elongation during cyclic loading between the 1st and the 20th cycle was 3.4±0.9 mm for group P and 3.1±1 mm for group S. Between the 20th and the 500th cycle, elongation was 4.2±2.3 mm in group P and 2.5±0.9 mm in group S (not significant, P>0.05. This is the first study investigating the biomechanical properties of tibial press-fit fixation of the patellar tendon with accessory bone plug in posterior cruciate ligament reconstruction. The implant-free tibial inlay technique shows equal biomechanical characteristics compared to an interference screw fixation. Further in vivo studies are desirable to compare the biological behavior and clinical relevance of this fixation device.

  5. Comparison of effects of different screw materials in the triangle fixation of femoral neck fractures.

    Science.gov (United States)

    Gok, Kadir; Inal, Sermet; Gok, Arif; Gulbandilar, Eyyup

    2017-05-01

    In this study, biomechanical behaviors of three different screw materials (stainless steel, titanium and cobalt-chromium) have analyzed to fix with triangle fixation under axial loading in femoral neck fracture and which material is best has been investigated. Point cloud obtained after scanning the human femoral model with the three dimensional (3D) scanner and this point cloud has been converted to 3D femoral model by Geomagic Studio software. Femoral neck fracture was modeled by SolidWorks software for only triangle configuration and computer-aided numerical analyses of three different materials have been carried out by AnsysWorkbench finite element analysis (FEA) software. The loading, boundary conditions and material properties have prepared for FEA and Von-Misses stress values on upper and lower proximity of the femur and screws have been calculated. At the end of numerical analyses, the best advantageous screw material has calculated as titanium because it creates minimum stress at the upper and lower proximity of the fracture line.

  6. Treatment of neuromuscular scoliosis with posterior-only pedicle screw fixation.

    Science.gov (United States)

    Modi, Hitesh N; Suh, Seung-Woo; Song, Hae-Ryong; Fernandez, Harry M; Yang, Jae-Hyuk

    2008-06-10

    To determine whether posterior-only approach using pedicle screws in neuromuscular scoliosis population adequately addresses the correction of scoliosis and maintains the correction over time. Between 2003 and 2006, 26 consecutive patients (7 cerebral palsy, 10 Duchenne muscular dystrophy, 5 spinal muscular atrophy and 4 others) with neuromuscular scoliosis underwent posterior pedicle screw fixation for the deformity. Preoperative, immediate postoperative and final follow-up Cobb's angle and pelvic obliquity were analyzed on radiographs. The average age of the patients was 17.5 years (range, 8-44 years) and the average follow-up was 25 months (18-52 months). Average Cobb's angle was 78.53 degrees before surgery, 30.70 degrees after surgery (60.9% correction), and 33.06 degrees at final follow-up (57.9% correction) showing significant correction (p vertebral column resection due to the presence of a rigid curve. The average spinal-pelvic obliquity was 16.27 degrees before surgery, 8.96 degrees after surgery, and 9.27 degrees at final follow-up exhibited significant correction (p maintained with posterior-only pedicle screw instrumentation without anterior release procedure.

  7. Treatment of neuromuscular scoliosis with posterior-only pedicle screw fixation

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    Fernandez Harry M

    2008-06-01

    Full Text Available Abstract Background To determine whether posterior-only approach using pedicle screws in neuromuscular scoliosis population adequately addresses the correction of scoliosis and maintains the correction over time. Methods Between 2003 and 2006, 26 consecutive patients (7 cerebral palsy, 10 Duchenne muscular dystrophy, 5 spinal muscular atrophy and 4 others with neuromuscular scoliosis underwent posterior pedicle screw fixation for the deformity. Preoperative, immediate postoperative and final follow-up Cobb's angle and pelvic obliquity were analyzed on radiographs. The average age of the patients was 17.5 years (range, 8–44 years and the average follow-up was 25 months (18–52 months. Results Average Cobb's angle was 78.53° before surgery, 30.70° after surgery (60.9% correction, and 33.06° at final follow-up (57.9% correction showing significant correction (p Conclusion Results indicate that in patients with neuromuscular scoliosis, acceptable amounts of curve correction can be achieved and maintained with posterior-only pedicle screw instrumentation without anterior release procedure.

  8. Evaluation of Occipitocervical Arthrodesis Rates with Screw-based Fixation and Osteoinductive Fusion Adjuncts.

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    Stone, Jeremy G; Panczykowski, David M; Tempel, Zachary J; Tormenti, Matthew; Kanter, Adam S; Okonkwo, David O

    2015-09-01

    Occipitocervical (OC) instability may be associated with neurologic impairment and even death. There is a paucity of research on the rate of arthrodesis utilizing modern screw-based constructs coupled with adjuvant osteoinductive agents. We reviewed our experience with OC constructs and compared the fusion rate, functional outcome, and rate of adverse events between recombinant human bone morphogenetic protein (BMP)-2, autologous iliac crest bone graft (ICBG), a combination of BMP and ICBG, and local bone autograft alone. We performed a retrospective cohort analysis of all adult admissions for operative treatment of OC instability utilizing segmental screw-based constructs for OC arthrodesis between January 2003 and September 2012. Data concerning demographic characteristics, diagnostic and procedural details, radiographic pathology, and clinical course were abstracted from medical records. The primary end point was evidence of stable fixation and osseous union on either dynamic lateral radiographs or computed tomography (CT) imaging at most recent follow-up. Secondary end points included functional outcome as determined by Nurick scale and Neck disability index (NDI) at ≥ 1year postoperation, as well as perioperative morbidity and mortality at 30 days and 3 months. During the study period, 94 patients (mean age: 62 ± 18 years) underwent OC fixation with segmental screw-based constructs. The four fusion adjunct cohorts analyzed included local autograft alone (32%), ICBG (41%), BMP (14%), or a combination of ICBG and BMP (14%). Notably, demineralized bone matrix was also used in 61% of cases overall, but its use did not differ significantly among the four cohorts (p = 0.28). Median radiographic follow-up was 6 months postoperatively (range: 1.5-54 months). Clinical outcomes were assessed at a median postoperative follow-up of 45 months (range: 12-87 months). Overall, radiographic evidence of arthrodesis was present in 83% of patients assessed and was

  9. Comparison of the safety of three methods of lumbar transpedicular screw fixation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To choose a proper method of lumbar transpedicular screw fixation at different lumbar levels among the three methods ( Roy-Camille's method, Magerl's method and Du's method) in the Chinese population.Methods: Three-dimensional ( 3-D ) images were reconstructed with image data of 42 adult lumbar segments that were scanned by Electron Beam CT. The three methods of lumbar pedicle screw fixation were simulated on the 3-D reconstructed images and the parameters of implanting pedicle screws were measured.Results: There was statistically significant difference at the distance from the entrance point to the pedicle axis between the three methods (P < 0. 001). The distances measured by Du's method were shortest from L1 to L4,and the distances measured by Magerl's method were shortest at L5 (P < 0.05). There was no significant difference from L1 to L2 (P > 0.05) but significant difference from L3 to L5 at inserting safe ranges of TSA (transverse section angle) was found between the three methods (P <0.05). From L3 to L4, the inserting safe ranges of TSA measured by Du's and Magerl's methods were significantly larger than that measured by Roy-Camille's method (P <0.05), but there was no significant difference between them (P > 0.05). At L5, the inserting safe ranges of TSA measured by Magerl's method were largest among the three methods (P < 0.05).Conclusions: Among the three methods, Du's method is the best choice from L1 to LA because its distance from the entrance point to the pedicle axis is shortest and the safe range of TSA is largest; Magerl's method can be used from L3 to L5 and is the best choice at L5; Roy-Camille's method is applicable at L1 and L2.

  10. Odontoid balloon kyphoplasty associated with screw fixation for Type II fracture in 2 elderly patients.

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    Terreaux, Luc; Loubersac, Thomas; Hamel, Olivier; Bord, Eric; Robert, Roger; Buffenoir, Kevin

    2015-03-01

    Anterior screw fixation is a well-recognized technique that is used to stabilize Type IIB fractures of the odontoid process in the elderly. However, advanced age and osteoporosis are 2 risk factors for pseudarthrosis. Kyphoplasty has been described in the treatment of lytic lesions in C-2. The authors decided to combine these 2 techniques in the treatment of unstable fractures of the odontoid. Two approximately 90-year-old patients were treated for this type of fracture. Instability was demonstrated on dynamic radiography in one patient, and the fracture was seen on static radiography in the other. Clinical parameters, pain, range of motion, 36-Item Short Form Health Survey (SF-36) score (for the first patient), and radiological examinations (CT scans and dynamic radiographs) were studied both before and after surgery. After inflating the balloon both above and below the fracture line, the authors applied a high-viscosity polymethylmethacrylate cement. Some minor leakage of cement was noted in both cases but proved to be harmless. The screws were correctly positioned. The clinical result was excellent, both in terms of pain relief and in the fact that there was no reduction in the SF-36 score. The range of motion remained the same. A follow-up CT scan obtained 1 year later in one of the patients showed no evidence of change in the materials used, and the dynamic radiographs showed no instability. This combination of kyphoplasty and anterior screw fixation of the odontoid seems to be an interesting technique in osteoporotic Type IIB fractures of the odontoid process in the elderly, with good results both clinically and radiologically.

  11. A STUDY OF FUNCTIONAL AND RADIOLOGICAL OUTCOME OF UNDISPLACED SCAPHOID FRACTURES TREATED WITH PERCUTANEOUS HEADLESS SCREW FIXATION

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    Tarigopula

    2016-04-01

    Full Text Available BACKGROUND Scaphoid is the most commonly fractured carpal bone, accounting for approximately 60% of all carpal fractures. This injury is commonly seen in active young adults after a fall on an outstretched hand. Management of scaphoid fractures is controversial. Displaced scaphoid fractures are associated with risk of non-union and osteonecrosis. Surgical fixation is recommended for displaced scaphoid fractures of proximal pole, fractures with delayed treatment or diagnosis and non-union. Open reduction and internal fixation of acute scaphoid fractures has been reported to give good results in several nonrandomised, retrospective studies. The incidence of complications after operative treatment of non-displaced fractures has decreased with the advent of safer, more reliable implants and percutaneous techniques. CONCLUSION Percutaneous headless screw fixation is a well-documented surgical procedure. Undisplaced scaphoid fractures fixed by percutaneous headless screw fixation yield better results than patients treated conservatively. Good range of motion is achieved after fixation. It relieves pain and functional disability experienced by patients. Patients achieve good range of motion. Trabecular continuity is achieved in most of the patients before 8 weeks. Most of the patients had resumed normal daily activities before 3 months. This study suggests that percutaneous headless screw fixation for undisplaced scaphoid fractures provides satisfactory clinical and radiographic outcomes after an intermediate duration follow-up. Even though the procedure is not free of complications, the overall functional and clinical outcome had shown good results.

  12. Percutaneous Cement-Augmented Screws Fixation in the Fractures of the Aging Spine: Is It the Solution?

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    Sébastien Pesenti

    2014-01-01

    Full Text Available Introduction. Management of elderly patients with thoracolumbar fractures is still challenging due to frequent osteoporosis and risk of screws pull-out. The aim of this study was to evaluate results of a percutaneous-only procedure to treat these fragile patients using cement-augmented screws. Methods. 12 patients diagnosed with a thoracolumbar fracture associated with an important loss of bone stock were included in this prospective study. Surgical procedure included systematically a percutaneous osteosynthesis using cemented fenestrated screws. When necessary, additional anterior support was performed using a kyphoplasty procedure. Clinical and radiographic evaluations were performed using CT scan. Results. On the whole series, 15 fractures were diagnosed and 96 cemented screws were inserted. The difference between the pre- and postoperative vertebral kyphosis was statistically significant (12.9° versus 4.4°, P=0.0006. No extrapedicular screw was reported and one patient was diagnosed with a cement-related pulmonary embolism. During follow-up period, no infectious complications, implant failures, or pull-out screws were noticed. Discussion. Aging spine is becoming an increasing public health issue. Management of these patients requires specific attention due to the augmented risk of complications. Using percutaneous-only screws fixation with cemented screw provides satisfactory results. A rigorous technique is mandatory in order to achieve best outcomes.

  13. Biomechanical Comparison Between Bashti Bone Plug Technique and Biodegradable Screw for Fixation of Grafts in Ligament surgery

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    Kaveh Bashti

    2015-01-01

    Full Text Available Background: Ligament reconstruction is a common procedure in orthopedic surgery. Although several popular techniques are currently in use, new methods are proposed for secure fixation of the tendon graft into the bone tunnel. Purposes: We sought to introduce our new technique of Bashti bone plug for fixation of soft tissue graft in anterior cruciate ligament (ACL reconstruction and to compare its biomechanical features with conventional absorbable interference screw technique in a bovine model. Methods: Twenty pairs of bovine knees were harvested after death. Soft tissue was removed and the Achilles tendon was harvested to be used as an ACL graft. It was secured into the bone tunnel on the tibial side via two different methods: Bashti Bone Plug technique and conventional screw method. Biomechanical strength was measured using 200 N and 300 N cyclic loading on the graft. Pull out strength was also tested until the graft fails. Results: No graft failure was observed after 200 N and 300 N cyclic loading in either fixation methods. When testing for pull out failure, 21 tendons (53% were torn and 19 tendons (48% slipped out. No fixation failure occurred, which did not reveal a significant difference between the bone plug or interference screw group (P=0.11. The mean pull out force until failure of the graft was 496±66 N in the screw group and 503±67 N in the bone plug group (P=0.76. Conclusions: Our suggested fixation technique of Bashti bone plug is a native, cheap, and feasible method that provides comparable biomechanical strength with interference screw when soft tissue fixation was attempted in bovine model.

  14. Biomechanical Comparison Between Bashti Bone Plug Technique and Biodegradable Screw for Fixation of Grafts in Ligament surgery

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    Kaveh Bashti

    2015-01-01

    Full Text Available   Background: Ligament reconstruction is a common procedure in orthopedic surgery. Although several popular techniques are currently in use, new methods are proposed for secure fixation of the tendon graft into the bone tunnel. Purposes: We sought to introduce our new technique of Bashti bone plug for fixation of soft tissue graft in anterior cruciate ligament (ACL reconstruction and to compare its biomechanical features with conventional absorbable interference screw technique in a bovine model. Methods: Twenty pairs of bovine knees were harvested after death. Soft tissue was removed and the Achilles tendon was harvested to be used as an ACL graft. It was secured into the bone tunnel on the tibial side via two different methods: Bashti Bone Plug technique and conventional screw method. Biomechanical strength was measured using 200 N and 300 N cyclic loading on the graft. Pull out strength was also tested until the graft fails. Results: No graft failure was observed after 200 N and 300 N cyclic loading in either fixation methods. When testing for pull out failure, 21 tendons (53% were torn and 19 tendons (48% slipped out. No fixation failure occurred, which did not reveal a significant difference between the bone plug or interference screw group (P=0.11. The mean pull out force until failure of the graft was 496±66 N in the screw group and 503±67 N in the bone plug group (P=0.76. Conclusions: Our suggested fixation technique of Bashti bone plug is a native, cheap, and feasible method that provides comparable biomechanical strength with interference screw when soft tissue fixation was attempted in bovine model.

  15. Biomechanical Comparison Between Bashti Bone Plug Technique and Biodegradable Screw for Fixation of Grafts in Ligament surgery.

    Science.gov (United States)

    Bashti, Kaveh; Tahmasebi, Mohammad N; Kaseb, Hasan; Farahmand, Farzam; Akbar, Mohammad; Mobini, Amir

    2015-01-01

    Ligament reconstruction is a common procedure in orthopedic surgery. Although several popular techniques are currently in use, new methods are proposed for secure fixation of the tendon graft into the bone tunnel. We sought to introduce our new technique of Bashti bone plug for fixation of soft tissue graft in anterior cruciate ligament (ACL) reconstruction and to compare its biomechanical features with conventional absorbable interference screw technique in a bovine model. Twenty pairs of bovine knees were harvested after death. Soft tissue was removed and the Achilles tendon was harvested to be used as an ACL graft. It was secured into the bone tunnel on the tibial side via two different methods: Bashti Bone Plug technique and conventional screw method. Biomechanical strength was measured using 200 N and 300 N cyclic loading on the graft. Pull out strength was also tested until the graft fails. No graft failure was observed after 200 N and 300 N cyclic loading in either fixation methods. When testing for pull out failure, 21 tendons (53%) were torn and 19 tendons (48%) slipped out. No fixation failure occurred, which did not reveal a significant difference between the bone plug or interference screw group (P=0.11). The mean pull out force until failure of the graft was 496±66 N in the screw group and 503±67 N in the bone plug group (P=0.76). Our suggested fixation technique of Bashti bone plug is a native, cheap, and feasible method that provides comparable biomechanical strength with interference screw when soft tissue fixation was attempted in bovine model.

  16. Minimally invasive unilateral pedicle screw fixation and lumbar interbody fusion for the treatment of lumbar degenerative disease.

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    Lin, Bin; Xu, Yang; He, Yong; Zhang, Bi; Lin, Qiuyan; He, Mingchang

    2013-08-01

    Minimally invasive unilateral pedicle screw fixation for the treatment of degenerative lumbar diseases has won the support of many surgeons. However, few data are available regarding clinical research on unilateral pedicle screw fixation associated with minimally invasive techniques for the treatment of lumbar spinal diseases. The purpose of this study was to evaluate clinical outcomes in a selected series of patients with lumbar degenerative diseases treated with minimally invasive unilateral vs classic bilateral pedicle screw fixation and lumbar interbody fusion. Patients in the unilateral group (n=43) underwent minimally invasive unilateral pedicle screw fixation with the Quadrant system (Medtronic, Memphis, Tennessee). The bilateral group (n=42) underwent bilateral instrumentation via the classic approach. Visual analog scale pain scores, Oswestry Disability Index scores, fusion rate, operative time, blood loss, and complications were analyzed. Mean operative time was 75 minutes in the unilateral group and 95 minutes in the bilateral group. Mean blood loss was 220 mL in the unilateral group and 450 mL in the bilateral group. Mean postoperative visual analog scale pain score was 3.10±0.16 in the unilateral group and 3.30±1.10 in the bilateral group. Mean postoperative Oswestry Disability Index score was 15.67±2.3 in the unilateral group and 14.93±2.6 in the bilateral group. Successful fusion was achieved in 92.34% of patients in the unilateral group and 93.56% of patients in the bilateral group. Minimally invasive unilateral pedicle screw fixation is an effective and reliable option for the surgical treatment of lumbar degenerative disease. It causes less blood loss, requires less operative time, and has a fusion rate comparable with that of conventional bilateral fixation. Copyright 2013, SLACK Incorporated.

  17. A new concept for implant fixation: bone-to-bone biologic fixation

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    D-Y Kim

    2015-05-01

    Full Text Available Many attempts have been made to reduce complications of bone implant, such as pedicle screw loosening. To address this problem, the authors suggest a new concept of bone-to-bone biologic fixation using recombinant human bone morphogenetic protein-2 (rhBMP-2-loaded cannulated pedicle screws. Recombinant human bone morphogenetic protein-2 is an osteoinductive cytokine. Four types of titanium pedicle screws were tested (uncannulated, cannulated with no loading, beta-tricalcium phosphate (TCP-loaded, and TCP/BMP2 loaded using 16 miniature pigs. Radiological evaluation was conducted to assess the fusion and loosening of pedicle screws. Twelve weeks after implantation, peak torsional extraction torque was measured, and the pedicle screw and bone interface was evaluated by micro-computed tomography (µCT and histologic examination. The mean value of the radiological score was significantly greater in the TCP/BMP2 loaded group at 12 weeks post-operation compared to those in the other groups. CT images showed distinct bone formation surrounding TCP/BMP2 loaded cannulated pedicle screws compared to the other groups. Mean extraction torsional peak torque at 12 weeks postoperative was more than 10-fold higher in the TCP/BMP2 loaded pedicle screw group than in the other groups. Bone surface and bone volume, as quantitated through µCT, were higher in the TCP/BMP2 loaded group. Histologic examination revealed bone-to-bone fixation at the interface of pedicle screws and pre-existing bone. Bone-to-bone biologic fixation through the holes of TCP/BMP2 loaded pedicle screws significantly increased fixation strength and represents a novel method that can be applied to osteoporotic or tumour spine surgeries.

  18. A 3D navigation template for guiding a unilateral lumbar pedicle screw with contralateral translaminar facet screw fixation: a study protocol for multicentre randomised controlled trials.

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    Shao, Zhen-Xuan; He, Wei; He, Shao-Qi; Lin, Sheng-Lei; Huang, Zhe-Yu; Tang, Hong-Chao; Ni, Wen-Fei; Wang, Xiang-Yang; Wu, Ai-Min

    2017-07-21

    The incidence of lumbar disc degeneration disease has increased in recent years. Lumbar interbody fusion using two unilateral pedicle screws and a translaminar facet screw fixation has advantages of minimal invasiveness and lower costs compared with the traditional methods. Moreover, a method guided by a three-dimensional (3D) navigation template may help us improve the surgical accuracy and the success rate. This is the first randomised study using a 3D navigation template to guide a unilateral lumbar pedicle screw with contralateral translaminar facet screw fixation. Patients who meet the criteria of the surgery will be randomly divided into experimental groups and control groups by a computer-generated randomisation schedule. We will preoperatively design an individual 3D navigation template using CATIA software and MeditoolCreate. The following primary outcomes will be collected: screw angles compared with the optimal screw trajectories in 3D digital images, length of the wound incision, operative time, intraoperative blood loss and complications. The following secondary outcomes will be collected: visual analogue scale (VAS) for back pain, VAS for leg pain and the Oswestry Disability Index. These parameters will be evaluated on day 1 and then 3, 6, 12 and 24 months postoperatively. The study has been reviewed and approved by the institutional ethics review board of the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University. The results will be presented at scientific communities and peer-reviewed journals. ChiCTR-IDR-17010466. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  19. [Analysis of reason and strategy for the failure of posterior pedicle screw short-segment internal fixation on thoracolumbar fractures].

    Science.gov (United States)

    Xing, Jin-Ming; Peng, Wen-Ming; Shi, Chu-Yun; Xu, Lei; Pan, Qi-Huao

    2013-03-01

    To analyze the reason and strategy for failure of posterior pedicle screw short-segment internal fixation on thoracolumbar fractures. From March 2008 to December 2010,the clinical data of 18 patients with thoracolumbar fracture failed in posterior pedicle screw short-segment internal fixation were retrospectively analyzed. There were 11 males and 7 females with an average age of 37.2 years (ranged, 19 to 63). The time from the first operation to complication occurrence was from 6 to 44 months with an average of 14.3 months. Of them,fusion failure was in 7 cases (combined with screw breakage in 4 cases), the progressive neuro-dysfunction was in 5 cases,the progressive lumbodorsal pain was in 6 cases. All 18 patients with kyphosis were treated with anterior internal fixation remaining posterior fixation (9 cases) and anterior internal fixation after posterior fixation removal (9 cases). All the patients were followed up from 18 to 50 months with an average of 30.5 months. No intetnal fixation loosening and breakage were found, moreover, X-ray and lamellar CT showed bone healing well. Preoperative, postoperative at 3 months and at final follow-up, ODI score was respectively 31.6+/-5.1, 8.6+/-5.7, 8.3+/-3.2; VAS score was respectively 7.2+/-2.3, 2.3+/-0.7, 2.1+/-1.1; kyphosis angle was respectively (-21.2/-+7.8 degreeso, (-5.3+/-6.8 degrees ), (-5.8+/-7.8 )degrees. Compared with preoperative data ,above-listed items had obviously ameliorated(Pinternal fixation may result in the complications such as bone nonunion ,internal fixation breakage and progressive kyphosis. Anterior reconstruction may be a good strategy for the failure of posterior operation.

  20. Biomechanical effects of polyaxial pedicle screw fixation on the lumbosacral segments with an anterior interbody cage support

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    Chen Hsiang-Ho

    2007-03-01

    Full Text Available Abstract Background Lumbosacral fusion is a relatively common procedure that is used in the management of an unstable spine. The anterior interbody cage has been involved to enhance the stability of a pedicle screw construct used at the lumbosacral junction. Biomechanical differences between polyaxial and monoaxial pedicle screws linked with various rod contours were investigated to analyze the respective effects on overall construct stiffness, cage strain, rod strain, and contact ratios at the vertebra-cage junction. Methods A synthetic model composed of two ultrahigh molecular weight polyethylene blocks was used with four titanium pedicle screws (two in each block and two rods fixation to build the spinal construct along with an anterior interbody cage support. For each pair of the construct fixed with polyaxial or monoaxial screws, the linked rods were set at four configurations to simulate 0°, 7°, 14°, and 21° lordosis on the sagittal plane, and a compressive load of 300 N was applied. Strain gauges were attached to the posterior surface of the cage and to the central area of the left connecting rod. Also, the contact area between the block and the cage was measured using prescale Fuji super low pressure film for compression, flexion, lateral bending and torsion tests. Results Our main findings in the experiments with an anterior interbody cage support are as follows: 1 large segmental lordosis can decrease the stiffness of monoaxial pedicle screws constructs; 2 polyaxial screws rather than monoaxial screws combined with the cage fixation provide higher compression and flexion stiffness in 21° segmental lordosis; 3 polyaxial screws enhance the contact surface of the cage in 21° segmental lordosis. Conclusion Polyaxial screws system used in conjunction with anterior cage support yields higher contact ratio, compression and flexion stiffness of spinal constructs than monoaxial screws system does in the same model when the spinal segment

  1. Posterior lumbar interbody fusion using one diagonal fusion cage with transpedicular screw/rod fixation.

    Science.gov (United States)

    Zhao, Jie; Hou, Tiesheng; Wang, Xinwei; Ma, Shengzhong

    2003-04-01

    Posterior lumbar interbody fusion (PLIF) using threaded cages has gained wide popularity for lumbosacral spinal disease. Our biomechanical tests showed that PLIF using a single diagonal cage with unilateral facetectomy does add a little to spinal stability and provides equal or even higher postoperative stability than PLIF using two posterior cages with bilateral facetectomy. Studies also demonstrated that cages placed using a posterior approach did not cause the same increase in spinal stiffness seen with pedicle screw instrumentation, and we concluded that cages should not be used posteriorly without other forms of fixation. On the other hand, placement of two cages using a posterior approach does have the disadvantage of risk to the bilateral nerve roots. We therefore performed a prospective study to determine whether PLIF can be accomplished by utilizing a single diagonal fusion cage with the application of supplemental transpedicular screw/rod instrumentation. Twenty-seven patients underwent a PLIF using one single fusion cage (BAK, Sulzer Spine-Tech, Minneapolis, MN, USA) inserted posterolaterally and oriented anteromedially on the symptomatic side with unilateral facetectomy and at the same level supplemental fixation with a transpedicular screw/rod system. The internal fixation systems included 12 SOCON spinal systems (Aesculap AG, Germany) and 15 TSRH spinal systems (Medtronic Sofamor Danek, USA). The inclusion criteria were grade 1 to 2 lumbar isthmic spondylolisthesis, lumbar degenerative spondylolisthesis, and recurrent lumbar disc herniations with instability. Patients had at least 1 year of low back pain and/or unilateral sciatica and a severely restricted functional ability in individuals aged 28-55 years. Patients with more than grade 2 spondylolisthesis or adjacent-level degeneration were excluded from the study. Patients were clinically assessed prior to surgery by an independent assessor; they were then reassessed at 1, 3, 6, 12, 18, and 24

  2. Maxillo Mandibular Fixation in Edentulous Scenarios: Combined MMF Screws and Gunning Splints.

    Science.gov (United States)

    Chaudhary, Zainab; Sharma, Rakesh; Krishnan, Sriram

    2014-06-01

    A fracture of the maxillary or mandibular bone requires the afflicted to undergo a maxillo mandibular fixation for the establishment of pre traumatic occlusion. This process is quiet tedious and consumes a considerable period of time before any surgical procedure can commence. Such a situation can be complicated in case the individual with maxillomandibular fracture has sparse or absent dentition; for such cases a splint is fabricated or an erstwhile existing denture is used for maintaining a vertical jaw proportion. Stabilizing such splints to the jaw requires various invasive approaches that can bring into harm's way, adjacent soft tissue vital structures. We describe here an innovative technique combining the time tested method of the "gunning splint" and the advanced minimally invasive MMF screws for obtaining closed reduction in edentulous jaw fractures.

  3. Trans-sacral screw fixation in the treatment of high dyplastic developmental spondylolisthesis.

    Science.gov (United States)

    Landi, Alessandro; Marotta, Nicola; Mancarella, Cristina; Tarantino, Roberto; Delfini, Roberto

    2013-06-16

    We describe the case of a 67-year-old woman with L5-S1 ontogenetic spondylolisthesis treated with pedicle fixation associated with interbody arthrodesis performed with S1-L5 trans-sacral screwing according to the technique of Bartolozzi. The procedure was followed by a wide decompressive laminectomy. The patient had a progressive improvement of the symptoms which gradually disappeared in 12 mo. The radiograph at 6 and 12 mo showed complete fusion system. The choice of treatment in L5-S1 ontogenetic spondylolithesis is related to a correct clinical and diagnostic planning (X-ray, computer tomography magnetic resonance imaging, Measurement). In particular, the severity index and the square of unstable zone, and the standard measurements already described in the literature, are important to understand and to plane the correct surgical strategy, that require, in most of the times, fusion and interbody artrodesis.

  4. Determination of the most appropriate stress distribution by Finite Element Analysis in fixation with resorbable screws after Bilateral Sagittal Split Ramus Osteotomy surgery

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    Sarkarat F.

    2009-12-01

    Full Text Available "nBackground and Aim: Due to the complications associated with fixation by Titanium screws and plates in Bilateral Sagittal Split Ramus Osteotomy (BSSRO surgery, the use of resorbable polymers has been increasingly recommended. Since there are not enough studies on this issue, this study aimed to assess the most appropriate stress distribution in fixation with resorbable screws after BSSRO surgery by Fnite Element Analysis (FEA."nMaterials and Methods: This experimental study was performed on simulated human mandible using Ansys and Catia softwares. The osteotomy line was applied to the simulated model and experimental loads of 75, 135 and 600 N were respectively exerted according to the natural direction of occlusal force. The distribution pattern of stress was assessed and compared for fixation with one resorbable screw, two resorbable screws in vertical pattern, two resorbable screws in horizontal pattern, three resorbable screws in L pattern and three resorbable screws in inverted backward L pattern using Ansys software."nResults: Among the four simulated fixations, L pattern showed the highest primary stability. Two screws in vertical pattern were also associated with sufficient primary stability and less trauma and cost for patients. One screw did not provide enough stability under 600 N."nConclusion: Polymer-based resorbable screws (polyglycolic acid and D, L polylactide acid provided satisfactory primary stability in BSSRO surgery.

  5. One-stage posterior C2 and C3 pedicle screw fixation or combined anterior C2-C3 fusion for the treatment of unstable hangman's fracture.

    Science.gov (United States)

    Liu, Jingchen; Li, Ye; Wu, Yuntao

    2013-03-01

    The present study aimed to evaluate the effect of using one-stage posterior C2 and C3 pedicle screw fixation or combined anterior C2-C3 fusion in the treatment of unstable hangman's fracture. A total of 13 patients with unstable hangman's fractures underwent C2 and C3 pedicle screw fixation, lamina interbody fusion or combined anterior C2-C3 fusion and imaging examinations to evaluate the fracture fixation and healing condition at three days and three months following surgery. Postoperative X-ray and computed tomography (CT) results showed high fracture reduction, good internal fixation position and reliable fracture fixation. The three-month postoperative CT showed good vertebral fracture healing. C2 and C3 pedicle screw fixation has a good curative effect in the treatment of unstable hangman's fracture. The direct fixation of the fracture enables early ambulation by the patients.

  6. Bone cement enhanced pedicle screw fixation combined with vertebroplasty for elderly patients with malignant spinal tumors

    Institute of Scientific and Technical Information of China (English)

    TAN Jiang-wei; SHEN Bing-hua; DU Wei; LIU Jiang-qing; LU Shi-qiao

    2013-01-01

    Background Older patients with malignant spinal tumors are difficult to treat because they have many co-morbidities including osteoporosis.The purpose of this research is to discuss the technique and clinical outcome of bone cement enhanced pedicle screw fixation combined with vertebroplasty (the Sandwich Procedure) for elderly patients with severe osteoporosis and malignant spinal tumors.Methods This study includes 28 consecutive elderly patients with malignant thoracic or lumbar spinal tumors.There were nine patients with myelomas,and 19 patients with metastatic bone tumors.The Sandwich Procedure began with curettage of the tumor and a vertebroplasty with bone cement (polymethyl methacrylate,PMMA),followed by PMMA enhanced pedicle screw fixation.Patients were evaluated with the visual analogue scale (VAS),oswestry disability index (ODI),American Spinal Cord Injury Association (ASIA) neurological function classification,and the radiographic degree of kyphosis (Cobb angle).Data were analyzed using paired t-test to compare the pre-and post-operative values.The complications,local recurrences,and the survival status were also recorded.Results There was no operative mortality,and the mean operative time was 210 minutes (range 150-250 minutes).The average blood loss was 1550 ml (range 650-3300 ml).The average amount of cement for vertebroplasty was 3.6 ml (range 3-5 ml).The VAS,ODI,and ASIA scores were significantly improved after surgery (P <0.05).However,we found no differences between the pre and post-operative Cobb angles.The shortest survival time was 3 months,and we found no evidence of local recurrence in this group of patients.Conclusion The Sandwich Procedure is a safe operation and provides symptomatic relief in these difficult patients,permitting further treatment with chemotherapy or radiotherapy.

  7. Ununited fracture neck of femur treated with closed reduction and internal fixation with cancellous screw and fibular strut graft

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    Singh Daria

    2006-01-01

    Full Text Available Background: Ununited fracture neck of femur in young adults has been tackled in various ways. Methods: Twenty five patients of ununited fracture neck of femur in age group 21-55 years were treated by closed reduction, cancellous screw fixation and fibular strut graft and followed up for 2-6 years. Time gap between injury and operation was 6 weeks to 58 weeks. Five cases were previously fixed with various fixation devices. Results: Osseous union was achieved in 24 cases with average time of 18.16 weeks. Main complication encountered in follow-up was avascular necrosis of femoral head, others were joint stiffness and shortening. Functional end results were good to excellent in 24 cases. Conclusion: Closed reduction with internal fixation by cancellous screw and fibular strut grafting is easy and useful procedure.

  8. Three-dimensional image-guided placement of S2 alar screws to adjunct or salvage lumbosacral fixation.

    Science.gov (United States)

    Nottmeier, Eric W; Pirris, Stephen M; Balseiro, Sarah; Fenton, Douglas

    2010-07-01

    lateral boundary of the sacral ala. An independent radiologist graded the placement of the screws on the intraoperative CT scan obtained with the O-ARM or on postoperative CT scans. Lumbosacral fusion was assessed on postoperative CT scans obtained at follow-up. No complications occurred in this study as a result of S2 alar screw placement or image guidance. Five screws did penetrate the anterior cortex of the sacrum, with no clinical consequence. At the time of abstract submission, 16 patients were able to have follow-up CT scans, 15 of which were graded as solid fusion at the lumbosacral junction by the grading radiologist. Three-dimensional image guidance allows for safe placement of large S2 sacral alar screws that can provide additional biomechanical stability to lumbosacral constructs or serve as an alternate point of sacral fixation when S1 pedicle screws cannot be salvaged or placed in a medial trajectory. Copyright 2010 Elsevier Inc. All rights reserved.

  9. Number and locations of screw fixation for volar fixed-angle plating of distal radius fractures: biomechanical study.

    Science.gov (United States)

    Mehling, Isabella; Müller, Lars P; Delinsky, Katharina; Mehler, Dorothea; Burkhart, Klaus J; Rommens, Pol M

    2010-06-01

    To compare the biomechanical properties of different numbers and locations of screws in a multidirectional volar fixed-angle plate in a distal radius osteotomy cadaver model. We created an extra-articular fracture in 16 pairs of fresh-frozen human cadaver radiuses. The 32 specimens were randomized into 4 groups. All fractures were fixated with a multidirectional volar fixed-angle plate. We tested 4 different screw-placement options in the distal fragment. The distal fragment was fixed with 4 locking screws in the distal row of the plate in group a, and with 4 locking screws alternately in the distal and proximal rows in group b. In group c, 3 locking screws were used in the proximal row; in group d, 7 locking screws were used, filling all screw holes in the distal and proximal rows of the plate. The proximal fragment was fixed with 3 screws. The specimens were loaded with 80 N under dorsal and volar bending and with 250 N axial loading. Finally, load to failure tests were performed. Group d had the highest mean stiffness, 429 N/mm under axial compression, and was statistically significantly stiffer than the other groups. Group b had a mean stiffness of 208 N/mm, followed by group a, with 177 N/mm. Group c showed only a mean stiffness of 83 N/mm under axial compression. There were no statistically significant differences under dorsal and volar bending. In this model of distal radial fractures, there was a difference regarding the stiffness and the placement of screws in the distal rows of a volar fixed-angle plate. Inserting screws in all available holes in the distal fragment offered the highest stability. Using only the proximal row with 3 screws created an unstable situation. Based on these findings, we recommend placing at least 4 screws in the distal fragment and assigning at least 2 screws to the distal row of the multidirectional screw-holes. Copyright 2010 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  10. Evaluation of a prototype correction algorithm to reduce metal artefacts in flat detector computed tomography of scaphoid fixation screws

    Energy Technology Data Exchange (ETDEWEB)

    Filli, Lukas; Finkenstaedt, Tim; Andreisek, Gustav; Guggenberger, Roman [University Hospital of Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); Marcon, Magda [University Hospital of Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Udine, Institute of Diagnostic Radiology, Department of Medical and Biological Sciences, Udine (Italy); Scholz, Bernhard [Imaging and Therapy Division, Siemens AG, Healthcare Sector, Forchheim (Germany); Calcagni, Maurizio [University Hospital of Zurich, Division of Plastic Surgery and Hand Surgery, Zurich (Switzerland)

    2014-12-15

    The aim of this study was to evaluate a prototype correction algorithm to reduce metal artefacts in flat detector computed tomography (FDCT) of scaphoid fixation screws. FDCT has gained interest in imaging small anatomic structures of the appendicular skeleton. Angiographic C-arm systems with flat detectors allow fluoroscopy and FDCT imaging in a one-stop procedure emphasizing their role as an ideal intraoperative imaging tool. However, FDCT imaging can be significantly impaired by artefacts induced by fixation screws. Following ethical board approval, commercially available scaphoid fixation screws were inserted into six cadaveric specimens in order to fix artificially induced scaphoid fractures. FDCT images corrected with the algorithm were compared to uncorrected images both quantitatively and qualitatively by two independent radiologists in terms of artefacts, screw contour, fracture line visibility, bone visibility, and soft tissue definition. Normal distribution of variables was evaluated using the Kolmogorov-Smirnov test. In case of normal distribution, quantitative variables were compared using paired Student's t tests. The Wilcoxon signed-rank test was used for quantitative variables without normal distribution and all qualitative variables. A p value of < 0.05 was considered to indicate statistically significant differences. Metal artefacts were significantly reduced by the correction algorithm (p < 0.001), and the fracture line was more clearly defined (p < 0.01). The inter-observer reliability was ''almost perfect'' (intra-class correlation coefficient 0.85, p < 0.001). The prototype correction algorithm in FDCT for metal artefacts induced by scaphoid fixation screws may facilitate intra- and postoperative follow-up imaging. (orig.)

  11. Influence of hooks and a lag screw on internal fixation plates for lateral malleolar fracture: a biomechanical and ergonomic study.

    Science.gov (United States)

    Sakai, Rina; Uchino, Masataka; Yoneo, Terumasa; Ohtaki, Yasuaki; Minehara, Hiroaki; Matsuura, Terumasa; Gomi, Tsutomu; Ujihira, Masanobu

    2017-02-23

    For internal fixation of AO classification Type B lateral malleolar fracture, insertion of lag screws into the fracture plane and fixation with a one-third tubular plate as a neutralization plate are the standard treatment procedures. The one-third tubular plate is processed to a hook shape and hung on the distal end of the fibula. In this study, to compare the function of the hook and lag screws of a one-third tubular plate and LCP for osteosynthesis of lateral malleolar fracture, mechanical indices of internal fixation were compared among the one-third tubular plates with lag screws with and without the hook and a locking compression plate. As mechanical tests, a compression test was performed in which compression in the bone axis direction produced by supporting the body weight was simulated, and a torsion test was performed in which external rotation of the bone axis caused by plantar flexion of the ankle joint was simulated. Muscle strength during walking and the force and torque acting on the ankle and knee joints were determined using inverse dynamic analysis. Finite element analysis was performed to analyze the function of hooks and lag screws. The joint reaction force determined by inverse dynamic analysis was adopted as the loading condition of finite element analysis. A stiffness equivalent to that of healthy bone could be achieved by all three internal fixations. It was clarified that the presence of the hook does not make a difference in stiffness. Displacement of the one-third tubular plate was small regardless of the presence or absence of the hook compared with those of locking compression plates. The presence of the hook did not make any difference in stiffness, suggesting that active preparation of the hook is unnecessary. We also clarified that lag screws inhibit displacement.

  12. Analysis of the stress and displacement distribution of inferior tibiofibular syndesmosis injuries repaired with screw fixation: a finite element study.

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    Qinghua Liu

    Full Text Available BACKGROUND: Studies of syndesmosis injuries have concentrated on cadaver models. However, they are unable to obtain exact data regarding the stress and displacement distribution of various tissues, and it is difficult to compare models. We investigated the biomechanical effects of inferior tibiofibular syndesmosis injuries (ITSIs and screw fixation on the ankle using the finite element (FE method. METHODOLOGY/PRINCIPAL FINDINGS: A three-dimensional model of a healthy ankle complex was developed using computed tomography (CT images. We established models of an ITSI and of screw fixation at the plane 2.5 cm above and parallel to the tibiotalar joint surface of the injured syndesmosis. Simulated loads were applied under three conditions: neutral position with single-foot standing and internal and external rotation of the ankle. ITSI reduced contact forces between the talus and fibula, helped periarticular ankle ligaments withstand more load-resisting movement, and increased the magnitude of displacement at the lower extreme of the tibia and fibula. ITSI fixation with a syndesmotic screw reduced contact forces in all joints, decreased the magnitude of displacement at the lower extreme of the tibia and fibula, and increased crural interosseous membrane stress. CONCLUSIONS/SIGNIFICANCE: Severe syndesmosis injuries cause stress and displacement distribution of the ankle to change multidirectional ankle instability and should be treated by internal fixation. Though the transverse syndesmotic screw effectively stabilizes syndesmotic diastasis, it also changes stress distribution around the ankle and decreases the joint's range of motion (ROM. Therefore, fixation should not be performed for a long period of time because it is not physiologically suitable for the ankle joint.

  13. A meta-analysis of unilateral versus bilateral pedicle screw fixation in minimally invasive lumbar interbody fusion.

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    Zheng Liu

    Full Text Available STUDY DESIGN: Meta-analysis. BACKGROUND: Bilateral pedicle screw fixation (PS after lumbar interbody fusion is a widely accepted method of managing various spinal diseases. Recently, unilateral PS fixation has been reported as effective as bilateral PS fixation. This meta-analysis aimed to comparatively assess the efficacy and safety of unilateral PS fixation and bilateral PS fixation in the minimally invasive (MIS lumbar interbody fusion for one-level degenerative lumbar spine disease. METHODS: MEDLINE/PubMed, EMBASE, BIOSIS Previews, and Cochrane Library were searched through March 30, 2014. Randomized controlled trials (RCTs and controlled clinical trials (CCTs on unilateral versus bilateral PS fixation in MIS lumbar interbody fusion that met the inclusion criteria and the methodological quality standard were retrieved and reviewed. Data on participant characteristics, interventions, follow-up period, and outcomes were extracted from the included studies and analyzed by Review Manager 5.2. RESULTS: Six studies (5 RCTs and 1 CCT involving 298 patients were selected. There were no significant differences between unilateral and bilateral PS fixation procedures in fusion rate, complications, visual analogue score (VAS for leg pain, VAS for back pain, Oswestry disability index (ODI. Both fixation procedures had similar length of hospital stay (MD = 0.38, 95% CI = -0.83 to 1.58; P = 0.54. In contrast, bilateral PS fixation was associated with significantly more intra-operative blood loss (P = 0.002 and significantly longer operation time (P = 0.02 as compared with unilateral PS fixation. CONCLUSIONS: Unilateral PS fixation appears as effective and safe as bilateral PS fixation in MIS lumbar interbody fusion but requires less operative time and causes less blood loss, thus offering a simple alternative approach for one-level lumbar degenerative disease.

  14. Both unilateral and bilateral pedicle screw fixation are effective for lumbar spinal fusion—A meta-analysis-based systematic review

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    Jiaquan Luo

    2014-04-01

    Full Text Available A series of studies have been conducted to evaluate the effectiveness of unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion, but there is still controversy about which one is more superior. We performed a meta-analysis to more accurately estimate the effectiveness of unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion. Studies on the comparison between unilateral and bilateral pedicle screw fixation in lumbar spinal fusion were identified from PubMed, SpringerLink, China National Knowledge Infrastructure (CNKI, the Wanfang database and the China Biology Medical literature database (CBM and related references were searched. The included trials were screened according to the criteria of inclusion and exclusion. The quality of included trials was evaluated. Data were extracted by two reviewers independently. RevMan 5.1.1 was used for data analysis. The fixed or random effect model was selected based on the heterogeneity test among studies evaluated using the I2 statistic. A total of nine studies involving 567 patients were included in the analyses for the effectiveness of unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion. Unilateral pedicle screw fixation was performed in 287 patients and bilateral pedicle screw fixation in 280 patients. The results of the meta-analysis indicated that statistically significant differences were observed between the two fixation procedures with regard to mean operation time and amount of bleeding. There were no differences in hospitalisation days, fusion rate, complication rate, and excellent and good rates. This meta-analysis suggested that both unilateral and bilateral pedicle screw fixation are effective in one or two segmental lumbar spinal fusion. In comparison with bilateral fixation, unilateral fixation can shorten the operation time, reduce the amount of bleeding, and reduce medical expenses. There were similar effects with regard to

  15. Biomechanical comparison of 2 anterior cruciate ligament graft preparation techniques for tibial fixation: adjustable-length loop cortical button or interference screw.

    Science.gov (United States)

    Mayr, Raul; Heinrichs, Christian Heinz; Eichinger, Martin; Coppola, Christian; Schmoelz, Werner; Attal, René

    2015-06-01

    Cortical button fixation at the femoral side and interference screws within the tibial bone tunnel are widely used for anterior cruciate ligament graft fixation. Using a bone socket instead of a full tunnel allows cortical button fixation on the tibial side as well. If adjustable-length loop cortical button devices are used for femoral and tibial fixation, the tendon graft has to be secured with sutures in a closed tendon loop. The increased distance of fixation points and potential slippage of the tendon strands at the securing sutures might lead to greater risk of postoperative graft elongation when compared with conventional graft preparation with tibial interference screw fixation. Compared with an anterior cruciate ligament graft with tibial adjustable-length loop cortical button fixation, a graft with tibial interference screw fixation will show less graft elongation during cyclic loading and lower ultimate failure loads. Controlled laboratory study. Grafts with tibial adjustable-length loop cortical button fixation and grafts with tibial interference screw fixation were biomechanically tested in calf tibiae (n = 10 per group). Femoral fixation was equivalent for both groups, using an adjustable-length loop cortical button. Specimens underwent cyclic loading followed by a load-to-failure test. Grafts with screw fixation showed significantly less initial elongation (cycles 1-5: 1.46 ± 0.26 mm), secondary elongation (cycles 6-1000: 1.87 ± 0.67 mm), and total elongation (cycles 1-1000: 3.33 ± 0.83 mm) in comparison with grafts with button fixation (2.47 ± 0.26, 3.56 ± 0.39, and 6.03 ± 0.61 mm, respectively) (P button fixation were able to withstand significantly higher ultimate failure loads (908 ± 74 vs 693 ± 119 N) (P button fixation resulted in higher graft elongation during cyclic loading and showed higher ultimate failure loads in comparison with conventional graft preparation with tibial interference screw fixation at time zero. The results of this

  16. Efficacy of radial styloid targeting screws in volar plate fixation of intra-articular distal radial fractures: a biomechanical study in a cadaver fracture model

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    Yamashita Toshihiko

    2010-12-01

    Full Text Available Abstract Background The locking screws target the radial styloid, theoretically provide greater stability against radial styloid fragment. However, it is unknown whether the radial styloid locking screws increased the stability of the volar plating system fixation along the entire distal radius or not. In this study, we evaluated the stability of the volar plating system fixation with or without the radial styloid screws using a biomechanical study in a cadaver fracture model. Methods Six matched pairs of fresh-frozen human cadaver wrists complete from the proximal forearm to the metacarpal bones were prepared to simulate standardized 3-part intra-articular and severe comminuted fractures. Specimens were fixed using the volar plating system with or without 2 radial styloid screws. Each specimen was loaded at a constant rate of 20 mm/min to failure. Load data was recorded and, ultimate strength and change in gap between distal and proximal fragments were measured. Data for ultimate strength and screw failure after failure loading were compared between the 2 groups. Results The average ultimate strength at failure of the volar plate fixation with radial styloid screws (913.5 ± 157.1 N was significantly higher than that without them (682.2 ± 118.6 N. After failure loading, the average change in gap between the ulnar and proximal fragment was greater than that between the radial and proximal fragment. The number of bent or broken screws in ulnar fragment was higher than that in radial fragment. The number of specimens with bent or broken screws in cases with radial styloid screws was fewer than that in the fixation without radial styloid screws group. Conclusion The ulnar fragment is more intensively stressed than the radial fragment under axial loading of distal radius at full wrist extension. The radial styloid screws were effective in stable volar plate fixation of distal radial fractures.

  17. Effect of Crosslinks on the Stability of the Spine and the Pedicle Screw Fixation.

    Science.gov (United States)

    Xiang-Yu, Zhang; Feng, S U; Shi, Yan; Zhi-Min, Zhang; Pei-Nan, Zhang

    2015-06-01

    To evaluate the effect of crosslinks on the stability of the spine and pedicle screws. Compression fracture of the L1 vertebra was produced in 30 fresh thoracic and lumbar vertebrae samples obtained from adult sheep, which were divided into 3 groups (n=10)with lot-drawing method. Four screws were fixed onto the superior and inferior pedicles of vertebral arch close to the fractured vertebrae, with different number of crosslinks (0 in Group A,1 in Group B, and 2 in Group C) on the rods. After fixation, the samples were subject to 10 000 times of fatigue test with 1.5 Hz load on the HY-3080 computer-control electronic universal test machine and HY-1000NM computer-control torsion test machine. The axial compressive stiffness, maximum pullout strength,and range of motion (ROM) of 6 directions, i.e., flexion, extension, left and right lateral bending, and left and right axial rotation of the 3 groups were measured and compared. There were no statistically significant differences in axial compressive stiffness as well as the ROM of flexion, extension, and left and right lateral bending (all P>0.05). The maximum pullout strength was significantly smaller in Group A and Group B than in Group C [(129.56±29.63)N vs.(294.67±23.25) N,P=0.000;(254.02±36.29)vs.(294.67±23.25)N, P=0.006]. The ROM of left axial rotation was the highest in Group A(13.35°±1.06°), followed by Group B(12.23°±1.06°)and Group C (11.04°±0.74°)(F=13.44, P=0.000; Group B vs. Group A, P=0.000; Group B vs. Group C, P=0.001; Group C vs. Group A,P=0.000). The ROM of right axial rotation was also the highest in Group A(13.56°±1.15°), lower in Group B (12.39°±1.01°) and the lowest in Group C (10.81°±0.51°) (F=21.91, P=0.000; Group B vs. Group A,P=0.002; Group B vs. Group C, P=0.001; Group C vs. Group A, P=0.000). Crosslinks may reinforce the pullout strength of the screws and improve the axial stability of the spine.

  18. Motion-preserving reduction and fixation of C1 Jefferson fracture using a C1 lateral mass screw construct.

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    Jo, Kwang-Wook; Park, Ik-Seong; Hong, Jae Taek

    2011-05-01

    The treatment of C1 Jefferson fractures is controversial. Non-surgical treatment with halo fixation always bears the risk of insufficient healing with further instability and increasing neck pain. However, a C1-2 fusion can markedly decrease the rotatory motion of the neck. The aim of this report is to describe a new treatment for C1 Jefferson fractures. We used open reduction and C1 fixation using a bilateral C1 lateral mass screw construct. The screws were connected with a rod and nuts to reduce lateral spread of the lateral masses. This method is an alternative surgical option for C1 Jefferson fractures in select patients and can maintain important C1-2 joint motion.

  19. Analysis of the Stress and Displacement Distribution of Inferior Tibiofibular Syndesmosis Injuries Repaired with Screw Fixation: A Finite Element Study

    OpenAIRE

    Qinghua Liu; Kun Zhang; Yan Zhuang; Zhong Li; Bin Yu; Guoxian Pei

    2013-01-01

    BACKGROUND: Studies of syndesmosis injuries have concentrated on cadaver models. However, they are unable to obtain exact data regarding the stress and displacement distribution of various tissues, and it is difficult to compare models. We investigated the biomechanical effects of inferior tibiofibular syndesmosis injuries (ITSIs) and screw fixation on the ankle using the finite element (FE) method. METHODOLOGY/PRINCIPAL FINDINGS: A three-dimensional model of a healthy ankle complex was devel...

  20. Treatment of Displaced Sacroiliac Fracture Using the Lateral Window for Short Plate Buttress Reduction and Percutaneous Sacroiliac Screw Fixation.

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    Colin Murphy

    2016-04-01

    Full Text Available Fractures through the sacroiliac joint are very challenging to treat, technically difficult to reduce through closed methods on account of the multiaxial displacement of fractures fragments, frequently occur in very unwell patients, and have poor outcomes if malreduction is present. We describe a technique utilising the lateral window and a short buttress plate to reduce and stabilize the fragments prior to percutaneous fixation with sacroiliac screws.

  1. A comparative study of pedicle screw fixation in dorsolumbar spine by freehand versus image-assisted technique: A cadaveric study

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    Archit Agarwal

    2016-01-01

    Full Text Available Background: New and expensive technology such as three-dimensional computer assisted surgery is being used for pedicle screw fixation in dorsolumbar spine. Their availability, expenses and amount of radiation exposure are issues in a developing country. On the contrary, freehand technique of pedicle screw placement utilizes anatomic landmarks and tactile palpation without fluoroscopy or navigation to place pedicle screws. The purpose of this study was to analyze and compare the accuracy of freehand and image-assisted technique to place pedicle screws in the dorsolumbar spine of cadavers by an experienced surgeon and a resident. Evaluation was done using dissection of pedicle and computed tomography (CT imaging. Materials and Methods: Ten cadaveric dorsolumbar spines were exposed by a posterior approach. Titanium pedicle screws were inserted from D5 to L5 vertebrae by freehand and image-assisted technique on either side by an experienced surgeon and a resident. CT was obtained. A blinded radiologist reviewed the imaging. The spines were then dissected to do a macroscopic examination. Screws, having evidence of cortical perforation of more than 2 mm on CT, were considered to be a significant breach. Results: A total of 260 pedicle screws were placed. The surgeon and the resident placed 130 screws each. Out of 130 screws, both of them placed 65 screws each by freehand and image- assisted technique each. The resident had a rate of 7.69% significant medial and 10.76% significant lateral breach with freehand technique while with image-assisted had a rate of 3.07% significant medial and 9.23% significant lateral breach. The expert surgeon had a rate of 6.15% significant medial and 1.53% significant lateral breach with freehand technique while with image-assisted had a rate of 3.07% significant medial and 6.15% significant lateral breach on CT evaluation. Conclusion: Freehand technique is as good as the image-assisted technique. Under appropriate

  2. Laminoplasty with lateral mass screw fixation for cervical spondylotic myelopathy in patients with athetoid cerebral palsy: A retrospective study.

    Science.gov (United States)

    Zhou, Hua; Liu, Zhong-Jun; Wang, Shao-Bo; Pan, Sheng-Fa; Yan, Ming; Zhang, Feng-Shan; Sun, Yu

    2016-09-01

    Although several studies report various treatment solutions for cervical spondylotic myelopathy in patients with athetoid cerebral palsy, long-term follow-up studies are very rare. None of the reported treatment solutions represent a gold standard for this disease owing to the small number of cases and lack of long-term follow-up. This study aimed to evaluate the outcomes of laminoplasty with lateral mass screw fixation to treat cervical spondylotic myelopathy in patients with athetoid cerebral palsy from a single center.This retrospective study included 15 patients (9 male patients and 6 female patients) with athetoid cerebral palsy who underwent laminoplasty with lateral mass screw fixation for cervical spondylotic myelopathy at our hospital between March 2006 and June 2010. Demographic variables, radiographic parameters, and pre- and postoperative clinical outcomes determined by the modified Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), and visual analog scale (VAS) scores were assessed.The mean follow-up time was 80.5 months. Developmental cervical spinal canal stenosis (P = 0.02) and cervical lordosis (P = 0.04) were significantly correlated with lower preoperative modified JOA scores. The mean modified JOA scores increased from 7.97 preoperatively to 12.1 postoperatively (P cerebral palsy. Laminoplasty with lateral mass screw fixation is an effective treatment for cervical spondylotic myelopathy in patients with athetoid cerebral palsy and developmental cervical spinal canal stenosis.

  3. Treatment of wrist joint dislocation by movable external fixator and Anchor screws%可活动外固定支架结合Anchor钉治疗腕关节脱位

    Institute of Scientific and Technical Information of China (English)

    尹自飞; 韩培; 柴益民; 蒋垚

    2012-01-01

    目的 探讨应用可活动外固定支架结合Anchor钉治疗腕关节脱位的可行性及治疗效果.方法 对16例腕关节脱位患者进行腕关节可活动外固定支架固定,同时切开复位,加压空心钉固定骨折,Anchor钉修复腕骨间韧带和桡腕韧带,克氏针临时固定腕骨.结果 随访3~6个月,16例患者均基本恢复腕关节功能,未出现再脱位、舟骨月骨坏死等.采用Cooney评价标准:优7例,良7例,可2例.结论 可活动外固定支架结合Anchor钉治疗腕关节脱位可有效固定腕关节,韧带修复可靠,利于破损韧带愈合及促进早期逐步功能锻炼,疗效满意.%Objective To discuss feasibility and clinical result of wrist joint dislocation by movable external fixator and Anchor screw. Methods 16 cases of wrist joint dislocations were treated with movable external fixators, open reduction , and cannulated screws fixation of fracture. Anchor screws were used to repaire intercarpal and radiocarpal ligaments and Kirschner wire fixing fracture temperately. Results All cases were followed up for 3 ~ 6 months. 16 patients recoveried wrist joint functions basically, and no dislocations and osteonecrosis were found. Based on Cooney's clinical scoring system,the scores of our series were 7 excellent ,7 good and 2 fair. Conclusions Treatment of wrist joint dislocations by movable external fixator and Anchor screw can fix wrist joint effectively, repairing ligaments reliably and allow function movements early.

  4. Interference screw for fixation of FDL transfer in the treatment of adult acquired flat foot deformity stage II.

    Science.gov (United States)

    Charwat-Pessler, Christoph Georg; Hofstaetter, Stefan Gerhard; Jakubek, Doris Elvira; Trieb, Klemens

    2015-10-01

    Flexor digitorum longus transfer and medial displacement calcaneal osteotomy have shown favourable results in the treatment of adult acquired flat foot deformity stage 2. Little is known about the resorbable interference screw for tendon fixation and postoperative patient satisfaction though. Moreover possible changes of radiographic parameters at final follow-up, possible implant-associated complications and differences concerning clinical results at final follow-up to other studies using bone tunnel techniques for fixation of the FDL tendon were investigated. 21 feet in 21 patients with a mean age of 51 years were evaluated pre- and postoperatively after a standardised operative procedure using MDCO and FDL transfer with interference screw fixation. Patients were evaluated with the American Orthopaedic Foot and Ankle Society Hindfoot Score and the Visual Analogue Scale at an average follow-up of 20 months. Hindfoot radiographic parameters were evaluated according to AOFAS guidelines. For statistical analysis SPSS v.15.0.1 was used. The average AOFAS Score (from 42 to 95 points) and VAS (from 0.5 to 8 points) both increased significantly (p < 0.001 each) from preoperative to final follow-up as well as the hindfoot valgus (from 10 to 4 degrees (p = 0.005)) and the lateral talo-first metatarsal angle (from 13.6 preoperative to 5.2° at follow-up). 88 percent of patients evaluated the postoperative result with "very good" or "good". Implant-associated complications could not be detected. We conclude that interference screw fixation for FDL transfer is a safe and promising operative technique, allowing a smaller skin incision without disrupting the normal interconnections at the knot of Henry, while achieving very high patient satisfaction and improving postoperative function as well as relieving pain. This method is technically easy to perform, has a low complication risk and we, therefore, recommend this fixation technique in patients with adult acquired

  5. When Planning Screw Fracture Fixation Why the 5.5 mm Screw is the Goldilocks Screw. An Observational Computer Tomographic Study of Fifth Metatarsal Bone Anatomy in a Sample of Patients.

    Science.gov (United States)

    Iselin, Lukas D; Ramawat, Sunil; Hanratty, Brian; Klammer, Georg; Stavrou, Peter

    2015-05-01

    We wanted to verify our clinical experience that the 5.5 mm screw was ideal in the majority of fifth metatarsal fracture fixation. The size of a screw is important for the successful surgical treatment of these fractures in order to obtain the maximal stability while reducing the risk for iatrogenic fracture.A sample of patients undergoing computer tomographic imaging of the foot for investigation other than fifth metatarsal pathology were recruited. The parameters of the fifth metatarsal bone anatomy were measured.These parameters of the 5.5 mm screw were correlated with this data. The upper parameter (the diameter of the threads) was 5.5 and the lower parameter (the diameter of the shank) was 4.0 mm.Twenty seven patients were recruited.The proximal third internal diameter ranged from 3.6 to 7.0 mm with a mean of 5.0 mm. 93% of the metatarsals could easily accommodate the 5.5 mm screw. Two of the metatarsals had an internal diameter of < 4 mm (7%).It is our belief that the 5.5 mm screw may be used safely in the majority of patients with fifth metatarsal fractures.

  6. Combined circular external fixation and open reduction internal fixation with pro-syndesmotic screws for repair of a diabetic ankle fracture

    Directory of Open Access Journals (Sweden)

    Zacharia Facaros

    2010-10-01

    Full Text Available The surgical management of ankle fractures among the diabetic population is associated with higher complication rates compared to the general population. Efforts toward development of better methods in prevention and treatment are continuously evolving for these injuries. The presence of peripheral neuropathy and the possible development of Charcot neuroarthropathy in this high risk patient population have stimulated much surgical interest to create more stable osseous constructs when open reduction of an ankle fracture/dislocation is required. The utilization of multiple syndesmotic screws (pro-syndesmotic screws to further stabilize the ankle mortise has been reported by many foot and ankle surgeons. In addition, transarticular Steinmann pins have been described as an adjunct to traditional open reduction with internal fixation (ORIF of the ankle to better stabilize the talus, thus minimizing risk of further displacement, malunion, and Charcot neuroarthropathy. The authors present a unique technique of ORIF with pro-syndesmotic screws and the application of a multi-plane circular external fixator for management of a neglected diabetic ankle fracture that prevented further deformity while allowing a weight-bearing status. This technique may be utilized for the management of complex diabetic ankle fractures that are prone to future complications and possible limb loss.

  7. Optimal screw orientation for the fixation of cervical degenerative disc disease using nonlinear C3-T2 multi-level spinal models and neuro-genetic algorithms.

    Science.gov (United States)

    Chang, Ting-Kuo; Hsu, Ching-Chi; Chen, Kuan-Ting

    2015-01-01

    Anterior cervical discectomy and fusion is a common surgical procedure performed to remove a degenerative or herniated disc in cervical spine. Unfortunately, clinical complications of anterior cervical plate (ACP) systems still occur, such as weak fixation stability and implant loosening. Previous researchers have attempted to ameliorate these complications by varying screw orientations, but the screw orientations are mainly determined according to the investigator's experiences. Thus, the aim of this study was to discover the optimal screw orientations of ACP systems to achieve acceptable fixation stability using finite element simulations and engineering algorithms. Three-dimensional finite element models of C3-T2 multi-level segments with an ACP system were first developed to analyze the fixation stability using ANSYS Workbench 14.5. Then, artificial neural networks were applied to create one objective function, and the optimal screw orientations of an ACP system were discovered by genetic algorithms. Finally, the numerical models and the optimization study were validated using biomechanical tests. The results showed that the optimal design of the ACP system had highest fixation stability compared with other ACP designs. The neuro-genetic algorithm has effectively reduced the time and effort required for discovering for the optimal screw orientations of an ACP system. The optimum screw orientation of the ACP system could be successfully discovered, and it revealed excellent fixation stability for the treatment of cervical degenerative disc disease. This study could directly provide the biomechanical rationale and surgical suggestion to orthopedic surgeons.

  8. Screw augmentation reduces motion at the bone-implant interface: a biomechanical study of locking plate fixation of proximal humeral fractures.

    Science.gov (United States)

    Schliemann, Benedikt; Seifert, Robert; Rosslenbroich, Steffen B; Theisen, Christina; Wähnert, Dirk; Raschke, Michael J; Weimann, Andre

    2015-12-01

    Shear forces at the bone-implant interface lead to a loss of reduction after locking plate fixation of proximal humeral fractures. The aim of the study was to analyze the roles of medial support screws and screw augmentation in failure loads and motion at the bone-implant interface after locking plate fixation of proximal humeral fractures. Unstable 3-part fractures were simulated in 6 pairs of cadaveric humeri and were fixed with a DiPhos-H locking plate (Lima Corporate, Udine, Italy). An additional medial support screw was implanted in 1 humerus of every donor. The opposite humerus was stabilized with a medial support screw and additional bone cement augmentation of the 2 anteriorly directed head screws. Specimens were loaded in the varus bending position. Stiffness, failure loads, plate bending, and the motion at the bone-implant interface were evaluated using an optical motion capture system. The mean load to failure was 669 N (standard deviation [SD], 117 N) after fixation with medial support screws alone and 706 N (SD, 153 N) after additional head screw augmentation (P = .646). The initial stiffness was 453 N/mm (SD, 4.16 N/mm) and 461 N/mm (SD, 64.3 N/mm), respectively (P = .594). Plate bending did not differ between the 2 groups. However, motion at the bone-implant interface was significantly reduced after head screw augmentation (P Board of Trustees. Published by Elsevier Inc. All rights reserved.

  9. Improving the trajectory of transpedicular transdiscal lumbar screw fixation with a computer-assisted 3D-printed custom drill guide

    Directory of Open Access Journals (Sweden)

    Zhen-Xuan Shao

    2017-07-01

    Full Text Available Transpedicular transdiscal screw fixation is an alternative technique used in lumbar spine fixation; however, it requires an accurate screw trajectory. The aim of this study is to design a novel 3D-printed custom drill guide and investigate its accuracy to guide the trajectory of transpedicular transdiscal (TPTD lumbar screw fixation. Dicom images of thirty lumbar functional segment units (FSU, two segments of L1–L4 were acquired from the PACS system in our hospital (patients who underwent a CT scan for other abdomen diseases and had normal spine anatomy and imported into reverse design software for three-dimensional reconstructions. Images were used to print the 3D lumbar models and were imported into CAD software to design an optimal TPTD screw trajectory and a matched custom drill guide. After both the 3D printed FSU models and 3D-printed custom drill guide were prepared, the TPTD screws will be guided with a 3D-printed custom drill guide and introduced into the 3D printed FSU models. No significant statistical difference in screw trajectory angles was observed between the digital model and the 3D-printed model (P > 0.05. Our present study found that, with the help of CAD software, it is feasible to design a TPTD screw custom drill guide that could guide the accurate TPTD screw trajectory on 3D-printed lumbar models.

  10. Anatomic and radiological study on posterior pedicle screw fixation in the atlantoaxial vertebrae of children

    Institute of Scientific and Technical Information of China (English)

    DENG Xiong-wei; MIN Zhi-hai; LIN Bin; ZHANG Fa-hui

    2010-01-01

    Objective: To investigate the feasibility of posterior fixation with 3.5-mm pedicle screws in the atlantoaxial vertebrae of children.Methods: In this study, atlantoaxial vertebrae specimens were obtained from 10 cadavers of children aged 6-8 years. We measured the height and width of the C1 pedicle and the midportion of C1 lateral mass; the width of C1 posterior arch under the vertebral artery groove and the height of the external and internal one-third of this part; the external,internal height and the superior, middle, inferior width of the C2 pedicle (transverse foramen). Furthermore, computed tomography (CT) axial scan was performed on 20 agematched volunteers to obtain relative data of their atlantoaxial vertebrae. We measured the length and width of the C1 and C2 pedicles in the atlantoaxial cross-sectional plane. On CT workstation, we also measured the angles between the longitudinal axes of the atlantoaxial pedicles and the midsagittal plane.Results: For the cadaveric specimen group, the height and width of the C1 pedicle were (5.26±0.44) mm and (6.26±0.75) mm respectively. The height of the medial one-third of the C1 posterior arch under the vertebral artery groove was (4.07±0.24) mm. The external, internal height and superior,middle, inferior width of the C2 pedicle was (6.86±0.48) mm,(6.67±0.49) mm, (6.63 ±0.61 ) mm, (5.41±0.39) mm and (3.71±0.30) mm, respectively. For the volunteer group measured by CT scan, the height and width of the Ct pedicle were (5.47±0.34) mm and (6.63±0.54) mm respectively, while (6.59±0.51) mm and (5.13±0.42) mm of the C2 pedicle. The angles between the atlas, axis pedicles and the midsagittal plane were (9.60±1.32)° and (27.80±2.22)° respectively.Conclusion: It is feasible to place a 3.5-mm pedicle screw in the C1 and C2 pedicles of children aged 6-8 years old.

  11. Interference screw versus Endoscrew fixation for anterior cruciate ligament reconstruction: A biomechanical comparative study in sawbones and porcine knees

    Directory of Open Access Journals (Sweden)

    Chu-Chih Hung

    2014-04-01

    Full Text Available Interference screw fixation is one of the most common methods for ligament reconstruction. Although the advantages and clinical outcomes of this procedure have been widely reported, post-surgical complications often arise. The purpose of this study was to evaluate a new femoral fixation device, the Endoscrew, for anterior cruciate ligament (ACL reconstruction. We performed a mechanical test in accordance with American Society for Testing and Materials (ASTM standards and an in vitro biomechanical study. An axial pullout test was conducted to evaluate the mechanical properties of the new device and the interference screw when implanted in solid rigid polyurethane foam test blocks. The biomechanical test used porcine femora to evaluate the initial fixation strength between these two implants. The maximum pullout force of the interference screw group [722.05 ± 130.49 N (N] was significantly greater (p < 0.01 than the Endoscrew group (440.79 ± 26.54 N when implanted in polyurethane foam 320 kg/m3 density. With polyurethane foam 160 kg/m3 density, the maximum pullout forces were (242.61 ± 37.36 N (p < 0.001 and (99.33 ± 30.01 N for the interference screw group and Endoscrew group, respectively. In the in vitro mechanical study, the Endoscrew (646.39 ± 72.38 N required a significantly greater ultimate load prior to failure (p < 0.05 when compared with the interference screw (489.72 ± 138.64 N. With regard to pullout stiffness, there was no statistically significant difference (p < 0.13 between the Endoscrew group (99.15 ± 12.16 N/mm and the interference screw group (87.96 ± 11.12 N/mm. The cyclic stiffness was also not significantly different (p < 0.44 between the Endoscrew group (93.09 ± 16.07 N/mm and the interference screw group (85.78 ± 14.76 N/mm. The axial pullout test showed that the strength of the Endoscrew was close to the fixation strength required for daily activities, but it is

  12. Three-Dimensional Analysis of Fibular Motion After Fixation of Syndesmotic Injuries With a Screw or Suture-Button Construct.

    Science.gov (United States)

    LaMothe, Jeremy M; Baxter, Josh R; Murphy, Conor; Gilbert, Susannah; DeSandis, Bridget; Drakos, Mark C

    2016-12-01

    Suture-button constructs are an alternative to screw fixation for syndesmotic injuries, and proponents advocate that suture-button constructs may allow physiological motion of the syndesmosis. Recent biomechanical data suggest that fibular instability with syndesmotic injuries is greatest in the sagittal plane, but the design of a suture-button construct, being a rope and 2 retention washers, is most effective along the axis of the rope (in the coronal plane). Some studies report that suture-button constructs are able to constrain fibular motion in the coronal plane, but the ability of a tightrope to constrain sagittal fibular motion is unknown. The purpose of this study was to assess fibular motion in response to an external rotation stress test in a syndesmotic injury model after fixation with a screw or suture-button constructs. Eleven fresh-frozen cadaver whole legs with intact tibia-fibula articulations were secured to a custom fixture. Fibular motion (coronal, sagittal, and rotational planes) in response to a 6.5-Nm external rotation moment applied to the foot was recorded with fluoroscopy and a high-resolution motion capture system. Measures were taken for the following syndesmotic conditions: intact, complete lateral injury, complete lateral and deltoid injury, repair with a tetracortical 4.0-mm screw, and repair with a suture button construct (Tightrope; Arthrex, Naples, FL) aimed from the lateral fibula to the anterior medial malleolus. The suture-button construct allowed significantly more sagittal plane motion than the syndesmotic screw. Measurements acquired with mortise imaging did not detect differences between the intact, lateral injury, and 2 repair conditions. External rotation of the fibula was significantly increased in both injury conditions and was not restored to intact levels with the screw or the suture-button construct. A single suture-button placed from the lateral fibula to the anterior medial malleolus was unable to replicate the motion

  13. Minimally invasive transforaminal lumbar interbody fusion with unilateral pedicle screw fixation: comparison between primary and revision surgery.

    Science.gov (United States)

    Kang, Moo Sung; Park, Jeong Yoon; Kim, Kyung Hyun; Kuh, Sung Uk; Chin, Dong Kyu; Kim, Keun Su; Cho, Yong Eun

    2014-01-01

    Minimally invasive surgery with a transforaminal lumbar interbody fusion (MIS TLIF) is an important minimally invasive fusion technique for the lumbar spine. Lumbar spine reoperation is challenging and is thought to have greater complication risks. The purpose of this study was to compare MIS TLIF with unilateral screw fixation perioperative results between primary and revision surgeries. This was a prospective study that included 46 patients who underwent MIS TLIF with unilateral pedicle screw. The patients were divided into two groups, primary and revision MIS TLIF, to compare perioperative results and complications. The two groups were similar in age, sex, and level of operation, and were not significantly different in the length of follow-up or clinical results. Although dural tears were more common with the revision group (primary 1; revision 4), operation time, blood loss, total perioperative complication, and fusion rates were not significantly different between the two groups. Both groups showed substantial improvements in VAS and ODI scores one year after surgical treatment. Revision MIS TLIF performed by an experienced surgeon does not necessarily increase the risk of perioperative complication compared with primary surgery. MIS TLIF with unilateral pedicle screw fixation is a valuable option for revision lumbar surgery.

  14. Minimally Invasive Transforaminal Lumbar Interbody Fusion with Unilateral Pedicle Screw Fixation: Comparison between Primary and Revision Surgery

    Directory of Open Access Journals (Sweden)

    Moo Sung Kang

    2014-01-01

    Full Text Available Minimally invasive surgery with a transforaminal lumbar interbody fusion (MIS TLIF is an important minimally invasive fusion technique for the lumbar spine. Lumbar spine reoperation is challenging and is thought to have greater complication risks. The purpose of this study was to compare MIS TLIF with unilateral screw fixation perioperative results between primary and revision surgeries. This was a prospective study that included 46 patients who underwent MIS TLIF with unilateral pedicle screw. The patients were divided into two groups, primary and revision MIS TLIF, to compare perioperative results and complications. The two groups were similar in age, sex, and level of operation, and were not significantly different in the length of follow-up or clinical results. Although dural tears were more common with the revision group (primary 1; revision 4, operation time, blood loss, total perioperative complication, and fusion rates were not significantly different between the two groups. Both groups showed substantial improvements in VAS and ODI scores one year after surgical treatment. Revision MIS TLIF performed by an experienced surgeon does not necessarily increase the risk of perioperative complication compared with primary surgery. MIS TLIF with unilateral pedicle screw fixation is a valuable option for revision lumbar surgery.

  15. The Use of Percutaneous Lumbar Fixation Screws for Bilateral Pedicle Fractures with an Associated Dislocation of a Lumbar Disc Prosthesis

    Directory of Open Access Journals (Sweden)

    William D. Harrison

    2013-01-01

    Full Text Available Study Design. Case report. Objective. To identify a safe technique for salvage surgery following complications of total disc replacement. Summary of Background Data. Lumbar total disc replacement (TDR is considered by some as the gold standard for discogenic back pain. Revision techniques for TDR and their complications are in their infancy. This case describes a successful method of fixation for this complex presentation. Methods and Results. A 48-year-old male with lumbar degenerative disc disease and no comorbidities. Approximately two weeks postoperatively for a TDR, the patient represented with acute severe back pain and the TDR polyethylene inlay was identified as dislocated anteriorly. Subsequent revision surgery failed immediately as the polyethylene inlay redislocated intraoperatively. Further radiology identified bilateral pedicle fractures, previously unseen on the plain films. The salvage fusion of L5/S1 reutilized the anterior approach with an interbody fusion cage and bone graft. The patient was then turned intraoperatively and redraped. The percutaneous pedicle screws were used to fix L5 to the sacral body via the paracoccygeal corridor. Conclusion. The robust locking screw in the percutaneous screw allowed a complete fixation of the pedicle fractures. At 3-year followup, the patient has an excellent result and has returned to playing golf.

  16. Computer-assisted navigation systems for insertion of cannulated screws in femoral neck fractures: a comparison of bi-planar robot navigation with optoelectronic navigation in a Synbone hip model trial

    Institute of Scientific and Technical Information of China (English)

    WANG Jun-qiang; ZHAO Chun-peng; SU Yong-gang; ZHOU Li; HU Lei; WANG Tian-miao; WANG Man-yi

    2011-01-01

    Background Computer-assisted procedures have recently been introduced for navigated femoral neck screw placement.Currently there is little information available regarding accuracy and efficiency of the different navigated procedures.The aim of this study was to compare two fluoroscopic navigation tracking technologies,a novel bi-planar robot navigation and standardized optoelectronic navigation,versus standard freehand fluoroscopic insertion in a Synbone hip model.Methods Eighteen fixed Synbone hip models were divided into 3 groups.C-arm navigated cannulated screws (AO-ASIF,diameter 7.3 mm) were inserted using freehand targeting (control group).A novel bi-planar robot system (TINAV,GD2000) and an optoelectronic system (Stryker OTS Navigation System) were used for the navigated procedures (robot group and optoelectronic group).Accuracy was measured using radiographic evaluation including the measurement of screw parallelism and decentralization,and joint penetration.To evaluate the efficiency,the number of guidewire passes,operative time and fluoroscopic images taken were noted.Results The two computer-assisted systems provided significantly improved accuracy compared to the freehand technique.Each of the parameters,including guidewire passes and number of fluoroscopy images,was significantly lower when using the computer-assisted systems than for freehand-unguided insertion (P <0.05),but operative time was significantly shorter when using freehand-unguided insertion than for the computer-assisted systems (P <0.05).Accuracy,operative time and number of fluoroscopy images taken were similar among the two navigated groups (P >0.05),but guidewire passes in the robot group were significantly less than in the optoelectronic group (P <0.05).Conclusions Both bi-planar robot navigation and optoelectronic navigation were similarly accurate and have the potential to improve accuracy and reduce radiation for freehand fluoroscopic targeting for insertion of cannulated

  17. Atlantoaxial screw fixation for the treatment of isolated and combined unstable jefferson fractures - experiences with 8 patients.

    Science.gov (United States)

    Hein, C; Richter, H-P; Rath, S A

    2002-11-01

    The unstable atlas burst fracture ("Jefferson fracture") is a fracture of the anterior and posterior atlantal arch with rupture of the transverse atlantal ligament and an incongruence of the atlanto-occipital and the atlanto-axial joint facets. The question whether it has to be treated surgically or nonsurgically is still discussed and remains controversial. During the last decade 8 patients with unstable atlas burst fractures were examined and treated in our department. Five of the eight patients were first treated conservatively by external immobilization. Because of continuing instability due to insufficient bony fusion of the atlantal fracture all five patients underwent atlanto-axial transarticular screw fixation and fusion - as described by Magerl - with good results. In all 8 patients a good bony fusion of the atlanto-axial segment was achieved. None of the patients exhibited neurological deficits after surgical treatment. Although immobilization with a halo vest is recommended by most authors, from our view primary transarticular C1-C2 screw fixation has to be discussed as an alternative for unstable atlas burst fractures. Nonsurgical treatment with halo extension always bears the risk of insufficient healing with further instability and a fixated incongruence of the atlanto-occipital and the atlanto-axial joints, leading to arthrosis, immobility and increasing neck pain. After 10 weeks of insufficient immobilization secondary pre- and intra-operative reposition manoeuvres and surgical fixation hardly can reverse this fixated incongruence. Moreover, halo-extension needs an immobilization of the cervical spine for about 10 weeks and more, which is very uncomfortable and leads to further complications especially in elderly patients.

  18. Subtrochanteric femur fracture after removal of screws for femoral neck fracture in a child.

    Science.gov (United States)

    Song, Kwang Soon; Lee, Si Wook

    2015-01-01

    Displaced femoral neck fractures are rare in children and are associated with a high rate of complications. Subtrochanteric fractures after cannulated screw fixation of femoral neck fractures in adults are well recognized, and there are several reports on the topic. However, there are no reports on complications related to hardware or subtrochanteric fractures after removal of the screws in the treatment of femoral neck fractures in children. Here we report the case of a 10-year-old boy who sustained a subtrochanteric fracture after the screw removal and healing that followed a femoral neck fracture.

  19. Effect of heparin on hemorheology and inflammatory cytokines in patients with spinal trauma after PCS pedicle screw fixation

    Institute of Scientific and Technical Information of China (English)

    Nan-Xiang Huang; Hong Lin; Wei Li

    2016-01-01

    Objective:To explore the effect of low molecular weight heparin (LMWH) on the hemorheology, inflammatory cytokines, and coagulation funtion in patients with spinal trauma after PCS pedicle screw fixation.Methods: A total of 80 patients with spinal trauma who were admitted in our hospital were included in the study and randomized into the treatment group and the control group with 40 cases in each group. The patients in the two groups were performed with PCS pedicle screw fixation. The patients in the treatment group were given subcutaneous injection of LMWH after operation. The hemorheology indicators, inflammatory cytokines levels, and coagulation function change before and after operation in the two groups were compared.Results: The difference of RBV (low shear, middle shear, and high shear) (mPa•s), PAR, and PAR (1 min) (%) before operation between the two groups was not statistically significant (P>0.05), the above indicators 24 h after operation in the two groups were significantly elevated when compared with before operation (P<0.05), and the above indicators 24 h after operation in the treatment group were significantly lower than those in the control group (P<0.05). The above indicators 48 h and 1 week after operation in the control group were significantly elevated, while those in the treatment group were significantly reduced when compared with before treatment (P<0.05). CRP, IL-6, and IL-10 levels after operation in the treatment group were significantly lower than those in the control group (P<0.05). PT, APTT, and FIB after operation in the treatment group were significantly lower than those in the control group (P<0.05).Conclusions:LMWH can effectively reduce the blood viscosity, inhibit the inflammatory reaction, and contribute to postoperative rehabilitation in patients with spinal trauma after PCS pedicle screw fixation.

  20. Totally absorbable screws in fixation of subtalar extra articular arthrodesis in children with spastic neuromuscular disease: preliminary report of a randomized prospective study of fourteen arthrodeses fixed with absorbable or metallic screws.

    Science.gov (United States)

    Partio, E K; Merikanto, J; Heikkilä, J T; Ylinen, P; Mäkelä, E A; Vainio, J; Törmälä, P; Rokkanen, P

    1992-01-01

    Seven patients with spastic neuromuscular disease and severe hindfoot valgus deformity were treated by subtalar arthrodesis. Arthrodesis was performed in both feet at the same operation and fixed on one side with a self-reinforced poly-L-lactide (SR-PLLA) screw, and with a standard AO screw on the other side. The functional status state was improved, and radiographic union of the arthrodesis occurred in all feet. The radiograph showed better solid fusion in five feet treated with PLLA screws, similar fusion in both sides in one patient, and one slower fusion in the side treated initially with a PLLA screw. Totally absorbable SR-PLLA screws appear to be firm enough for fixation of subtalar extraarticular arthrodesis in children.

  1. Posterior Titanium Screw Fixation without Debridement of Infected Tissue for the Treatment of Thoracolumbar Spontaneous Pyogenic Spondylodiscitis

    Science.gov (United States)

    Iacoangeli, Maurizio; Nasi, Davide; Nocchi, Niccolo; Di Rienzo, Alessandro; di Somma, Lucia; Colasanti, Roberto; Vaira, Carmela; Benigni, Roberta; Liverotti, Valentina; Scerrati, Massimo

    2016-01-01

    Study Design Retrospective study. Purpose The aim of our study was to analyze the safety and effectiveness of posterior pedicle screw fixation for treatment of pyogenic spondylodiscitis (PSD) without formal debridement of the infected tissue. Overview of Literature Posterior titanium screw fixation without formal debridement of the infected tissue and anterior column reconstruction for the treatment of PSD is still controversial. Methods From March 2008 to June 2013, 18 patients with PSD underwent posterior titanium fixation with or without decompression, according to their neurological deficit. Postero-lateral fusion with allograft transplantation alone or bone graft with both the allogenic bone and the autologous bone was also performed. The outcome was assessed using the visual analogue scale (VAS) for pain and the Frankel grading system for neurological status. Normalization both of C-reactive protein (CRP) and erythrocyte sedimentation rate was adopted as criterion for discontinuation of antibiotic therapy and infection healing. Segmental instability and fusion were also analyzed. Results At the mean follow-up time of 30.16 months (range, 24–53 months), resolution of spinal infection was achieved in all patients. The mean CRP before surgery was 14.32±7.9 mg/dL, and at the final follow-up, the mean CRP decreased to 0.5±0.33 mg/dL (p <0.005). Follow-up computed tomography scan at 12 months after surgery revealed solid fusion in all patients. The VAS before surgery was 9.16±1.29 and at the final follow-up, it improved to 1.38±2.03, which was statistically significant (p <0.05). Eleven patients out of eighteen (61.11%) with initial neurological impairment had an average improvement of 1.27 grades at the final follow-up documented with the Frankel grading system. Conclusions Posterior screw fixation with titanium instrumentation was safe and effective in terms of stability and restoration of neurological impairment. Fixation also rapidly reduced back pain

  2. A comparison of unilateral and bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion for lumbar degenerative diseases

    Institute of Scientific and Technical Information of China (English)

    Yang Xiaoming; Wang Hong; Zhao Quanlai; Xu Hongguang; Liu Ping; Jin Yuelong

    2014-01-01

    Background Bilateral transpedicular screw fixation in conjunction with interbody fusion is widely used to treat lumbar degenerative diseases; however,there are some disadvantages of using this fixation system.This study comparatively analyzes the results of unilateral and bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion (TLIF) for one-level lumbar degenerative diseases.Methods Sixty-six cases with one-level lumbar degenerative diseases were studied.The patients were divided according to surgical approach into a unilateral group (Group A) and a bilateral group (Group B).The patients were evaluated for pain by visual analog scale (VAS) and Oswestry Disability Index (ODI).Operating time,blood loss,duration of hospitalization,and complication rate were also evaluated.Patients were examined at 1,3,6,and 12 months postoperatively and every year thereafter.Results Group A patients' average preoperative VAS and ODI scores were 7.03 ± 0.98 and (64.22±6.38)%,respectively,significantly decreased to 2.91 ± 0.88 and (14.42±2.08)%,respectively,at the last follow-up (P =0.000).In Group B,the average preoperative VAS and ODI scores were 6.79±0.86 and (63.22±4.70)%,respectively,significantly decreased to 3.12±0.96 and (14.62±2.08)%,respectively,at the last follow-up (P=0.000).No significant difference in the duration of hospitalization was found between groups.Operating time and blood loss of (125.9±13.0) minutes and (211.4±28.3) ml,respectively,in Group A were significantly less than (165.2±15.3) minutes and (258.6±18.3) ml,respectively,in Group B (P=-0.000).All patients achieved good bone union and had no pseudarthrosis at the last follow-up.Conclusions There are no clinical differences between unilateral and bilateral pedicle screw fixation combined with TLIF for one-level lumbar degenerative diseases.Unilateral fixation reduces operating time,bleeding,and cost of hospitalization.

  3. Evaluation of initial biomechanical stability of screw-rod fixation system with lateral mass screw and pedicle screw for cervical vertebra%颈椎侧块与颈椎弓根内固定后初始稳定性评价及实验研究

    Institute of Scientific and Technical Information of China (English)

    袁欣华; 庞清江; 许柯; 张宗凯; 祝惠敏; 叶奕; 赵卫东

    2013-01-01

    目的 评价钉棒系统分别行颈椎侧块及椎弓根固定后的初始稳定性,为临床应用提供理论依据.方法 取8具新鲜冷冻人体颈椎标本,切断C4,5棘上韧带、棘间韧带、双侧关节囊,制成C4,5后柱不稳损伤模型,每个标本分别行正常标本、双侧C4,5侧块及椎弓根固定标本三维运动范围测定.结果 两种内固定组的三维运动范围均明显小于正常组,椎弓根固定组三维运动组小于侧块螺钉固定组,两组差异有统计学意义.结论 在颈椎后柱损伤模型中,用钉棒系统分别行侧块及椎弓根固定后均能明显提高脊柱三维稳定性,椎弓根内固定稳定性优于侧块钉棒系统.%Objective To investigate the initial biomechanical stability of the screw-rod system with lateral mass screw and pedicle screw for cervical vertebra fixation, and to provide theoretical basis for clinical applications of the screw-rod system. Methods Eight fresh human cervical specimens were obtained. Each specimen received a 3-D range of movement (ROM) test (normal group). Then the model of instable posterior column of C4.5 injury was set up by transection of supraspinous, interspinous ligament and bilateral articular capsule. For each specimen, another two 3-D ROM tests were carried out after receiving a lateral mass screw fixation and a pedicle screw fixation respectively. Results The ROM of the internal fixation groups was notably smaller than the normal group. There was significant difference. Conclusion For the instable cervical posterior column injury model, the screw-rod fixation system with lateral mass screw and pedicle screw for cervical vertebra fixation would evidently improve the 3-D stability of the vertebral column. And the stability of pedicle screw fixation is superior to it of mass screw fixation. within the internal fixation groups. The ROM of the pedicle screw group is much smaller.

  4. 应用皮质支撑原理固定股骨颈骨折的生物力学研究%Biomechanical study on femoral neck fracture fixation based on cortical screw support theory

    Institute of Scientific and Technical Information of China (English)

    王立江; 魏海强; 郭连江; 黎宁; 彭阿钦

    2009-01-01

    Objective To evaluate the biomechanical effect of cortical screw support technique in fixation of the femoral neck fractures. Methods The models of subcapital femoral neck fracture were made in eight matched pairs of embamled cadaver femurs and decided into experiment group and control group (four pairs per group). The side of experiment group was fixed using three cannulated compression screws with cortical screw support and that of control group with conventional screw placement. The speci-mens in two groups were tested in aspects of torsion and axial loading. Results In axial load test at load of 600 N and 800 N, the displacements in cortical screw support group were (0.677±0.135) mm and (0.907±0.132) mm respectively, while those of femoral head in conventional screw placement group were (0.899±0.160) mm and (1.202±0.152) nun respectively (P <0.05). There was signifi-cant difference between the two groups (P < 0.05). The maximal vertical loading for failure of the fixa-tion was (2 782±228) N in cortical screw support group and (1 950±281) N in conventional screw placement group (P < 0.01). In torsibility test at 4° and 6° torsibility, the torque-moments of cortical screw support group were (10.406±1.515) Nm and (15.328 ±1.471) Nm respectively and those of conventional screw placement group (6.628±1.163) Nm and (9.072±1.570) Nm respectively, with statistical difference between two groups (P <0.01). The maximal torque-moment for failure of the fixa-tion was (25.437±5.213) Nm in cortical screw support group and (13.235±3.012) Nm in conven-tional screw placement group (P < 0.01). Conclusion Fixation of femoral neck fractures by using cortical screw support can significantly enhance anti-torsion and anti-compression of internal fixation.%目的 根据皮质支撑的方法 ,探讨应用空心螺钉固定股骨颈骨折的生物力学效果.方法 选择8具成人防腐股骨标本,用随机数字表法分成两组,每组4具,制成股

  5. In vivo study of extracellular matrix coating enhancing fixation of the pedicle screw-bone's interface

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-min; ZHANG Xing-yi; XU Chuan-jie; ZHU Xiao-min; WANG Jun; LIU Yi

    2011-01-01

    Background Based on in vivo research on the effect of the coating of the extracellular matrix composition of pedicle screws on the conduction and induction of bone formation in young sheep,the aim of this study was to investigate the application of coated pedicle screws in sheep with scoliosis whose spines are under constant development.Methods Four groups of pedicle screws were randomly implanted into bilateral L2-L5 pedicles of 2.5- to 3-month-old sheep.A static experiment was performed on one side and a loading test was performed on the other side by implanting connecting rods at the L2-L3 and L4-L5 segments.The changes in the force on the coated screws and the combination of the surface of the coated screws with the surrounding bone in the growth process of young sheep's spines with aging were observed.After 3 months,the lumbar vertebrae with the screws were removed and examined by micro-CT,histological,and biomechanical analyses.Results Under nonloading conditions,there is bone formation around the surfaces of coated screws.The bone forming on the surface of collagen/chondroitin sulfate/hydroxyapatite coating of pedicle screws is the most,the one of the collagen / chondrcitin sulfate coating and hydroxyapatite coating is followed,and no significant difference between the two groups.In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws,such as bone mineral content,bone mineral density,tissue mineral content,tissue bone mineral density,bone volume fraction,and connection density,those associated with collagen/chondroitin sulfate/hydroxyapatite coatings are largest and those unassociated with coatings are smallest.Under nonloading conditions,the pullout strength of the collagen/chondroitin sulfate/hydroxyapatite-coated screws was largest,and that of the uncoated screws was minimal (P <0.01).Under loading conditions,the maximum pullout strength of each group of pedicle screws was less than that

  6. [Design and experimental study of individual drill templates for atlantoaxial pedicle screw fixation].

    Science.gov (United States)

    Qin, Wei; Quan, Zhengxue; Liu, Yang; Ou, Yunsheng

    2010-10-01

    To explore and evaluate the accuracy and feasibility of individual rapid prototype (RP) drill templates for atlantoaxial pedicle screw implantation. Volumetric CT scanning was performed in 8 adult cadaveric atlas and axis to collect Dicom format datas. Then three-dimensional (3D) images of atlas and axis were reconstructed and the parameters of pedicles of 3D model were measured by using software Mimics 10.01. The 3D model was saved by STL format in Mimics. The scattered point cloud data of 3D model were processed and the 3D coordinate system was located in software Imageware 12.1. The curves and surfaces of 3D model were processed in software Geomagic Studio 10. The optimal trajectory of pedicle screw was designed and a template was constructed which accorded with the anatomical morphology of posterior arch of atlas and lamina of axis by using software Pro/Engineer 4.0. The optimal trajectory of pedicle screw and the template were integrated into a drill template finally. The drill template and physical models of atlas and axis were manufactured by RP (3D print technology). The accuracy of pilot holes of drill templates was assessed by visually inspecting and CT scanning. The individual drill template was used conveniently and each template could closely fit the anatomical morphology of posterior arch of atlas and lamina of axis. Template loosening and shifting were not found in the process of screw implantation. Thirty-two pedicle screws were inserted. Imaging and visual inspection revealed that the majority of trajectories did not penetrate the pedicle cortex, only 1 cortical penetration was judged as noncritical and did not injury the adjacent spinal cord, nerve roots, and vertebral arteries. The accuracy of atlas pedicle screw was grade 0 in 15 screws and grade I in 1 screw, and the accuracy of axis pedicle screw was grade 0 in 16 screws. The potential of individual drill templates to aid implantation of atlantoaxial pedicle screw is promising because of its

  7. A comparative study on cervical biomechanical stability of lateral fixation piece and pedicle screws of screw fixation%颈椎侧块螺钉内固定和椎弓根螺钉内固定的生力学稳定性比较研究

    Institute of Scientific and Technical Information of China (English)

    冯灿林; 黄海珊; 黎霭云; 刘庆浩; 雷明; 祝城华; 许国增

    2014-01-01

    目的 比较颈椎侧块螺钉内固定和椎弓根螺钉内固定的生物力学稳定性.方法 取12具成人尸体的颈椎作为标本,于C4~C5处切断,造成颈椎不稳定模型.对标本依次行非内固定、侧块螺钉内固定和椎弓根螺钉内固定三种方式.然后进行柔韧性以及左右旋转扭矩和刚度测试,评价两种内固定术的稳定性效果.结果 在三维运动范围方面,侧块螺钉内固定比椎弓根螺钉内固定的三维运动范围有不同程度减小(P<0.05);侧块螺钉左右旋转的刚度比椎弓根螺钉内固定强(P<0.05).结论 从生物力学稳定性的角度来看,下颈椎不稳采用侧块螺钉内固定的生物力学稳定性较好.%Objective To compare the cervical biomechanical stability of lateral fixation piece and pedicle screws of screw fixation.Methods The 12 cervical vertebras as experimental sample,and from C4 to C5 were cut off and caused cervical instability model.Three ways of non fixation,lateral mass screw fixation and pedicle screw fixation were implemented.Then flexibility and rotation torque and stiffness were tested.Stability of two kinds of internal fixation was evaluated.Results In the 3-D range of movement,lateral mass screw fixation was notably smaller than that of pedicle screws fixation (P < 0.05).The lateral mass screw fixation had more strength than pedicle screws fixation (P < 0.05).Conclusion The instability of lower cervical spine patients may use lateral mass screw fixation,and its biomechanical stability is better.

  8. Efficacy of open reduction and internal fixation with a miniplate and hollow screw in the treatment of Lisfranc injury

    Directory of Open Access Journals (Sweden)

    Li Baoliang

    2015-07-01

    Full Text Available Purpose: To investigate efficacy of open reduction and internal fixation with the miniplate and hollow screw in the treatment of Lisfranc injury. Methods: Ten cases of Lisfranc injury treated by open reduction, miniplate and hollow screw in our hospital were retrospectively analyzed. There were 6 males and 4 females with age ranging from 25 to 45 years (mean 32 years. Among them, one case was classified as Type A, six Type B and three Type C. Injury mechanism included road traffic accidents (3 cases, fall from height (5 cases and hit by heavy object (2 cases. All injuries were closed without cerebral trauma or other complicated injuries. The time interval between injury and operation was 6e10 days (average 6.6 days. Postoperatively, the foot function was assessed using Visual Analogue Scales (VAS and American Orthopaedic Foot and Ankle Society (AOFAS Scales. Healing time and complications were observed. Results: All patients were followed up for 18e24 months (average 20 months. Anatomic reduction was achieved in all patients on images. There was statistical significance between preoperative score (7.89 ± 0.34 and score at postoperative 8 weeks (0.67 ± 0.13. According to the AOFAS score, 5 cases were defined as excellent, 3 cases as good and 2 cases as fair. During follow-up, there was no wound infection or complications except for osteoarthritis in 2 cases. Healing time ranged from 3 to 6 months with an average of 3.6 months. Conclusion: Anatomical reduction of Lisfranc injury can be achieved by open reduction and internal fixation with the miniplate and hollow screw. Normal structure of Lisfranc joint is regained to a great extent; injured ligaments were also repaired. Therefore, this method offers excellent curative effect and can avoid postoperative complications and improve the patients' quality of life.

  9. Efficacy of open reduction and internal fixation with a miniplate and hollow screw in the treatment of Lisfranc injury

    Institute of Scientific and Technical Information of China (English)

    Baoliang Li; Wenbo Zhao; Lei Liu; Fuguo Huang; Guanglin Wang; Yue Fang

    2015-01-01

    Purpose:To investigate efficacy of open reduction and internal fixation with the miniplate and hollow screw in the treatment of Lisfranc injury.Methods:Ten cases of Lisfranc injury treated by open reduction,miniplate and hollow screw in our hospital were retrospectively analyzed.There were 6 males and 4 females with age ranging from 25 to 45 years (mean 32 years).Among them,one case was classified as Type A,six Type B and three Type C.Injury mechanism included road traffic accidents (3 cases),fall from height (5 cases) and hit by heavy object (2 cases).All injuries were closed without cerebral trauma or other complicated injuries.The time interval between injury and operation was 6-10 days (average 6.6 days).Postoperatively,the foot function was assessed using Visual Analogue Scales (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) Scales.Healing time and complications were observed.Results:All patients were followed up for 18-24 months (average 20 months).Anatomic reduction was achieved in all patients on images.There was statistical significance between preoperative score (7.89 ± 0.34) and score at postoperative 8 weeks (0.67 ± 0.13).According to the AOFAS score,5 cases were defined as excellent,3 cases as good and 2 cases as fair.During follow-up,there was no wound infection or complications except for osteoarthritis in 2 cases.Healing time ranged from 3 to 6 months with an average of 3.6 months.Conclusion:Anatomical reduction of Lisfranc injury can be achieved by open reduction and internal fixation with the miniplate and hollow screw.Normal structure of Lisfranc joint is regained to a great extent;injured ligaments were also repaired.Therefore,this method offers excellent curative effect and can avoid postoperative complications and improve the patients' quality of life.

  10. Graft osteolysis and recurrent instability after the Latarjet procedure performed with bioabsorbable screw fixation.

    Science.gov (United States)

    Balestro, Jean-Christian; Young, Allan; Maccioni, Cristobal; Walch, Gilles

    2015-05-01

    The Latarjet procedure is a reliable treatment of recurrent anterior shoulder instability. The coracoid process is usually fixed with metallic screws; however, these can lead to irritation and the necessity for hardware removal and also can produce artifacts on imaging studies. The use of resorbable screws could avoid these complications. The purpose of this study was to assess the clinical results of the Latarjet procedure performed with bioabsorbable screws in addition to healing of the graft and resorption of the screws. In 2009, we performed a prospective study (case series, IV) of 11 patients (12 shoulders) who underwent a Latarjet procedure fixed with resorbable screws. Each patient was observed clinically and had a computed tomography scan at 3 months and 2 years of follow-up. Every graft healed at 3-month follow-up. At 2-year follow-up, 4 patients had at least one instability episode, and one underwent a revision surgery. Three of these 4 patients were unhappy or disappointed. The Walch-Duplay score was excellent or good for 7 shoulders and medium or poor for 5. Screw resorption appeared complete in every case. No drill hole enlargement was observed. Every drill hole was partially filled with bone. Of 12 shoulders, 8 (66.67%) were associated with a severe osteolysis and an almost complete disappearance of the graft. Coracoid graft osteolysis, previously reported after the Latarjet procedure, appears to be exacerbated with a risk of complete disappearance of the graft when the procedure is performed with the bioabsorbable screws used in this study. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  11. Computer navigated percutaneous screw fixation for traumatic pubic symphysis diastasis of unstable pelvic ring injuries

    Institute of Scientific and Technical Information of China (English)

    MU Wei-dong; WANG Hong; ZHOU Dong-sheng; YU Ling-zhi; JIA Tang-hong; LI Lian-xin

    2009-01-01

    Displaced and unstable pelvic ring injuries have been treated mainly by open reduction and internal fixation. The goal of treatment relies on restoration of pelvic anatomy with stable internal fixation, allowing early mobilization of the patient.1,2 The symphysis pubis dislocation (>25 mm) is consistent indication for anterior internal fixation.3 In most situations, the fixation of the displaced symphysis pubis requires extensive exposure, which may lead to complications including blood loss, neural or vascular injury, postoperative infections, wound healing problems and heterotopic bone formation.

  12. Novel fixation method of a periprosthetic fracture of the acetabulum using burr holes through the retained cup for locking screw fixation.

    Science.gov (United States)

    Browne, James A; Weiss, David B

    2015-03-01

    The incidence of periprosthetic fractures of the acetabulum associated with a total hip arthroplasty is relatively low but may be increasing. Treatment options depend upon the stability of the prosthesis. In this case, we report an unusual fracture pattern where a large portion of posterior column remained osseointegrated to a displaced uncemented acetabular component and removal of the cup would have resulted in massive structural bone loss and potential pelvic discontinuity. A metal cutting burr was used to create additional screw holes in the cup to allow us to retain the original implant and also obtain fixation of the fracture. The patient had a good outcome at one year with a healed fracture, stable implant, and excellent function. To our knowledge, this technique has not been previously described and offers surgeons an approach to fix these challenging fractures.

  13. Malposition and revision rates of different imaging modalities for percutaneous iliosacral screw fixation following pelvic fractures

    DEFF Research Database (Denmark)

    Zwingmann, Jörn; Hauschild, Oliver; Bode, Gerrit;

    2013-01-01

    INTRODUCTION: Percutaneous iliosacral screw placement following pelvic trauma is associated with high rates of revisions, screw malpositioning, the risk of neurological damage and inefficient stability. The correct entry point and the small target corridor may be difficult to visualize using only...... an image intensifier. Therefore, 2D and 3D image-based navigation and reconstruction techniques could be helpful tools. The aim of this systematic review and meta-analysis was to evaluate the best available evidence regarding the rate of malpositioning and revisions using different techniques for screw...... implantation, i.e., conventional, 2D and 3D image-based navigation and reconstruction techniques, CT navigation. METHODS: A systematic review and meta-analysis were performed using the data available on Ovid Medline. 430 studies published between 1/1948 and 2/2011 were identified by two independent...

  14. Atlantoaxial arthrodesis using C1-C2 transarticular screw fixation in a case of Morquio syndrome.

    Science.gov (United States)

    Kulkarni, Arvind G; Shah, Siddharth M

    2011-09-01

    Prophylactic or therapeutic arthrodesis is recommended for atlantoaxial instability in Morquio syndrome. Occipitocervical fusion, the common approach for upper cervical fusion in Morquio syndrome sacrifices the movements at the occipitoatlantal joints. The use of C1-C2 transarticular screws for achieving C1-C2 arthrodesis, without compromising mobility at the occipitoatlantal joint in Morquio syndrome has not been reported. We report a case of Morquio syndrome with atlantoaxial instability and odontoid hypoplasia, where we successfully achieved C1-C2 arthrodesis using transarticular screws and bone graft. The advantages of this method over other methods of atlantoaxial arthrodesis in Morquio syndrome have also been discussed.

  15. Atlantoaxial arthrodesis using C1-C2 transarticular screw fixation in a case of Morquio syndrome

    Directory of Open Access Journals (Sweden)

    Arvind G Kulkarni

    2011-01-01

    Full Text Available Prophylactic or therapeutic arthrodesis is recommended for atlantoaxial instability in Morquio syndrome. Occipitocervical fusion, the common approach for upper cervical fusion in Morquio syndrome sacrifices the movements at the occipitoatlantal joints. The use of C1-C2 transarticular screws for achieving C1-C2 arthrodesis, without compromising mobility at the occipitoatlantal joint in Morquio syndrome has not been reported. We report a case of Morquio syndrome with atlantoaxial instability and odontoid hypoplasia, where we successfully achieved C1-C2 arthrodesis using transarticular screws and bone graft. The advantages of this method over other methods of atlantoaxial arthrodesis in Morquio syndrome have also been discussed.

  16. Safety screw fixation technique in a case of coracoid base fracture with acromioclavicular dislocation and coracoid base cross-sectional size data from a computed axial tomography study.

    Science.gov (United States)

    Kawasaki, Yoshiteru; Hirano, Tetsuya; Miyatake, Katsutoshi; Fujii, Koji; Takeda, Yoshitsugu

    2014-07-01

    Coracoid base fracture accompanied by acromioclavicular joint dislocation with intact coracoclavicular ligaments is a rare injury. Generally, an open reduction with screw fixation is the first treatment choice, as it protects the important structures around the coracoid process. This report presents a new technique of screw fixation for coracoid base fracture and provides anatomic information on cross-sectional size of the coracoid base obtained by computed tomography (CT). An axial image of the coracoid base was visualized over the neck of the scapula, and a guidewire was inserted into this circle under fluoroscopic guidance. The wire was inserted easily into the neck of scapula across the coracoid base fracture with imaging in only 1 plane. In addition, 25 measurements of the coracoid base were made in 25 subjects on axial CT images. Average length of the long and short axes at the thinnest part of the coracoid base was 13.9 ± 2.0 mm (range 10.6-17.0) and 10.5 ± 2.2 mm (6.6-15.1), respectively. This new screw fixation technique and measurement data on the coracoid base may be beneficial for safety screw fixation of coracoid base fracture.

  17. Iatrogenic Injury of Profunda Femoris Artery Branches after Intertrochanteric Hip Screw Fixation for Intertrochanteric Femoral Fracture: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Nikolaos Patelis

    2014-01-01

    Full Text Available A case of arterial rupture of the profunda femoris arterial branches, following dynamic hip screw (DHS fixation for an intertrochanteric femoral fracture, is presented. Bleeding is controlled by coil embolization, but, later on, the patient underwent orthopedic material removal due to an infection of a large femoral hematoma.

  18. Evaluation the treatment outcomes of intracapsular femoral neck fractures with closed or open reduction and internal fixation by screw in 18-50-year-old patients in Isfahan from Nov 2010 to Nov 2011

    Directory of Open Access Journals (Sweden)

    Mohammad Javdan

    2013-01-01

    Conclusion: This study showed that femoral neck fracture is associated with several complications, especially if open reduction was necessary. So, the surgical method and necessary equipments such as radiolucent bed, C-ARM machine, and implant cannulated screw set should be considered.

  19. Clinical study on minimally invasive transforaminal lumbar interbody fusion combined with percutaneous pedicle screw fixation for degenerative lumbar scoliosis

    Directory of Open Access Journals (Sweden)

    Hao WU

    2016-04-01

    Full Text Available Objective To discuss the operative essentials and therapeutic effects of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF combined with percutaneous pedicle screw fixation for degenerative lumbar scoliosis (DLS.  Methods A total of 17 DLS patients without prior spinal diseases were treated by MIS-TLIF and percutaneous pedicle screw fixation from January 2013 to September 2015 in Xuanwu Hospital, Capital Medical University. The operation time, intraoperative blood loss, hospital stay, and postoperative complication were recorded in each patient. Visual Analogue Scale (VAS and Oswestry Disability Index (ODI were used to evaluate postoperative improvement of low back and leg pain, and clinical effects were assessed according to Medical Outcome Study 36-Item Short-Form Health Survey (SF-36. Coronal Cobb angle, sagittal lordosis angle and spinal deviation distances on coronal and sagittal plane were measured before operation, one week, 3 months after operation and in the last follow-up in spinal full-length X-ray examination. Fusion rate was calculated according to X-ray or CT scan, and the degree of decompression was evaluated by MRI.  Results Decompression and fusion levels ranged from T12-S1 vertebrae, and interbody fusion was performed in 17 patients and 56 levels were fused. Average operation time was 200 min (180-300 min, intraoperative blood loss was 320 ml (200-1000 ml and hospital stay was 8.21 d (5-12 d. All patients were followed-up for 12.13 months (5-24 months. Compared with preoperation, VAS (P = 0.000, for all and ODI scores (P = 0.000, for all decreased significantly, SF-36 score increased (P = 0.000, for all, coronal Cobb angle (P = 0.000, for all, sagittal lordosis angle (P = 0.000, for all, coronal and sagittal deviation (P = 0.000, for all decreased significantly one week and 3 months after operation and in the last follow-up. The improvement rate of ODI was (86.51 ± 6.02%, fusion rate of vertebral bodies

  20. 单侧腰椎弓根螺钉及经椎板关节突螺钉固定与双侧固定的比较*☆%Clinical outcomes of unilateral lumbar pedicle screw combined with translamina facet screw fixation versus bilateral fixation

    Institute of Scientific and Technical Information of China (English)

    薛剑; 靳安民; 孙小平; 王延斌; 谢伟勇

    2013-01-01

    BACKGROUND: The translaminar facet joint screw fixation and interbody fusion in the treatment of spinal disorders is a unique fixation method which can be used for degenerative lumbar spinal fusion. OBJECTIVE: To observe the clinical effect of the minimal y invasive transforaminal lumbar interbody fusion combined with unilateral lumbar pedicle screw and translamina facet screw fixation versus conventional posterior lumbar interbody fusion combined with bilateral pedicle screw fixation for the treatment of low back pain. METHODS: Forty-nine patients had lumbar disc herniation with lumbar spinal mild instability were selected from Wu Jing Zong Dui Hospital of Guangdong Province between June 2010 and June 2012. Al the patients were treated with posterior decompression and interbody fusion and internal fixation. Among the 49 patients, 24 patients were treated with minimal y invasive transforaminal lumbar interbody fusion combined with unilateral lumbar pedicle screw and translamina facet screw fixation, and 25 patients were treated with conventional posterior lumbar interbody fusion combined with bilateral pedicle screws fixation. The clinical effects of the two methods above were compared. RESULTS AND CONCLUSION: There were no significant differences of vertebral fusion rate, Japanese Orthopedic Association score and visual analogue scale score between two groups (P > 0.05). These two approaches had similar clinical outcomes for single-level lumbar degenerative disorders with no instability. These two methods could effectively improve intervertebral fusion rate, make the smal joint stability, relieve clinical symptoms and make outpatient fol ow-up satisfaction. In addition the incision length, operative time, intraoperative blood loss, postoperative incision drainage of minimal y invasive transforaminal lumbar interbody fusion combined with unilateral lumbar pedicle screw and translamina facet screw fixation technology were significantly reduced (P 0.05)。可见对

  1. A Biomechanical Study Comparing Helical Blade with Screw Design for Sliding Hip Fixations of Unstable Intertrochanteric Fractures

    Directory of Open Access Journals (Sweden)

    Qiang Luo

    2013-01-01

    Full Text Available Dynamic hip screw (DHS is a well-established conventional implant for treating intertrochanteric fracture. However, revision surgery sometimes still occurs due to the cutting out of implants. A helical blade instead of threaded screw (DHS blade was designed to improve the fixation power of the osteoporotic intertrochanteric fracture. In this study, the biomechanical properties of DHS blade compared to the conventional DHS were evaluated using an unstable AO/OTA 31-A2 intertrochanteric fracture model. Fifty synthetic proximal femoral bone models with such configuration were fixed with DHS and DHS blade in five different positions: centre-centre (CC, superior-centre (SC, inferior-center (IC, centre-anterior (CA, and centre-posterior (CP. All models had undergone mechanical compression test, and the vertical and rotational displacements were recorded. The results showed that DHS blade had less vertical or rotational displacement than the conventional DHS in CC, CA, and IC positions. The greatest vertical and rotational displacements were found at CP position in both groups. Overall speaking, DHS blade was superior in resisting vertical or rotational displacement in comparison to conventional DHS, and the centre-posterior position had the poorest performance in both groups.

  2. Comparison of the effect of posterior lumbar interbody fusion with pedicle screw fixation and interspinous fixation on the stiffness of adjacent segments

    Institute of Scientific and Technical Information of China (English)

    LI Chun-de; SUN Hao-lin; LU Hong-zhang

    2013-01-01

    stiffness of the cephalic adjacent segment L3/4 after fixation in the Wallis group was significantly higher than that of the PLIF group (P <0.05).Cadaver experiments showed that the stiffness of the cephalic adjacent segment in the Wallis group was significantly higher than that of the PLIF group after L4/5 segment fixation (P <0.05); the stiffness of the L5/S1 segment showed no significant difference between PLIF surgery and Wallis implantation (P >0.05).Conclusions After interspinous (Wallis) fixation,the stiffness of the cephalic adjacent segment increased.After PLIF with pedicle screw fixation,the stiffness of the cephalic adjacent segment decreased.An interspinous fixation system (Wallis) has a protective effect for cephalic adjacent segments for the immediate post-operative state.

  3. Unilateral versus bilateral pedicle screw fixation of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF): a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Wang, Liang; Wang, Yipeng; Li, Zhengyao; Yu, Bin; Li, Ye

    2014-11-06

    A few studies focused on unilateral or bilateral pedicle screw (PS) fixation of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) to treat lumbar degenerative diseases have been published. There is still debate over whether one method is superior to another. A systematic review and meta-analysis of randomized controlled trials (RCT) was performed to compare the efficacy of the two methods. We searched the established electronic literature databases of MEDLINE, EMBASE, Web of Science and the Cochrane Central Register of Controlled Trials databases for RCTs comparing the unilateral with bilateral pedicle screw fixation of MIS-TLIF. Pooled mean differences (MD) and odds ratios (OR) and with 95% CIs were calculated for the outcomes. Three RCTs were identified and analyzed. The results showed that there is no significant difference between the two methods in terms of postoperative VAS-BP score (WMD = -0.09; 95% CI: -0.69 to 0.51; P =0.78), ODI (WMD, -0.09; 95% CI -5.85 to 5.67; P =0.98), fusion rate (OR = 2.99; 95% CI 0.55 to 16.38; P = 0.21) or complication rate (OR = 1.61, 95% CI: 0.49 to 5.37; P =0.43). Unilateral pedicle screw fixation was associated with less blood loss (WMD = -87.83; 95% CI: -160.70 to -14.96; P =0.02). The existing evidence indicate that no superiority exists between the two fixation methods of MIS-TLIF in terms of functional outcome, fusion rate and complication rate, in spite of that unilateral pedicle screw fixation can achieve less blood loss than bilateral fixation.

  4. Feasibility study of patient-specific surgical templates for the fixation of pedicle screws.

    Science.gov (United States)

    Salako, F; Aubin, C-E; Fortin, C; Labelle, H

    2002-01-01

    Surgery for scoliosis, as well as other posterior spinal surgeries, frequently uses pedicle screws to fix an instrumentation on the spine. Misplacement of a screw can lead to intra- and post-operative complications. The objective of this study is to design patient-specific surgical templates to guide the drilling operation. From the CT-scan of a vertebra, the optimal drilling direction and limit angles are computed from an inverse projection of the pedicle limits. The first template design uses a surface-to-surface registration method and was constructed in a CAD system by subtracting the vertebra from a rectangular prism and a cylinder with the optimal orientation. This template and the vertebra were built using rapid prototyping. The second design uses a point-to-surface registration method and has 6 adjustable screws to adjust the orientation and length of the drilling support device. A mechanism was designed to hold it in place on the spinal process. A virtual prototype was build with CATIA software. During the operation, the surgeon places either template on patient's vertebra until a perfect match is obtained before drilling. The second design seems better than the first one because it can be reused on different vertebra and is less sensible to registration errors. The next step is to build the second design and make experimental and simulations tests to evaluate the benefits of this template during a scoliosis operation.

  5. Anatomy of the biceps tendon: implications for restoring physiological length-tension relation during biceps tenodesis with interference screw fixation.

    Science.gov (United States)

    Denard, Patrick J; Dai, Xuesong; Hanypsiak, Brian T; Burkhart, Stephen S

    2012-10-01

    The purpose of this study was to characterize the normal length and diameter of the long head of the biceps tendon (BT) to provide guidelines for interference screw tenodesis. Twenty-one cadaveric shoulders were dissected. The BT length was measured from its origin to the humeral head articular margin (AM), lower subscapularis, upper pectoralis major, musculotendinous junction of the biceps (MTJ), and lower pectoralis major (LPM). Tendon diameter was measured at levels corresponding to tenodesis: (1) at the AM, (2) suprapectorally, and (3) subpectorally. The mean tendon length was 24.9 mm from the origin to the AM, 56.1 mm to the lower subscapularis, 73.8 mm to the upper pectoralis major, 98.5 mm to the MTJ, and 118.4 mm to the LPM. The mean tendon diameter was 6.6 mm for tenodesis at the AM, 5.1 mm for suprapectoral tenodesis, and 5.3 mm for subpectoral tenodesis. During biceps tenodesis with interference screw fixation, restoring the normal length-tension relation of the BT depends on the site of tenodesis and the depth of the bone socket. At the AM, a 25-mm bone socket on average will maintain the length-tension relation. For tenodesis more distally, the length of tendon resection varies with bone socket length. Because the MTJ is above the LPM, subpectoral tenodesis should be performed proximal to the LPM. This study provides guidelines for restoring the normal length-tension relation during biceps tenodesis with interference screw fixation. The simplest way to restore this relation is with tenodesis adjacent to the humeral head AM and a bone socket of 25 mm in depth. For tenodesis at more distal locations, both the length of the BT and the depth of the bone socket must be considered. Information about the normal BT may be useful in preserving the physiological length-tension relation during biceps tenodesis. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  6. Stress analysis between“X”-shaped spine dynamic fixation and traditional pedicle screw fixation%“X”形弹性脊柱内固定与传统椎弓根内固定的应力分析

    Institute of Scientific and Technical Information of China (English)

    王宇; 梅继文; 穆尚强; 高峰; 黄锐

    2015-01-01

    背景:目前国内外许多学者研发了多种动态弹性脊柱内固定器,经过生物力学研究、动物实验及临床应用发现,尚无一种脊柱弹性内固定器得到临床上的普遍认可。  目的:比较自制“X”形弹性内固定器与传统椎弓根螺钉内固定的应力差异。  方法:根据成人脊柱影像学资料,分别建立“X”形弹性脊柱内固定器与传统椎弓根螺钉内固定系统三维有限元模型,比较两组模型在垂直压缩、屈、伸、侧屈、扭转时的力学差异。  结果与结论:两模型在垂直压缩状态应下的应力均小于屈、伸、侧屈及扭转状态下的应力;在垂直压缩、前屈、后伸、侧弯及旋转时,“X”形弹性脊柱内固定器的应力更多集中在“X”形连接棒上,而传统椎弓根螺钉内固定的应力更多集中在螺钉近棒段,且“X”形弹性脊柱内固定器螺钉所受应力明显小于传统椎弓根螺钉内固定(P<0.001)。表明“X”形弹性内固定器较传统椎弓根螺钉内固定系统更能分担螺钉应力,减少螺钉术后应力集中情况。%BACKGROUND:Many scholars have developed a variety of dynamic elastic spine fixator. After biomechanical research, animal experiments and clinical application found that no one elastic spine fixator was general y recognized clinical y. OBJECTIVE:To compare the stress difference between“X”-shaped spine dynamic fixation and traditional pedicle screw fixation. METHODS:Three-dimensional finite element models of“X”-shaped spine dynamic fixation and traditional pedicle screw fixation were established according to adult spine imaging data. Mechanical differences in vertical compression, flexion, extension, lateral bending and rotation were compared between the two groups. RESULTS AND CONCLUSION:The stress at vertical compression was lower than that at flexion, extension, lateral bending and rotation in both groups. The stress at

  7. Application of C2 Transpedicular Screw Fixation Combined with C3 Lateral Mass Screw Plate Fixation in Posterior Treatment of Old Hangman's Fracture%经后路C2椎弓根C3侧块短节段固定治疗陈旧性枢椎椎弓骨折

    Institute of Scientific and Technical Information of China (English)

    曹成刚; 梁益建; 何睿; 石化洋; 曾勇; 陈伶

    2012-01-01

    Objective To approach the therapeutic effect of C2 transpedicular screw fixation combined with C3 lateral mass screw plate fixation on old Hangman' s fracture. Methods Nine patients with old Hangman' s fracture were treated with C2 transpedicular screw fixation combined with C3 lateral mass screw plate fixation as well as bone gr'aft fusion in our hospital from 2002. Results A mean follow-up time was 8 months(6 to 15 months). All cases got bony union. No infection, neurological deficits, or other complications were found. Conclusion It can be an effective and simple way to treat old Hangman' s fracture with C2 transpedicular screw fixation combined with C3 lateral mass screw plate fixation, which can ultimately preserve the cervical function.%目的 探讨经后路C2椎弓根C3侧块短节段内固定治疗陈旧性枢椎椎弓骨折(Hangman骨折)的疗效.方法 2002年以来9例陈旧性Hangman骨折采用经后路C2椎弓根C3侧块短节段固定,植骨融合治疗.结果 所有患者随访6~15个月,平均8个月.所有患者均骨性愈合,未出现感染、神经损伤等并发症.结论 经后路C2椎弓根C3侧块短节段内固定治疗陈旧性Hangman骨折是一种安全有效并能最大程度保留患者颈部功能的方法.

  8. Comparisons of front plate, percutaneous sacroiliac screws, and sacroiliac anterior papilionaceous plate in fixation of unstable pelvic fractures.

    Science.gov (United States)

    Gu, Ronghe; Huang, Weiguo; Yang, Lijing; Liu, Huijiang; Xie, Kegong; Huang, Zonggui

    2017-09-01

    This observational study was aimed at comparing the clinical efficacy of sacroiliac anterior plate fixation (SAPF), sacroiliac anterior papilionaceous plate (SAPP), and percutaneous sacroiliac screw internal fixation (PSCIF) introduced for patients with unstable pelvic fracture. Seventy-eight patients with unstable pelvic fracture (Tile type B or C) were recruited. Twenty-six patients underwent SAPF, 26 underwent SAPP, and 26 underwent PSCIF. Matta scores were calculated to evaluate the reduction of pelvic fractures, and Majeed scores were applied for the assessment of functional recoveries after surgery. Other perioperative clinical indicators were also recorded, including operation time, bleeding status, length of incision, ambulation time, fracture healing time, and incision infection. Total operation time of PSCIF was remarkably shorter than that of SAPF and SAPP (P SAPP group was almost 26∼29 times as high as that of PSCIF group (P SAPP resulted in significant blood loss compared with SAPF (P SAPP and PSCIF (P SAPP groups than in the PSCIF group (P SAPP was associated with fewer complications than SAPF, and complications were barely observed in the PSCIF group. PSCIF may be more appropriate for patients with unstable pelvic fractures in comparison with SAPP and SAPF. Besides, SAPP is likely to be more efficacious than SAPF especially for Tile C patients.

  9. 空心加压螺钉与动力髋螺钉螺旋刀片治疗股骨颈骨折的临床疗效及生物力学分析%Cannulated compression screw versus dynamic hip screw-blade in the treatment of femoral neck fractures

    Institute of Scientific and Technical Information of China (English)

    骆东; 孙大辉; 姚霁航; 杨凯; 张晓猛; 鞠维娜; 祁宝昌

    2016-01-01

    Objective To compare the curative effect and biomechanical performance of cannulated compression screw (CCS) and dynamic hip screw-blade (DHS-B) in the treatment of patients with femoral neck fracture.Methods Between February 2010 and February 2014,102 patients with femoral neck fracture were treated with CCS or DHS-B at our department.They were 54 males and 48 females,aged from 15 to 86 years.There were 30 subcapital fractures,51 transcervical ones and 21 base ones.CCS was used in 60 patients and DHS-B in 42.In-hospital data were collected retrospectively to compare the curative effects in 2 groups.Furthermore,femoral neck fracture models were established using 12 adult cadaveric femoral specimens.The 12 models were randomized into 2 equal groups (n =6).Group A was subjected to fixation by 3 CCSs and group B to fixation by DHS-B.The 2 groups were compared in terms of axial loading test,rotation test and destructive axial loading test.Results The operation time (59.4 ± 20.2 min),incision size (4.1 ±0.6 cm) and intraoperative blood loss (25.9 ±9.9 mL) in the CCS group were significantly less than those in the DHS-B group (88.6±22.9 min,12.1 ±1.2cmand 156.7±107.1 mL) (P <0.05).The Harris hip score for the DHS-B group (91.9±9.8) was significantly higher than that for the CCS group (87.2 ± 9.2) (P < 0.05).There were no significant differences between the 2 groups in hospital stay,partial weight-bearing time,or postoperative complications (P > 0.05).At 500 N vertical loading,the stress values at both medial and lateral sides of the femur in group A were significantly smaller than those in group B (P < 0.05).There were no significant differences between groups A and B in the average sinking displacement of femoral head or the torque at a torsion angle of 6° (P > 0.05).The maximum load in group A (2,135 ±120 N) was significantly smaller than that in group B (2,986 ± 98 N) (P < 0.05).Conclusion In treatment of femoral neck fracture,DHS-B fixation is

  10. Free Hand Insertion Technique of S2 Sacral Alar-Iliac Screws for Spino-Pelvic Fixation: Technical Note, Acadaveric Study

    Science.gov (United States)

    Park, Jong-Hwa; Kim, Ki-Jeong; Jahng, Tae-Ahn

    2015-01-01

    A rigid spino-pelvic fixation to anchor long constructs is crucial to maintain the stability of long fusion in spinal deformity surgery. Besides obtaining immediate stability and proper biomechanical strength of constructs, the S2 alar-iliac (S2AI) screws have some more advantages. Four Korean fresh-frozen human cadavers were procured. Free hand S2AI screw placement is performed using anatomic landmarks. The starting point of the S2AI screw is located at the midpoint between the S1 and S2 foramen and 2 mm medial to the lateral sacral crest. Gearshift was advanced from the desired starting point toward the sacro-iliac joint directing approximately 20° angulation caudally in sagittal plane and 30° angulation horizontally in the coronal plane connecting the posterior superior iliac spine (PSIS). We made a S2AI screw trajectory through the cancellous channel using the gearshift. We measured caudal angle in the sagittal plane and horizontal angle in the coronal plane. A total of eight S2AI screws were inserted in four cadavers. All screws inserted into the iliac crest were evaluated by C-arm and naked eye examination by two spine surgeons. Among 8 S2AI screws, all screws were accurately placed (100%). The average caudal angle in the sagittal plane was 17.3±5.4°. The average horizontal angle in the coronal plane connecting the PSIS was 32.0±1.8°. The placement of S2AI screws using the free hand technique without any radiographic guidance appears to an acceptable method of insertion without more radiation or time consuming. PMID:26819698

  11. Analysis of Orbital Volume Measurements Following Reduction and Internal Fixation Using Absorbable Mesh Plates and Screws for Patients With Orbital Floor Blowout Fractures.

    Science.gov (United States)

    Hwang, Won Joo; Lee, Do Heon; Choi, Won; Hwang, Jae Ha; Kim, Kwang Seog; Lee, Sam Yong

    2017-08-22

    Hinge-shaped fractures are common type of orbital floor blowout fractures, for which reduction and internal fixation is ideal. Nonetheless, orbital floor reconstruction using alloplastic materials without reducing the number of bone fragments is the most frequently used procedure. Therefore, this study analyzed and compared the outcomes between open reduction and internal fixation using absorbable mesh plates and screws, and orbital floor reconstruction, by measuring the orbital volume before and after surgery. Among patients with orbital floor blowout fractures, this study was conducted on 28 patients who underwent open reduction and internal fixation, and 27 patients who underwent orbital floor reconstruction from December 2008 to September 2015. The mechanism of injury, ophthalmic symptoms before and after surgery, and the degree of enophthalmos were examined; subsequently, the volumes of the affected and unaffected sides were measured before and after surgery based on computed tomography images. This study compared the degree of recovery in the correction rate of the orbital volume, ophthalmic symptoms, and enophthalmos between the 2 groups. The patients who underwent open reduction and internal fixation, and the patients who underwent orbital floor reconstruction showed average correction rates of 100.36% and 105.24%, respectively. Open reduction and internal fixation showed statistically, significantly superior treatment outcomes compared with orbital floor reconstruction. The ophthalmic symptoms and incidence of enophthalmos completely resolved in both groups. For orbital floor blowout fractures, open reduction and internal fixation using absorbable mesh plates and screws was a feasible alternative to orbital floor reconstruction.

  12. A novel computed method to reconstruct the bilateral digital interarticular channel of atlas and its use on the anterior upper cervical screw fixation.

    Science.gov (United States)

    Wu, Ai-Min; Wang, Wenhai; Xu, Hui; Lin, Zhong-Ke; Yang, Xin-Dong; Wang, Xiang-Yang; Xu, Hua-Zi; Chi, Yong-Long

    2016-01-01

    Purpose. To investigate a novel computed method to reconstruct the bilateral digital interarticular channel of atlas and its potential use on the anterior upper cervical screw fixation. Methods. We have used the reverse engineering software (image-processing software and computer-aided design software) to create the approximate and optimal digital interarticular channel of atlas for 60 participants. Angles of channels, diameters of inscribed circles, long and short axes of ellipses were measured and recorded, and gender-specific analysis was also performed. Results. The channels provided sufficient space for one or two screws, and the parameters of channels are described. While the channels of females were smaller than that of males, no significant difference of angles between males and females were observed. Conclusion. Our study demonstrates the radiological features of approximate digital interarticular channels, optimal digital interarticular channels of atlas, and provides the reference trajectory of anterior transarticular screws and anterior occiput-to-axis screws. Additionally, we provide a protocol that can help make a pre-operative plan for accurate placement of anterior transarticular screws and anterior occiput-to-axis screws.

  13. Computed tomography-based morphometric analysis of cervical pedicles in Indian population: A pilot study to assess feasibility of transpedicular screw fixation

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    A R Patwardhan

    2012-01-01

    Full Text Available Background: Cervical transpedicular screw fixation is safe and is probably going to be the gold standard for cervical spine fixation. However, cervical transpedicular screw use in the Asian population can be limited as the transverse diameter in this group of patients may not be adequate to accommodate the 3.5-mm pedicular screw thus injuring the vital structures located in the close proximity of the pedicles. Thus lateral mass fixation remains the mainstay of treatment. The present study evaluated the transverse cervical pedicle diameter of C2-C7 vertebrae in a pilot study in 27 Indian subjects using computed tomography (CT imaging and evaluated the feasibility of transpedicular screw fixation in them. Aims: To evaluate the feasibility of transpedicular screw fixation in the Indian population. Settings and Design: The cervical pedicle diameter size differs between the Asian and non-Asian population. The authors studied the transverse pedicle diameter of the C2-C7 of the cervical spine in the Indian population using CT measurements. This cross-sectional study was carried out at a tertiary care centre for a period of four months from October 2010 to December 2010. Material and Methods: Measurements of cervical pedicles in the subjects were performed on the CT workstation from the CT images taken at 2.5-mm interval. The transverse pedicle diameter was defined as the outermost diameter of the pedicle, taken perpendicular to the axis of the pedicle at the narrowest point and measured in millimeters±0.1 mm. Statistical Analysis: Descriptive statistics was used to represent percentage of transverse diameter of cervical pedicles less than 5 mm in male and female subjects at C2-C7 levels. Since there is no previous study done in India, we initiated the study with sample size of 27 as a pilot study. The statistical analysis was performed using SPSS software. Results: The mean transverse diameters of the cervical pedicles of C2, C3, C4, C5, C6 and C7 in

  14. Talar neck fractures treated with closed reduction and percutaneous screw fixation:a case series.

    Science.gov (United States)

    Fernandez, Michael L; Wade, Allison M; Dabbah, Michael; Juliano, Paul J

    2011-02-01

    Talus fractures are relatively rare injuries, accounting for approximately 3% of all foot fractures. Fractures of the talar neck account for almost 50% of all talus fractures. Diagnosis and treatment of these fractures play an important role in patients' outcomes. Treatment of talar neck fractures has slowly evolved from closed treatment to open reduction and internal fixation. Treatment of type I and type II talar neck fractures is debated in the orthopedic community. Choosing which treatment to perform depends on injury severity, associated injuries, and surgeon experience and preference. In this article, we report on our retrospective review of all talar neck fractures treated with closed reduction and percutaneous fixation between 1996 and 2001 at the Pennsylvania State University Milton S. Hershey Medical Center.

  15. Biomechanical comparison of dynamic condylar screw and locking compression plate fixation in unstable distal femoral fractures: An in vitro study

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    Ashutosh Kumar Singh

    2013-01-01

    Full Text Available Background: Distal femur fractures are difficult to manage and the selection of implant for internal fixation remains controversial. The objective of this study is to establish the relative strength of fixation of a distal femoral locking plate (DFLP compared with the dynamic condylar screw (DCS in the distal femur fractures. Materials and Methods: Study was conducted on 16 freshly harvested cadaveric distal femoral specimens, eight implanted with DCS and other eight with DFLP. The construct was made unstable by removing a standard sized medial wedge of 1 cm base (gap-osteotomy beginning 6 cm proximal to the lateral joint line in distal metaphyseal region with the loss of medial buttress. Fatigue test was conducted under load control mode at the frequency of I Hz. Specimens were subjected to cyclic loading of 2 kN, under observation for 50,000 cycles or until failure/cutout, which ever occurred earlier. Results: In DFLP group, there was no implant failure and the average number of cycles sustained was 50,000. Six out of eight specimens completed 50,000 cycles and two failed in DCS group. The average number of cycles sustained by DCS was 46150. Though the bone quality as assessed by dual energy X-ray absorptiometry DEXA was comparable in both DFLP and DCS group ( P = 0.06, none failed in DFLP group and subsidence was 1.02 ± 0.34 mm (range: 0.60-1.32 mm, which was significantly 43% lower ( P = 0.006 than subsidence in DCS group (1.82 ± 0.58; range: 1.20-3.08 mm. The average stiffness of DCS group was 52.8 ± 4.2 N/mm, which was significantly lower than average stiffness of locked condylar plate group (71.2 ± 5.1 N/mm ( P = 0.02. Conclusions: DFLP fixation of the distal femur fractures resulted in stronger construct than the DCS fixation in both cyclic loading and ultimate strength in biomechanical testing of a simulated A3 distal femur fracture.

  16. POST TRAUMATIC INSTABILITY OF SUB - AXIAL CERVICAL SPINE - REDUCTION AND INTERNAL FIXATION BY LATERAL MASS SCREWS : A LONG TERM FOLLOW - UP STUDY

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    Godagu

    2015-10-01

    Full Text Available AIM: We present here the clinical results of 24 patients who were operated for cervical instability following trauma by lateral mass fixation at our institution between July 2010 and Dec 2013 and to assess the stability of the construct at 2yr follow - up study. MATERIALS AND METHODS: Between July 2010 and Dec 2013 a total of 24 pts. Were operated by lateral mass fixation for cervical spine instability following trauma to subaxial cervical spine between C3 - C6. Presenting with posterior element injury like facet locking and subluxation injuries were included in the study. Al l these patients were evaluated postoperatively for neurologic improvement , complications and Results were analyzed. RESULTS: A total of 104 screws were placed in to the lateral masses during the study. There were 8(33.3% deaths in this series not related to the surgical procedure. There were no immediate complications related to the procedure. There was no evidence of neurovascular injury either during the procedure or immediately following the surgery. There was CSF leak in one case of badly traumatized cord injury during the procedure. Neurological improvement was seen in 13(81.2% out of surviving 16 cases of trauma at the end of 3m to the extent of self - ambulation and the rest three did not show any improvement and remained quadriplegic. CONCLUSION: In this study we report good long term stability achieved by the lateral mass fixation with rods and screws with least morbidity and the safety of the procedure compared to other methods of posterier elements fixations. Both Roy Camille and Magerl technique can be followed for screw placement, where in Magerl technique has slight advantage of avoiding the nerve root injury and a longer screw can be placed to achieve a good bony purchase. Over all it is very safe and efficacious procedure in the hands of an ex perienced surgeon

  17. Novel pedicle screw and plate system provides superior stability in unilateral fixation for minimally invasive transforaminal lumbar interbody fusion: an in vitro biomechanical study.

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    Jie Li

    Full Text Available This study aims to compare the biomechanical properties of the novel pedicle screw and plate system with the traditional rod system in asymmetrical posterior stabilization for minimally invasive transforaminal lumbar interbody fusion (MI-TLIF. We compared the immediate stabilizing effects of fusion segment and the strain distribution on the vertebral body.Seven fresh calf lumbar spines (L3-L6 were tested. Flexion/extension, lateral bending, and axial rotation were induced by pure moments of ± 5.0 Nm and the range of motion (ROM was recorded. Strain gauges were instrumented at L4 and L5 vertebral body to record the strain distribution under flexion and lateral bending (LB. After intact kinematic analysis, a right sided TLIF was performed at L4-L5. Then each specimen was tested for the following constructs: unilateral pedicle screw and rod (UR; unilateral pedicle screw and plate (UP; UR and transfacet pedicle screw (TFS; UP and TFS; UP and UR.All instrumented constructs significantly reduced ROM in all motion compared with the intact specimen, except the UR construct in axial rotation. Unilateral fixation (UR or UP reduced ROM less compared with the bilateral fixation (UP/UR+TFS, UP+UR. The plate system resulted in more reduction in ROM compared with the rod system, especially in axial rotation. UP construct provided more stability in axial rotation compared with UR construct. The strain distribution on the left and right side of L4 vertebral body was significantly different from UR and UR+TFS construct under flexion motion. The strain distribution on L4 vertebral body was significantly influenced by different fixation constructs.The novel plate could provide sufficient segmental stability in axial rotation. The UR construct exhibits weak stability and asymmetrical strain distribution in fusion segment, while the UP construct is a good alternative choice for unilateral posterior fixation of MI-TLIF.

  18. The Use of Posterior Short Segment Screw Fixation and Balloon Kyphoplasty in the Surgical Treatment of Traumatic Vertebral Fracture: A Case Report

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    Sevim Ondul

    2012-04-01

    Full Text Available Surgical treatments for the fracture of the spine are frequently used in clinical practice. Posterior spine stabilization with transpedicular screw fixation is one of the surgical treatment methods in the surgical treatment of spinal fractures. A 48-year old male patient was admitted to our hospital with a diagnosis of the L1 compression fracture resulting from traumatic injury. Posterior transpedicular screws were placed at one level above and one level below of the fractured vertebrate. Anterior column of the fractured vertebrate was strengthened with balloon kyphoplasty application. The system was completed with the placement of transverse rods. Fusion with allograft was performed. According to the ASIA neurological grading system, the patient was assessed as Grade E. 10 cm skin and fascia incision was done. Operation time of about 70 minutes and blood loss was less than 100 cc. The patient was mobilized on the first day of surgery and was discharged from the hospital on the third day after the surgery. Short segment transpedicular fixation on the one level above and one level below of the fractured vertebrate together with balloon kyphoplasty on the corpus of the fractured vertebrate may be used as a minimally invasive surgical treatment in such kind of injuries. The advantages are short duration of hospital stay, less blood loss, providing early mobilization, and a reliable method for fixation and stabilization. In this article, a case with traumatic fracture that fixed and stabilized with short segment transpedicular screw placement and balloon kyphoplasty application was presented.

  19. Successful fusion of remote type II odontoid fracture using anterior screw fixation of the odontoid and rhBMP-2: report of two cases.

    Science.gov (United States)

    Morgan, Jeremy P; Asfora, Wilson T

    2013-05-01

    Anterior screw fixation of the odontoid is contraindicated in remote type II fractures. The alternative surgical treatment consists of a posterior C1 to C2 or an occiput to C3 fusion, which is met with much resistance by patients as this option limits head motion, especially rotational movement. Furthermore, elderly patients may not be medically fit to undergo surgery of this magnitude. This report presents two remote type II odontoid fractures in elderly patients (67 and 73 years of age) who were successfully treated by means of anterior screw fixation of the odontoid along with an injection of recombinant human bone morphogenic protein (rhBMP-2) (Medtronic Inc.) into the fracture line with infiltration of the fibrous union tissue and adjacent anterior longitudinal ligament. To our knowledge, this is the first documented report of solid fusion of remote type II odontoid fracture treated with rhBMP-2 and anterior screw fixation. The authors believe that this technique may be a viable alternative for the treatment of failed odontoid fractures older than six months.

  20. Functional Recovery Following Pertrochanteric Hip Fractures Fixated with the Dynamic Hip Screw vs. the Percutaneous Compression Plate

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    Yocheved Laufer

    2005-01-01

    Full Text Available The Dynamic Hip Screw (DHS is currently the most frequently used implant for the treatment of pertrochanteric hip fractures. The Percutaneous Compression Plate (PCCP is a recently developed, alternative device that involves minimal invasive surgery. The objective of the present study was to compare functional recovery following these two surgical procedures. A total of 76 consecutive elderly subjects (mean age and standard deviation, 80.6 ± 5.5 following pertrochanteric hip fracture fixation were evaluated prospectively. Functional recovery was assessed 3 and 12 weeks and 2 years following surgery. Differences between groups 3 weeks postsurgery were found only in pain level during ambulation and in the weight-bearing capability of the operated extremity, which were both in favor of the PCCP. By 3 months, both groups had improved in all measures, but did not reach their preinjury level of independence. However, the PCCP group ambulated with fewer assistive devices and demonstrated better recovery of basic activities of daily living (BADL. While the majority of the subjects from both groups ambulated independently 2 years postsurgery, the PCCP group exhibited less pain during ambulation, was more independent in ADL, and required fewer assistive devices for ambulation. To summarize, the PCCP presents enhanced short- and long-term recovery of functional abilities in comparison to DHS. However, given the limited number of patients, further studies are necessary to substantiate these results.

  1. Percutaneous Pedicle Screw Fixation with Polymethylmethacrylate Augmentation for the Treatment of Thoracolumbar Intravertebral Pseudoarthrosis Associated with Kummell’s Osteonecrosis

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    Hyeun-Sung Kim

    2016-01-01

    Full Text Available Purpose. The purpose of our study is to evaluate the therapeutic efficacy of short-segment percutaneous pedicle screw fixation with polymethylmethacrylate (PMMA augmentation for the treatment of osteoporotic thoracolumbar compression fracture with osteonecrosis. Methods. Osteoporotic thoracolumbar compression fractures with avascular necrosis were treated by short-segment PPF with PMMA augmentation. Eighteen were followed up for more than 2 years. The kyphotic angle, compression ratio, visual analog scale (VAS score for back pain, and the Oswestry Disability Index (ODI were analyzed. In addition, radiologic and clinical parameters of PPF group were compared with percutaneous vertebroplasty (PVP group. Results. Vertebral height and kyphotic angle of the compressed vertebral bodies were significantly corrected after the operation (P<0.05. Further, restored vertebral height was maintained during the 2 or more years of postoperative follow-up. Compared to the PVP group the postoperative compression ratio and kyphotic angle were significantly lower in the PPF group (P<0.05. The postoperative ODI and VAS of the PVP group were significantly higher than the PPF (P<0.05. Conclusions. According to our results, short-segment PPF with PMMA augmentation may be an effective minimally invasive treatment for osteoporosis in cases of osteoporotic vertebral compression fractures with Kummell’s osteonecrosis.

  2. 空心钉结合带筋膜跗外侧血管蒂骰骨骨膜瓣移位治疗距骨颈骨折%Cannulated screws combined with transposition of cuboid periosteal flap pedicled with fascia and lateral tarsal artery in the treatment of talus neck fractures

    Institute of Scientific and Technical Information of China (English)

    周炎; 刘世清; 瞿新丛; 廖琦; 余铃; 黄涛

    2014-01-01

    目的 探讨空心钉结合带筋膜跗外侧血管蒂骰骨骨膜瓣移位治疗距骨颈骨折的手术方法及临床疗效. 方法 2008年3月至2011年6月,对收治的12例距骨颈骨折采用空心钉结合带筋膜跗外侧血管蒂骰骨骨膜瓣移位治疗.术后非负重功能位外固定12~14周,并根据X线片显示骨折愈合情况确定负重时间.末次随访时根据美国足与踝关节外科协会踝与后足功能评分系统评价术后功能. 结果 12例术后随访12 ~ 48个月,平均24个月.1例出现切口皮缘坏死,经换药处理后愈合.距骨颈骨折均获愈合,愈合时间为16~ 24周,平均20周.末次随访时AOFAS踝与后足功能评分为55~ 96分,平均82.5分,其中优4例,良5例,可3例.2例发生距下关节轻度创伤性关节炎,口服消炎镇痛药后疼痛缓解;1例发生距骨体缺血性坏死,X线片显示距骨体骨质硬化,但未塌陷,嘱患者减少负重并定期随访观察. 结论 应用空心钉结合带筋膜跗外侧血管蒂骰骨骨膜瓣移位治疗距骨颈骨折,能改善距骨体血供,降低距骨缺血性坏死的发生,是有效的治疗手段.%Objective To investigate the surgical techniques and clinical efficacy of cannulated screws combined with transposition of cuboid periosteal flap pedicled with fascia and lateral tarsal artery in the treatment of talus neck fractures.Methods From March 2008 to June 2011,12 cases with talus neck fractures were treated with cannulated screws combined with transposition of cuboid periosteal flap pedicled with fascia and lateral tarsal artery.External fixation in functional position for 12-14 weeks,and the load time was determined by X-ray fracture healing.Functional results were assessed according to AOFAS (American Orthopaedic Foot and Ankle Society) score at last follow-up.Results Twelve cases were followed up for an average of 24 months (12 to 48 months).One case of skin flap necrosis healed by dressing.All the fractures healed

  3. CT morphometric analysis to determine the anatomical basis for the use of transpedicular screws during reconstruction and fixations of anterior cervical vertebrae.

    Directory of Open Access Journals (Sweden)

    Chun Chen

    Full Text Available BACKGROUND: Accurate placement of pedicle screw during Anterior Transpedicular Screw fixation (ATPS in cervical spine depends on accurate anatomical knowledge of the vertebrae. However, little is known of the morphometric characteristics of cervical vertebrae in Chinese population. METHODS: Three-dimensional reconstructions of CT images were performed for 80 cases. The anatomic data and screw fixation parameters for ATPS fixation were measured using the Mimics software. FINDINGS: The overall mean OPW, OPH and PAL ranged from 5.81 to 7.49 mm, 7.77 to 8.69 mm, and 33.40 to 31.13 mm separately, and SPA was 93.54 to 109.36 degrees from C3 to C6, 104.99 degrees at C7, whereas, 49.00 to 32.26 degrees from C4 to C7, 46.79 degrees at C3 (TPA. Dl/rSIP had an increasing trend away from upper endplate with mean value from 1.87 to 5.83 mm. Dl/rTIP was located at the lateral portion of the anterior cortex of vertebrae for C3 to C5 and ipsilateral for C6 to C7 with mean value from -2.70 to -3.00 mm, and 0.17 to 3.18 mm. The entrance points for pedicular screw insertion for C3 to C5 and C6 to C7 were recommended -2∼-3 mm and 0-4 mm from the median sagittal plane, respectively, 1-4 mm and 5-6 mm from the upper endplate, with TPA being 46.79-49.00 degrees and 40.89-32.26 degrees, respectively, and SPA being 93.54-106.69 degrees and 109.36-104.99 degrees, respectively. The pedicle screw insertion diameter was recommended 3.5 mm (C3 and C4, 4.0 mm (C5 to C7, and the pedicle axial length was 21-24 mm for C3 to C7 for both genders. However, the ATPS insertion in C3 should be individualized given its relatively small anatomical dimensions. CONCLUSIONS: The data provided a morphometric basis for the ATPS fixation technique in lower cervical fixation. It will help in preoperative planning and execution of this surgery.

  4. The Treatment of Sacroiliac Joint Dislocation by Fixation Using Pedicle Screws Combined with Iliac Screws%髂骨置钉联合同侧椎弓根钉复位固定治疗骶髂关节脱位

    Institute of Scientific and Technical Information of China (English)

    孙海浪; 朱国太; 郝跃东; 唐晓明

    2012-01-01

    To explore the clinical effect of the treatment of sacroiliac joint dislocation by fixation using pedicle screws combined with iliac screws, total of 9 patients (3 female, 6 male) diagnosed as sacroiliac joint dislocation treated with the fixation using pedicle screws combined with iliac screws were studied. The mean age was 36. 4 years(range 21 - 55). The reason for trauma was traffic accident in 5, fall in 4. The type was 6C1, 2C2, 1C3, according to the Tile. Of the 9 patients, 5 had femur fracture, 2 had lung contusion, 2 had separation symphysis pubis, 7 had fracture of all 4 public. All patients were followed-up for 6 ~ 30 months (average 16 months). X-rays after operation showed that all the dislocations were replaced satisfied and sacroiliac joint fused. There was no screw loose and break. No re-dislocation of sacroiliac joint happened. It was safety and perfect surgical procedure that using pedicle screws combined with iliac screws to treat sacroiliac joint dislocation.%探讨髂骨置钉联合同侧椎弓根钉复位固定治疗骶髂关节脱位方法及效果.收治9例骶髂关节脱位患者,男6例,女3例,年龄21岁~55岁,平均36.4岁.5例为交通事故伤,4例为高处坠落伤,C1型6例,C2型2例,C3型1例.其中3例患者合并有股骨干骨折,2例合并有肺挫伤,2例合并有耻骨联合分离,7例伴耻骨支骨折.结果,术后9例患者均获得随访,随访6个月~30个月,平均16月,术后X线片复查示骶髂关节脱位复位满意,骶髂关节均获融合.内固定无松动断裂,骶髂关节无再脱位.应用髂骨置钉联合同侧椎弓根钉复位固定治疗技术是治疗骶髂关节脱位的一种直接而可靠的固定方法.

  5. The influence of sacral morphology on the existence of secure S1 and S2 transverse bone corridors for iliosacroiliac screw fixation.

    Science.gov (United States)

    Mendel, T; Noser, H; Kuervers, J; Goehre, F; Hofmann, G O; Radetzki, F

    2013-12-01

    Sacroiliac (SI) screw fixation for unstable pelvic fractures stands out as the only minimally invasive method among all other ORIF procedures. A strictly transverse screw trajectory is needed for central or bilateral fracture patterns up to a complete iliosacroiliac fixation. However, secure screw insertion is aggravated by a narrow sacroiliac bone stock. This study investigates the influence of a highly variable sacral morphology to the existence of S1 and S2 transverse corridors. The analysis contained in this study is based on 125 CT datasets of intact human pelvises. First, sacral dysplasia was identified using the "lateral sacral triangle" method in a lateral 3-D semi-transparent pelvic view. Second, 3-D corridors for a 7.3mm screw in the upper two sacral levels were visualised using a proprietary IT workflow of custom-made programme scripts based on the Amira(®)-software. Shape-describing measurement variables were calculated as output variables. The results show a significant linear correlation between ratioT and the screw-limiting S1 isthmus height (Pearson coefficient of 0.84). A boundary ratio of 1.5 represented a positive predictive value of 96% for the existence of a transverse S1-corridor for at least one 7.3mm screw. In 100 out of 125 pelvises (80%), a sufficient S1 corridor existed, whereas in 124 specimens (99%), an S2 corridor was found. Statistics revealed significantly larger S1 and S2 corridors in males compared to females (pS1 and 1 screw in S2. The expanse of the S1 corridor is highly influenced by the dimensions of the dysplastic elevated upper sacrum, whereas the S2 corridor is not affected. Hence, in dysplastic pelvises, sacroiliac screw insertion should be recommended into the 2nd sacral segment. Our IT workflow for the automatic computation of 3-D corridors may assist in surgical pre-operative planning. Furthermore, the workflow could be implemented in computer-assisted surgery applications involving pelvic trauma.

  6. One-stage posterior C2 and C3 pedicle screw fixation or combined anterior C2-C3 fusion for the treatment of unstable hangman’s fracture

    OpenAIRE

    Liu, Jingchen; Li, Ye; Wu, Yuntao

    2013-01-01

    The present study aimed to evaluate the effect of using one-stage posterior C2 and C3 pedicle screw fixation or combined anterior C2-C3 fusion in the treatment of unstable hangman’s fracture. A total of 13 patients with unstable hangman’s fractures underwent C2 and C3 pedicle screw fixation, lamina interbody fusion or combined anterior C2-C3 fusion and imaging examinations to evaluate the fracture fixation and healing condition at three days and three months following surgery. Postoperative X...

  7. Compressive Force With 2-Screw and 3-Screw Subtalar Joint Arthrodesis With Headless Compression Screws.

    Science.gov (United States)

    Matsumoto, Takumi; Glisson, Richard R; Reidl, Markus; Easley, Mark E

    2016-12-01

    Joint compression is an essential element of successful arthrodesis. Although subtalar joint compression generated by conventional screws has been quantified in the laboratory, compression obtainable with headless screws that rely on variable thread pitch to achieve bony contact has not been assessed. This study measured subtalar joint compression achieved by 2 posteriorly placed contemporary headless, variable-pitch screws, and quantified additional compression gained by placing a third screw anteriorly. Ten, unpaired fresh-frozen cadaveric subtalar joints were fixed sequentially using 2 diverging posterior screws (one directed into the talar dome, the other into the talar neck), 2 parallel posterior screws (both ending in the talar dome), and 2 parallel screws with an additional anterior screw inserted from the plantar calcaneus into the talar neck. Joint compression was quantified directly during screw insertion using a novel custom-built measuring device. The mean compression generated by 2 diverging posterior screws was 246 N. Two parallel posterior screws produced 294 N of compression, and augmentation of that construct with a third, anterior screw increased compression to 345 N (P < .05). Compression subsequent to 2-screw fixation was slightly less than that reported previously for subtalar joint fixation with 2 conventional lag screws, but was comparable when a third screw was added. Under controlled testing conditions, 2 tapered, variable-pitch screws generated somewhat less compression than previously reported for 2-screw fixation with conventional headed screws. A third screw placed anteriorly increased compression significantly. Because headless screws are advantageous where prominent screw heads are problematic, such as the load-bearing surface of the foot, their effectiveness compared to other screws should be established to provide an objective basis for screw selection. Augmenting fixation with an anterior screw may be desirable when conditions for

  8. Biomechanical considerations in slipped capital femoral epiphysis and insights into prophylactic fixation.

    Science.gov (United States)

    Leblanc, E; Bellemore, J M; Cheng, T; Little, D G; Birke, O

    2017-04-01

    Slipped capital femoral epiphysis (SCFE) is a deformity of the proximal femur secondary to widened and unstable physis. In stabilising the slip, gold standard treatments stop growth and involve premature physeal closure, which prevents the remodelling of the acquired deformity and creates a leg length discrepancy that may be significant in younger patients. We measured the impact of placing threaded screws across the proximal femoral physis by measuring the centre-trochanteric distance (CTD) and articulo-trochanteric distance (ATD) in participants with or without prophylactic fixation. We then compared the mechanical performance of static (stainless and titanium cannulated Synthes screws) and potentially growing implants (Synthes SCFE screw and Pega Medical Free Gliding screw) in a validated synthetic bone model. In the review of 30 non-fixed and 60 fixated hips over a mean follow-up of 1.9 years, we have noted a significant difference in pre/post CTD and ATD, as well as the change in CTD and ATD over time. In the biomechanical study, the newer implants allowing growth (Synthes SCFE screw and Pega Medical Free Gliding screw) were both shown to be at least non-inferior. The primary deformity of a SCFE in itself alters hip mechanics. Also, as confirmed in this study, there is a secondary deformity that is created by static fixation and relative trochanteric overgrowth. To help remodel mild deformities and prevent secondary trochanteric overgrowth, growing implants seem to be non-inferior to the more standard means of fixation in static testing.

  9. Advances in cervical anterior transpedicular screw fixation technique%颈椎前路椎弓根螺钉内固定技术的研究进展

    Institute of Scientific and Technical Information of China (English)

    欧阳钧; 吴卫东

    2013-01-01

    Cervical posterior transpedicular screw technique was first introduced to clinic in 1994. Due to its good biomechanical stability and satisfactory fusion effect,it has become a major solution to some cervical spine diseases.However,most of the diseases involved in vertebral body and posterior transpedicular screw technique is complex and difficult,these factors prevent the technique be widely used in cervical spine surgery.In 2008,a new concept of cervical anterior transpedicular screw fixation technique was first proposed.This new technique inherited advantages of posterior transpedicular screw fixation,and of course,it also overcomes drawbacks of conventional anterior vertebral body screw fixa-tion.This review presents an overview of anterior transpedicular screw fixation technique on anatomical and biomechanical field.%颈椎后路椎弓根螺钉固定技术于1994年首次应用于临床,鉴于其稳定的固定融合效果,已成为多种颈椎疾病的主要治疗手段。然而,由于颈椎病灶的好发部位多位于前部,且颈椎后路椎弓根螺钉操作难度较大,在一定程度上限制了该技术的发展。2008年颈椎前路椎弓根螺钉固定技术的概念被首次提出,此技术继承了后路椎弓根螺钉生物力学性能卓越的优点,且克服传统颈椎前路椎体螺钉稳定性较差的缺点。本文主要就颈椎前路椎弓根螺钉固定技术的解剖学及生物力学研究进展进行综述。

  10. Percutaneous internal fixation using sacroiliac screw in dorsal position for treatment of pelvic posterior ring injuries%仰卧位经皮骶髂置钉固定术治疗骨盆后环损伤

    Institute of Scientific and Technical Information of China (English)

    王亮; 藏卫东; 甄相周; 李付彬; 徐向峰; 杨彦亭

    2009-01-01

    Objective To explore the feasibility, operative procedure and the result for the tech-nique of sacroiliac percutaneous screws fixation in dorsal position for treatment of pelvic posterior ring in-juries. Methods From October 2004 to October 2007, 14 patients with the pelvic posterior ring injuries were treated with width 7.2 mm sacroiliac cannulated screws fixation under monitoring of "C"-arm, which in-cluded 7 males and 7 females, with the mean age of 41.6 years (range, 28-75 years). According to the Tile classification, there were 4 cases for type B, 10 for type C. During the operation, the patients were kept on domal position. The inserting point was the intersection point of anterior 2 cm of superior iliac spine and posterior axillary line, or the posterior-middle 1/3 point of the line between anterior superior iliac spine and posterior superior iliac spine. The screw inclined anterior 20°~30°, 5°~15° toward foot. The pelvic preceding ring injuries and the other bone joint damages were dealt with at the same time. After the operation, screen the X-ray polished section of the pelvic A-P position and the lumbar vertebrae lateral position, and scan pelvic posterior ring by CT, watch the screw entering position in S1 centrum. Results All 14 patients were available at follow up with mean duration of 16 months (range, 6-36 months). All cases attained bone union in 3 months. Fifteen hollow titanium screws inserted into 14 patients. There were no nerve injuries and breakage or loosening of the screws, and no pelvic deformities and pain of sacroiliac. According to Majeed e-valuation, the excellent and good rate was 92.9%. Conclusion To use two ways to decide position on per-cutaneous internal fixation using sacroiliac screw in dorsal position for treatment of pelvic posterior ring in-juries is safe, convenient and feasible.%目的 探讨仰卧位经皮骶髂置钉固定术治疗骨盆后环损伤的可行性、手术方法及疗效.方法 在10

  11. Biomechanical comparison of bilateral pedicle screw and unilateral pedicle screw fixation%双侧钉棒及同侧单钉棒置入内固定的生物力学比较

    Institute of Scientific and Technical Information of China (English)

    陈立业; 夏虹; 王建华; 尹庆水

    2011-01-01

    BACKGROUND: Most of lumbar degenerative diseases, such as lumbar instability and lumbar spondylolisthesis, need lumbarspinal fusion for the spine stability, but the choice of internal fixation approaches is an argument.OBJECTIVE: To investigate the biomechanical difference of unilateral and bilateral minimally I nvasive transforaminal lumbarinterbody fusion (TLIF) for the treatment of lumbar degenerative diseases.METHODS: Minimally invasive TLIF with different internal fixations were performed on L4-5 segments from six fresh frozenhuman lumbar cadaveric specimens. Then, the specimens were divided into two groups according to different internal fixationmethods: bilateral pedicle screw group and unilateral pedicle screw group. Range of motion (ROM) for the lumbar function unitwas measured on the biomechanical machine and compared between the two groups.RESULTS AND CONCLUSION: Compared with the compact lumbar function unit, the ROM of the two fixation groups weresignificantly lower (P < 0.05). The ROM value of the bilateral pedicle screw group was significantly lower than that of the unilateralpedicle screw group in all working states (P < 0.05). Biomechanical experiments show that unilateral TLIF provides favorablebiomechanical effect and stiffness, which offers the dependable stability of the lumbar vertebra e. However, compared with thebilateral pedicle screw fixation, there are still gaps in the unilateral pedicle screw fixation.%背景:腰椎失稳、腰椎滑脱等腰椎退行性疾病常常需要实施腰椎融合,其目标是稳定脊柱,但究竟采取何种内固定方式仍存在争论.目的:比较单侧与双侧经椎间孔减压椎体间融合治疗腰椎退行性病变的生物力学差异.方法:人新鲜尸体腰椎标本6具,L4~5模拟微创经椎间孔减压椎体间融合,根据不同的内固定组合方式分为2组,即双侧钉棒组及同侧单钉棒组.在生物力学试验机上测量各种固定方式不同工况下的运动范围(ROM

  12. Functionality Evaluation of a Novel Smart Expandable Pedicle Screw to Mitigate Osteoporosis Effect in Bone Fixation: Modeling and Experimentation

    Directory of Open Access Journals (Sweden)

    Ahmadreza Eshghinejad

    2013-01-01

    Full Text Available This paper proposes a novel expandable-retractable pedicle screw and analyzes its functionality. A specially designed pedicle screw is described which has the ability to expand and retract using nitinol elements. The screw is designed to expand in body temperature and retract by cooling the screw. This expansion-retraction function is verified in an experiment designed in larger scale using a nitinol antagonistic assembly. The results of this experiment are compared to the results of a finite element model developed in Abaqus in combination with a user material subroutine (UMAT. This code has been developed to analyze the nonlinear thermomechanical behavior of shape memory alloy materials. The functionality of the proposed screw is evaluated with simulation and experimentation in a pullout test as well. The pullout force of a normal screw inserted in a normal bone was simulated, and the result is compared with the results of the expandable screw in osteoporotic bone. Lastly, strength of the designed pedicle screw in a foam block is also verified with experiment. The reported finite element simulations and experiments are the proof for the concept of nitinol expandable-retractable elements on a pedicle screw which validate the functionality in a pullout test.

  13. Role of Joshi's external stabilization system with percutaneous screw fixation in high-energy tibial condylar fractures associated with severe soft tissue injuries

    Institute of Scientific and Technical Information of China (English)

    Ashish Kumar Gupta; Rahul Sapra; Rakesh Kumar; Som Prakash Gupta; Devwart Kaushik; Sahil Gaba; Mahesh Chand Bansal

    2015-01-01

    Purpose: The treatment of high-energy tibial condylar fractures which are associated with severe sott tissue injuries remains contentious and challenging.In this study, we assessed the results of Joshi's external stabilization system (JESS) by using the principle of ligamentotaxis and percutaneous screw fixation for managing high-energy tibial condylar fractures associated with severe soft tissue injuries.Methods: Between June 2008 and June 2010, 25 consecutive patients who were 17-71 years (mean, 39.7), underwent the JESS fixation for high-energy tibial condylar fractures associated with severe soft tissue injuries.Out of 25 patients, 2 were lost during follow-up and in 1 case early removal of frame was done, leaving 22 cases for final follow-up.Among them, 11 had poor skin condition with abrasions and blisters and 2 were open injuries (Gustilo-Anderson grade Ⅰ & Ⅱ).The injury mechanisms were motor vehicle accidents (n =19), fall from a height (n =2) and assault (n =1).The fractures were classified according to Schatzker classification system.Results: There were 7 type-Ⅴ, 14 type-Ⅵ and 1 type-Ⅳ Schatzker's tibial plateau fractures.The average interval between the injury and surgery was 6.8 days (range 2-13).The average hospital stay was 13 days (range, 7-22).The average interval between the surgery and full weight bearing was 13.6 weeks (range 11-20).The average range of knee flexion was 121° (range 105°-135°).The normal extension of the knee was observed in 20 patients, and an extensor lag of 5°-8° was noted in 2 patients.The complications included superficial pin tract infections (n =4) with no knee stiffness.Conclusion: JESS with lag screw fixation combines the benefit of traction, external fixation, and limited internal fixation, at the same time as allowing the ease of access to the soft tissue for wound checks, pin care, dressing changes, measurement of compartment pressure, and the monitoring of the neurovascular status.In a nutshell, JESS

  14. Quantitative Gross and CT measurements of Cadaveric Cervical Vertebrae (C3 – C6) as Guidelines for the Lateral mass screw fixation

    Science.gov (United States)

    Heinneman, Thomas E.; Conti, Mathew S.; Dossous, Paul-Michel F.; Dillon, David J.; Tsiouris, Apostolos J.; Pyo, Se Young; Mtui, Estomih P.; Härtl, Roger

    2016-01-01

    Background Lateral mass screw fixation is the treatment of choice for posterior cervical stabilization. Long or misdirected screws carry a risk of injury to spinal nerve roots or vertebral artery. This study was aimed to assess the gross anatomic and CT measurements of typical cervical vertebrae for the selection of lateral mass screws. Methods Dimensions of the articular pillars were measured on 1) Dry cervical vertebrae with Vernier calipers and 2) Multiplanar reformations of CT scans of the same vertebrae with Viewer software package. The data was statistically evaluated. Results The transverse diameter of the articular pillars with Vernier calipers varied from 6.0 to 15.4 mm (mean=10.5 mm ± 1.5) and on CT scans ranged from 8.2 – 16.1 mm (mean=11.6 mm ± 1.4). The antero-posterior diameter, an estimate of the screw length by Roy-Camille technique varied from 3.9 to 12.7 mm (mean=8.6 mm ± 1.6) by Vernier calipers and from 6.4 to 13.3 mm (mean=9.1 ± 1.2) on CT scans. The oblique AP diameter, an estimate of screw length by Magerl method varied from 10.8 to 20.3 mm (mean=14.9 mm ± 1.8) by Vernier calipers and from 11.4 to 19.3 mm (mean=14.5 mm ± 1.7) on CT. The CT measurements for height, transverse and AP diameter of the articular pillars were 0.5 - 1.0 mm larger than dimensions by Vernier calipers. No statistically significant difference was observed between the caliper and CT measurements for the oblique AP diameter. Conclusion CT measurements of the articular pillars may slightly overestimate the desired screw length selected by spine surgeons when compared to actual anatomy. Although means of the articular pillars correspond to the screw lengths used, substantial number of observations below 10 mm for Roy-Camille trajectory and below 14 mm for Magerl trajectory requires careful preoperative planning and intra-operative confirmation to avoid long/misdirected lateral mass screws. PMID:28377857

  15. Anterior subaxial cervical spine fixation using a plate with single screw per vertebral body: A simple and efficient construct - Clinical series and a cadaver study

    Directory of Open Access Journals (Sweden)

    Vannemreddy Prasad

    2009-01-01

    Full Text Available Objective: To report our experience with a novel construct for traumatic and nontraumatic cervical spine lesions that was validated by biomechanical studies of cadaver cervical spine. Study Design: Consecutive cases of anterior cervical spine fixation performed over six years reviewed for stability offered by a construct comprising of a plate fixed by a single screw to each vertebral body. Setting: A university hospital and a biomechanical lab. Materials and Methods: Data were coded and entered into a statistical worksheet for multivariate analysis. Cadaver spine models applied for biomechanical study of stability. Results: Total of 103 cases reviewed; 86 with single-level disease; traumatic in 66 (64% cases and degenerative in 33 (32% cases, including hard disks, OPLL, and spondylitis (4% with other causes. Fixation was with diskectomy in 59 and with corpectomy in 40. A bone graft was utilized for fusion in 87 and a bone-filled titanium spacer in 13. A single screw was placed in each vertebral body with a locking plate (having linear arrangement of holes. This construct remained strong in 95% of cases at the end of 6-24 months. Five cases failed requiring reoperation. Five patients with cervical spinal cord injury (SCI died. On statistical analysis, construct was stronger with diskectomy compared with corpectomy. Construct used on cadavers confirmed the biomechanical stability in short segment fixation (C5-6. Conclusion: A conservative construct utilizing a single screw per vertebral body and a one-holed plate system appears to be strong enough to afford stability in both traumatic and nontraumatic lesions of subaxial cervical spine, comparable to others.

  16. C1-C2 transarticular screw fixation for atlantoaxial instability due to rheumatoid arthritis: a seven-year analysis of outcome.

    LENUS (Irish Health Repository)

    Nagaria, Jabir

    2009-12-15

    STUDY DESIGN.: Observational study. Retrospective analysis of prospectively collected data. OBJECTIVE.: The purpose of this article was to report long-term (minimum 7 years) clinical and radiologic outcome of our series of patients with Rheumatoid Arthritis who underwent transarticular screw fixation to treat atlantoaxial subluxation. SUMMARY OF BACKGROUND DATA.: The indications for intervention in patients with atlantoaxial instability are pain, myelopathy, and progressive neurologic deficit. The various treatment options available for these patients are isolated C1-C2 fusion, occipitocervical fusion with or without transoral surgery. Review of current literature suggests that C1-C2 transarticular screw fixation has significant functional benefits, although there is discrepancy in this literature regarding improvement in function following surgery. METHODS.: Myelopathy was assessed using Ranawat myelopathy score and Myelopathy Disability Index. Pain scores were assessed using Visual Analogue Scale. The radiologic imaging was assessed and the following data were extracted; atlanto-dens interval, space available for cord, presence of signal change on T2 weighted image, and fusion rates. RESULTS.: Thirty-seven patients, median age 56, were included in the study. Average duration of neck symptoms was 15.8 months. Average duration of rheumatoid arthritis before surgery was 20.6 years. Preoperative symptoms: suboccipital pain in 26 patients; neck pain, 32; myelopathy, 22; and 5 were asymptomatic. After surgery: suboccipital pain, 2; neck pain, 3; and myelopathy, 10. Ninety percent patients with neck and suboccipital pain improved after surgery in their Visual Analogue pain scores, with all of them having >50% improvement in VAS scores (6.94-2.12 [P < 0.05]).Preoperative Ranawat grade was as follows: grade 1 in 15 patients, grade 2 in 7, and grade 3a in 14, grade 3b in 1.After surgery: grade 1 in 27 patients, grade 2 in 7, grade 3a in 1, and grade 3b in 2. The mean

  17. 寰枢椎椎弓根螺钉置钉技术的临床应用%Clinical application of atlantoaxial pedicle screw system fixation

    Institute of Scientific and Technical Information of China (English)

    吴长沙; 李攀; 李恩贤; 李让贤; 夏兴平; 刘超; 涂国能

    2015-01-01

    Objective To investigate the effect of atlantoaxial pedicle screw system fixation to treat upper cervical in-juries.Methods Patients with upper cervical injuries were treated with atlantoaxial pedicle screw system fixation, which included 5 cases of Jefferson fractures,11 odontoid fractures and 9 Hangman fractures.Results No patient had the injury of spinal cord,nerve root and vertebral artery.There was 1 case with vertebral vein injury,which had been controlled by compression.1 case with Jefferson fracture showed incomplete reduction.All patients were followed up from 1 year to 2 years.All fusion bone got union from CT scan and X-ray a year after surgeries.The clinical symp-toms were improved and the screws were verified to be in a proper position without breakage or loosening.Conclusions The atlantoaxial pedicle screw system fixation is an effective method,which provide stable fixation and high fusion rate for fracture to treat upper cervical injuries.%目的:探讨寰枢椎椎弓根螺钉置钉技术在上颈椎损伤临床应用的效果。方法选择性应用寰枢椎椎弓根螺钉固定技术治疗 Jefferson 骨折5例,齿状突骨折11例,Hangman 骨折9例。结果术中无椎动脉、脊髓及神经根损伤发生。1例暴露时损伤静脉丛,予以压迫即能止血;1例寰枢椎骨折不完全复位。患者均获随访,时间1~2年。患者临床症状明显改善,术后1年行 X 线及 CT 检查,显示所有骨折均骨性愈合,螺钉位置良好,无松动、断钉。结论寰枢椎椎弓根螺钉内固定技术具有固定可靠及骨折愈合率高等特点,为上颈椎损伤提供了坚固的稳定性。

  18. Anterior subcutaneous fixation with screw-rod internal fixator for the treatment of unstable anterior pelvic ring fractures%经皮钉-棒内支架治疗不稳定骨盆前环骨折

    Institute of Scientific and Technical Information of China (English)

    王朝晖; 何波涌; 曾敏川; 郭建辉; 唐艳平; 赵快平; 刘建伟

    2016-01-01

    目的探讨经皮钉-棒内支架治疗不稳定骨盆前环骨折临床应用。方法回顾性分析经皮钉-棒内支架治疗的12例不稳定骨盆前环骨折患者的临床资料,男性8例,女性4例;年龄23~63岁,平均43.8岁。骨盆骨折按照Tile分类:B34例,C14例,C23例,C31例。后环损伤采用经皮骶髂螺钉固定2例,髂腰固定1例,钢板固定6例,其中M张力带钢板固定4例。结果前环固定平均出血70mL(50~90mL),平均手术时间65min(50~85min)。单侧股外侧皮神经损伤5例,均恢复正常;随访4~15个月,无切口感染、内固定失效等,骨折均获骨性愈合,疗效满意。结论经皮钉-棒内支架是治疗不稳定骨盆前环骨折微创舒适、简便、安全的方法,疗效好,但术中应警惕股外侧皮神经损伤。%Objective To study percutaneous internal fixation with screw-rod system for the treatment of unstable anterior pelvic ring fractures .Methods The clinical data of 12 cases of unstable anterior pelvic ring frac-tures treated with anterior subcutaneous fixation with screw-rod system was retrospectively analyzed . According to the Tile’s classification,4 cases were B3,4 cases were C1,3 cases were C2,and 1 case was C3.In all these poste-rior ring fractures,2 cases were treated with percutaneous iliosacral screw fixation ,1 case with ilio-lumbar fixation,and 6 cases with plate fixation (including M-shaped tension plate fixation in 4 cases).Results The average blood loss and operation time of anterior pelvic ring fixation were 70 mL ( ranged from 50 to 90 mL) and 65 min( ranged from 50 to 85min)respectively.Unilateral lateral femoral cutaneous nerves were inpaired in 5 cases and the symptoms resolved after 2 weeks.All cases were followed up for 4 to 15 months,indicating bone healing and satisfactory clinical results , without wound infection or fixation failure .Conclusion The percutaneous internal fixation with screw-rod system

  19. Advances of pedicle screw fixation for thoracolumbar fractures%椎弓根螺钉内固定术治疗胸腰椎骨折的进展

    Institute of Scientific and Technical Information of China (English)

    丁浩洋; 柯珍勇

    2014-01-01

    0BJECTIVE:To systemic il ustrate advances of pedicle screw internal fixation in treating thoracolumbar fracture. METHODS:A computer-based online search(1993-01/2014-01) of PubMed database(http://www. ncbi.nlm.nih.gov/pubmed/) and WANFANG database (http://www.wanfangdata.com.cn/) was performed for related articles with keywords“pedicular screw,internal fixation,thoracolumbar fracture”in English and in Chinese.A total of 65 articles were col ected,and 28 were included according to inclusion and exclusion criteria. RESULTS:Pedicle screws have a good biomechanical characteristic.Cooperated with different ways of operation,pedicle screws can be used for reconstructing the stability of vertebral fracture,providing three-dimensional correction,restoring the hight of vertebral body and physiological bending of the spine,and decompressing spinal canal.With the technological development in recent years,the application of intermediate screw and percutaneous pedicle screw fixation optimized the surgical approach, reduced the trauma and postoperative adverse reactions. CONCLUSION:With the application of various kinds of techniques,pedicle screw fixation can be used for the treatment of various types of thoracolumbar fractures.%目的:系统阐述椎弓根螺钉内固定术应用于胸腰椎骨折治疗的进展。方法使用计算机及因特网检索(1993-01/2014-01) PubMed数据库(http://www.ncbi.nlm.nih.gov/pubmed/)、中国万方数据库(http://www.wanfangdata.com.cn/)中相关文章,英文关键词为“pedicular screw,internal fixation,thoracolumbar fracture”,中文关键词为“椎弓根螺钉,内固定,胸腰椎骨折”。共检索到65篇文献,根据纳入及排除标准,共纳入28篇文章。结果椎弓根螺钉具有良好生物力学特性,配合不同的手术方式,可重建骨折椎稳定性,提供三维矫正,恢复椎体高度及脊柱的生理弯曲,行椎管减压。而近年来随技术发展,伤椎内固定

  20. A STUDY OF POSTERIOR LUMBAR INTERBODY FUSION WITH LOCALLY HARVESTED SPINOLAMINECTOMY BONE GRAFT AND PEDICLE SCREW FIXATION IN SPONDYLOLISTHESIS

    Directory of Open Access Journals (Sweden)

    Pardhasaradhi M

    2017-08-01

    Full Text Available BACKGROUND Posterior Lumbar Interbody Fusion (PLIF and Transforaminal Lumbar Interbody Fusion (TLIF create intervertebral fusion by means of a posterior approach. Successful results have been reported with allograft, various cages (for interbody support, autograft and recombinant human bone morphogenetic protein‐2. Interbody fusion techniques facilitate reduction and enhance fusion. Corticocancellous laminectomy bone chips alone can be used as a means of spinal fusion in patients with single level instrumented PLIF. This has got a good fusion rate. PLIF with cage gives better fusion on radiology than PLIF with iliac bone graft, but no statistical difference in the clinical outcome. Cage use precludes complications associated with iliac bone harvesting. The reported adjacent segment degeneration was 40.5% and reoperation was 8.1% after 10 years of follow up. MATERIALS AND METHODS 30 cases of spondylolisthesis who attended the Orthopaedic Outpatient Department of Andhra Medical College, Visakhapatnam, from 2014 to 2016 were taken up for study. All the cases were examined clinically and confirmed radiologically. The patient’s age, sex, symptoms and duration were noted and were examined clinically for the status of the spine. Straight leg raising test was done and neurological examination of the lower limbs performed. All the patients were subjected to the radiological examination of the lumbosacral spine by taking anteroposterior, lateral (flexion and extension views, oblique views to demonstrate spondylolysis and spondylolisthesis. MRI and x-rays studies were done in all the cases to facilitate evaluation of the root compression disk changes and spinal cord changes. RESULTS In our study, we followed all the 30 patients after the surgery following procedure of removal of loose lamina, spinous process and fibrocartilaginous mass, PLIF with only the laminectomy bone mass and CD screw system fixation up to 2 years. 12 patients (40% had excellent

  1. How to cannulate?

    DEFF Research Database (Denmark)

    Löhr, J-Matthias; Aabaken, Lars; Arnelo, Urban

    2012-01-01

    endoscopist are taking; especially, what makes a papilla difficult to cannulate and how to approach this. We devised a structured online questionnaire, sent to all endoscopists registered with SADE, the Scandinavian Association for Digestive Endoscopy. A total of 141 responded. Of those, 49 were experienced...... ERCP-endoscopists (>900 ERCPs). The first choice of cannulation is with a sphincterotome and a preinserted wire. Both less experienced and more experienced endoscopists agreed on the criteria to describe a papilla difficult to cannulate and both would choose the needle-knife sphincterotomy (NKS) to get...

  2. CT-guided percutaneous screw fixation plus cementoplasty in the treatment of painful bone metastases with fractures or a high risk of pathological fracture

    Energy Technology Data Exchange (ETDEWEB)

    Pusceddu, Claudio; Ballicu, Nicola; Fele, Rosa Maria; Sotgia, Barbara; Melis, Luca [Oncological Hospital ' ' A. Businco' ' , Regional Referral Center for Oncologic Diseases, Division of Interventional Radiology, Department of Oncological Radiology, Cagliari (Italy); Fancellu, Alessandro [University of Sassari, Department of Clinical and Experimental Medicine, Sassari (Italy)

    2017-04-15

    To evaluate the feasibility and effectiveness of computed tomography (CT)-guided percutaneous screw fixation plus cementoplasty (PSFPC), for either treatment of painful metastatic fractures or prevention of pathological fractures, in patients who are not candidates for surgical stabilization. Twenty-seven patients with 34 metastatic bone lesions underwent CT-guided PSFPC. Bone metastases were located in the vertebral column, femur, and pelvis. The primary end point was the evaluation of feasibility and complications of the procedure, in addition to the length of hospital stay. Pain severity was estimated before treatment and 1 and 6 months after the procedure using the visual analog scale (VAS). Functional outcome was assessed by improved patient walking ability. All sessions were completed and well tolerated. There were no complications related to either incorrect positioning of the screws during bone fixation or leakage of cement. All patients were able to walk within 6 h after the procedure and the average length of hospital stay was 2 days. The mean VAS score decreased from 7.1 (range, 4-9) before treatment to 1.6 (range, 0-6), 1 month after treatment, and to 1.4 (range 0-6) 6 months after treatment. Neither loosening of the screws nor additional bone fractures occurred during a median follow-up of 6 months. Our results suggest that PSFPC might be a safe and effective procedure that allows the stabilization of the fracture and the prevention of pathological fractures with significant pain relief and good recovery of walking ability, although further studies are required to confirm this preliminary experience. (orig.)

  3. Biomechanical comparison of cervical transfacet pedicle screws versus pedicle screws

    Institute of Scientific and Technical Information of China (English)

    LIU Guan-yi; XU Rong-ming; MA Wei-hu; SUN Shao-hua; HUANG Lei; YING Jiang-wei; JIANG Wei-yu

    2008-01-01

    Background Transfacet pedicle screws provide another alternative for standard pedicle screw placement for plate fixation in the Iumbar spine. However, few studies looking at transfacet pedicle screw fixation in the cervical spine are available. Therefore, cervical transfacet pedicle screw fixation and standard pedicle screw fixation techniques were biomechanically compared in this study.Methods Ten fresh human cadaveric cervical spines were harvested. On one side, transfacet pedicle screws were placed at the C3-4, C5-6, and C7-T1 levels. On the other side, pedicle screws were placed at the C3, C5, and C7 levels. The screw insertion technique at each level was randomized for right or left. The starting point for the transfacet pedicle screw insertion was located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50° caudally in the sagittal plane and about 45° toward the midline in the axial plane. Screws were placed from the inferior articular process, across the facet complex and the pedicle into the body of the caudal vertebra. The entry point for the pedicle screw was located at the midpoint of the superolateral quadrant of the lateral mass, and the direction of the screw was about 45° toward the midline in the axial plane and toward the upper third of the vertebral body in the sagittal plane. After screw placement we performed axial pullout testing.Results All the cervical transfacet pedicle screws and the pedicle screws were inserted successfully. The mean pullout strength for the transfacet pedicle screws was 694 N, while for the pedicle screws 670 N (P=-0.013). In all but six instances (10%), the pedicle screw pullout values exceeded the values for the transfacet pedicle screws; this occurred three times at the C3/C4 level, twice at the C5/C6 level and once at the C7/T1 level. The greatest pullout strength difference at a single level was observed at the C5/C6 level, with a mean difference of 38 N (t

  4. 髓内固定与钉板固定治疗股骨粗隆间骨折的疗效比较%A comparison study of intramedullary fixation and screw-plate fixation treatment on intertrochanteric fracture

    Institute of Scientific and Technical Information of China (English)

    孔祥安; 董力军; 金韡

    2014-01-01

    目的:对比观察两种方法(髓内固定系统和钉板固定系统)治疗股骨粗隆间骨折的临床疗效,为临床推广作出指导。方法选择53例股骨粗隆间骨折患者为研究对象,按手术方法分为髓内组和钉板组,髓内组采用髓内固定系统治疗,钉板组采用钉板固定系统治疗,比较两组患者术中、术后的各项指标以及治疗后的临床疗效。结果①两组患者术中、术后各项指标的比较:髓内组术中、术后各项指标均优于钉板组,其结果比较差异有统计学意义(P<0.05);②两组患者临床疗效的比较:髓内组的优良率为88.89%,钉板组的优良率为88.57%,其结果比较差异无统计学意义( P>0.05)。结论髓内固定系统和钉板固定系统治疗股骨粗隆间骨折的临床疗效均较好,但髓内固定系统具有切口小、出血少和恢复快等优势。%Objective To explore two different internal fixation methods ,intramedullary fixation system and screw -plate fixation system for the treatment of intertrochanteric fractures ,in order to direct the clinical application .Methods From Jan.2007 to May 2013,53 cases of intertrochanteric fractures were retrospectively studied ,and the patients were divided into two groups:the intramedullary fixation group and the screw-plate fixation group .Procedure related index and postoperative recover situation of the two groups were compared .Results ①Procedure related index in the intramedullary fixation group were better than those of the screw -plate fixation group with a statistically signifi-cant difference(P0.05).Conclusion Both of the two treatment methods for intertrochanteric fractures can get excellent clinical efficacy .However,the intramedullary fixation system has advantages in smaller surgical injury ,less blood loss and faster recovery ,which is worth clinical application .

  5. Biomechanical study on the posterior screw fixation in the lower cervical spine%下颈椎后路螺钉固定的生物力学研究进展

    Institute of Scientific and Technical Information of China (English)

    林华杰; 徐荣明; 刘观燚

    2011-01-01

    So far,the fixation in the lower cervical spine through posterior approach technology has commonly been used,besides the lateral screw and pedicle screw techniques,transarticular screw and laminar screw techniques have being paid more attention recently. This article introduced four screw fixation ways in the lower cervical spine through posterior approach and reviewed the recent biomechanics studies of four screw fixation techniques. The biomechanics study includes stabilization,pollout strength, insertion technique, and screw characteristic and so on. Lateral screw and pedicle screw techniques have become an effective internal fixation way for the lower cervical spine instability because of their superior stabilization and higher pollout strength. Transarticular screw fixation has become a new way to fix the lower cervical spine through posterior approach,which has widely surgical indications. Besides, this technique is relatively safe, simple and has achieved favorable curative effect in clinic. Laminar screw fixation technique is rarely used in clinic, but the study of anatomy and biomechanics confirmed that this technique can be applied as a salvage technique in clinic. Above four techniques of the screw fixation in the lower cervical spine through posterior approach have advantages and disadvantages, respectively, and the application in clinic is different. Through the biomechanics study of these techniques will contribute to the development of the techniques of the screw fixation in the lower cervical spine through posterior approach and guide the clinical work effectively.%目前,下颈椎后路螺钉固定除侧块螺钉和椎弓根螺钉技术已普遍应用外,经关节螺钉和经椎板螺钉固定技术也逐渐被重视.本文就此介绍下颈椎后路4种螺钉固定方式,并对各自固定技术的生物力学研究现状进行综述.生物力学研究内容包括三维稳定性、抗拔出力、置钉技术和螺钉特点等.侧块螺钉和椎

  6. Fixation of multifragmentary patella fractures using a bilateral fixed-angle plate.

    Science.gov (United States)

    Thelen, Simon; Betsch, Marcel; Schneppendahl, Johannes; Grassmann, Jan; Hakimi, Mohssen; Eichler, Christian; Windolf, Joachim; Wild, Michael

    2013-11-01

    This biomechanical study is the first to compare 3 fixation methods-bilateral fixed-angle plate, modified anterior tension wiring, and cannulated lag screws with anterior tension wiring-in multifragmentary distal patella fractures. A T-shaped 3-part fracture simulating a multifragmentary articular distal patella fracture (AO/OTA 34-C2.2) was created in 18 human cadaver knee specimens. Three groups were created using homogenous ages and bone mineral densities based on the fixation method received. Repetitive testing over 100 cycles was performed by moving the knee against gravity from 90° flexion to full extension. Failure was defined as fracture displacement greater than 2 mm. In all patellae using fixed-angle plates, an anatomical fracture reduction could be maintained throughout cyclic testing, whereas anterior tension wiring and lag screws with tension wiring showed significant fracture displacement after 100 cycles, with mean fracture gaps of 2.0±1.3 and 1.9±1.6 mm, respectively. The differences in fracture gaps between the fixed-angle plate group and the other 2 groups were statistically significant. In both groups using tension wiring, half of the constructs (3 of 6 in each group) failed due to a fracture displacement greater than 2 mm. The bilateral fixed-angle plate was the only fixation method that sustainably stabilized a multifragmentary articular distal patella fracture during cyclic loading when compared with modified anterior tension wiring and cannulated lag screws with anterior tension wiring.

  7. Comparison of Head Center Position and Screw Fixation Options Between a Jumbo Cup and an Offset Center of Rotation Cup in Revision Total Hip Arthroplasty: A Computer Simulation Study.

    Science.gov (United States)

    Faizan, Ahmad; Black, Brandon J; Fay, Brian D; Heffernan, Christopher D; Ries, Michael D

    2016-01-01

    Jumbo acetabular cups are commonly used in revision total hip arthroplasty (THA). A straightforward reaming technique is used which is similar to primary THA. However, jumbo cups may also be associated with hip center elevation, limited screw fixation options, and anterior soft tissue impingement. A partially truncated hemispherical shell was designed with an offset center of rotation, thick superior rim, and beveled anterior and superior rims as an alternative to a conventional jumbo cup. A three dimensional computer simulation was used to assess head center position and safe screw trajectories. Results of this in vitro study indicate that a modified hemispherical implant geometry can reduce head center elevation while permitting favorable screw fixation trajectories into the pelvis in comparison to a conventional jumbo cup.

  8. Central tarsal bone fractures in horses not used for racing: Computed tomographic configuration and long-term outcome of lag screw fixation.

    Science.gov (United States)

    Gunst, S; Del Chicca, F; Fürst, A E; Kuemmerle, J M

    2016-09-01

    There are no reports on the configuration of equine central tarsal bone fractures based on cross-sectional imaging and clinical and radiographic long-term outcome after internal fixation. To report clinical, radiographic and computed tomographic findings of equine central tarsal bone fractures and to evaluate the long-term outcome of internal fixation. Retrospective case series. All horses diagnosed with a central tarsal bone fracture at our institution in 2009-2013 were included. Computed tomography and internal fixation using lag screw technique was performed in all patients. Medical records and diagnostic images were reviewed retrospectively. A clinical and radiographic follow-up examination was performed at least 1 year post operatively. A central tarsal bone fracture was diagnosed in 6 horses. Five were Warmbloods used for showjumping and one was a Quarter Horse used for reining. All horses had sagittal slab fractures that began dorsally, ran in a plantar or plantaromedial direction and exited the plantar cortex at the plantar or plantaromedial indentation of the central tarsal bone. Marked sclerosis of the central tarsal bone was diagnosed in all patients. At long-term follow-up, 5/6 horses were sound and used as intended although mild osteophyte formation at the distal intertarsal joint was commonly observed. Central tarsal bone fractures in nonracehorses had a distinct configuration but radiographically subtle additional fracture lines can occur. A chronic stress related aetiology seems likely. Internal fixation of these fractures based on an accurate diagnosis of the individual fracture configuration resulted in a very good prognosis. © 2015 EVJ Ltd.

  9. Femoral stiffness after osteosynthesis of a subcapital osteotomy in osteoporotic bone: an in-vitro comparison of nine fixation methods.

    Science.gov (United States)

    Hernefalk, L; Messner, K

    1995-01-01

    Restitution of normal bone mechanics after osteosynthesis of a proximal femoral fracture in the elderly is assumed to be a prerequisite for optimal healing. To find the most appropriate fixation device for this purpose, the stiffness of 79 cadaver femora from donors with a history of osteoporosis was measured during axial loading before and after a subcapital osteotomy stabilized with one of nine different osteosynthesis devices. Only an osteotomy stabilized with an experimental device consisting of 2 von Bahr screws (Ericsson AB, Göteborg, Sweden) supported by acrylic cement gave similar mean values as the intact femur. A femur stabilized with the Deyerle device (Biomet, Bridge End, Wales, U.K.), with cannulated screws type Uppsala (Olmed AB, Uppsala, Sweden), or with von Bahr screws had an approximately 20-30% lower stiffness than tested intact. However, these devices provided a higher femoral stiffness than the hook-pin technique type LiH (Söderström AB, Gothenburg, Sweden), cannulated screws (Smith & Nephew, Memphis, TN, U.S.A.), a sliding screw plate (Smith & Nephew), a compression screw with variable length (Biomet), or an experimental screw providing expansion and compression. Despite attempted compression of the osteotomy by some of the devices, all of the commercially available devices resulted in a decrease of femoral stiffness after fixation, which may adversely influence the healing of femoral neck fractures in the elderly. Only a combination of screws and bone cement resulted in normal femoral stiffness, probably because of better device anchorage in the osteoporotic cancellous bone. However, this combination might have the potential risk of vascular damage.

  10. 三维重建虚拟置钉指导前路寰枢椎侧方关节螺钉内固定和齿状突螺钉内固定:3D打印模型的实验研究%Using simulated screw trajectories in three dimensional reconstruction to guide anterior C1-C2 transarticular screw fixation and odontoid screw fixation in 3D printed models

    Institute of Scientific and Technical Information of China (English)

    翁万青; 田乃锋; 王鉴顺; 王胜; 王向阳; 徐华梓; 吴爱悯; 池永龙

    2016-01-01

    目的 探讨术前运用3D打印模型进行三维重建虚拟置钉指导前路寰枢椎侧方关节螺钉和齿状突螺钉内固定的可行性. 方法 对30例正常成人的寰枢椎CT数据进行三维重建并打印骨骼模型.首先模拟前路寰枢椎侧方关节螺钉内固定术,测量最内侧方角度、最外侧方角度,取平均值为侧偏角;最小向后角度、最大向后角度,取平均值为后偏角.再次模拟齿状突螺钉内固定术,测量侧偏角、后偏角.以三维虚拟置钉结果为参考,指导三维打印模型实验置钉,分别测量前路寰枢椎侧方关节螺钉、齿状突螺钉的侧偏角和后偏角,侧偏角和后偏角,与对应的影像学数据进行对比. 结果 前路寰枢椎侧方关节螺钉内固定术三维重建虚拟置钉测得左、右侧侧偏角平均分别为21.80°±3.97°、21.54°±4.04°,后偏角平均分别为29.34°±4.48°、28.90°±4.49°.在3D打印模型中实验置钉测得左、右侧侧偏角分别为21.18°±4.95°、20.69°±4.40°,后偏角平均分别为28.88°±4.84°、28.22°±4.48°.齿状突螺钉内固定术三维虚拟置钉测得侧偏角和后偏角平均分别为0.40°±0.86°、27.16°±3.38°.在3D打印模型中实验置钉测得侧偏角和后偏角平均分别为0.24°±0.85°、27.52°±3.64°.对比分析发现三维重建模型置钉数据与相应的3D打印模型实验置钉数据基本相近,差异均无统计学意义(P>0.05). 结论 术前运用3D打印模型可以进行CT三维重建模拟精确置钉指导前路寰枢椎相应的螺钉和齿状突螺钉内固定.这种术前模拟实验手术可以作为教学和临床应用参考.%Objective To provide a preoperative protocol for surgeons by investigating the optimal screw trajectories in 3D images to guide the internal fixation with anterior atlantoaxial transarticular screws and anterior odontoid screws in 3D printed models of upper cervical spine.Methods Computed tomography (CT) scans of 30 adult

  11. Intra- and postoperative complications of navigated and conventional techniques in percutaneous iliosacral screw fixation after pelvic fractures

    DEFF Research Database (Denmark)

    Zwingmann, Jörn; Südkamp, Norbert P; König, Benjamin;

    2013-01-01

    and the small target corridor for the iliosacral screw may be difficult to visualise using an image intensifier. 2D and 3D navigation techniques may therefore be helpful tools. The aim of this multicentre study was to evaluate the intra- and postoperative complications after percutaneous screw implantation...... by classifying the fractures using data from a prospective pelvic trauma registry. The a priori hypothesis was that the navigation techniques have lower rates of intraoperative and postoperative complications. METHODS: This study is based on data from the prospective pelvic trauma registry introduced...... were identified. Out of these a further analysis was performed in 597 patients suffering injuries of the SI joint (187×with surgical interventions) and 597 patients with sacral fractures (334×with surgical interventions). The rate of intraoperative complications was not significantly different, with 10...

  12. A prospective, randomized, controlled trial of robot-assisted vs freehand pedicle screw fixation in spine surgery.

    Science.gov (United States)

    Kim, Ho-Joong; Jung, Whan-Ik; Chang, Bong-Soon; Lee, Choon-Ki; Kang, Kyoung-Tak; Yeom, Jin S

    2017-09-01

    The purpose of this study was to compare the accuracy and safety of an instrumented posterior lumbar interbody fusion (PLIF) using a robot-assisted minimally invasive (Robot-PLIF) or a conventional open approach (Freehand-PLIF). Patients undergoing an instrumented PLIF were randomly assigned to be treated using a Robot-PLIF (37 patients) and a Freehand-PLIF (41 patients). For intrapedicular accuracy, there was no significant difference between the groups (P = 0.534). For proximal facet joint accuracy, none of the 74 screws in the Robot-PLIF group violated the proximal facet joint, while 13 of 82 in the Freehand-PLIF group violated the proximal facet joint (P Robot-PLIF and Freehand-PLIF groups, respectively (P Robotic-assisted pedicle screw placement was associated with fewer proximal facet joint violations and better convergence orientations. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Clinical effects of posterior pedicle screw fixation on spinal deformity in growing period: a report of 360 cases

    Directory of Open Access Journals (Sweden)

    Zheng-lei WANG

    2011-08-01

    Full Text Available Objective To observe the effect of a new kind of pedicle screw frame system with sliding terminus and locked middle segment on spinal deformity in growing period.Methods Three hundred and sixty patients in growing period were involved in the present study,and among them 82 were suffering from congenital scoliosis,218 idiopathic scoliosis and 60 kyphosis.All the patients were treated with the pedicle screw frame system with sliding terminus and locked middle segment.The treatment effects and postoperative complications were observed,and the Cobb angle before and after the operation was compared.Results The Cobb angle of 300 scoliosis patients was corrected from 53°±3° to 8°±2°,and the Cobb angle of 60 kyphosis patients was corrected from 60°±2° to 25°±3°,and the corrective effect was satisfactory.The correction rate of patients with Cobb angle ≤50° was 80%.Two hundred and ten patients were followed-up for 1 to 6 years,and the longitudinal growth of spine was 1.5-4.0cm.No severe complication,such as screw fracture,rod fracture or nerve injury,occurred.Conclusion The pedicle screw frame system with sliding terminus had a favorable three-dimensional correction effect,and the spine growth would not be restricted,and there was no stiffness,vertebral rotation,or distortion of shaft after operation.

  14. Pedicle lag screw fixation in the treatment of Hangman's fracture%椎弓根拉力螺钉内固定治疗Hangman骨折

    Institute of Scientific and Technical Information of China (English)

    刘德宝; 张复文; 卜海富; 胡孔足; 周健

    2012-01-01

    探讨应用椎弓根拉力螺钉技术治疗Hangman骨折的临床疗效.方法 对12例Hangman骨折患者经颅骨牵引获得复位后,行C2椎弓根拉力螺钉内固定术治疗.术后行X线片检查观察骨折复位及愈合情况.结果 手术时间50~90min,失血量100~300ml.术中无脊髓神经损伤,骨折复位满意.12例均获随访,时间3~36个月.骨折完全愈合,无迟发畸形.2例脊髓神经损伤者术前Franke1分级为D级,术后3~6个月均恢复至E级.结论 C2椎弓根拉力螺钉技术治疗Hangman骨折,复位满意,固定可靠,疗效满意.%Objective To stuty the clinical outcomes of Hangman's fracture treated by using pedicle lag screw fixation. Methods 12 patients with Hangman's fracture were recruited. All patients achieved reduction by skull traction, and fixed with C2 pedicle lag screw. X-ray was performed during the follow-up to observe fracture reduction and healing process. Results The operation time was 50 ~ 90 minutes, and the blood loss was 100 ~ 300 ml. And intra-operative no spinal nerves injury the reduction of the Hangman's fracture was satisfied. No postoperative complications were confirmed. 12 cases were followed up for 3~36 months. All got healing without deformity. 2 cases of Frankel D were restored to E in 3 ~ 6 months. Conclusions Pedicle lag screw fixation provides good reduction and stability to Hangman's fracture. It is a less trauma, safe and effective method in the treatment of Hangman's fracture.

  15. Surgical Technique of Cannulated Screw Placement Guided by 3D Printing Template in Pediatric Femoral Neck Fracture%3D打印个体化手术导航模板引导儿童股骨颈骨折空心螺钉置入的应用

    Institute of Scientific and Technical Information of China (English)

    郑朋飞; 楼跃; 徐鹏; 唐凯

    2016-01-01

    目的:探讨利用计算机辅助设计和3D打印技术制作的个体化手术导航模板实现儿童股骨颈骨折空心螺钉精确置入的可行性。方法:选取1例儿童股骨颈骨折患者,依据CT数据使用计算机辅助模拟骨折复位和股骨颈空心螺钉置入过程,通过软件设计并打印出与复位后股骨近端匹配的经颈螺钉置入导航模板,术前3D模型模拟手术验证可行后,术中在导航模板辅助下置入导针及螺钉。结果:3D打印的导航模板术中与股骨近端骨性标志匹配良好,能够辅助螺钉精确置入股骨颈并稳定骨折端,螺钉置入后经术中X检查与术前设计基本一致。螺钉置入的手术时间约为12min,术中使用X线透视仅4次。术后X线片示股骨颈骨折复位良好,两枚空心螺钉的进钉点、进钉方向、螺钉长度均与术前设计方案一致,螺钉未损伤骺板。术后3个月随访,股骨颈骨折临床愈合,按Ratliff评价标准评价髋关节术后功能情况为优,螺钉无松动、断裂。结论:3D打印个体化手术导航模板可以辅助股骨颈空心螺钉的精确置入,减少医源性股骨颈骨骺及血供损伤,节省手术时间,减少术中出血,减少患者及手术操作人员的射线暴露,值得推广应用。%Objective: To investigate the feasibility and accuracy of a drill template for the placement of screws in femoral neck based on digital design and 3D printing technology. Methods: The preoperative CT images of 1child with femoral neck fracture were collected. With the data, the individual proximal femur model was made by the 3D printer. The reduction of fracture and the cannulated screw of femoral neck were simulated by the computer. The screw which was through the femoral neck designed by the software and printed to match the proximal femur after reduction was placed into the navigate template. After the feasibility of the 3D model operation was

  16. Biomechanical changes and clinical characteristics of cervical pedicle screws internal fixation%颈椎椎弓根螺钉置入内固定的生物力学变化及其临床特性

    Institute of Scientific and Technical Information of China (English)

    王华刚; 杨飞

    2011-01-01

    背景:颈椎椎弓根钉由于其独特的三维稳定性,越来越多的学者对其进行更加广泛的研究.目的:综述颈椎椎弓根解剖特点及椎弓根螺钉置钉的安全性和临床应用.方法:应用计算机检索1994-01/2010-09 CNKI及PubMed数据库相关文章,中文检索词为"颈椎弓根螺钉",英文检索词为"cervical pedicle screws",共检索到文献292篇,最终纳入符合标准的文献43篇.结果与结论:通过文献检索获得目前一致的观点认为颈椎弓根内固定由于是三维固定,因此可以获得良好的生物力学.但是,由于颈椎弓根周围毗邻部特殊的解剖结构,潜在血管、神经根和颈髓损伤的危险性,置入内固定风险及难度大,所以临床应用要做到个体化置钉.%BACKGROUND: More and more scholars have focused on cervical pedicle screws because of their unique three-dimensional stability.OBJECTIVE: To review the anatomic characteristics of the cervical pedicle, and to investigate the safety and clinical application of cervical pedicle screws.METHODS: The literature concerning the cervical pedicle screw internal fixation in recent years were extensively searched from CNKl and PubMed databases (1994-01/2010-09) using the keywords of "cervical pedicle screws" in Chinese and English. Forty-three articles of 292 were included in the result analysis.RESULTS AND CONCLUSION: Cervical pedicle screw fixation can obtain a good biomechanics based on its three-dimensional fixation. However, due to the special anatomic structures of the cervical pedicle adjacent to the surrounding, potential risks of blood vessel, nerve root and cervical spinal cord injuries, it is difficult to the internal fixation of cervical pedicle screws with a certain risk. The clinical application of pedicle screws should be individualized.

  17. Análise fotoelástica de parafuso de sistema de fixação vertebral The photoelastic analisys of vertebral fixation system screws

    Directory of Open Access Journals (Sweden)

    Sarah Fakher Fakhouri

    2009-01-01

    Full Text Available INTRODUÇÃO: A fotoelasticidade é utilizada para avaliar as tensões/deformações produzidas nos materiais fotoelásticos, quando submetidos a determinado carregamento, através da observação de efeitos óticos. O desempenho do parafuso e as funções mecânicas estão diretamente relacionados com a qualidade da fixação dos parafusos nas vértebras. A fotoelasticidade é uma ferramenta importante para realizar estudos comparativos desta natureza. OBJETIVO: O objetivo deste estudo foi comparar por meio da fotoelasticidade, as tensões internas produzidas pelo parafuso com 6 mm de diâmetro externo, quando submetido a duas diferentes forças de arrancamento. MATERIAIS E MÉTODOS: Para isso, foram confeccionados quatro modelos fotoelásticos. A simulação foi realizada utilizando duas forças de arrancamento 0,75 e 1,50 kgf. As tensões cisalhantes foram calculadas nos 19 pontos em torno dos parafusos, utilizando o método de compensação de Tardy. RESULTADOS: Os valores das tensões cisalhantes foram maiores quando utilizada a força de arrancamento de 1,50 kgf. CONCLUSÃO: Assim sendo, o parafuso estará mais suscetível ao arrancamento com a aplicação de força de maior intensidade. De acordo com as análises realizadas verificamos também que o local de maior tensão cisalhante foi observado no pico das cristas, principalmente próxima às pontas dos parafusos, independente da força utilizada.INTRODUCTION: The photoelasticity is used for assessing the tensions/deformations involved in photoelastic materials when submitted to a given load by the observation of optical effects. The screw performance and mechanical functions are directly associated to the quality of the screws fixation in the vertebrae. Photoelasticity is an important tool to perform comparative studies of this nature OBJECTIVE: The aim of this study was to compare, by using photoelasticity, internal stresses produced by the screw with an external diameter of 6 mm

  18. Patella fracture fixation with suture and wire: you reap what you sew.

    Science.gov (United States)

    Egol, Kenneth; Howard, Daniel; Monroy, Alexa; Crespo, Alexander; Tejwani, Nirmal; Davidovitch, Roy

    2014-01-01

    Operative fixation of displaced inferior pole patella fractures has now become the standard of care. This study aims to quantify clinical, radiographic and functional outcomes, as well as identify complications in a cohort of patients treated with non-absorbable braided suture fixation for inferior pole patellar fractures. These patients were then compared to a control group of patients treated for mid-pole fractures with K-wires or cannulated screws with tension band wiring. In this IRB approved study, we identified a cohort of patients who were diagnosed and treated surgically for a displaced patella fracture. Demographic, injury, and surgical information were recorded. All patients were treated with a standard surgical technique utilizing non-absorbable braided suture woven through the patellar tendon and placed through drill holes to achieve reduction and fracture fixation. All patients were treated with a similar post-operative protocol and followed up at standard intervals. Data were collected concurrently at follow up visits. For purpose of comparison, we identified a control cohort with middle third patella fractures treated with either k-wires or cannulated screws and tension band technique. Patients were followed by the treating surgeon at regular follow-up intervals. Outcomes included self-reported function and knee range of motion compared to the uninjured side. Forty-nine patients with 49 patella fractures identified retrospectively were treated over 9 years. This cohort consisted of 31 females (63.3%) and 18 males (36.7%) with an average age of 57.1 years (range 26-88 years). Patients had an average BMI of 26.48 (range 19-44.08). Thirteen patients with inferior pole fractures underwent suture fixation and 36 patients with mid-pole fractures underwent tension band fixation (K-wire or cannulated screws with tension band). In the suture cohort, one fracture failed open repair (7.6%), which was revised again with sutures and progressed to union. Of the 36

  19. Posterior transodontoid fixation: A new fixation (Kotil technique

    Directory of Open Access Journals (Sweden)

    Kadir Kotil

    2011-01-01

    Full Text Available Anterior odontoid screw fixation or posterior C1-2 fusion techniques are routinely used in the treatment of Type II odontoid fractures, but these techniques may be inadequate in some types of odontoid fractures. In this new technique (Kotil technique, through a posterior bilateral approach, transarticular screw fixation was performed at the non-dominant vertebral artery (VA side and posterior transodontoid fixation technique was performed at the dominant VA side. C1-2 complex fusion was aimed with unilateral transarticular fixation and odontoid fixation with posterior transodontoid screw fixation. Cervical spinal computed tomography (CT of a 40-year-old male patient involved in a motor vehicle accident revealed an anteriorly dislocated Type II oblique dens fracture, not reducible by closed traction. Before the operation, the patient was found to have a dominant right VA with Doppler ultrasound. He was operated through a posterior approach. At first, transarticular screw fixation was performed at the non-dominant (left side, and then fixation of the odontoid fracture was achieved by directing the contralateral screw (supplemental screw medially and toward the apex. Cancellous autograft was scattered for fusion without the need for structural bone graft or wiring. Postoperative cervical spinal CT of the patient revealed that stabilization was maintained with transarticular screw fixation and reduction and fixation of the odontoid process was achieved completely by posterior transodontoid screw fixation. The patient is at the sixth month of follow-up and complete fusion has developed. With this new surgical technique, C1-2 fusion is maintained with transarticular screw fixation and odontoid process is fixed by concomitant contralateral posterior transodontoid screw (supplemental screw fixation; thus, this technique both stabilizes the C1-2 complex and fixes the odontoid process and the corpus in atypical odontoid fractures, appearing as an

  20. Biomechanical rationale for implant choices in femoral neck fracture fixation in the non-elderly.

    Science.gov (United States)

    Panteli, Michalis; Rodham, Paul; Giannoudis, Peter V

    2015-03-01

    Femoral neck fractures represent a relatively uncommon injury in the non-elderly population often resulting from high-energy trauma. The cornerstone of their management is anatomic reduction and stable internal fixation of the femoral neck in an attempt to salvage the femoral head. Complications including avascular necrosis of the femoral head, non-union and post-traumatic osteoarthritis are not uncommon. The clinical outcomes of these patients can be improved with good pre-operative planning, optimization of surgical procedures and introduction of new improved implants and techniques. In the herein study, we attempt to describe the biomechanical properties of the hip and compare the performance of the most commonly used devices. Experimental evidence suggests that in Pauwels type III fracture patterns a cephalomedullary nail was significantly stronger in axial loading. Moreover, in unstable basicervical patterns cannulated screws (triangular configuration) demonstrated a lower ultimate load to failure, whereas in subcapital or transervical patterns both the cannulated screws (triangular configuration) and the sliding hip screw demonstrated no compromise in fixation strength. The fracture pattern appears to be the major determinant of the ideal type of implant to be selected. For a successful outcome each patient needs to be considered on an individual basis taking into account all patient and implant related factors.

  1. C2椎弓根 C3侧块螺钉固定治疗不稳定性 Hangman 骨折%C2 Pedicle Screw C3 Lateral Mass Screw Fixation for Treatment of Unstable Hangman Fracture

    Institute of Scientific and Technical Information of China (English)

    吴磊磊; 邱玉金; 李攀

    2012-01-01

      Objective To evaluate the clinical effect of unstable Hangman fracture treated with C 2 pedicle screw C3 lateral mass screw fixation.Methods From July 2003 to July 2011,32 cases of patients with unstable Hangman fracture were treated in our hospital . Based on Levine-Edwards classification,typeⅡ-14 cases,typeⅡA -15 cases,type Ⅲ -3 cases.All the cases were treated with C 2 pedicle screw C3 lateral mass screw fixation.Results There was no spinal cord and vertebral artery injury or other complications during the opera -tion.All the patients were followed up from 3th to 24th months,average of 13.7months and got bony fusion.The preoperative displacement of C2 ~3 vertebral bodies was (5.7 ±1.3)mm,the postoperative displacement of C 2 ~3 vertebral bodies followed up for 6 months was(2.3 ±1.7) mm,P <0.05;The preoperative angulation of C 2 ~3 vertebral bodies was 12.6°±1.4°,the postoperative angulation of C 2 ~3 vertebral bodies followed up for 6 months was 7.3°±1.7°,P <0.05;based on JOA 17 scores for assessment of spinal cord function ,the preoperative score was 6.3 ±0.3,the postoperative score followed up for 6 months was 13.5 ±1.1,the recovery rate of nervous function was 67%.Conclusion For treatment of unstable Hangman fracture ,C2 pedicle screw C3 lateral mass screw fixation is an effective method .

  2. Coracoid bone graft osteolysis after Latarjet procedure: A comparison study between two screws standard technique vs mini-plate fixation.

    Science.gov (United States)

    Giacomo, Giovanni Di; Costantini, Alberto; de Gasperis, Nicola; De Vita, Andrea; Lin, Bernard K H; Francone, Marco; Beccaglia, Mario A Rojas; Mastantuono, Marco

    2013-01-01

    One of the reason for Latarjet procedure failure may be coracoid graft osteolysis. In this study, we aimed to understand if a better compression between the coracoid process and the glenoid, using a mini-plate fixation during the Latarjet procedure, could reduce the amount of coracoid graft osteolysis. A computed tomography scan analysis of 26 prospectively followed-up patients was conducted after modified Latarjet procedure using mini-plate fixation technique to determine both the location and the amount of coracoid graft osteolysis in them. We then compared our current results with results from that of our previous study without using mini-plate fixation to determine if there is any statistical significant difference in terms of corcacoid bone graft osteolysis between the two surgical techniques. The most relevant osteolysis was represented by the superficial part of the proximal coracoid, whereas the deep part of the proximal coracoid graft is least involved in osteolysis and has best bone healing. The current study showed a significant difference only for the deep part of the distal coracoid with our previous study (P Latarjet procedure. Our study suggests that there is a significant difference only for the deep part of the distal coracoid in terms of osteolysis. At clinical examination, this difference did not correspond with any clinical findings. Level 4. Prospective case series, Treatment study.

  3. Bony healing of unstable thoracolumbar burst fractures in the elderly using percutaneously applied titanium mesh cages and a transpedicular fixation system with expandable screws.

    Directory of Open Access Journals (Sweden)

    Anica Eschler

    Full Text Available There is a high incidence of vertebral burst fractures following low velocity trauma in the elderly. Treatment of unstable vertebral burst fractures using the same principles like in stable vertebral burst fractures may show less favourable results in terms of fracture reduction, maintenance of reduction and cement leakage. In order to address these shortcomings this study introduces cementless fixation of unstable vertebral burst fractures using internal fixators and expandable intravertebral titanium mesh cages in a one-stage procedure via minimum-invasive techniques.A total of 16 consecutive patients (median age 76 years, range 58-94 with unstable thoracolumbar burst fractures and concomitant osteoporosis were treated by an internal fixator inserted via minimum invasive technique one level above and below the fractured vertebra. Fracture reduction was achieved and maintained by transpedicular placement of two titanium mesh cages into the fractured vertebral body during the same procedure. Intra- and postoperative safety of the procedure as well as analysis of reduction quality was analysed by 3D C-arm imaging or CT, respectively. Clinical and radiographic follow-up averaged 10.4 months (range 4.5-24.5.Stabilization of the collapsed vertebral body was achieved in all 16 cases without any intraoperative complication. Surgical time averaged 102 ± 6.6 minutes (71-194. The postoperative kyphotic angle (KA and Cobb angle revealed significant improvements (KA 13.7° to 7.4°, p < 0.001; Cobb 9.6° to 6.0°, p < 0.002 with partial loss of reduction at final follow-up (KA 8.3°, Cobb 8.7°. VAS (Visual Analogue Scale improved from 7.6 to 2.6 (p < 0.001. Adjacent fractures were not observed. One minor (malposition of pedicle screw complication was encountered.Cementless fixation of osteoporotic burst fractures revealed substantial pain relief, adequate maintenance of reduction and a low complication rate. Bony healing after unstable osteoporotic burst

  4. One Case of Patient had an Allergy to Internal Fixation with Metal of Pedicle Screw System%椎弓根系统内固定金属过敏一例报道

    Institute of Scientific and Technical Information of China (English)

    王勇; 陈久毅

    2013-01-01

    Internal fixation with metal in the Department of orthopedics is a common treatment method. Metal implants allergy have been reported, but relatively rare. This paper reported a case of patient in our hospital had an allergy to internal fixation with metal of pedicle screw system.%  金属内固定在骨科为常见的治疗方法,金属内植物过敏曾有报道,但较为少见,现将我院椎弓根系统内固定过敏一例报道如下。

  5. Therapeutic efficacy of pedicle screw-rod internal fixation after one-stage posterior transforaminal lesion debridement and non-structural bone grafting for tuberculosis of lumbar vertebra

    Directory of Open Access Journals (Sweden)

    Jia-ming LIU

    2015-11-01

    Full Text Available Objective To evaluate the efficacy and safety of pedicle screw-rod internal fixation after one-stage posterior transforaminal lesion debridement and non-structural bone grafting in the treatment of tuberculosis of mono-segmental lumbar vertebra. Methods From January 2010 to April 2013, 21 patients (9 males and 12 females with an average age of 49.1 years with mono-segmental tuberculosis of lumbar vertebra underwent surgery in our hospital were included. Eight patients had neurological deficit. The focus of tuberculosis was located on one side of the vertebral body, and all the patients had obvious signs of bone destruction on CT and MRI. All the patients were given anti-tuberculosis chemotherapy for 2-3 weeks before surgery. The local bone chips and autologous iliac cancellous bone were used as the intervertebral bone graft. Postoperative plain radiographs and CT were obtained to evaluate the fusion rate and degree of lumbar lordosis. The visual analogue scale score (VAS, erythrocyte sedimentation rate (ESR, and C-reactive protein (CRP before and after operation, and at final follow-up date were recorded. Results All the patients were followed up for 25.3±4.2 months. The mean operation time was 157±39 minutes, and the average blood loss was 470±143ml. The fusion rate of the interbody bone graft was 95.2%, with an average fusion period of 6.1±2.5 months. The neurological function was improved by 100%, and no severe complication or neurological injury occured. The preoperative and postoperative lordosis angles of the lumbar spine were 21.4°±5.7° and 33.6°±3.1°, respectively, and it was 31.3°±2.7° at the final follow up. The preoperative and postoperative VAS scores were 7.8±2.6 and 2.4±1.7 respectively, and it was 0.9±0.7 at the final follow up. The ESR and CRP were significantly decreased 3 months after surgery, and they became normal at 6 months. Conclusion Pedicle screw-rod internal fixation after one-stage posterior

  6. Treatment of acute thoracolumbar burst fractures with kyphoplasty and short pedicle screw fixation: Transpedicular intracorporeal grafting with calcium phosphate: A prospective study

    Directory of Open Access Journals (Sweden)

    Korovessis Panagiotis

    2007-01-01

    Full Text Available Background: In the surgical treatment of thoracolumbar fractures, the major problem after posterior correction and transpedicular instrumentation is failure to support the anterior spinal column, leading to loss of correction and instrumentation failure with associated complaints. We conducted this prospective study to evaluate the outcome of the treatment of acute thoracolumbar burst fractures by transpedicular balloon kyphoplasty, grafting with calcium phosphate cement and short pedicle screw fixation plus fusion. Materials and Methods : Twenty-three consecutive patients of thoracolumbar (T 9 to L 4 burst fracture with or without neurologic deficit with an average age of 43 years, were included in this prospective study. Twenty-one from the 23 patients had single burst fracture while the remaining two patients had a burst fracture and additionally an adjacent A1-type fracture. On admission six (26% out of 23 patients had neurological deficit (five incomplete, one complete. Bilateral transpedicular balloon kyphoplasty with liquid calcium phosphate to reduce segmental kyphosis and restore vertebral body height and short (three vertebrae pedicle screw instrumentation with posterolateral fusion was performed. Gardner kyphosis angle, anterior and posterior vertebral body height ratio and spinal canal encroachment were calculated pre- to postoperatively. Results : All 23 patients were operated within two days after admission and were followed for at least 12 months after index surgery. Operating time and blood loss averaged 45 min and 60 cc respectively. The five patients with incomplete neurological lesions improved by at least one ASIA grade, while no neurological deterioration was observed in any case. The VAS and SF-36 (Role physical and Bodily pain domains were significantly improved postoperatively. Overall sagittal alignment was improved from an average preoperative 16° to one degree kyphosis at final follow-up observation. The anterior

  7. Coracoid bone graft osteolysis after Latarjet procedure: A comparison study between two screws standard technique vs mini-plate fixation

    Directory of Open Access Journals (Sweden)

    Giovanni Di Giacomo

    2013-01-01

    Full Text Available Aims: One of the reason for Latarjet procedure failure may be coracoid graft osteolysis. In this study, we aimed to understand if a better compression between the coracoid process and the glenoid, using a mini-plate fixation during the Latarjet procedure, could reduce the amount of coracoid graft osteolysis. Materials and Methods: A computed tomography scan analysis of 26 prospectively followed-up patients was conducted after modified Latarjet procedure using mini-plate fixation technique to determine both the location and the amount of coracoid graft osteolysis in them. We then compared our current results with results from that of our previous study without using mini-plate fixation to determine if there is any statistical significant difference in terms of corcacoid bone graft osteolysis between the two surgical techniques. Results: The most relevant osteolysis was represented by the superficial part of the proximal coracoid, whereas the deep part of the proximal coracoid graft is least involved in osteolysis and has best bone healing. The current study showed a significant difference only for the deep part of the distal coracoid with our previous study (P < 0.01. Discussion: To our knowledge, there are no studies in literature that show the causes of coracoid bone graft osteolysis after Latarjet procedure. Conclusion: Our study suggests that there is a significant difference only for the deep part of the distal coracoid in terms of osteolysis. At clinical examination, this difference did not correspond with any clinical findings. Level of Evidence: Level 4. Clinical Relevance: Prospective case series, Treatment study.

  8. 螺钉置入内固定修复后踝骨折的适应证%Indications for screw fixation of posterior malleolas fractures

    Institute of Scientific and Technical Information of China (English)

    程渊; 高仕长; 倪卫东; 梁安霖

    2015-01-01

    BACKGROUND:Posterior maleolar fractures are often accompanied by ankle joint instability,if the stability of ankle joint is not recovered,it is prone to traumatic arthritis of the ankle.However,the indications of internal fixation of posterior maleolar fractures remain controversial.OBJECTIVE:To explore the indications for internal fixation of posterior maleolar fractures by comparing the clinical effects of posterior maleolar fractures treated with internal fixation or not.METHODS:42 patients with maleolar fractures involving posterior ankle were recruited from the First Affiliated Hospital of Chongqing Medical University from January 2007 to January 2012.According to preoperative CT scans of ankle joint,42 cases were divided into the internal fixation group and the non-fixation group.27 cases in the fixation group had posterior maleolar fractures in more than 10%of the distal tibial articular surface and/or dislocation of the posterior maleolar fractures greater than 2 mm,and were treated with screws.15 cases in the non-fixation group had posterior maleolar fractures in less than 10%of the distal tibial articular surface anddislocation of the posterior maleolar fractures less than 2 mm,and were treated with non-operation.The average healing time of posterior maleolar fractures,postoperative complications,ankle-hindfoot scores of American Orthopedic Foot and Ankle Society were compared during the folow-up postoperatively.RESULTS AND CONCLUSION:Al of 42 patients with ankle fractures achieved bony union within 6 months.In the fixation group,1 case had postoperative superficial infection of the wounds in the medial ankle and lateral ankle,and the wound got healed completely with anti-infection therapy.One case in each group had postoperative superficial necrosis in the incisional edges,and got healed by dress changing.For the other cases,there was no wound infection,internal fixation loosening,breakage or failure and other adverse events during the folow

  9. 单侧椎弓根螺钉固定在腰椎退行性疾病的研究进展%Research advances in the fixation of unilateral pedicle screw for lumber degenerative

    Institute of Scientific and Technical Information of China (English)

    黄凯; 刘展亮; 刘少喻

    2014-01-01

    The patients with lumber degenerative spondylolisthesis often have to undergo surgical treatment. Conventional surgical approach is performed by bilateral pedicle screw fixation in lumbar interbody fusion, and this maybe accelerate segment degeneration of adjacent vertebral bodies. The recent studies indicate that unilateral pedicle screw fixation in lumbar interbody fusion can achieve the same effect on stability and interbody fusion by using conventional bilateral pedicle screw fixation in lumbar interbody fusion,.and prevent from segment degeneration of vertebral bodies. But the operation indication must be restrictedly controlled, the operation technique be skilled.%保守失败的腰椎退行性疾病常需要手术治疗,传统的双侧椎弓根螺钉腰椎融合术可能增加邻近节段退变的发生率。近年研究表明,单侧椎弓根螺钉结合椎体间融合术治疗腰椎退行性疾病可获得与传统双侧椎弓根螺钉固定相似的稳定性与融合率,并可预防固定融合节段的邻近节段退变,但应用单侧椎弓根螺钉固定需要严格掌握手术适应证。

  10. Clinical observation of posterior internal fixation with vertebral pedicle screw and rod system on thoracolumbar spine fractures%椎弓根钉棒系统在胸腰椎骨折的疗效分析

    Institute of Scientific and Technical Information of China (English)

    黎华茂; 李敬中; 向峥; 林晓岗

    2012-01-01

    Objective To observe the clinical efficacy of posterior internal fixation of vertebral pedicle screw and rod system for thoracolumbar spine fractures. Methods Totally 59 patients with thoracic or lumbar vertebral fractures were treated with internal fixation of vertebral pedicle screw and rod system. The Frankel scale combined with X ray and CT images was used for the judgment of efficacy. Results Radiographic parameters were significantly improved after the experiment, the Frankel degree of cases with nerve injury symptoms was improved 2-4 degrees after surgery. Conclusions Internal fixation of vertebral pedicle screw and rod system is efficient for thoraco lumbar spine fractures.%目的 观察椎弓根钉棒系统内固定治疗胸腰椎骨折的临床疗效.方法 应用椎弓根钉棒系统内固定治疗胸腰椎骨折59例,采用Frankel分级结合X线片、CT影像表现判断疗效.结果 术后各项影像学指标均有明显改善,患者术后神经功能Frankel分级大多数都有2~4级提高.结论 椎弓根钉棒系统内固定是治疗胸腰椎骨折的一种有效方法,值得临床推广应用.

  11. Treatment of stress fracture of the olecranon in throwing athletes with internal fixation through a small incision

    Directory of Open Access Journals (Sweden)

    Fujioka Hiroyuki

    2012-12-01

    Full Text Available Abstract The present study is a report of retrospective case series of stress fracture of the olecranon. Six patients presented posterior elbow pain in throwing in baseball and softball, but fracture was not diagnosed in radiographs. We detected stress fracture of the olecranon using computed tomographic (CT scan and treated the patient with internal fixation with a headless cannulated double threaded screw through a small skin incision. All patients returned to competitive level without elbow complaints after the operation. When throwing athletes present with unusual posterior elbow pain and no significant findings on radiographs, a CT scan examination should be performed. We recommend surgical treatment of internal fixation with a screw through a small skin incision, as a good option for stress fracture of the olecranon in order to allow early return to sports activity in competitive athletes.

  12. 中青年胸腰椎骨折经皮椎弓根钉棒系统短节段内固定术后螺钉断裂浅析%Analysis on Percutaneous Pedicle Screw Rod System With Short Segment Fixation After Screw Fracture in Young Thoracolumbar Fractures

    Institute of Scientific and Technical Information of China (English)

    高飞; 阿日奔吉日嘎啦; 姜富祥; 王兴; 张弘来; 王高强

    2016-01-01

    Objective TTo explore the causes of percutaneous pedicle screw rod system with short segment ifxation after screw fracture in young thoracolumbar fractures.Methods54 cases of thoracolumbar vertebral fracture percutaneous pedicle nail stick system short segment internal fixation in young patients, 4 cases of postoperative screw fracture, the clinical data were retrospectively analyzed.Results in this group of patients appear screw breakage was 7.40%. The main cause of the fracture of the screw for pedicle screw insertion angle deviation, connecting rod camber is too large.Conclusion The mechanical stability and gravity load of the percutaneous pedicle screw rod system are important reasons for the screw breakage.%目的:探讨中青年胸腰椎骨折经皮椎弓根钉棒系统短节段内固定术后螺钉断裂的原因。方法54例行胸腰段椎体骨折经皮椎弓根钉棒系统短节段内固定术的中青年患者中,4例术后发生螺钉断裂,将其临床资料进行回顾性分析。结果本组病例出现螺钉断裂为7.40%,原因为椎弓根钉置入角度不适,连接棒弯度过大。对比剩余50例螺钉未出现断裂病例(P<0.05)。结论经皮椎弓根钉棒系统自身的力学稳定性和重力负荷是导致螺钉断裂的重要原因。

  13. Pectoralis Major Tear with Retracted Tendon: How to Fill the Gap? Reconstruction with Hamstring Autograft and Fixation with an Interference Screw.

    Science.gov (United States)

    Baverel, L; Messedi, K; Piétu, G; Crenn, V; Gouin, F

    2017-01-01

    Rupture of the pectoralis major tendon is considered an uncommon injury and a significant number of ruptures are missed or diagnosed late, leading to a chronic tear. We report an open reconstruction technique and its outcomes in a case of chronic and retracted PM tear. At the last follow-up (12 months), the patient was pain-free, with a visual analogic scale at 0 all the time. He was very satisfied concerning the cosmetic and clinical results. The constant score was 93%, the SST value 95%, and the Quick DASH score 4.5. MRI performed one year postoperatively confirmed the continuity between PM tendon and graft, even if the aspect of the distal tendon seemed to be thinner than normal PM tendon. The excellent clinical outcomes at one-year follow-up suggest that PM tear with major tendon retraction can be reliably reconstructed with hamstring autograft, using a bioabsorbable screw to optimize the fixation device. This technique has proven its simplicity and efficiency to fill the gap.

  14. Pectoralis Major Tear with Retracted Tendon: How to Fill the Gap? Reconstruction with Hamstring Autograft and Fixation with an Interference Screw

    Directory of Open Access Journals (Sweden)

    L. Baverel

    2017-01-01

    Full Text Available Rupture of the pectoralis major tendon is considered an uncommon injury and a significant number of ruptures are missed or diagnosed late, leading to a chronic tear. We report an open reconstruction technique and its outcomes in a case of chronic and retracted PM tear. At the last follow-up (12 months, the patient was pain-free, with a visual analogic scale at 0 all the time. He was very satisfied concerning the cosmetic and clinical results. The constant score was 93%, the SST value 95%, and the Quick DASH score 4.5. MRI performed one year postoperatively confirmed the continuity between PM tendon and graft, even if the aspect of the distal tendon seemed to be thinner than normal PM tendon. The excellent clinical outcomes at one-year follow-up suggest that PM tear with major tendon retraction can be reliably reconstructed with hamstring autograft, using a bioabsorbable screw to optimize the fixation device. This technique has proven its simplicity and efficiency to fill the gap.

  15. 空心螺钉内固定术治疗Jones骨折32例分析%The analyses of 32 Jones fracture by using hollow screw internal fixation

    Institute of Scientific and Technical Information of China (English)

    唐兵; 秦定扬

    2010-01-01

    目的 观察空心螺钉内固定术治疗Jones骨折的临床疗效.方法 回顾性分析采用切开复位空心螺钉内固定术治疗Jones骨折32例患者的临床资料.结果 32例患者均治愈出院,平均随访18个月,根据Maryland足部评分系统评分:优25例,良6例,差1例,优良率96.9%.结论 空心螺钉内固定术治疗Jones骨折,操作简单,术后不用外固定,功能恢复快,并发症少,疗效满意.%Objective To analyze the therapy method and the therapeutic effect of Jones fracture by using hollow screw internal fixation.Methods All the Jones fractures were treated by open reduction hollow screw internal fixation and the plaster external fixation were not used after operation.Results The 32 cases with Jones fractures got excellent 25 cases,good 6cases and poor 1 case which used by Maryland foot score system to appraisal.All the cases were followed up for 6 months to 30 months and the average follow-up time is 18 months.Conclusion The treatment of hollow screw internal fixation was a satisfactory method to cure Jones fracture,which had get advantages of simple operation,small wound,short operation time,not external fixation,quick recovery and few complications.

  16. Biomechanics and stability of the spine after implantation with pedicle screw and cervical vertebral screw fixation%椎弓根螺钉及颈椎体螺钉置入内固定后的生物力学及稳定性比较

    Institute of Scientific and Technical Information of China (English)

    刘淼; 尚显文; 宁旭; 庄勇; 许顺恩

    2016-01-01

    BACKGROUND:From the point of view of human anatomy, the load of the spine is more. When the body moves, the range of activities, and activity are relatively large. After screws were implanted in the spine, if biomechanical properties and stability are not up to the standard, it easily leads to lack of grip force of screw and screw loosening so as to increase the incidence of complications after treatment. OBJECTIVE:To compare biomechanical properties and stability of the spine after insertion of pedicle screw and cervical vertebral screw into the spine. METHODS:100 vertebrae under human cervical spine specimens were analyzed and randomly divided into cervical vertebral screw fixation group and pedicle screw fixation group. Cervical vertebral screws and pedicle screws were implanted in lower cervical spine specimens. Electro Force 3510 material testing machine was used to test axial pul-out force, axial pul-out strength after the fatigue loading, and fixed stability. The biomechanical properties and stability were compared after two kinds of screws were implanted in the spine. RESULTS AND CONCLUSION:(1) Instantaneous pul out force and immediate pul out stiffness were significantly higher in the pedicle screw fixation group than in the cervical vertebral screw fixation group (P  目的:对比内固定椎弓根螺钉与颈椎体螺钉置入脊柱后的生物力学性能及其稳定性。  方法:选取100个人体下颈椎椎体标本进行分析,随机分为颈椎体螺钉组与内固定椎弓根螺钉组。分别将内固定椎弓根螺钉与颈椎体螺钉置入人体下颈椎标本中,采用Electro Force 3510材料试验机对标本进行轴向拔出力、疲劳加载后轴向拔出力、固定稳定性等生物力学测试,比较2种螺钉置入脊柱后的生物力学性能及其稳定性。  结果与结论:①内固定椎弓根螺钉组即时拔出力、即时拔出刚度均显著高于颈椎体螺钉组(P<0.05);②2组虽然疲劳

  17. 创伤性颈椎不稳后路钉棒固定重建稳定%Stability reconstruction of traumatic cervical vertebra by screw-rod fixation through posterior approach

    Institute of Scientific and Technical Information of China (English)

    周章彦; 朱轶; 谢彬; 林义文

    2012-01-01

    Objective To explore the therapeutic effect on treatment of traumatic instability of cervical vertebra by pedicel screw through posterior approach or screw-rod fixation in lateral mass. Methods 30 patients of traumatic cervical vertebra instability were treated with grafting in cervical spinal lamina or between small joints by posterior transpedicular screw through posterior approach or screw-rod fixation in lateral mass. Results All cervical symptoms disappeared after operation and the damaged neurological function of cervical spinal cord were significantly improved. No complication was found in the follow up visits for 3 ~ 52 ( 10 ± 3. 2 ) months. The recovered cervical vertebra of all patients was of well fused and stable without looseness, fracture of interior fixation or displacement of grafting bone; the fracture was well healing and grafting bone was gradually fused with flexion range of extensible i05°±i0.5°, lateral 80° ±7. 2°, and axial rotation 96° ±9. 3°. Conclusions The treatment of the traumatic cervical vertebra by posterior transpedicular screw through posterior approach or screw-rod fixation in lateral mass reveals good reconstructed stability.%目的 探讨颈后路椎弓根钉或侧块螺钉-棒内固定治疗颈椎创伤性不稳临床效果.方法 对30例创伤性颈椎不稳患者行后路椎弓根钉或侧块螺钉-棒内固定,椎板或小关节间植骨.结果 术后颈部症状完全消失,受损颈髓神经功能明显改善.30例均获随访,时间3~52(10±3.2)个月,未发生并发症.颈椎复位良好,序列稳定;无内固定松动、断裂、植骨块移位;骨折愈合好,植骨渐进融合.颈椎伸屈角度105°±10.5°,侧屈角度80°±7.2°,轴向旋转功能96°±9.3°.结论 颈椎创伤性不稳采用经后路椎弓根钉或侧块螺钉-棒内固定治疗能够达到良好的稳定效果.

  18. Hollow screw and suture fixation for treatment of tibial intercondylar eminence fractures under arthroscopy%关节镜下空心螺钉与缝线内固定治疗胫骨髁间棘骨折

    Institute of Scientific and Technical Information of China (English)

    陈维东

    2013-01-01

    BACKGROUND:Intercondylar eminence fractures of the tibia are often treated by arthroscopic surgery, but the fixation methods are controversial. OBJECTIVE:To compare curative effect of hol ow screw and suture fixation in treatment of tibial intercondylar eminence fractures under arthroscopy. METHODS:A total of 46 patients with tibial intercondylar eminence fractures were recruited from the Third People’s Hospital of Yancheng, China from June 2010 to January 2013. According to the patient’s wil ing and physician’s suggestions, the involved patients were divided into hol ow screw group (n=25) and suture fixation group (n=21), undergoing hol ow screw and suture fixation under arthroscopy, respectively. RESULTS AND CONCLUSION:According to Ikeuchi grade, the excellent and good rate after fixation showed no significant differences between the two groups (P>0.05), but the functional training time in hol ow screw group was significantly shorter than that in suture fixation group (P  目的:比较关节镜下应用空心螺钉与缝线内固定治疗胫骨髁间棘骨折的临床疗效。  方法:收集盐城市第三人民医院自2010年6月至2013年1月收治的46例胫骨髁间棘骨折患者,根据患者意愿及医师建议分为空心螺钉组(n=25)和缝线组(n=21),分别在关节镜下行空心螺钉与缝线内固定。  结果与结论:空心螺钉组与缝线组胫骨髁间棘骨折患者固定后 Ikeuchi 膝关节评分优良率差异无显著性意义(P >0.05),但空心螺钉组患者固定后功能训练时间明显比缝线组短(P <0.05)。提示关节镜下空心螺钉治疗胫骨髁间棘骨折比缝线有利于胫骨髁间棘骨折患者的恢复。

  19. CT-guided screw fixation of vertical sacral fractures in local anaesthesia using a standard CT; CT-kontrollierte Schraubenosteosynthese von vertikalen Frakturen des hinteren Beckenringes in Lokalanaesthesie

    Energy Technology Data Exchange (ETDEWEB)

    Reuther, G.; Dehne, I. [Thueringen-Klinik, Saalfeld (Germany). Radiologische Klinik; Roehner, U.; Will, T.; Petereit, U. [Thueringen-Klinik, Saalfeld (Germany). Orthopaedics and Trauma Surgery

    2014-12-15

    To evaluate time efficiency, radiation dose, precision and complications of percutaneous iliosacral screw placement under CT-guidance in local anaesthesia. Retrospective analysis of 143 interventions in 135 patients during a period of 42 months. Implant failures could be evaluated in 85/182 screws and bony healing or refracturing in 46/182 screws. A total of 182 iliosacral screw placements in 179 vertical sacral fractures (105 unilateral, 37 bilateral) took place in 135 patients. 166/179 of the sacral fractures were detected in Denis zone 1, 10 in Denis zone 2 and 3 in Denis zone 3. No screw misplacements including the simultaneous bilateral procedures were noted. The average time for a unilateral screw placement was 23 minutes (range: 14-52 minutes) and 35 minutes (range: 21-60 minutes) for simultaneous bilateral screwing. The dose length product was 365 mGy x cm (range: 162-1014 mGy x cm) for the unilateral and 470 mGy x cm (range: 270-1271 mGy x cm) for the bilateral procedure. 1 gluteal bleeding occurred as the only acute minor complication (0.7%). Fracture healing was verified with follow-up CTs in 42/46 sacral fractures after screw placement. Backing out occurred in 12/85 screws between 6 and 69 days after intervention. In 8 patients contralateral stress fractures were detected after unilateral screw placement between day 10 and 127 (average: 48 days). CT-guided iliosacral screw placement in sacral fractures is a safe tool providing a very high precision. The radiation dose is in the order of a diagnostic CT of the pelvis for both unilateral and bilateral screws. Contralateral stress fractures in unilateral screw placements have to be considered during the first weeks after intervention.

  20. 三种置钉方法在下颈椎经椎弓根螺钉置入过程中的比较%A comparative study on pedicle screw internal fixation to the lower cervical vertebra by three screw place methods

    Institute of Scientific and Technical Information of China (English)

    尹华; 赵银必

    2011-01-01

    背景:目前各种下颈椎椎弓根置钉方法的准确率报道不一,特别是国内常用的椎板部分切除置钉法、Abumi法、管道疏通法缺乏比较.目的:探讨下颈椎(C3~7)经椎弓根螺钉内固定的可行性,比较椎板部分切除置钉法、Abumi法、管道疏通法在置钉满意率、出血量、置钉时间、并发症等方面的差异.方法:选择60例需颈后路经椎弓根螺钉内固定治疗的下颈椎疾患病例,随机分成3组,各置入椎弓根螺钉80枚,分别采用椎板部分切除置钉法、Abumi法及管道疏通法.术中计算各方法置钉时间、出血量;出院前观察置钉满意率及在颈椎椎弓根四壁损伤例数的构成比;比较C3~7每一节段的椎弓根外侧壁损伤发生率.结果与结论:椎板部分切除组、Abumi组及管道疏通组置钉时间依次递减(P 0.05),椎弓根损伤好发生于外壁.C4、C5节段外壁损伤发生率明显高于C3、C6、C7.提示管道疏通法在经颈后路椎弓根螺钉内固定常规置钉法中优势明显.%BACKGROUND: Nowadays there are so many screw place methods in lower cervical vertebra. But they have different accuracy.There was no comparative study on the pedicle screw internal fixation in lower cervical vertebra by three screw place methods such as vertebral plate partial resection screw place method, Abumi place screw method and pipeline dredge method.OBJECTIVE: To explore the feasibility of the pedicle screw internal fixation in lower cervical vertebra (C3-7), and to compare the differences in screw satisfaction rate, blood loss, screw placing time, complications among vertebral plate partial resection screw place method, Abumi screw place method, and pipeline dredge method.METHODS: Totally 60 patients with lower cervical spine disease who needed the pedicle screw internal fixation through cervical posterior approach were chosen and divided into three groups each with 80 pedicle screws by vertebral plate partial resection

  1. A clinical comparative analysis of the treatment between open short-segment pedicle screw fixation and percutaneous short-segment pedicle screw fixation for thoracolumbar fractures%伤椎置钉和经皮短节段固定治疗胸腰段椎体骨折的疗效比较

    Institute of Scientific and Technical Information of China (English)

    杨晓明; 徐宏光; 刘平; 王弘

    2016-01-01

    目的:对比开放伤椎置钉和经皮微创短节段固定治疗胸腰段椎体骨折的近期临床疗效。方法回顾性分析35例胸腰段椎体骨折患者,分为开放伤椎置钉短节段固定组(A 组)和经皮微创短节段固定组(B 组),测量手术前后骨折椎体压缩程度,椎体后凸畸形角度,疼痛视觉模拟评分(VAS)以及术后腰椎功能障碍指数(ODI),统计两组患者住院时间,手术失血和手术时间,并对以上参数进行对比分析。结果两组患者一般资料,术前骨折椎体压缩程度和 VAS 评分差异无统计学意义(P >0.05)。两组患者术后骨折椎体高度均有效恢复(P <0.05),且良好维持,术后 VAS 和 ODI 评分均较术前改善(P <0.05),且 B 组术后 ODI 评分优于 A 组。B 组在手术时间,失血量和住院时间上较 A 组缩短。结论两种手术方式均能有效恢复骨折椎体高度,改善术后功能,但经皮微创短节段固定在手术时间,失血量,住院时间和功能上要优于伤椎置钉短节段固定组。%Objective To comparatively analyze the clinical efficacies of the treatment between open short-segment pedicle screw fixa-tion including the fractured vertebra and percutaneous short-segment pedicle screw fixation for thoracolumbar fractures.Methods A retrospective analysis was made of 35 cases of thoracolumbar fractures which were assigned into open short-segment pedicle screw fixa-tion including the fractured vertebra(group A)and minimally invasive percutaneous short-segment pedicle screw fixation group(group B).The compression percentage of the fractured vertebra,vertebral kyphosis angle,visual analogue scale(VAS)of back pain and Oswe-stry Disability Index(ODI)were measured before and after surgery.Hospitalized time,blood loss and surgical time were also compara-tively analyzed between the two groups.Results The demographic data,compression percentage of vertebral

  2. Biomechanical comparison of interspinous distraction device and facet screw fixation system on the motion of lumbar spine: a finite element analysis

    Institute of Scientific and Technical Information of China (English)

    Wang Hongwei; Wang Xiaohong; Chen Wenchuan; Zhao Fuqiang; Xiang Liangbi; Zhou Yue; Cheng Chengkung

    2014-01-01

    Background A large amount of biomechanical and clinical evidence from previous studies suggest the efficiency of the two different posterior lumber non-fusion methods,interspinous distraction device (ISDD) and facet screw fixation system (FSS),but the biomechanical comparison of ISDD and FSS has not been thoroughly clarified.Methods In the current study,finite element methods were used to investigate the biomechanical comparison of ISDD and FSS.The range of motion (ROM),intradiscal pressure (IDP) and the protective effects gained by maintaining disc heights were evaluated.Results The ROM was similar between the two non-fusion methods under static standing,flexion and lateral bending.The FSS appeared to be more effective in resisting extension.At the implanted level L3/4,FSS displayed better results for maintaining and increasing posterior disc heights.At the L4/5 level in extension and lateral bending,FSS was better than ISDD,with comparable results observed in other motions.Comparing the posterior and lateral disc heights,FSS appeared to be more effective than ISDD.FSS also had a minor effect on the inferior adjacent segment than ISDD.FSS was more effective in reducing IDP than ISDD in extension.Conclusion Through the finite element analysis study,it can be seen that FSS demonstrates more beneficial biomechanical outcomes than does ISDD,such as being more effective in resisting extension,maintaining and increasing lumbar disc heights and reducing the inferior adjacent IDP in extension.

  3. 距骨颈骨折螺钉固定的三维有限元分析%Three dimensional finite element analysis of talar neck fracture with screw fixations

    Institute of Scientific and Technical Information of China (English)

    田文; 王富明; 黄俭; 陈璐瑶; 杨芳梅

    2013-01-01

    目的 通过三维有限元法对距骨颈骨折不同螺钉内固定方式进行对比评价,比较不同内固定方式生物力学稳定性,为临床应用提供理论依据.方法 利用CT扫描数据,根据距骨颈骨折不同的内固定方式,建立距骨颈骨折内固定三维有限元模型,研究不同内固定von Mises应力分布和骨折面接触压力及张开位移,分析骨折固定后生物力学稳定性.结果 获得距骨颈骨折不同内固定固定有限元模型,静止站立和踝关节背伸时,不同内固定生物力学稳定性不同,双螺钉由前向后固定螺钉的应力及骨折面张开位移较小,骨折面压力较大.结论 利用双螺钉由前向后固定距骨颈骨折,可以取得较好的生物力学稳定性.%Objective To explore the biomechanical properties of different internal fixations for talar neck fracture through three dimensional finite element ( FE ) analysis and therefore to provide scientific foundation for clinic application. Methods CT scan data were used to develop FE models of the talar neck fracture with different fixations. The different fixations were compared for stress and strain, the fracture surface contact pressure and contact gap were also compared for analysing the biological mechanical stability of different internal fixations. Results The FE models of the talar neck fracture with different fixations were developed. Finite element simulation showed differences between the different fixations with regard to the distributions of stress and contact gap at the fracture surfaces and the von Mises stress in the implant. Anterior to posterior fixation using two screws were shown maximum von Mises stress in the implants, maximum contact press and minimum contact gap in contact surface. Conclusions Anterior to posterior fixation using two screws exhibits fine fixation stability for talar neck fracture.

  4. Simultaneous anterior and posterior screw fixations confined to the axis for stabilization of a 3-part fracture of the axis (odontoid, dens, and hangman fractures): report of 2 cases.

    Science.gov (United States)

    Shinbo, Jun; Sameda, Hiroaki; Ikenoue, Sumio; Takase, Kan; Yamaguchi, Takeshi; Hashimoto, Eiko; Enomoto, Takahiro; Kanazuka, Aya; Mimura, Masaya

    2014-03-01

    Fractures of the axis are considered to be one of the most common injuries to the cervical spine, accounting for more than 20% of all cervical spine fractures. Multiple fractures of the axis are much rarer, accounting for 1% of all cervical fractures. Management of such complex fractures is still challenging, and there is no strong consensus for the treatment. The authors describe the cases of 2 patients who presented with 3-part fractures of the axis consisting of an odontoid Type II fracture and a Levine-Edwards Type IA fracture, which were treated with concurrent insertion of an anterior odontoid screw and bilateral posterior pedicle screws. The cases presented were characterized by 1) a Type II odontoid fracture; 2) a Type IA traumatic spondylolisthesis with no or a little translation and angulation of C-2 on C-3 in a ring fracture of the axis; and 3) no disorders at the C2-3 disc on MR images. Therefore, the authors performed surgery confined to the axis by concurrently inserting an anterior odontoid screw and posterior bilateral pedicle screws without arthrodesis of C2-3. This was followed with cervical soft collar fixation for only 1-2 weeks. The outcomes were favorable, including good osteosynthesis, high primary stability, early patient mobilization, and preserved range of motion of the cervical spine at C2-3 as well as at C1-2.

  5. Biomechanical evaluation of connectible skills using iliac screw and lumbar-sacral spine pedicle screw in the fixation between lumbar-sacral spine and pelvis%髂骨钉与腰骶椎弓根钉连接技术在腰骶骨盆固定中的生物力学评价

    Institute of Scientific and Technical Information of China (English)

    苏汝堃; 刘兴漠; 邓颖辉; 李佛保; 潘滔

    2008-01-01

    BACKGROUND: There have been many methods of fixation between lumbar-sacral spine and pelvis. However, a safe, firm, and ideal method of internal fixation has not been found.OBJECTIVE: This study was designed to investigate the stability of the fixation between lumbar-sacral spine and pelvis with the connectible skills using iliac screw and lumbar-sacral spine pedicle screw.DESIGN, TIME AND SETTING: This study, a control experiment, was performed at the Institute of Biomechanics, Sun Yat-sen University, Guangzhou, Guangdong Province, China between January 2006 and December 2007.MATERIALS: The lumbar-sacral spine and pelvis specimens were collected from six freshly cryo-preserved male adult corpses caused by trauma. Iliac screw (8.5mm×100mm), L5 pedicle screw (6.5mm×45mm), and S1 pedicle screw (6.5mm×35mm) were provided by Sofamor Company, USA. MTS 858 Bionix Material Testing System (USA) was also used.METHODS: The lumbar and iliac vertebrae, pelvis from six fresh frozen cadaveric specimens were operated in three different ways of fixation respectively: iliac ala lag screw, L5-S1 pedicle screw rod system, iliac screw and L5 pedicle screw connecting system. Three ways of fixation as mentioned above were compared with the intact group in biomechanical stability.MAIN OUTCOME MEASURES: The mobility of whirl, lateral bending, proneness, and backward stretching among groups.RESULTS: Using iliac screw for the fixation between lumbar-sacral spine and pelvis turned out to be the best in stability. The range of motion (ROM) decreased obviously in each situation. The three-dimensional mobility in the 6.4Nm moment of force was (1.07±0.86)° for whirl, (0.95±0.47)° for lateral bending, (1.22±0.67)° for proneness, and (1.80±0.73)° for backward stretching. There was significant difference between the intact group and the group carried out by iliac screw and L5 pedicle screw for the fixation between lumbar-sacral spine and pelvis (P<0.01).CONCLUSION: The connectible skills

  6. 单侧椎弓根螺钉内固定治疗腰椎退行性疾病的研究进展%Progress of unilateral pedicle screw internal fixation for the treatment of lumbar degenerative diseases

    Institute of Scientific and Technical Information of China (English)

    谷金(综述); 梁斌(审校)

    2015-01-01

    Unilateral pedicle screw internal fixation is one of the important means of treatment of lumbar de-generative diseases.It plays an important role on solving the postoperative immediate stability of the lumbar spine, and provide enough rigid internal fixation for intervertebral fusion.This paper expounds the research present situation, advantages, limitations and future research direction of unilateral pedicle screw internal fixation.%单侧椎弓根螺钉内固定是治疗腰椎退行性疾病的重要手段之一,其在解决腰椎术后的即刻稳定性方面起着重要作用,为椎间融合术提供足够刚性内固定。该文对单侧椎弓根螺钉内固定的研究现状、优势、局限性与未来的研究方向进行综述。

  7. Treatment of pedicle screw rod system internal fixation on sacroiliac joint fracture and dislocation%椎弓根钉棒系统固定治疗骶髂关节骨折及脱位分析

    Institute of Scientific and Technical Information of China (English)

    唐理英

    2013-01-01

    Objective To analyze the treatment effects of the iliac screw and pedicle screw rod internal fixation on sacroiliac joint fracture and dislocation and discuss the clinical application value of the pedicle screw rod system in fixation of sacroiliac joint. Methods The double plates fixation via posterior approach was adopted for the patients with sacroiliac joint fracture and dislocation in the control group (n=24),while the iliac screw and pedicle screw rod system internal fixation was adopted for the patients with sacroiliac joint fracture and dislocation in the treatment group (n=24).The clinical effects of the surgeries and the postoperative follow-up of the two groups were compared. Results There were no significant differences (P < 0.05) of the operation time,intraoperative blood loss and fracture healing time between the two groups; All the patients were followed up for 12-18 months. The Majeed score of the treatment group was 95.8%(23/24), which was better than the control group (70.8%(17/24))with significant difference (P<0.05). Conclusion The treatment effect of the iliac screw and pedicle screw rod internal fixation on sacroiliac joint fracture and dislocation is good,which can recover the normal function of joint to the greatest degree and improve the patient’s quality of life.%  目的分析应用髂骨钉与椎弓根钉棒内固定治疗骶髂关节骨折、脱位的治疗效果,探讨椎弓根钉棒系统固定骶髂关节的临床应用价值。方法对照组(n=24)骶髂关节骨折、脱位采用后路双钢板固定治疗,治疗组(n=24)为骶髂关节骨折、脱位患者采用髂骨钉与椎弓根钉棒系统固定术治疗,对比两组的手术临床效果及术后随访情况。结果两组的手术时间、术中出血量、骨折愈合时间均无显著性差异(P<0.05);所有患者均随访12~18个月, Majeed评分治疗组优良率为95.8%(23/24),明显优于对照组的70.8%(17/24),两

  8. Reconstruction of multiplanar deformity of the hindfoot and midfoot with internal fixation techniques.

    Science.gov (United States)

    Dreher, Thomas; Hagmann, Sebastién; Wenz, Wolfram

    2009-09-01

    Reconstruction surgery of the midand hindfoot is a demanding challenge for foot surgeons. Satisfactory results depend not only on surgical technique and skills but also on the knowledge of underlying disorders, pathomechanics, and indication criteria. The cavovarus foot, the planovalgus foot, and Charcot's foot are some of the most challenging foot deformities, requiring different surgical strategies for their correction. Most of the osteotomies and fusions in children and adults can be fixed with transcutaneous Kirschner wires, which are inexpensive and easy to use and remove. The use of alternative fixation systems such as cannulated screws, compression screws, or angle-stable locking plates depends on patient age, vascular situation, risk for nonunion, and underlying pathology.

  9. 经皮内固定术与传统后路开放内固定术治疗胸腰椎骨折不良事件比较的Me ta分析%Comparison of the adverse events of percutaneous pedicle screw fixation and traditional open pedicle screw fixation for thoracolumbar fractures:a Meta-analysis

    Institute of Scientific and Technical Information of China (English)

    孙祥耀; 海涌; 张希诺

    2016-01-01

    常差异无统计学意义(OR=1.04,95%CI:0.43~2.56,P=0.92),术后感染差异无统计学意义(OR=0.39,95%CI:0.12~1.26,P=0.12)。结论 PPSF能够缩短手术时间、减少手术出血量、减小手术创伤等,能够达到与TOPSF相似的置钉准确度,保证手术安全性,有效的保护周围软组织,减少术后Cobb角矫正度的丢失,降低术后疼痛及功能恢复异常等不良事件的发生率。%Objective To systematically review the adverse events of percutaneous pedicle screw fixation (PPSF)and traditional open pedicle screw fixation (TOPSF)for thoracolumbar fracture,in order to provide more evidence for the effective treatment of thoracolumbar fracture.Methods Databases including Pubmed,Cochrane Central Register of Controlled Trails (CENTRAL),and Embase were retrieved with computer.Journal ofBone and Joint Surgery,Spine, and European Spine Journal were manually searched.The searching terms were thoracolumbar fracture,lumbar frac-ture,percutaneous pedicle screw fixation,open fixation,posterior surgery,sextant,traditional fixation,conventional fixation,minimally invasive surgery,comparative study,randomized controlled trail,and clinical trail.Data were then screened,extracted,assessed,and analyzed with RevMan 5.3 software.Results A total of 18 studies including 4 ran-domized controlled trials,3 prospective comparative studies,1 1 retrospective comparative studies were enrolled,invol-ving 1 ,034 patients.Meta-analysis showed that the PPSF group,compared with the TOPSF group,had shorter surgery time (WMD= -0.95,95%CI:-1.33--0.57,P<0.001),less intraoperative blood loss (WMD= -2.97,95%CI:-3.69--2.25,P<0.001),less postoperative drainage amount (WMD= -2.43,95%CI:-3.04--1.83,P<0.001),shorter hospital stay (WMD= -5.37,95%CI:-6.69--4.05,P<0.001),less time from surgery to walk-ing (WMD= -2.51,95%CI:-3.66--1.36,P<0.001),less overall postoperative visual analogue scale (WMD=-1.14,95%CI:-1

  10. 齿状突螺钉钢板内固定系统的生物力学研究%A biomechanical evaluation of odontoid screw plate fixation system

    Institute of Scientific and Technical Information of China (English)

    胡勇; 董伟鑫; 孙肖阳; 袁振山; 张蛟; 谢辉; 邬春晖

    2016-01-01

    目的 评价自行设计的齿状突螺钉钢板内固定系统在治疗Ⅰ型Hangman骨折伴Ⅱ型齿状突骨折联合C2~C3椎间盘损伤时的生物力学性能.方法 选取8具新鲜尸体颈椎标本(包括C1~C3颈椎节段),在生物力学试验机上依次测试以下各组C1~C2及C2~C3节段的三维运动范围(ROM)值及中性区值:完整标本状态(A组);失稳状态:Hangman Ⅰ型骨折+Ⅱ型齿状突骨折+C2~C3椎间盘切除(B组);颈椎前路钢板+齿状突螺钉+ cage固定组(C组);齿状突螺钉钢板固定组(D组);后路C2~C3椎弓根侧块螺钉+齿状突螺钉固定组(E组)和后路C1~C3椎弓根侧块螺钉固定组(F组),并对结果进行统计学分析.结果 在C1~C2节段,D组和F组的ROMC1~c2值在各个方向上差异均有统计学意义(P<0.05).在C2~C3节段,D组与C组相比,ROMC2~c3值在各个方向上均较小,且差异有统计学意义(P<0.05);D组与E、F组相比,ROMC2~C3值在前屈、后伸方向上较小,且差异有统计学意义(P<0.05).结论 齿状突螺钉钢板内固定系统在治疗Hangman Ⅰ型骨折伴Ⅱ型齿状突骨折联合C2~ C3椎间盘损伤时具有良好的生物力学性能,可以作为治疗此类合并伤的一种补充方法.%Objective To evaluate the biomechanical stability of anterior odontoid screw plate (AOSP).Methods Eight fresh-frozen cadaveric cervical spine specimens were subjected to stepwise destabilization of the C1-Ca complex,simulating a type Ⅰ Hangman fracture,type Ⅱ odontoid fracture,and the C2-3 disc injury.Intact specimens,fractured specimens,and fractured specimens with posterior,anterior fixation techniques were divided into six groups:control group (intact),injury group of type Ⅱ odontoid fracture and type Ⅰ Hangman fracture combined with C2-3 disk injury,after anterior cervical plate + odontoid screw + cage (ACP + OS + cage) group,after anterior odontoid screw plate (AOSP) fixation system group,after affixing rods from

  11. Early efficacy analysis on Herbert screw internal fixation for carpal scaphoid fracture%Herbert螺钉治疗腕舟状骨骨折的早期临床疗效分析

    Institute of Scientific and Technical Information of China (English)

    施纯南; 庄志伟; 王志杰; 吴金凤; 张金山; 李懿

    2014-01-01

    目的:分析 Herbert螺钉治疗腕舟状骨骨折的早期临床疗效.方法:2010年1月~2013年6月我院通过手术方法使用 Herbert螺钉内固定治疗23例腕舟状骨骨折,通过随访评价骨折愈合情况和腕关节功能.结果:随访6~18个月(平均12.6个月),所有骨折均达到骨性愈合,腕关节功能通过 Mayo法评分:其中优15例,良7例,差1例,优良率达86.9%.结论:腕舟状骨骨折采用方法通过 Herbert进行内固定治疗,骨折愈合率高,腕关节功能恢复良好,疗效确切.%Objective:To analyze the early clinical ef ect of carpal scaphoid fracture treated by Herbert screw fixation.Methods:From 2010.01-2013.06,23 carpal scaphoid fracture patients were operated by Herbert screw internal fixation in our Hospital.To observe the union of fracture and the function of wrist was evaluated according to Mayo score system.Conclusion:Carpal scaphoid fracture treated by Herbert screw fixation can elevate the rate of union of fracture and improved the wrist function,the clinical ef ect is gratification.

  12. A rapid and simple cannulation technique for repeated sampling of cerebrospinal fluid in freely moving rats

    NARCIS (Netherlands)

    Bouman, H.J.; Wimersma Greidanus, T.B. van

    1979-01-01

    A cannulation technique for frequent sampling of cerebrospinal fluid (CSF) in unanaesthetized freely moving rats is described. A permanent stainless steel cannula, constructed in such a way that no loss of CSF occurs, is placed into the rat's cisterna magna and fixed to the skull by anchoring screws

  13. Four-corner fusion and scaphoid excision using headless compression screws for SLAC and SNAC wrist deformities.

    Science.gov (United States)

    Richards, Allison Alexander; Afifi, Ahmed M; Moneim, Moheb S

    2011-06-01

    Scapholunate advanced collapse and scaphoid nonunion advanced collapse wrist deformities are the most common causes of traumatic arthritis of the wrist. Four-corner fusion and scaphoid excision has proven to be an effective procedure for relieving pain and preserving range of motion in the wrist joint. Several methods for providing fixation of the midcarpal joint during fusion have been used, including K-wires, staples, and the Spider plate. K-wire fixation has proven effective, but requires a period of cast immobilization to protect the fusion mass. The Spider plate was promising, but has not been without complications. The development and improvements in cannulated headless compression screws has resulted in increased indications for their use, including fixation for 4-corner fusion. We review the technique and tips developed by the senior author over the last several years using headless compression screws for fixation of the midcarpal joint. Acutrak 2 Standard implants were used. This technique has allowed for early range of motion with reliable fusion rates.

  14. 股骨颈骨折空心加压螺钉内固定后股骨头坏死分析%Cannulated Compression Screws for the Treatment of Adult Femoral Neck Fractures Clinical Analy-sis of Risk Factors for Avascular Necrosis of the Femoral Head

    Institute of Scientific and Technical Information of China (English)

    顾小明; 黄立新

    2014-01-01

    Objective To explore the related factors femoral head necrosis after the operation on adult femoral neck frac-tures by compressed hollow screws fixation. Methods The author reviewed the patients who were treated by compressed hol-low screws fixation from January 1st,2001 to December 31st,2010 and then made a statistical analysis on the following eight factors:age,gender,fracture type(Garden type),surgical reduction quality(Garden index),the time gap between injury and the operation,reset mode( open reduction or close reduction),the partial weight-bearing time after the operation,whether the fixation is removed. Among these eight factors,the statistically significant factors were selected and then analyzed by logistic re-gression analysis one by one. Results There are 185 cases with a complete set of follow-up data and the follow-up lasts from three to ten years(the average duration is 5. 5 years). Among the 185 cases,28 patients suffered from femoral head ischemic necrosis,which accounts for 15. 14% and the independent factors influencing femoral head necrosis included the following:fracture type,fracture reduction,the time gap between injury and the operation,the partial weight-bearing time after the opera-tion. Conclusion The major complication of femoral neck fractures operation by compressed hollow screws fixation is femoral head ischemic necrosis and the major risk factors are fracture type,fracture reduction,the time gap between injury and the op-eration and the partial weight-bearing time after the operation. Among those factors,reduction quality,the time gap between in-jury and the operation and the partial weight-bearing time after the operation are controlling factors and it is found that femoral head ischemic necrosis can be lowered down when the patient receives compressed hollow screws fixation at an earlier time,im-proves reduction quality and tries to bear partial weight after three months'fixation. The present data shows that compressed hol

  15. Finite element analysis of abruption of lower tibiofibular ligament union with single screw fixation%下胫腓联合分离单螺钉固定的有限元分析

    Institute of Scientific and Technical Information of China (English)

    戴海飞; 余斌; 张凯瑞; 熊小龙; 崔壮; 陈志刚

    2012-01-01

    [Objective] To explore the biomechanical characteristics of different ways of single screw internal fixation for abruption of lower tibiofibular ligament union through finite element (FE) analysis and therefore to provide scientific foundation for clinic application. [ Method ] Three-dimensional FE models of the different ways of single screw internal fixation for abruption of lower tibiofibular ligament union were established by helical CT scan data of normal adult human ankles. The static weight-bearing state of human body in neutral position with one foot standing were simulated to compare the differences between different ways of internal fixation in screw von Mises stress distribution,the displacement of the tibia and fibula. [ Result] A total of twelve types of abruption of lower tibiofibular ligament union FE models including bones, ligaments and screw were constructed. FE simulation showed significant differences between the different ways of fixation with regard to the biomechanical characteristics in the model. A 4. 5 mm screw to be fixed through four layers of cortical bone at 2 cm away from the horizontal plane of the ankle showed minimum von Mises stress and displacement of the tibia and fibula. [ Conclusion ] A better fixation stability may be achieved by using 4. 5 mm screw through four layers of cortical bone at 2 cm away from the horizontal plane of the ankle for abruption of lower tibiofibular ligament union.%[目的]通过三维有限元法对下胫腓联合分离使用单螺钉固定的各方式进行对比评价,比较不同内固定生物力学特征,为临床提供理论依据.[方法]利用正常男性的足踝部螺旋CT扫描数据,建立下胫腓联合分离单螺钉内固定的三维有限元模型.模拟人体中立位单足站立踝关节受力方式,比较不同的内固定方式螺钉von Mises应力分布、胫腓骨的位移.[结果]建立12种包括骨、韧带在内的下胫腓联合分离单螺钉内固定的有限元模型.

  16. 3D打印模型辅助后路内固定治疗儿童颈椎畸形%Individualized 3-dimensional printing model-assisted posterior screw fixation in the treatment of cervical deformity of children

    Institute of Scientific and Technical Information of China (English)

    李浩; 李承鑫; 张学军; 郭东; 范敬一; 刘虎; 孙记航; 潘少川

    2015-01-01

    Objective To explore the method and efficacy of individualized 3-dimensional (3D) printing model-assisted posterior screw fixation for the treatment of cervical deformity of children.Methods A total of 29 surgical patients with cervical deformity associated with upper cervical instability as diagnosed by computed tomography (CT) were retrospectively analyzed.For 22 cases,3D printing cervical model was establisged by 3D printing technology.And screw insertion and fixation were simulated for assisting actual operations.At last implemented one-stage posterior orthomorphia plus internal fixation.Results Among them,22 patients with cervical deformity successfully underwent posterior screw fixation assisted by individual 3D printing model.Without injury to vertebral artery or nerve root,there was no internal fixation loosening or fracture.The average followup period was 13.5 (3-23) months.Postoperative atlantodens interval (ADI) significantly decreased,cervicomedullary angle (CMA) increased markedly while ventral compression of medulla oblongata diminished or even disappeared.There was no operative mortality.The procedures included secondary fusion of bone graft (n =1),sternocleidomastoid muscle amputationlysis (n =1),foramen magnum decompression (n =1) and posterior arch of atlas decompression (n =1).Conclusions Posterior screw fixation operation assisted by individualized 3D printing model can improve the success rate and safety of screw insertion and effectively protect vertebral artery and nerve root.And it is particularly suitable for children with cervical deformity.%目的 研究个体化3D打印模型辅助后路内固定治疗儿童颈椎畸形的方法和效果.方法 对北京儿童医院骨科2012年9月至2014年5月CT确诊并手术的29例颈椎畸形伴上颈椎不稳患儿的临床资料进行回顾性分析.其中22例采用3D打印技术建立颈椎个体化3D打印模型,在模型上进行模拟置钉及内固定手术,获得个体化置钉数据,再

  17. Geometric accuracy of 3D coordinates of the Leksell stereotactic skull frame in 1.5 Tesla- and 3.0 Tesla-magnetic resonance imaging: a comparison of three different fixation screw materials

    Science.gov (United States)

    Nakazawa, Hisato; Mori, Yoshimasa; Yamamuro, Osamu; Komori, Masataka; Shibamoto, Yuta; Uchiyama, Yukio; Tsugawa, Takahiko; Hagiwara, Masahiro

    2014-01-01

    We assessed the geometric distortion of 1.5-Tesla (T) and 3.0-T magnetic resonance (MR) images with the Leksell skull frame system using three types of cranial quick fixation screws (QFSs) of different materials—aluminum, aluminum with tungsten tip, and titanium—for skull frame fixation. Two kinds of acrylic phantoms were placed on a Leksell skull frame using the three types of screws, and were scanned with computed tomography (CT), 1.5-T MR imaging and 3.0-T MR imaging. The 3D coordinates for both strengths of MR imaging were compared with those for CT. The deviations of the measured coordinates at selected points (x = 50, 100 and 150; y = 50, 100 and 150) were indicated on different axial planes (z = 50, 75, 100, 125 and 150). The errors of coordinates with QFSs of aluminum, tungsten-tipped aluminum, and titanium were 2.0 mm in most positions. The geometric accuracy of the Leksell skull frame system with 1.5-T MR imaging was high and valid for clinical use. However, the geometric errors with 3.0-T MR imaging were larger than those of 1.5-T MR imaging and were acceptable only with aluminum QFSs, and then only around the central region. PMID:25034732

  18. Geometric accuracy of 3D coordinates of the Leksell stereotactic skull frame in 1.5 Tesla- and 3.0 Tesla-magnetic resonance imaging: a comparison of three different fixation screw materials.

    Science.gov (United States)

    Nakazawa, Hisato; Mori, Yoshimasa; Yamamuro, Osamu; Komori, Masataka; Shibamoto, Yuta; Uchiyama, Yukio; Tsugawa, Takahiko; Hagiwara, Masahiro

    2014-11-01

    We assessed the geometric distortion of 1.5-Tesla (T) and 3.0-T magnetic resonance (MR) images with the Leksell skull frame system using three types of cranial quick fixation screws (QFSs) of different materials-aluminum, aluminum with tungsten tip, and titanium-for skull frame fixation. Two kinds of acrylic phantoms were placed on a Leksell skull frame using the three types of screws, and were scanned with computed tomography (CT), 1.5-T MR imaging and 3.0-T MR imaging. The 3D coordinates for both strengths of MR imaging were compared with those for CT. The deviations of the measured coordinates at selected points (x = 50, 100 and 150; y = 50, 100 and 150) were indicated on different axial planes (z = 50, 75, 100, 125 and 150). The errors of coordinates with QFSs of aluminum, tungsten-tipped aluminum, and titanium were 2.0 mm in most positions. The geometric accuracy of the Leksell skull frame system with 1.5-T MR imaging was high and valid for clinical use. However, the geometric errors with 3.0-T MR imaging were larger than those of 1.5-T MR imaging and were acceptable only with aluminum QFSs, and then only around the central region.

  19. Resorbable screws versus pins for optimal transplant fixation (SPOT in anterior cruciate ligament replacement with autologous hamstring grafts: rationale and design of a randomized, controlled, patient and investigator blinded trial [ISRCTN17384369

    Directory of Open Access Journals (Sweden)

    Rademacher Grit

    2005-02-01

    Full Text Available Abstract Background Ruptures of the anterior cruciate ligament (ACL are common injuries to the knee joint. Arthroscopic ACL replacement by autologous tendon grafts has established itself as a standard of care. Data from both experimental and observational studies suggest that surgical reconstruction does not fully restore knee stability. Persisting anterior laxity may lead to recurrent episodes of giving-way and cartilage damage. This might at least in part depend on the method of graft fixation in the bony tunnels. Whereas resorbable screws are easy to handle, pins may better preserve graft tension. The objective of this study is to determine whether pinning of ACL grafts reduces residual anterior laxity six months after surgery as compared to screw fixation. Design/ Methods SPOT is a randomised, controlled, patient and investigator blinded trial conducted at a single academic institution. Eligible patients are scheduled to arthroscopic ACL repair with triple-stranded hamstring grafts, conducted by a single, experienced surgeon. Intraoperatively, subjects willing to engage in this study will be randomised to transplant tethering with either resorbable screws or resorbable pins. No other changes apply to locally established treatment protocols. Patients and clinical investigators will remain blinded to the assigned fixation method until the six-month follow-up examination. The primary outcome is the side-to-side (repaired to healthy knee difference in anterior translation as measured by the KT-1000 arthrometer at a defined load (89 N six months after surgery. A sample size of 54 patients will yield a power of 80% to detect a difference of 1.0 mm ± standard deviation 1.2 mm at a two-sided alpha of 5% with a t-test for independent samples. Secondary outcomes (generic and disease-specific measures of quality of life, magnetic resonance imaging morphology of transplants and devices will be handled in an exploratory fashion. Conclusion SPOT aims at

  20. 镁合金中空螺钉内固定齿状突ⅡA型骨折生物力学研究%Biomechanical study of magnesium alloy hollow screws in fixation of type Ⅱ A odontoid process fracture

    Institute of Scientific and Technical Information of China (English)

    王志坤; 夏虹; 谢文伟; 曾兴栋; 马立敏; 张余

    2013-01-01

    Objective To develop a new magnesium alloy hollow screw for anterior fixation of the type Ⅱ A odontoid process fracture and peffor a biomechanical study.Methods Thirty fresh human atlas specimens,according to age,gender,dentate size pairs were divided into 2 groups:magnesium alloy,titanium alloy screws screws group.Two groups of axis odontoid fractures type Ⅱ A were cut by sawing,causing uniform odontoid fracture model.Magnesium alloy titanium alloy screws were used for fixation.On the biomechanics machine the load-displacement relationship of odontoid process,torque and pullout force-displacement relationship in different vertical load were measured.Results Loaded with different vertical loads acting on the odontoid sagittal plane,when the load was <400 N,no significant displacement difference between the two groups (P >0.05),when the displacement difference load >500 N fracture had statistical significance (P <0.05).No statistical significance when the neck by <100 N/mm torque of two materials screw fixation of odontoid displacement difference (P >0.05),but the difference was statistically significant when the torque of the >200 N/mm (P <0.05).Conclusion Magnesium alloy hollow screw fixation of odontoid process fracture of type Ⅱ A in the end is enough to prevent a before and after the shift occurred,but the anti-torsion ability is poor,suggest that postoperative neck support brake.%目的 研制应用于齿状突ⅡA型骨折前路内固定的新型镁合金中空螺钉,并进行生物力学研究.方法 将30个新鲜人体枢椎标本,根据年龄、性别、齿状突大小配对分为2组:镁合金螺钉组、钛合金螺钉组.将2组枢椎按齿状突ⅡA型骨折锯断,造成统一齿状突骨折模型,分别用镁合金螺钉、钛合金螺钉固定,在生物力学机上测量不同垂直负荷下齿状突载荷-位移关系、扭矩-位移关系及最大拔出力.结果 分别加载不同垂直负荷作用于齿状

  1. Treatment of sacroiliac joint dislocation with percutaneous sacroiliac screw internal fixation%经皮骶髂螺钉内固定治疗骶髂关节脱位

    Institute of Scientific and Technical Information of China (English)

    陈红卫; 赵品益; 楼舒畅; 赵胜春; 陈欣; 赵钢生; 叶招明; 潘骏

    2008-01-01

    Objective To analyze the clinical effect of percutaneous sacroiliac screw internal fixation in treatment of sacroiliac joint dislocation. Methods From June 2002 to August 2006,16 patients with sacroiliac joint dislocation were treated with percutaneous sacroiliac screw internal fixation under C-arm X-ray tomography.There were 10 males and 6 females at age range of 10-58 years(mean 34.3 years).Results The operation lasted for 30-90 minutes(average 50.5 minutes).All patients were followed up for 12-36 months(average 18.3 months).The results of postoperative normotopia,lateral,ingate and egress Xray and CT scanning showed that all the screws were located within S1 and S2 of all,14 patients obtained satisfactory result of reduction,with no infection,nerve injuries,loosening or breakage of the screw fixation.The function and the sensation of the sacroiliac ioint and low extremities recovered to normal. Conclusions Percutaneous sacroiliac screw intemal fixation is an ideally safe and effective way to treat sacroiliac joint dislocation,for it has many advantages such as minimal invasion,reliable fixation,less complication and quick recovery.It is also very necessary to take caudad and cephalad view under an image intensifier during the operation to assure the accuracy of implantation.%目的 分析经皮骶髂螺钉内固定治疗骶髂关节脱位的临床疗效.方法 对2002年6月-2006年8月16例骶髂关节脱位患者的临床资料进行回顾性分析,其中男10例,女6例;年龄10~58岁,平均34.3岁.所有患者均在C形臂X线机监测下经皮骶髂螺钉内固定.结果 手术时间为30~90 min,平均50.5 min.术后行骨盆正位、侧位、人口位、出口位X线片和CT扫描,螺钉均位于S1、S2椎体内.16例均获得12~36个月(平均18.3个月)随访.14例骨折复位良好,无切口感染,无术中血管神经损伤,无内固定松动及断裂,腰骶及下肢活动、感觉均正常.结论 经皮骶髂螺钉内固定治疗骶髂关节脱

  2. Pullout performance comparison of novel expandable pedicle screw with expandable poly-ether-ether-ketone shells and cement-augmented pedicle screws.

    Science.gov (United States)

    Aycan, Mehmet Fatih; Tolunay, Tolga; Demir, Teyfik; Yaman, Mesut Emre; Usta, Yusuf

    2017-02-01

    Aim of this study is to assess the pullout performance of various pedicle screws in different test materials. Polyurethane foams (Grade 10 and Grade 40) produced in laboratory and bovine vertebrae were instrumented with normal, cannulated (cemented), novel expandable and normal (cemented) pedicle screws. Test samples were prepared according to the ASTM F543 standard testing protocols and surgical guidelines. To examine the screw placement and cement distribution, anteriosuperior and oblique radiographs were taken from each sample after insertion process was completed. Pullout tests were performed in an Instron 3369 testing device. Load versus displacement graphs were recorded and the ultimate pullout force was defined as the maximum load (pullout strength) sustained before failure of screw. Student's t-test was performed on each group whether the differences between pullout strength of pedicle screws were significant or not. While normal pedicle screws have the lowest pullout strength in all test materials, normal pedicle screws cemented with polymethylmethacrylate exhibit significantly higher pullout performance than others. For all test materials, there is a significant improvement in pullout strength of normal screws by augmentation. While novel expandable pedicle screws with expandable poly-ether-ether-ketone shells exhibited lower pullout performance than normal screws cemented with polymethylmethacrylate, their pullout performances in all groups were higher than the ones of normal and cannulated pedicle screws. For all test materials, although cannulated pedicle screws exhibit higher pullout strength than normal pedicle screws, there are no significant differences between the two groups. The novel expandable pedicle screws with expandable poly-ether-ether-ketone shells may be used instead of normal and cannulated pedicle screws cemented with polymethylmethacrylate due to their good performances.

  3. Dynamic Hip Screw Fixation Combined of Oral Medicine Treating Intertrochanteric Fracture%动力髋螺钉固定术配合口服中药治疗高龄股骨粗隆间骨折

    Institute of Scientific and Technical Information of China (English)

    徐爱民

    2012-01-01

    目的:探讨采用动力髋螺钉(DHS)固定术配合口服中药治疗高龄股骨粗隆间骨折的方法和疗效.方法:对2004年1月—2009年1月收治的股骨粗隆间骨折患者进行手术治疗.其中男25例,女21例,年龄65~83岁,平均年龄73岁,采用动力髋螺钉(DHS)固定术.结果:1例病人术后3天出现患肢深静脉血栓,经活血、溶栓治疗后恢复.2例因其他疾病死亡,43例骨折均全部愈合,已恢复原来生活能力,无内固定物松动及髋内翻畸形等并发症.结论:动力髋螺钉(DHS)固定术配合口服中药治疗高龄股骨粗隆间骨折具有操作简单、时间短、固定可靠、损伤小、出血少、骨折愈合率高、并发症少等优点,是值得推广应用的手术方法[1].%Objective:To investigate the method and effect of the dynamic hip screw ( DHS )fixation of intertrochanteric fracture. Methods; During January 2004-January 2009, patients admitted because of intertrochanteric fractures were treated surgically, including 25 males and 21 females, aged 65 to 83 years old, mean age was 73, using dynamic hip screw ( DHS ) fixation. Results: 3 days after surgery, 1 case limb deep vein thrombosis occurs, the blood circulation restored after thrombolytic therapy. 2 patients died due to other diseases,43 cases of fracture were all healed and returned to the original capacity, no loosening of internal fixation, or complications such as varus deformity. Conclusion: The dynamic hip screw ( DHS ) fixation combined with oral medicine treatment of intertrochanteric fracture is simple, treatment course is short, fixed and reliable, with less damage, less bleeding, high fracture healing rate, fewer complications, and is worthy of promoting application for the surgical method[1].

  4. Cancellous Screws Are Biomechanically Superior to Cortical Screws in Metaphyseal Bone.

    Science.gov (United States)

    Wang, Tim; Boone, Christopher; Behn, Anthony W; Ledesma, Justin B; Bishop, Julius A

    2016-09-01

    Cancellous screws are designed to optimize fixation in metaphyseal bone environments; however, certain clinical situations may require the substitution of cortical screws for use in cancellous bone, such as anatomic constraints, fragment size, or available instrumentation. This study compares the biomechanical properties of commercially available cortical and cancellous screw designs in a synthetic model representing various bone densities. Commercially available, fully threaded, 4.0-mm outer-diameter cortical and cancellous screws were tested in terms of pullout strength and maximum insertion torque in standard-density and osteoporotic cancellous bone models. Pullout strength and maximum insertion torque were both found to be greater for cancellous screws than cortical screws in all synthetic densities tested. The magnitude of difference in pullout strength between cortical and cancellous screws increased with decreasing synthetic bone density. Screw displacement prior to failure and total energy absorbed during pullout strength testing were also significantly greater for cancellous screws in osteoporotic models. Stiffness was greater for cancellous screws in standard and osteoporotic models. Cancellous screws have biomechanical advantages over cortical screws when used in metaphyseal bone, implying the ability to both achieve greater compression and resist displacement at the screw-plate interface. Surgeons should preferentially use cancellous over cortical screws in metaphyseal environments where cortical bone is insufficient for fixation. [Orthopedics.2016; 39(5):e828-e832.].

  5. Atlantoaxial stabilization using multiaxial C-1 posterior arch screws.

    Science.gov (United States)

    Donnellan, Michael B; Sergides, Ioannis G; Sears, William R

    2008-12-01

    The authors present a novel technique of atlantoaxial fixation using multiaxial C-1 posterior arch screws. The technique involves the insertion of bilateral multiaxial C-1 posterior arch screws, which are connected by crosslinked rods to bilateral multiaxial C-2 pars screws. The clinical results are presented in 3 patients in whom anomalies of the vertebral arteries, C-1 lateral masses, and/or posterior arch of C-1 presented difficulty using existing fixation techniques with transarticular screws, C-1 lateral mass screws, or posterior wiring. The C-1 posterior arch screws achieved solid fixation and their insertion appeared to be technically less demanding than that of transarticular or C-1 lateral mass screws. This technique may reduce the risk of complications compared with existing techniques, especially in patients with anatomical variants of the vertebral artery, C-1 lateral masses, or C-1 posterior arch. This technique may prove to be an attractive fixation option in patients with normal anatomy.

  6. C2 Pedicle Screw Combined with C3 Lateral Mass Screw Fixation for Treatment of Instable Hangman's Fracture%C2椎弓根螺钉联合C3侧块螺钉固定治疗不稳定性Hangman骨折

    Institute of Scientific and Technical Information of China (English)

    杨国进; 章筛林; 石志才

    2012-01-01

    Objective To evaluate the surgical management and result of C2 pedicle screw combined with C3 lateral mass screw fixation for treatment of instable Hangman's fracture. Methods From August 2005 to December 2010,16 patients with instable Hangman's fracture were all treated with C2 pedicle screw combined with C3 lateral mass screw fixation,which involved 11 males and 5 females with an average age of 35. 4 years old (range 19- 59). According to Levine-Edwards classification ,11 cases were type Ⅰ ,5 cases were type Ⅱ a,2 cases were type Ⅲ . All the patients complained neck pain and limitation of cervical movement. There were D spinal injury in 3 cases and E in 13 cases according to Frankel scale. Results All patients were followed up for a mean time of 13. 5 months (range 9~36 months). The operative time was 95~170 min (average 114 min) and the blood loss was 290~450 mL(average 353 mL). All fractures healed at 6 months postoperatively. There was no internal fixation fracture or loosing occurred. The cervical movement was excellent. Three cases of grade D spinal injury recovered to grade E. Conclusion C2 pedicle screw combined with C3 lateral mass screw fixation is an effective method for treatment of instable Hangman's fracture.%目的 探讨C2椎弓根螺钉联合C3侧块螺钉内固定治疗不稳定性Hangman骨折的临床效果及应用价值.方法 2005年8月至2010年12月采用后路C2椎弓根螺钉联合C3侧块螺钉内固定治疗16例不稳定性Hangman骨折患者,男11例,女5例;年龄19~59岁,平均35.4岁.骨折按Levine-Edwards分类,Ⅱ型9例,Ⅱa型5例,Ⅲ型2例.脊髓损伤按Frankel分级,D级3例,E级13例.结果 所有患者均获随访,随访时间9~36个月(平均18个月).手术时间95~170 min(平均114 min),术中出血290~450 mL(平均353mL),术后6个月复查时,骨折均愈合,无断钉、断棒及螺钉松动发生,颈部活动功能恢复良好.脊髓功能D级3例均恢复至E级.结论 经后路C2

  7. A 10-year follow-up of transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or intervertebral B-Twin system in failed back surgery syndrome

    Science.gov (United States)

    Cincu, Rafael; Lorente, Francisco de Asis; Gomez, Joaquin; Eiras, Jose; Agrawal, Amit

    2015-01-01

    Background: The spine surgeons have been combining anterior and posterolateral fusion (circumferential fusion) as the final solution to treat spinal disorders and many have been using it to treat failed back surgery syndrome (FBSS). In present study, we analyzed and compared the clinical and radiological outcomes in patients with transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or in patients with transpedicular screw fixation and intervertebral B-Twin system for FBSS with a follow-up period of 10 years after the surgery. Materials and Methods: This study was a retrospective case study performed on 55 patients with FBSS. Clinical and radiological changes were compared between the two groups of patients on the basis of improvement of back pain, radicular pain, and work capacity. Outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year from before surgery until 2012. We analyzed the evolution of 55 cases of FBSS those underwent segmental circumferential posterior fusions from June 2001 to February 2003, operated by a single surgeon and followed up during 10 years until February 2012. The patients were divided into 2 groups: In 25 patients, posterolateral fusions with Legacy™ (Medtronic, Inc. NYSE: MDT) screws and intersomatic autogenous posterior iliac crest bone graft was performed, and, in 30 patients, posterolateral fusions with the same screws and intersomatic fusion B-Twin (Biomet Spain Orthopaedics, S.L.) system was performed. In all cases, we used posterior lumbar interbody fusion (PLIF)/transforaminal lumbar interbody fusion (TLIF) approach for intervertebral graft, and the artrodesis was supplemented at intertransverse level with Autologus Growth Factor (AGF-MBA INCORPORADO, S.A.). The outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year and compared

  8. A 10-year follow-up of transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or intervertebral B-Twin system in failed back surgery syndrome.

    Science.gov (United States)

    Cincu, Rafael; Lorente, Francisco de Asis; Gomez, Joaquin; Eiras, Jose; Agrawal, Amit

    2015-01-01

    The spine surgeons have been combining anterior and posterolateral fusion (circumferential fusion) as the final solution to treat spinal disorders and many have been using it to treat failed back surgery syndrome (FBSS). In present study, we analyzed and compared the clinical and radiological outcomes in patients with transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or in patients with transpedicular screw fixation and intervertebral B-Twin system for FBSS with a follow-up period of 10 years after the surgery. This study was a retrospective case study performed on 55 patients with FBSS. Clinical and radiological changes were compared between the two groups of patients on the basis of improvement of back pain, radicular pain, and work capacity. Outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year from before surgery until 2012. We analyzed the evolution of 55 cases of FBSS those underwent segmental circumferential posterior fusions from June 2001 to February 2003, operated by a single surgeon and followed up during 10 years until February 2012. The patients were divided into 2 groups: In 25 patients, posterolateral fusions with Legacy™ (Medtronic, Inc. NYSE: MDT) screws and intersomatic autogenous posterior iliac crest bone graft was performed, and, in 30 patients, posterolateral fusions with the same screws and intersomatic fusion B-Twin (Biomet Spain Orthopaedics, S.L.) system was performed. In all cases, we used posterior lumbar interbody fusion (PLIF)/transforaminal lumbar interbody fusion (TLIF) approach for intervertebral graft, and the artrodesis was supplemented at intertransverse level with Autologus Growth Factor (AGF-MBA INCORPORADO, S.A.). The outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year and compared from before surgery to the final

  9. 骨水泥并椎弓根螺钉脊柱内固定的力学效应%Biomechanics Effect of Pedicle Screw with PMMA in Internal Fixation of Spine

    Institute of Scientific and Technical Information of China (English)

    吉浩宇; 霍洪军

    2011-01-01

    Objective To evaluate the effect of the strength of pedicle screw fixation with PMMA in human spine,to observe effect of pedicle screw with PMMA and revision with PMMA so as to provide basis for clinic.Methods Thirty fresh frozen adult vertebras were used,and were randomly divided into 2 groups,each which have 15 ones, and each which have 4 sides vertebral pedicle,which was named “A” side、“B”side、“C” side、and “D” side.All vertebras were good.One track was made in each “A”and “B” vertebral pedicle,then was drilled with tap.Before pedicle screw fixation,each track of “A” side was augmented with PMMA as testing side,then,“A” and “B” sides were served as contral with the pedicle screws ,which were size of 5.5 mm/40 mm.The vertebral pedicles of “C” side,which were drilled with tap,which were size of 5.5 mm、6.25 mm、and 7.0 mm,were augmented by PMMA,and finally, the 5.5 mm/40 mm screws were implanted in it.The vertebral pedicles of “D” side weredrilled with tap,which were size of 5.5 mm、6.25 mm、and 7.0 mm、then,the 7.0 mm/55 mm screws were implanted in it.The specimens were examined,and were good.Maximum incision strength was tested on both sides of eath vertebral body through electronical borer.Finally,data obtained in experiment was analyzed.Results Maximum strength was (805±64) N in “A” side, (1 198± 122) N in “B” side, (1 175±203) N in “C” side,and (953±97) N in “D” side.The differences between “A” side and “B” side were significant(P<0.05,the differences between “C” side and “D” side were significant(P<0.05),that showed that the effect of revision with PMMA was better than with the bigger screw,and that the effect of augmentation with PMMA was better than fixation with only screw.Conclusion Inner fixation through vertebral pedicle following augmentation and restoration with PMMA were the more firm,that had the effect of preventing from screw destroying vertebras, and

  10. "徒手法"个体化颈椎椎弓根螺钉技术治疗上颈椎骨折脱位%Free-hand cervical pedicle screw fixation for upper cervical fracture and instability

    Institute of Scientific and Technical Information of China (English)

    韩岳; 夏群; 徐宝山; 张继东; 苗军

    2011-01-01

    目的 探讨应用颈椎椎弓根钉治疗上颈椎骨折及脱位的临床效果.方法 2006年9月-2009年1月,应用颈椎椎弓根钉治疗的上颈椎骨折或脱位的患者15例.其中男11例,女4例;年龄18~60岁,平均41.2岁.寰椎骨折脱位5例,枢椎骨折脱位3例,齿状突陈旧骨折不愈合1例,C2,3骨折脱位2例,无骨折寰枢椎失稳4例.临床主要症状为颈部疼痛或伴有四肢麻木无力、步态不稳.患者术前均行Halo架牵引试行复位.所有患者均采用颈椎椎弓根钉固定并植骨融合,根据术前X线片及CT个体化确定入钉点及置钉角度,徒手法钻出骨性通道,选用22~26 mm长的Vertex或Summit钛金属螺钉固定,并行后路椎板间自体或同种异体骨植骨融合.术后1~2 d佩戴颈托离床活动.结果 本组15例共置入颈椎椎弓根螺钉64枚,均未发生椎动脉和脊髓损伤,无脑脊液漏.术后行X线正、侧位片和CT检查证实损伤节段复位满意、螺钉位置良好.术后疼痛症状基本消失,神经症状较术前有不同程度的改善.14例患者获得随访,时间12~36个月,患者颈椎序列良好,均获得骨性融合,未发生螺钉及钛棒的松动、脱出及折断.神经损伤症状较术前明显改善.结论 颈椎椎弓根钉是颈椎后路手术中坚强的固定方法,只要掌握手术操作技巧,严格个体化置钉,颈椎椎弓根钉具有固定可靠、术后并发症少、融合率高等优势,具有良好的临床疗效.%Objective To evaluate the clinical effect of the free-hand cervical pedicle screw fixation in treatment of the upper cervical fracture and instability.Methods A retrospective review was performed on 15 patients with upper cervical fracture and instability treated with cervical pedicle screw fixation and fusion from September 2006 to January 2009.There were 11 males and 4 females,at average age of 41.2 years(range,18-60 years).Of all,there were five patients with atlas fracture and dislocation

  11. 经后路寰枢椎椎弓根螺钉固定融合术治疗寰枢椎失稳%Atlanto-axial pedicle screw fixation through posterior approach for treatment of atlanto-axial joint instability

    Institute of Scientific and Technical Information of China (English)

    左春光; 刘夏君; 王新虎; 王建顺

    2013-01-01

    Objective:To discuss the therapeutic effects of the atlantoaxial pedicle screw system fixation in treatment of atlantoaxial instability. Methods:From June 2003 to March 2010,32 patients with atlantoaxial instability were treated by atlantoaxial pedicle screw system fixation, included 21 males and 11 females wiht an average age of 42.5 years old ranging from 28 to 66 years. Among them, 18 cases were odontoid process fractures,7 were congenital dissociate odontoid process,4 were Jefferson fracture combined with odontoid fracture, 3 were rheumatic arthritis causing atlantoaxial instability. All patients suffered from the atlantoaxial subluxation and atlantoaxial instability. The JOA score ranged from 4 to 14 (means 9.1±0.3) before operation. The patients had some image examination including the X-ray of cervical vertebrae (include of dynamic position film) ,spiral CT 3D reconstruction and/or MRI. The position of pedicle screw system implantation,the angle of pedicle screw system implantation and screw length were measured. Operating skull traction. Operation undewent general anesthesia, implanted the pedicle screw, reduction and bone fusion under direct vision. The bone was fixated between posterior arch of atlas and lamina of axis by the lateral combination bended to posterior. Results:One hundred and twenty-eight atlantoaxial pedicle screws were implanted in 32 patients. No patient had the injure of spinal cord,nerve root and vertebral artery. All patients were followed-up from 6 to 48 months (averaged 16 months). After operation,the JOA score ranged from 11 to 17 (averaged 15.9± 0.2) ,improvement rate was 86.1%. The fracture of odontoid process were healing completely. All fusion bone were combinated. The internal fixation wasn't loosening and breaking. Conclussion:The atlantoaxial pedicle screw system fixation was effective method to treat atlantoaxial instability. The method had many advantages, such as provide rigid and short segment fixation, safe and simple

  12. Safety of computer-assisted surgery for cannulated hip screws

    NARCIS (Netherlands)

    Hamelinck, H.K.M; Haagmans, M.; Snoeren, M.M.; Biert, J.; Vugt, A.B. van; Frolke, J.P.M.

    2007-01-01

    Computer-assisted orthopaedic surgery has developed considerably during the past few years. Several manufacturers produce hardware and software for use in trauma surgery. Validation of these systems before clinical application is mandatory to be sure they work accurately and safely. The accuracy of

  13. Clinical observation of posterior internal fixation with vertebral pedicle screw and rod system on thoracolumbar spine fracture%采用后路椎弓根钉棒系统治疗胸腰椎骨折疗效观察

    Institute of Scientific and Technical Information of China (English)

    王洽君

    2013-01-01

    目的 观察后路椎弓根钉棒系统治疗胸腰椎骨折的临床疗效.方法 回顾性分析32例采用后路椎弓根钉棒系统治疗胸腰椎骨折患者的临床资料,术后最长获得2年随访,分析椎体高度、椎体序列和Cobb角的改变.结果 32例患者获得6~ 48个月随访,平均15.8个月.术后椎体前、后缘高度分别为(96.85±14.33)%、(97.44±12.38)%,明显大于术前的(46.67±11.25)%、(76.76±12.62)%(均P<0.05);术后Cobb角为(7.45±2.12)°,显著小于术前的(20.56±7.51).(P<0.05).术后患者Frankel分级均有改善.结论 应用椎弓根钉棒系统治疗胸腰椎骨折能取得良好的临床疗效.%Objective To observe the clinical effect of posterior internal fixation with vertebral pedicle screw and rod system on thoracolumbar spine fracture.Methods The clinical data of 32 patients diagnosed as thoracolumbar spine fracture in our hospital who treated with posterior internal fixation with vertebral pedicle screw and rod system were retrospectively analyzed.The Frankel scale combined with X-ray and CT images were used for the judgment of efficacy.Results The vertebral Height and Cobb angles were improved significantly after the operations (P <0.05).And the Frankel degree of cases with nerve symptoms was also improved.Conclusion Posterior internal fixation with vertebral pedicle screw and rod system is effective in treating patients with thoracolumbar spine fracture.

  14. Clinical study of combined C2 laminar screw fixation technique for cervical vertebral injury%组合枢椎椎板螺钉固定技术治疗颈椎损伤的临床研究

    Institute of Scientific and Technical Information of China (English)

    胡勇; 马维虎; 徐荣明; 阮永平; 孙韶华

    2009-01-01

    目的 探讨组合枢椎椎板螺钉固定技术治疗颈椎损伤的可行性和应用价值.方法 对32具颈椎标本行枢椎椎板轴向CT加密扫描,测量枢椎椎板的长度、高度,枢椎椎板上、中、下部的厚度,椎板轴线与欠状面的夹角.8例颈椎损伤患者中,Anderson Ⅱ型齿状突骨折伴寰枢关节向后脱位2例、向前脱位1例、齿状突骨不愈合1例,Ⅲ型齿状突骨折伴寰枢关节不稳、横韧带撕裂2例,Ⅱ型Hangman骨折伴C不稳1例,寰枢关节前脱位伴横韧带断裂1例.牵引复位后,根据患者病情组合枢椎椎板螺钉进行组合式固定,并行后路自体髂骨植骨融合.结果 枢椎椎板的长度为(26.2±1.2)mm,高度为(12.8±1.6)mm,枢椎椎板上、中、下部的厚度分别为(300±1.4)mm、(6.0±1.6)mm、(5.6±1.2)mm、椎板轴线与矢状面的夹角平均为43.5°.8例患者枢椎椎板螺钉位于椎板中,无偏斜.全部患者随访6~14个月,平均10.5个月.术中和术后没有任何并发症发生,获得了良好的骨性愈合.本组无一例发生螺钉松动及断裂.结论 枢椎椎板螺钉固定技术避免了螺钉置入过程中损伤椎动脉的风险.此技术操作简单,不受C2横突孔中椎动脉的位置限制.全程在直视下进行,该方法可作为传统枢椎后路螺钉固定技术的补充.%Objective To explore the feasibility and application value of combined C2 laminar screw fixation technique in treatment of cervical vertebral injury. Methods Dense axial CT scanning was done on C2 laminar of 32 specimens of cervical vertebra to measure the length and height of the axis, the thickness of upper, middle and lower parts of the axis as well as the angle between the axial ray and the sagittal plane. There were eight patients with cervical vertebral injury including two with type Ⅱ odon-told process fractures combined with backward dislocation of atlanto-axial joint, one with forward disloca-tion of atlanto-axial joint, one with nonunion

  15. Anatomical parameters for percutaneous lag screw fixation of the sacroiliac joint%骶髂关节经皮拉力螺钉固定钉道参数的解剖学测量

    Institute of Scientific and Technical Information of China (English)

    游景扬; 王钢; 黎润光; 陈滨; 任高宏; 杨建涛; 刘善宇

    2010-01-01

    Objective To provide anatomic evidence for iliosacral screw fixation at the pedicle level of the first sacral vertebra(S1).Methods Virtual three-dimensional models were reconstructed on the basis of computed tomography(CT)scans obtained from 50 adult patients without any bony problem.The percutaneous lag screw fixation of the sacroiliac joint was simulated.The width and height of the S1 pedicle,the optimal entry points for iliosacral screws on the outer posterolateral ilium,the directions of screws,and the distances from the entry point to the contrary anterior cortex of the S1 vertebral body and to the posterior superior lilac spine were measured.Results The width and height of the S1 pedicle were(20.43 ±1.63)mm and(20.26±0.99)mm,respectively.The optimal entry points of the 2 iliosacral screws were on both above the line between the anterior superior iliac spine and the posterior superior iliac spine.The distances to the posterior superior lilac spine were(49.87 ± 6.80)mm and(51.11 ± 7.15)mm,respectively.Iliosacral screws got into the S1 pedicle in parallel,perpendicular to the outer posterolateral ilium,with 18.35°± 5.20°to the coronal plane and 77.62°± 3.98° to the sagittal plane.The distances from the entry points of 2 iliosacral screws to the contrary anterior cortex of S1 vertebral body were(76.08 ± 4.32)mm and(77.62 ± 3.98)mm,respectively.Differences in length,the width and height of the S1 pedicle,distance to the posterior superior iliac spine and angle to the coronal plane of the iliosacral screws between men and women were of statistical significance(P <0.05).Conclusions Two iliosacral screws of 6.5 mm in diameter can be implanted at the level of the first sacral vertebra in healthy adults.The anatomic parameters measured can be applied in design of the surgical navigation template for percutaneous lag screw fixation of the sacroiliac joint.%目的 为经S_1椎弓根水平骶髂关节拉力螺钉固定术提供应用解剖学依据.方法 2008

  16. Effect of expandable pedicle screw fixation on the fixation strength of osteoporotic thoracic and lumbar vertebrae%可膨胀椎弓根钉骨水泥强化与骨质疏松性胸腰椎固定强度的关系

    Institute of Scientific and Technical Information of China (English)

    周庆忠; 冯晓兰; 张戈; 贾叙锋; 雷飞; 叶飞; 冯大雄

    2017-01-01

    背景:研究表明,骨质疏松常导致椎弓根螺钉内固定失败.采用普通椎弓根螺钉固定骨质疏松椎体达不到坚强的稳定性,需要采取特殊强化措施.目的:评价骨水泥强化联合可膨胀椎弓根螺钉对骨质疏松性胸腰椎稳定性的影响.方法:将20个骨质疏松性人胸腰椎椎体标本随机分为4组,普通椎弓根钉组置入普通椎弓根螺钉,其余3组均置入可膨胀椎弓根螺钉;可膨胀椎弓根钉组不进行骨水泥强化,聚甲基丙烯酸甲酯骨水泥强化组及硫酸钙骨水泥强化组于钉道内分别注入聚甲基丙烯酸甲酯骨水泥及硫酸钙骨水泥之后再置入可膨胀椎弓根钉.选择一侧椎弓根,测试椎弓根螺钉的最大轴向拔出力及屈服能量吸收值(对螺钉的握力);选择另一侧椎弓根,测试最大旋出力矩;并观察骨水泥强化后的骨水泥渗漏情况.结果与结论:①与普通椎弓根钉组相比,其余3组的最大轴向拔出力、最大旋出力矩及屈服能量吸收值均显著增加(P0.05);②骨水泥强化后未发生骨水泥渗漏现象;③结果表明,骨水泥强化联合可膨胀椎弓根螺钉可显著增强骨质疏松胸腰椎椎体的稳定性,聚甲基丙烯酸甲酯骨水泥与硫酸钙骨水泥效果相似.%BACKGROUND: Studies have shown that osteoporosis often leads to a failure in pedicle screw fixation. Considering that the use of ordinary pedicle screw fixation cannot achieve a strong and stable fixation of the osteoporotic vertebra,special measures to strengthen the internal fixation is indispensable.OBJECTIVE: To evaluate the effect of bone cement augmentation combined with expandable pedicle screw fixation on the fixation strength of osteoporotic thoracolumbar vertebrae.METHODS: Twenty osteoporotic thoracolumbar vertebral specimens were randomly divided into four groups: conventional pedicle screw group implanted with normal pedicle screw, and the other three groups implanted with expandable

  17. Transpedicular screw fixation system for treatment of unstable fractures of arias vertebra%经后路单纯寰椎椎弓根螺钉内固定治疗不稳定性寰椎骨折

    Institute of Scientific and Technical Information of China (English)

    马维虎; 许楠健; 徐荣明; 赵刘军; 蒋伟宇; 孙韶华; 胡勇; 刘观燚; 顾勇杰

    2011-01-01

    目的 探讨经后路单纯寰椎椎弓根螺钉内固定治疗不稳定性寰椎骨折的临床疗效.方法 2007年3月~2010年4月,采用经后路寰椎椎弓根螺钉内固定治疗不稳定性寰椎骨折患者23例,其中8例为后3/4 Jefferson骨折;12例患者为半环Jefferson骨折;3例患者为后1/2 Jefferson骨折.患者均有不同程度的颈枕区疼痛,活动受限;日本骨科协会(Japanese Orthopaedic Association,JOA)评分为7~12分,平均9.5分.结果 所有患者随访12~39个月,平均18.8个月.手术时间为30~60 min,出血量为50~200 mL.术后X 线片及CT 示1例一侧寰椎椎弓根螺钉部分进入椎动脉孔,1例螺钉一侧偏内致椎弓根内侧皮质破裂,但均无神经症状,其余螺钉位置良好.术后JOA评分13~17分,平均14.7分.未发生与螺钉相关的神经血管并发症,无内固定松动或断钉现象,所有患者术后随访时均已达到骨性融合,寰枢关节旋转功能良好.结论 寰椎后路椎弓根螺钉技术是治疗不稳定性寰椎骨折的有效方法.%Objective To study the clinical outcomes of transpedicular screw fixation system for treatment of unstable fractures of the atlas vertebra. Methods From March 2007 to April 2010, transpedicular fixation was employed to treat 23 patients with unstable fractures of the atlas vertebra; the patients included l5 males and 8 females. Eight patients had posterior 3/4 Jefferson fracture, 12 had 1/2 ring Jefferson fracture and 3 had posterior 1/2 Jefferson fracture. The preoperative Japanese Orthopaedic Association(JOA) score was 7-12, with an average of 9.5. All patients were treated by single transpedicular fixation via the posterior approach. Results The patients were followed up for 12-39 months, with a mean of 18.8 months. The operative time ranged 30-60 min. Intraoperative blood loss ranged from 50-200 mL. Postoperative roentgenoghaph and CT scan showed that 1 screw was inserted so medially and penetrated the spinal canal, and 1

  18. A Biomechanical Comparison of Expansive Pedicle Screws for Severe Osteoporosis: The Effects of Screw Design and Cement Augmentation.

    Directory of Open Access Journals (Sweden)

    Ching-Lung Tai

    Full Text Available Expansive pedicle screws significantly improve fixation strength in osteoporotic spines. However, the previous literature does not adequately address the effects of the number of lengthwise slits and the extent of screw expansion on the strength of the bone/screw interface when expansive screws are used with or without cement augmentation. Herein, four designs for expansive pedicle screws with different numbers of lengthwise slits and different screw expansion levels were evaluated. Synthetic bones simulating severe osteoporosis were used to provide a comparative platform for each screw design. The prepared specimens were then tested for axial pullout failure. Regardless of screw design, screws with cement augmentation demonstrated significantly higher pullout strength than pedicle screws without cement augmentation (p 0.05. Taken together, our results show that pedicle screws combined with cement augmentation may greatly increase screw fixation regardless of screws with or without expansion. An increase in both the number of slits and the extent of screw expansion had little impact on the screw-anchoring strength. Cement augmentation is the most influential factor for improving screw pullout strength.

  19. Application of Posture Nursing Intervention in Posterior Pedicle Screw Internal Fixation%体位护理干预在脊柱后路椎弓根钉内固定术中的应用

    Institute of Scientific and Technical Information of China (English)

    马永玲

    2016-01-01

    Objective Application of posture nursing intervention in posterior pedicle screw internal fixation. Methods From October 2014 to October 2014, 100 cases of patients with posterior pedicle screw ifxation,divided into two groups:observation group (50 cases with patients treated with posture nursing intervention) and control group (50 cases of patients treated with conventional nursing intervention), compare the application effect of the two groups. Results After the intervention, the observation group nursing satisfaction is 98.0% better than the control group 86.0%(P<0.05). Conclusion The posture nursing intervention in the application of spinal posterior pedicle screw ifxation effect is good, which can improve patients' quality of life.%目的:体位护理干预在脊柱后路椎弓根钉内固定术中的应用。方法选取我院2014年10月~2015年10月收治的后路椎弓根钉内固定术患者100例,分成两组:观察组(n=50,施以体位护理干预),对照组(n=50,施以常规护理干预),对两组应用效果进行对照。结果干预后,观察组护理满意度为98.0%优于对照组86.0%(P<0.05)。结论体位护理干预在脊柱后路椎弓根钉内固定术中的应用效果良好,能提升患者生活质量。

  20. Screw and plate fixation for fractures of tibial shaft: three-dimensional finite element analysis%胫骨中段骨折钢板螺钉固定的有限元分析

    Institute of Scientific and Technical Information of China (English)

    胡新佳; 林博文; 王华; 张美超; 杨述华; 肖德明

    2011-01-01

    Objectives To determine biomechanical performances of limited contact-dynamic compression plate (LC-DCP) fixation with screws in different number and position for treatment of fractures of tibial shaft. Methods CT scan was performed for a fresh sample of adult tibia to construct a 3D finite element model of normal tibia using Mimics 10. 01 and Ansys 10. 0. Finite element models of oblique fractures of middle tibia were made on the basis of the normal model to be all fixed with LC-DCP of 14 holes but with screws in 5 different patterns. Model A was fixed with screws in the 1st, 2nd, 3rd, 12th, 13th and 14th holes; model B with screws in the 1st, 4th, 7th, 8th, 11th and 14th holes; model C with screws in the 1st,3rd, 6th, 9th, 12th and 14th holes; model D with screws in the 1st, 2nd, 7th, 8th, 13th and 14th holes;and model E with screws in all 14 holes. Finite element software Ansys 10. 0 was used to establish 3-D finite element models of 5 fixation models for tibial shaft fracture. Five kinds of digital loadings were simulated in computer, with 1000 N compressive load and 5 N · m torque moment for all models. Results In model A, the highest stresses were on the 3rd and 12th holes. In model B, the highest compressive stress was on the 1st hole, next by the 4th hole; the highest torsion stresses were on the 7th and 8th holes. In model C, the highest compressive stress was on the 1st hole, next by the 3rd hole; the highest torsion stresses were on the 6th and 9th holes. In models D and E, the highest compressive stress was on the 1st hole, next by the 2nd hole; the highest torsion stresses were on the 7th and 8th holes. Conclusions In treatment of tibia shaft fractures with minimally invasive percutaneous plate osteosynthesis, fixation with a 14-hole LC-DCP and 6 screws is appropriate. The appropriate fixation holes are the 1st, 2nd, 7th, 8th, 13 th and 14th holes.%目的 通过有限元分析探讨有限接触型动力加压钢板(LC-DCP)不同螺钉固定数目及

  1. Pedicle screw fixation and posterior lumbar interbody fusion in treatment of lumbar spondylolisthesis%椎弓根固定加椎间植骨治疗腰椎滑脱症

    Institute of Scientific and Technical Information of China (English)

    李源

    2008-01-01

    目的 探讨经后路椎弓根螺钉复位固定加椎体间植骨融合治疗腰椎滑脱的疗效.方法 采用椎弓根内固定系统,手术复位固定后,从两侧进入椎间隙取出椎间盘及纤维环,取髂骨块植骨融合.结果 29例患者获得随访,平均随访时间16个月(9~26个月).26例症状完全消失或缓解,优良率89.6%.结论 椎弓根固定系统加椎间植骨治疗腰椎滑脱症效果满意.%Objective To discuss the efficacy of reduction and fixation by pedicle screw system and iliac dowel graft placement in the treatment of lumbar spondylolisthesis.Methods From January 2003 to Decmber 2006.29 cases with lumbar spondylolisthesis were treated with pedicle screw system and iliac dowel graft placement.Results Twenty-nine patients were followed up from 9-26 months(16 months On average).26 cases were healed or alleviated.The excellent rate was 89.6%.Conclusion This technique has been found to be a safe,rapid effective procedure for lumbar spondylolisthesis and satisfaction.

  2. Complicaciones de los tornillos de bloqueo intermaxilar en el tratamiento de las fracturas mandibulares Complications of self-tapping bone screws for maxillomandibular fixation in the treatment of jaw fracture

    Directory of Open Access Journals (Sweden)

    J. Molina Montes

    2008-08-01

    Full Text Available Durante la última década se ha introducido el tornillo de bloqueo intermaxilar como método de fijación maxilomandibular en el tratamiento de las fracturas de mandíbula. El propósito del estudio es evaluar las complicaciones de la técnica y la yatrogenia dental que derivan de su aplicación durante un periodo de 4 años. Se han revisado un total de 62 pacientes y 272 tornillos y, aunque han aparecido complicaciones, su incidencia es baja.In the last decade, self-tapping bone screws have been used widely as a temporary maxillomandibular fixation method in the treatment of jaw fractures. The purpose of the present study was to evaluate the complications of the technique and potential dental iatrogenesis over a period of 4 years. We reviewed a total of 62 patients and 272 screws. Although complications appeared, the complication rate was low.

  3. Multiaxial inter-vertebral and vertebral pedicle pedicle screw fixation for spinal fractures: a biomechanical comparative study%经伤椎与跨伤椎万向钉置钉固定脊柱骨折的生物力学对比研究

    Institute of Scientific and Technical Information of China (English)

    王洪伟; 周跃; 李长青; 刘涛; 赵卫东

    2010-01-01

    Objective To compare the biomechanical stability of the multiaxial inter-vertebral and vertebral pedicle screw fixation in vertebral fracture fixation of the spinal fracture model. Methods Six lumbar fracture models were made on fresh calf lumbar spine specimens at L1 -L5 to compare the stability of four transpedicular multiaxial screws and six transpedicular multiaxial screws by examining the range of motion (ROM) in flexion, extension, lateral bending and torsion. Results Biomechanical experiment found that four multiaxial screws transpedicular fixation specimen exhibited a significantly larger ROM in flexion and extension than the intact specimens; while six multiaxial transpedicular screw fixation specimen exhibited a smaller ROM than the intact specimens (t =4. 844,P <0. 01 ;t =3. 722,P <0.05 ). The ROM of six multiaxial transpedicular screw fixation specimen was significantly smaller than that of four multiaxial transpedicular screw fixation specimen in flexion, extension, lateral bending and rotation ( P < 0. 01 ). Conclusions Compared with four multiaxial transpedicular screw fixation, six multiaxial transpedicular screw fixation exhibits a significantly larger stability in flexion, extension, lateral bending and rotation, as provides theoretical basis for treatment of thoracolumbar fractures with pedicular screw fixation.%目的 对比评估经伤椎6钉与跨伤椎4钉固定脊柱骨折的生物力学稳定性.方法 6具新鲜冰冻小牛腰椎标本L1~L5节段,制备成腰椎前中柱损伤模型.比较4钉固定组与6钉固定组的三维6个方向的运动范围.结果 生物力学试验证实,4钉固定组在屈曲、后伸运动方向上的稳定性都较对照组小,但差异无统计学意义.6钉固定组在屈曲、后伸运动方向上的稳定性均较完整对照组大,且差异有统计学意义(t=4.844,P<0.01;t=3.722,P<0.05).6钉固定组在各个方向的运动范围均小于4钉固定组,且两组在屈曲、后伸、侧屈

  4. 髂骨螺钉在成人腰椎骨盆固定术中的置钉路径及参数分析%Pelvic fixation paths and nailing parameter analysis on iliac screws in the adult lumbar spine

    Institute of Scientific and Technical Information of China (English)

    臧振华; 金昌洙; 张平

    2015-01-01

    ObjectiveToexplore the approach of iliac screw in lumbar vertebra pelvis arthrodesis. Methods Randomly selected 20 pelvic CT scan images of male and female separately, by reconstruction of 64 row spiral CT thin layer scanning image converted into 3D images. Firstly, you can select the nail screws O as entry point. Respectively from point O to the anterior superior, anterior inferior and upper edge of the acetabulum of the pelvis 3.5 mm cut, three cutting plane (OX, OY, OZ) were obtained, measured the length and width of each screw channel plane.ResultsThe narrowest diameter of three cutting plane (OX, OY, OZ) were more than 7 mm, all can be implanted iliac screw. Nail length range: Male OX plane (101.0±22)mm, OY plane (122.3±6.5)mm, OZ plane (110.8±9.0)mm; women OX plane (92.9±23.9)mm, OY plane (113.0±11.7)mm, OZ plane (110.6±11.2)mm. Statistical results also showed that there were no significance in the deflection angle of tailward and outward declination angle of screw channel between females and males (P>0.05).ConclusionThrough the pelvis three cutting plane (OX, OY, OZ) are permitted to implant screw. Through anterior inferior iliac spine (OY) is theoretically better iliac screw inserted position in the fixation of lumbar sacral vertebra pelvis.%目的:探讨腰椎骨盆融合术中髂骨螺钉入路。方法随机抽调进行过CT骨盆扫描的男女成年患者图像各20份,将其64排CT薄层图像重建转换为三维立体图像。选取可以进钉的螺钉入点O,从O点分别向髂前上棘、髂前下棘、髋臼上缘最高点处切割骨盆,得出3个切割平面(OX、OY、OZ),测量每个平面的钉道长度及宽度。结果3个切割平面(OX、OY、OZ)在最窄横径超过7 mm的条件下,均可以置入髂骨钉。钉长范围为:男性OX平面为(101.0±22)mm,OY平面为(122.3±6.5)mm,OZ平面为(110.8±9.0)mm;女性OX平面为(92.9±23.9)mm,OY平面为(113.0±11.7)mm,OZ

  5. Minimally Invasive Posterior Trans-muscular C1-C2 Screw Fixation Through an Anatomical Corridor to Preserve Occipitocervical Tension Band: Surgical Anatomy and Clinical Experience.

    Science.gov (United States)

    Díaz, Roberto; Berbeo, Miguel E; Villalobos, Luis M; Vergara, Manuel F; Osorio, Enrique

    2014-01-01

    The C1-C2 joint is affected by multiple entities that may produce biomechanical instability. Optimal management for atlantoaxial instability has been searched by ways of different surgical techniques with different results, generating discussion between second effects of a particular treatment. Lateral dissections can place the axial neck musculature and ligaments at risk of neural denervations or vascular compromise. Either of these entities may result in significant postoperative atrophy, pain, and instability. Minimally invasive techniques for the treatment of spinal disorders allow to our patients less morbid procedures with equal or better results compared to conventional surgery. In the following paper, we review the anatomy of the atlantoaxial joint and propose a minimally invasive trans-muscular C1-C2 fusion technique using C1 lateral-mass screws and C2 pedicular screws. We describe cases with surgical, clinical, and radiographic follow-up.

  6. 水平方向骶髂关节螺钉固定治疗骶骨纵形骨折的安全性评价%The safety of transverse iliosacral screw fixation of longitudinal sacral fracture

    Institute of Scientific and Technical Information of China (English)

    孙旭; 李宇能; 杨明辉; 吴新宝; 赵春鹏; 王满宜

    2011-01-01

    ObjectiveTo evaluate the safety of transverse iliosacral screw fixation of longitudinal sacral fracture.MethodsWe obtained CT scan data of the pelvis from 100 adults without any bony problems from September to December 2009. They were 52 males and 48 females, aged from 15 to 91 years (average, 43. 1 years) . We then reconstructed virtual three-dimensional models of the pelvis. The three-dimensional models were re-segmented through the sacral horizontal axis to obtain standard sagittal planes of the sacrum. To identify the safe zone for transverse screw fixation, we marked off the sacral margin on each sagittal plane. In simulation of the transverse screw ipsilateral fixation and transfixation, one single virtual cylindrical implant was inserted into the safe zone. The maximum diameter of the virtual cylindrical implant was measured.ResultsA 20. 0% rate of sacral variation was observed (80 normal versus 20 deformed morphological sacrums). In ipsilateral fixation, the average screw diameter of variant S2 (14. 92 ± 2.57 mm) >normal S2 ( 12. 37 ± 1.84 mm) ( P =0. 000) > normal S1 ( 11.87 ± 3.92 mm) ( P =0. 319 ) > variant S3 (9. 30 ± 2. 00 mm) ( P =0. 000). In transfixation, the average screw diameter of variant S2 ( 13.63 ± 2. 68 mm) > normalS2 (11.48 ±1.92mm) (P=0. 002) > normal S1(10. 40 ±4.05 mm) (P=0.033) >variant S3 (7.95 ± 2. 26 mm) ( P =0. 001 ) . The maximum screw diameter of normal S2 showed a slightly negative correlation with that of normal S1, but there was no correlation between the maximum screw diameter for each sacral vertebra and the acetabulum diameter. The normal male S2 was significantly larger than the female one ( P < 0.05), but there was no significant difference in S1 between genders ( P > 0.05) .ConclusionsIn most Chinese people, the posterior pelvic ring could be fixed with 2 iliosacral screws of 6. 5 mm in diameter simultaneously in horizontal direction, but care should be taken because the safety zone is quite

  7. Morphometric evaluation of subaxial cervical spine using multi-detector computerized tomography (MD-CT) scan: the consideration for cervical pedicle screws fixation

    OpenAIRE

    Chanplakorn, Pongsthorn; Kraiwattanapong, Chaiwat; Aroonjarattham, Kitti; Leelapattana, Pittavat; Keorochana, Gun; Jaovisidha, Suphaneewan; Wajanavisit, Wiwat

    2014-01-01

    Background Cervical pedicle screw (CPS) insertion is a technically demanding procedure. The quantitative understanding of cervical pedicle morphology, especially the narrowest part of cervical pedicle or isthmus, would minimize the risk of catastrophic damage to surrounding neurovascular structures and improve surgical outcome. The aim of this study was to investigate morphology and quantify cortical thickness of the cervical isthmus by using Multi-detector Computerized Tomography (MD-CT) sca...

  8. Absorbable screw and metal screw fixation for ankle fractures:comparison of biocompatibility and ankle function%可吸收螺钉与金属螺钉内固定修复踝关节骨折:生物相容性及踝关节功能比较

    Institute of Scientific and Technical Information of China (English)

    赵学寨; 李海军; 孟彩云; 李岩; 张仕峰; 刘明辉

    2016-01-01

    BACKGROUND:Previous ankle fracture surgery mainly uses the internal fixation materials such as metal screws or Kirschner wire, which can achieve a strong internal fixation, but al need to be taken out in the secondary surgery. In recent years, elastic modulus of biodegradable absorbable screw is identical to that of cancel ous bone, and has been widely used in clinic. OBJECTIVE:To compare the biocompatibility and functional recovery of ankle joint in the repair of ankle fractures with absorbable screws and metal screws. METHODS:100 patients with ankle fractures were selected, including 70 males and 30 females, at the age of 19 to 55 years old. Fifty patients were repaired with absorbable screws and fifty patients were repaired with metal screws. Clinical efficacy, Kofoed score, fracture healing time and adverse events were observed between the two groups after repair. RESULTS AND CONCLUSION:Patients were fol owed up for over 6 months in both groups, showing good bony cal us, good contraposition and alignment at the fracture end. No delayed union or nonunion occurred. The excel ent and good rate of clinical effect was 96%and 94%in the absorbable screw group and metal screw group, respectively, showing no significant difference. There was no significant difference in ankle Kofoed score, fracture healing time and incidence of adverse events between the two groups (P>0.05). These results suggest that absorbable screw fixation for ankle fractures had good biocompatibility and could effectively restore ankle function;its effects are similar to that of traditional metal screws.%背景:传统踝关节骨折内固定修复中使用的材料多为金属螺钉或克氏针等,虽然可达到坚强内固定的目的,但均需二次手术取出。近年来,由于生物降解可吸收螺钉的弹性模量与松质骨相当,已作为金属螺钉替代物被广泛应用于临床。目的:比较可吸收螺钉与金属螺钉置入内固定修复踝关节骨折的生物

  9. Comparison Of Lateral Mass Screw Fixation Technique And Hartshill Rectangle Technique In The Treatment Of Sub-Axial Cervical Spine Fractures

    Directory of Open Access Journals (Sweden)

    Mohit KM

    2012-11-01

    Full Text Available INTRODUCTION: Cervical injury in a polytrauma patient is one of the most critical injuries. The aim of this study was to compare the lateral mass screw technique with the Hartshill rectangle technique for treatment of such cases. MATERIALS AND METHODS: This prospective study consisted of 40 patients. Both groups were followed for three years clinically and radiologically. RESULTS: In the lateral mass technique, there were no cases of vertebral artery injury, radiculopathy, screw pullout, dural tears, residual kyphosis or persistent pain. In the Hartshill technique 3 patients experienced intra- operative dural tears, 1 case of wire breakage at the six months follow up, 6 patients with persistent neck pain and 1 with worsening neurological status. One hundred per cent fusion was achieved in both groups. There was significant radiation exposure in the lateral mass group. Post-operative immobilisation was required only in the Hartshill. CONCLUSION: Lateral mass screw technique is definitely a relatively better procedure. But Hartshill rectangle still stands out in certain practical situations.

  10. Clinical pedicle screw accuracy and deviation from planning in robot-guided spine surgery: robot-guided pedicle screw accuracy

    NARCIS (Netherlands)

    Dijk, van Joris D.; Ende, Roy P.J.; Stramigioli, Stefano; Köchling, Matthias; Höss, Norbert

    2015-01-01

    STUDY DESIGN: A retrospective chart review was performed for 112 consecutive minimally invasive spinal surgery patients who underwent pedicular screw fixation in a community hospital setting. OBJECTIVE: To assess the clinical accuracy and deviation in screw positions in robot-assisted pedicle screw

  11. 腰椎椎弓根螺钉内固定术三维可视化设计%Design of three-dimensional visualization based on the posterior lumbar pedicle screw fixation

    Institute of Scientific and Technical Information of China (English)

    徐凯; 陈春; 黄山东; 章莹; 尹庆水

    2011-01-01

    目的 建立腰椎椎弓根内固定术后的三维可视化数字模型.方法 选择1名腰椎间盘突出和1名腰椎压缩性骨折患者,在腰椎内固定术前及术后行多排螺旋CT扫描,观测术前椎体压缩程度、手术前后腰椎结构形态,术后钉棒的位置及椎板减压情况,利用Amira 4.1软件,经剪切、分割、表面重建及绘制等步骤,对腰椎结构及内植物进行三维重建,获得立体形态的腰椎手术前后改变及内置物位置结构.结果 借助数字化导航平台,重建了手术前后的腰椎和内置物形态结构.重建的三维结构可以多彩色、透明或任意组合显示.经不同角度观察,重建的三维结构显示清晰、实体感强.在三维表面重建的图像中可清楚地观察到内固定物的位置形态,特别是可以充分评估脊髓或神经根的减压程度及椎体骨折和压缩程度.术前重建图像可以清晰显示椎弓根的位置,为术中精确定位提供参考.结论腰椎椎弓根内固定术的三维重建对基础研究、临床试验及手术规划具有重要价值,应用Amira软件可为三维建模提供基础.%Objective To establish a three-dimensional visualization model of posterior lumbar pedicle screw fixation. Methods A patient with lumbar intervertebral disc hernia and another patient with compression fracture of lumbar vertebra were involved in the present study. Both patients underwent multi-slice spiral CT scan before and after lumbar pedicle screw fixation. The degree of preoperative vertebral compression, vertebral morphology before and after surgery, postoperative pedicle screw position, and decompression effects were observed. The original data of the multi-slice spiral CT were inputted into the computer. The three-dimensional reconstructed images of the lumbar and implanted screws were obtained using the software Amira 4.1 to show the three-dimensional shape of the lumbar vertebrae before and after surgery and the location of the

  12. Effect of sustentaculum tali screw placement after open reduction and internal fixation of intraarticular calcaneal fractures%切开复位内固定跟骨关节内骨折后载距突固定效果

    Institute of Scientific and Technical Information of China (English)

    强敏菲; 陈雁西; 张坤; 李浩博; 戴号

    2014-01-01

    Objective To investigate the effect of sustentaculum tali screw placement on outcomes following open reduction and internal fixation (ORIF) of intraarticular calcaneal fractures.Methods A retrospective analysis was made on 139 patients with intraarticular calcaneal fractures treated by ORIF from April 2008 to January 2012.According to Sanders classification,there were 9 patients with type Ⅱ fractures,87 with type Ⅲ fractures and 43 with type Ⅳ fractures.Fracture reduction followed by placement of calcaneal anatomic plate or anatomic locking plate was performed via calcaneal lateral L-shape incision.All the patients received X-rays and CT scans within postoperative 2 weeks.Placement of screws in sustentaculum tail was detected by CT volume rendering to visualize implants combined with multiplanar reconstruction imaging (MPR).Patients were divided into accurate fixation group (Group A,n =28),marginal fixation group (Group B,n =58),and non-fixation group (Group C,n =53) based on radiological results.Intra-and peri-operative parameters,time to partial weight-bearing,time to full weight-bearing,fracture healing time,and clinical outcome were compared among groups.Functional outcome was assessed using American Orthopedic Foot and Ankle Society (AOFAS) Ankle Hindfoot Scale.Results Postoperative X-rays indicated accurate fixation of sustentaculum tail in 64 patients,marginal fixation in 22,and non-fixation in 53,but CT images manifested accurate fixation in 28 patients,marginal fixation in 58,and non-fixation in 53.Group A had operation duration of (93 ±11) min and intraoperative blood loss of (252 ± 27) ml,longer or higher than those in Group B [(85 ±8) min,(194±16) ml] and Group C [(57±6) min,(136 ±13) ml] (P<O.05).There was no significant difference in mean hospital stay among the three groups (P > 0.05).Ninety-two patients were followed-up for 12-38 months (mean 18.5 months) and 85 patients completed foot and ankle exercise as planned

  13. Efficacy of three methods of internal fixation on femoralneck fracture

    Institute of Scientific and Technical Information of China (English)

    闫洪印; 陈扬; 肖建德; 李振宇; 龚敏; 马若凡; 刘尚礼

    2002-01-01

    @@ From 1990 to 2000, we used Hansson pin, AOhollow-pulling screw, and bendable screw to treat150 cases of fresh femoral neck fracture and theresult was analysed to compare the efficacy of the threemethods of internal fixation.

  14. C2~3椎弓根-侧块螺钉系统治疗不稳定型Hangman骨折%Transpedicular with Pedicle Screw Fixation for the Treatment of Hangman's Fractures

    Institute of Scientific and Technical Information of China (English)

    王磊; 刘海龙; 徐卫松; 仇志学; 韩国栋

    2011-01-01

    目的 探讨C2~3椎弓根-侧块螺钉系统治疗Hangman骨折的疗效及临床效果.方法 我院2007年4月至2010年10月收治的11例Hangman骨折患者进行回顾性研究,男4例,女7例;年龄22~61岁,平均42.5岁.患者均表现为颈痛、颈部活动受限,2例单侧上肢,1例双侧上肢麻木无力.所有患者入院后均行X线、三维CT及MRI检查,并测量Cz~3椎体移位和成角,其中Levine- Edwards分型,Ⅰ型3例,Ⅰ型4例,Ⅰa型2倒,Ⅲ型2例.人院后常规行颅骨牵引,Ⅰ型患者予以halo-vest架外固定治疗,Ⅱ型、Ⅱa型、Ⅲ型患者行后路C2~3椎弓根侧块螺钉内固定术,术后用费城颈托保护6周.结果 随访2~44个月,平均20.6个月.平均6个月时骨折端愈合,颈痛、肢体麻木等症状消失,但颈部活动度较正常略有下降,无内固定失败及感染等并发症发生.结论 经后路C2~3椎弓根侧块螺钉系统是治疗Hangman骨折的良好手术方式.%Objective To determine the treatment efficacy of transpedicular with pedicle screw fixation for the treatment of Hangman's fracture. Methods A retrospective review of 11 cases,including 4 males and 7 females,with Hangman's fractures was performed. The age of the patients were 22~61 years, average 42. 5 years. All the patients complained neck pain and limitation of movement of the neck. Numbness and weakness appeard in unilateral upper limb in 2 cases, biliater upper limbs in 1 case. All patients received anterior-posterior and lateral X-rays,MRI andthree dimensional CT scans. Initial and final radiographs were measured for translation and angilation of C2~J. According to the Levine-Edwards classification,there were 3 cases for type I ,4 for type H ,2 for type JI a and 2 for type I . Skull tractions under extension position were used in all patients after admission. Halo-vest treatment option for type Ⅰ ,Then type Ⅱ ,Ⅱla, Ⅲ transpedicular with pedicle screw fixation were performed. Philadelphia collars

  15. Clinical effect of internal fixation of screw intramedullary nail in the treatment of midshaft tibia fracture: report of 13 cases.%旋入式髓内针内固定治疗胫骨中段骨折13例

    Institute of Scientific and Technical Information of China (English)

    郭岁利

    2012-01-01

    目的 观察开放复位旋入式髓内针内固定治疗胫骨中段骨折的疗效.方法 选择2009年5月至2011年5月胫骨中段骨折患者13例,采用开放复位旋入式髓内针内固定对其进行治疗,并随访6~9个月,观察临床疗效.结果 13例均达骨性愈合,膝踝关节活动范围正常;优11例,良2例,优良率100%.无髓内针断裂、松动、变形等并发症.结论 采用开放复位旋入式髓内针内固定治疗胫骨中段骨折是一种简便易行的手术方法.%Objective To observe the clinical effect of open reduction and internal fixation of screw intramedullary nail in the treatment of midshaft tibia fracture. Methods Thirteen cases of midshaft tibia fracture were treated with open reduction and internal fixation of intramedullary nail surgery. The patients were followed up for 6 to 9 months after surgery. Results All of the 13 cases reached osseous healing. The range of knee joint motion and the range of ankle joint motion were all normal. The rate of excellent and good was 100% ( excellent in 11 cases and good in 2 cases ). Conclusion Open reduction and internal fixation of intramedullary nail is a simple and feasible operation for the treatment of midshaft tibia fracture.

  16. Nurse cannulation: introducing an advanced clinical skill.

    LENUS (Irish Health Repository)

    Hoctor, Bridget

    2012-01-31

    Many patients admitted to emergency departments (EDs) require therapy delivered by cannula. Mid-Western Regional Hospital, Tipperary, used to run a system in which many patients had to endure two invasive procedures: on arrival their blood was taken by nurses and later they were cannulated by doctors. To reduce the number of procedures, ED nurses initiated a project to extend their skills to include cannulation. The new system of nurse cannulation at triage has also helped reduce waiting times.

  17. Treatment of craniovertebral anormalies through occipitocervical fusion by inter-diploe screw fixation%枕骨板障间螺钉固定枕颈融合术治疗颅颈部畸形

    Institute of Scientific and Technical Information of China (English)

    姚女兆; 王文军; 王麓山; 晏怡果; 王程; 朱一平

    2014-01-01

    Objective To explore the clinical outcome of the treatment of craniovertebral anormalies through occipitocervical fusion by inter-diploe screw fixation.Methods From January 2010 to January 2013,15 patients (9 males,6 females) in the First Affiliated Hospital of University of South China were diagnosed with craniovertebral anormalies.The age ranged from 29 to 60 years (40.4 ± 8.2) years.Eight patients had Arnold-Chiari deformitory,5 patients had basilar invagination with os odontoidem,2 patients had Klippel-Feil deformitory.All the patients had symptoms of spinal medulla compression.The Japanese orthopaedic association(JOA) score of preoperation ranged from 6 to 10 (8.1 ± 1.7).All the patients received head-shoulders traction through modified Halo-vest for 1-2 weeks.All cases received occipitocervical fusion by inter-diploe screw-rod-pedicel screw system.Results All patients underwent this technique operation successfully.The mean operation time was 100-220 min (140.2 ± 30.5) min,and blood loose was 190-710 ml(272.2 ±73.4) ml.There was no neurological function worsen and severely complications.The JOA after operation 3 days was 9-14 (11.0 ± 2.1),there was statistical differences compared to preoperation (t =0.003,P < 0.05).The postoperatively radological films indicated all the inter-diploe screw locations were satisfactory,there was no screw penetrating the medial occipital plate.All cases were followed up for 12-36 months(22.0 ± 6.3) months.Bone graft fusion was obtained in 3-9 months (5.1 ± 2.7) months.There was no internal fixation breakage and loosening.The JOA score of last follow-up was 12-16 (14.1 ± 1.6),there was statistical differences compared to preoperation(t =0.002,P < 0.05).All patients with limb numbness,muscle weakness and other symptoms were obviously improved than preoperation.Conclusions Occipitocervical fusion using inter-diploe screw-rod-pedicel screw system,is an effective method for the treatment of craniovertebral anormalies with

  18. 单侧椎弓根螺钉置入并椎间融合对邻近椎间盘节段退变的影响%Unilateral pedicle screw fixation with lumbar interbody infusion for adjacent segment degeneration

    Institute of Scientific and Technical Information of China (English)

    邵高海; 焦春燕; 余雨; 钟斌; 李波

    2011-01-01

    背景:坚强内固定和良好融合存在严重缺陷和不足.目前还未见临床应用单侧椎弓根螺钉固定结合椎间cage植骨融合治疗腰椎退变性疾病对邻近节段退变影响的相关报道.目的:回顾分析单侧椎弓根螺钉固定结合椎间cage植骨融合治疗部分腰椎退变性疾病后对固定融合邻近上下节段退变的影响.方法:2006-03/2009-12对收治的部分腰椎管狭窄症、腰椎失稳及腰椎间盘脱出症患者22例,进行了单侧椎弓根螺钉固定加椎间cage植骨融合,术中不显露对侧.在固定融合后3,6,12,20个月及取出内固定钉棒后3,6个月,随访X射线片及MRI.针对X射线片运用角平分线法测量固定融合邻近上位椎间隙高度变化,MRI测量椎间盘髓核退变情况.结果与结论:所有病例获得随访,患者椎管狭窄症状及神经根性症状消失,并且在随访期间内没有新的临床症状出现.固定融合前、固定融合后3,6,12,20个月邻近节段上位椎间隙高度分别为(7.420±0.035 4),(7.426 6±0.036 9),(7.453 3±0.036 9),(7.516 6±0.036 9),(7.430 8±0.036 9) mm,结果表明,腰椎单侧固定融合后邻近节段椎间隙高度无明显变化(P > 0.05).MRI测量结果显示,固定融合邻近上位椎间盘髓核信号在T2加权像无明显退变.提示单侧椎弓根螺钉固定结合椎间融合治疗部分腰椎退变性疾病能有效预防固定融合邻近上下节段退变.%BACKGROUND: There are no reports add ressing effects of unilateral pedicle screw plus cage internal fixation on adjacent segment degeneration in the treatment of lumbar degenerative disease.OBJECTIVE: To review the effects of unilateral pedicle screw plus cage internal fixation on adjacent segment degeneration in the treatment of lumbar degenerative disease.METHODS: From 2006 to 2009, 22 patients with partial lumbar spinal stenosis, lumbar instability, and lumbar intervertebral disc herniation received unilateral pedicle screw plus cage

  19. 经皮骶髂螺钉和骶髂关节前路钢板内固定治疗不稳定骨盆骨折的临床疗效比较%Clinical curative effect comparison on percutaneous sacroiliac screws internal fixation and sacroiliac joint anterior plate fixation in the treatment of unstable pelvic fractures

    Institute of Scientific and Technical Information of China (English)

    蔺广生

    2016-01-01

    目的:探讨经皮骶髂螺钉和骶髂关节前路钢板内固定治疗不稳定骨盆骨折的临床疗效。方法选取2012年1月~2014年1月收治的149例不稳定骨盆骨折患者,根据治疗方法将其分成骶髂钢板组和骶髂螺钉组。其中骶髂钢板组74例,给予骶髂关节前路钢板内固定治疗;骶髂螺钉组75例,给予经皮骶髂螺钉治疗。比较两组患者临床资料、手术相关指标、临床疗效以及术后并发症。结果两组患者性别、年龄、致伤原因、合并伤以及Tile分类等资料数据比较差异无统计学意义( P>0.05);骶髂螺钉组患者手术时间、出血量、切口长度以及住院时间[(86.1±11.2)min,(16.7±8.5)mL,(1.7±0.6)cm和(8.7±2.7)d]均显著低于骶髂钢板组患者[(122.3±20.5)min,(516.3±118.7)mL,(15.7±1.5)cm和(17.7±4.8)d,P<0.05];骶髂螺钉组患者骨折复位优良率和功能恢复优良率(97.3%和96.0%)均显著高于骶髂钢板组患者(79.7%和73.0%,P<0.05);骶髂螺钉组患者术后并发症发生率(4.0%)显著低于骶髂钢板组患者(24.3%,P<0.05)。结论经皮骶髂螺钉治疗不稳定骨盆骨折临床疗效显著,且具有出血量小、创伤小、恢复快、术后并发症少等优点,值得临床推广应用。%Objective To investigate clinical efficacy of percutaneous sacroiliac screws internal fixation and sacroiliac joint anterior plate fixation in the treatment of unstable pelvic fractures.Methods From Jan.2012 to Jan.2014,149 cases of unstable pelvic fracture were selected to study.According to the treatment method,all the patients were divided into sacroiliac plate group and sacroiliac screw group.There were 74 patients in the sacroiliac plate group treated with the sacroiliac joint anterior plate internal fixation and 75 patients in the sacroiliac screw group treated with percutaneous sacroiliac screw fixation

  20. 腰椎内固定中两种椎弓根钉加强技术与骨水泥的应用%Two strengthening pedicle screw techniques and bone cement in lumbar internal fixation

    Institute of Scientific and Technical Information of China (English)

    江泽华; 朱如森; 袁建军; 邵高升; 张学利

    2013-01-01

    BACKGROUND:Screw loosening and shedding may occur after osteoporosis associated with lumbar degenerative disease treated with pedicle screw fixation. Application of pedicle screw enhanced with cured materials can improve the therapeutic effect. OBJECTIVE:To compare the clinical effect of pedicle screws enhanced with poly(methyl methacrylate) and injectable calcium sulfate cement in the lumbar internal fixation of osteoporosis. METHODS:Sixty-one patients diagnosed with osteoporosis combined with lumbar spondylolisthesis, lumbar spinal instability, and severe lumbar spinal stenosis were col ected. Al patients were divided into two groups according to the treatment method:poly(methyl methacrylate) bone cement enhanced pedicle screw group and calcium sulfate bone cement enhanced pedicle screw group. RESULTS AND CONCLUSION:There were no significant differences in the operation time, blood loss, preoperative and postoperative visual analog scale score, Japanese Orthopedic Association scores and the Japanese Orthopedic Association score improvement rate between two groups (P>0.05). The results showed that two patients had bone cement leakage in poly(methyl methacrylate) group which had no neurological symptoms caused by new symptoms during fol ow-up period. The bone mineral density was not improved gradual y in poly(methyl methacrylate) group with fol ow-up time prolonging;however, in calcium sulfate group, the bone mineral density was increased significantly after treatment, and the change of bone mineral density was linearly related with Japanese Orthopaedic Association score improvement rate in calcium sulfate group. No screw loosening, pul ing out or neurological dysfunction occurred in both groups. The results indicate that like poly(methyl methacrylate), balcium sulfate bone cement can increase the stability of pedicle screws.%背景:骨质疏松伴腰椎退行性病变行椎弓根钉固定骨质疏松的椎体后可能会出现螺钉的松动、脱落,使用

  1. Clinical comparative analysis on percutaneous sacroiliac screws internal fixation and sacroiliac joint anterior plate fixation in the treatment of unstable pelvic fractures%经皮骶髂螺钉与骶髂关节前方钢板固定治疗不稳定性骨盆骨折的临床疗效分析

    Institute of Scientific and Technical Information of China (English)

    杨雷; 王洪飞; 王中海

    2012-01-01

    目的 探讨经皮骶髂螺钉与骶髂关节前方钢板固定治疗不稳定性骨盆骨折的临床疗效.方法 选取本院2008年1月至2011年6月收治的不稳定性骨盆骨折患者64例,随机分为两组,采用骶髂关节前方钢板固定治疗的患者32例为对照组,采用经皮骶髂螺钉内固定治疗的患者32例为观察组,比较两组患者围术期临床指标、术后Matta评分、术后Majeed功能评分.结果 观察组手术时间、术中出血量、伤口总长度、术后发热时间、住院时间均明显少于对照组,观察组并发症发生率(3.1%)明显低于对照组(21.9%),观察组术后Matta评分总优良率(96.9%)明显高于对照组(81.2%),观察组术后Majeed功能评分总优良率(93.8%)明显高于对照组(75.0%),差异均有统计学意义(P<0.05).结论 经皮骶髂螺钉内固定治疗不稳定性骨盆骨折具有损伤小、出血少、疼痛轻、恢复快等优点,是一种安全有效的微创手术方法,临床疗效明显好于骶髂关节前方钢板固定,术前充分准备及患者积极配合可以大幅降低并发症的发生率,值得临床推广使用.%Objective To investigate clinical efficacy of percutaneous sacroiliac screws internal fixation and sacroiliac joint anterior plate fixation in the treatment of unstable pelvic fractures. Methods Sixty-four patients with unstable pelvic fractures were selected in the hospital from January 2008 to June 2011, which were randomly divided into two groups. The control group (n=32) used sacroiliac joint anterior plate fixation, while the study group (n=32) used percutaneous sacroiliac screw internal fixation for treatment. The perioperative clinical indicators, postoperative Matta score, postoperative Majeed function score of all patients were compared. Results The operation time, intraop-erative blood loss, wound total length, postoperative fever time, duration of hospitalization in the study group were significantly less than those

  2. Estudo tomográfico do atlas relacionado com a inserção de implantes na massa lateral Tomographic study of the atlas concerning screw fixation on lateral mass

    Directory of Open Access Journals (Sweden)

    Max Franco de Carvalho

    2009-01-01

    Full Text Available INTRODUÇÃO: A técnica de Harms para a realização da artrodese atlantoaxial possibilita o uso de manobras de redução transoperatória da subluxação atlantoaxial e facilita a fixação dessa articulação, principalmente nos pacientes hipercifóticos e nas situações em que há impossibilidade da fixação com o parafuso transarticular C1-C2. OBJETIVOS: descrever os parâmetros morfométricos do atlas relacionados à técnica de Harms para a artrodese C1-C2, o trajeto ideal e o corredor de segurança da inserção do parafuso na massa lateral do atlas mensurados através de imagens de reconstrução multiplanar com tomografia computadorizada helicoidal nos planos. MATERIAIS E MÉTODOS: trinta atlas de origem local foram submetidos a tomografia computadorizada e mensurados com cursor digital. RESULTADOS: o comprimento posteroanterior do implante mediu 16,5 mm à direita e 16,3mm à esquerda. Quando utilizando como ponto de entrada na porção central da massa lateral imediatamente inferior ao arco posterior, o trajeto deve ter uma congruência de 15º no plano coronal e uma angulação superior de 20º no plano sagital. CONCLUSÃO: O corredor de segurança para um parafuso na massa lateral teria uma inclinação inferior de 22º e superior de 33º no plano sagital e no plano axial de 36º medial e 26º lateral.INTRODUCTION: Harms's technique for atlanto-axial arthrodesis fusion makes possible the use of intraoperative reduction maneuvers of the atlanto-axial dislocation and facilitates the fixation of this joint, especially in hiperkyphotic patients and in situations where the fixation with transarticular screw on C1-C2 segment is impossible. OBJECTIVE: to describe the morphometric parameters of atlases related to the Harms's technique for atlanto-axial arthrodesis, the optimal path and the safety aisle for screw insertion into atlas' lateral mass measured with multiplanar reconstruction imaging with helical computed tomography scan at

  3. Design and biomechanical study of a modified pedicle screw

    Institute of Scientific and Technical Information of China (English)

    LIU Tao; ZHENG Wen-jie; LI Chang-qing; LIU Guo-dong; ZHOU Yue

    2010-01-01

    Objective: In pedicle screw fixation,the heads of monoaxial screws need to be directed in the same straight line to accommodate the rod placement by backing out during operation, which decreases the insertional torque and internal fixation strength. While polyaxial screws facilitate the assembly of the connecting rod, but its ball-in-cup locking mechanism reduces the static compressive bending yield strength as compared with monoaxial screws. Our study aimed to assess the mechanical performance of a modified pedicle screw.Methods: In this study, the tail of the screw body of the modified pedicle screw was designed to be a cylindershaped structure that well matched the inner wall of the screw head and the screw head only rotated around the cyclinder. Monoaxial screws, modified screws and polyaxial screws were respectively assembled into 3 groups ofvertebrectomy models simulated by ultra high molecular weight polyethylene (UHMWPE) blocks. This model was developed according to a standard for destructive mechanical testing published by the American Society for Testing Materials (ASTM F1717-04). Each screw design had 6 subgroups, including 3 for static tension, load compression and torsion tests, and the rest for dynamic compression tests. In dynamic tests, the cyclic loads were 25%, 50%, and 75% of the compressive bending ultimate loads respectively.Yield load, yield ultimate load, yield stiffness, torsional stiffness, cycles to failure and modes of failure for the 3 types of screws were recorded. The results of modified screws were compared with those ofmonoaxial and polyaxial screws.Results: In static tests, results of bending stiffness,yield load, yield torque and torsional stiffness indicated no significant differences between the modified and monoaxial screws (P>0.05), but both differed significantly from those ofpolyaxial screws (P<0.05). In dynamic compression tests,both modified and monoaxial screws showed failures that occurred at the insertion point of screw

  4. Biomechanical evaluation of screw and plate fixation in pelvic fractures%螺钉与钢板在骨盆骨折置入内固定应用中的生物力学评价

    Institute of Scientific and Technical Information of China (English)

    赵艳

    2011-01-01

    ofpelvic fractures and play a very important role in the final choice of treatment. Anatomic reduction and solid fixation of pelvicfractures as well as screws and plate internal fixation are very important. To develop an implant with small wound, low infectionrate, stable fixation and good compatibility is the current direction in the treatment of unstable pelvic fractures.

  5. Percutaneous triple anterior screw fixation of acute combined atlas-axis fractures in elderly patients:a primary report%前路经皮三钉固定治疗老年寰枢椎联合骨折

    Institute of Scientific and Technical Information of China (English)

    王向阳; 徐华梓; 池永龙; 林焱; 黄其杉; 倪文飞; 王胜; 徐晖

    2011-01-01

    目的 探讨经皮内固定技术治疗老年(特别是合并颅脑损伤)患者急性寰枢椎联合骨折的方法及其疗效.方法 2006年3月至2011年2月,共7例老年急性寰枢椎联合骨折患者.男6例,女1例;年龄64~84岁,平均72.4岁.寰椎骨折:Jefferson骨折2例,前弓骨折2例,前后弓两处骨折2例,前后弓骨折+侧块骨折1例.枢椎齿状突骨折:AndersonⅡ型骨折6例,浅Ⅲ型骨折1例.颅脑损伤5例,均合并不同程度意识朦胧、谵妄或昏迷.对所有患者均在“C”型臂X线机监视下行经皮前路枢椎齿状突和两侧寰枢关节螺钉内固定术治疗,并分析其治疗效果.结果 手术时间36~78 min,平均56 min.同时行植骨术的患者出血20~50 ml,未行植骨术者无明显出血.7例患者均获得满意治疗效果,螺钉位置正确.无神经根、脊髓、椎动脉和食管损伤等并发症发生.全组病例平均随访10.7个月,无脱钉、弯钉及断钉发生,枢椎齿状突骨折均骨性愈合,无寰枢关节不稳.结论 对于老年特别是合并颅脑损伤患者的急性寰枢椎联合骨折,经皮前路三钉固定技术是一种简单、安全和有效的方法,有利于对患者临床护理和早期功能训练,减少并发症的发生.%Objective To evaluate the clinical effect of the percutaneous fixation for atlas-axis combined fractures in the elderly patients,especially with brain injury.Methods From March 2006 to February 2011,a total of 7 cases with C1,2 combined fractures entered the study,including 5 males and 1 female with an average age of 72.4 years (range,64-84 years).Fracture combinations included two Jefferson/type Ⅱ odontoid,two anterior ring/type Ⅱ odontoid,two anterior and posterior ring/type Ⅱ odontoid,and one anterior and posterior ring+lateral mass/type Ⅲ odontoid.There were 5 patients with head injuries in varying degrees of coma.All patients underwent percutaneous placement of odontoid screw and anterior C1,2 transarticular screws

  6. 椎弓根钉棒系统固定治疗齿状突骨折合并寰枢关节不稳%Transpedicular Screw Fixation System for the Treatment of Dens Fracture Complicated with Atlantoaxial Instability

    Institute of Scientific and Technical Information of China (English)

    张毅; 黄象望; 沈雄杰; 常磊

    2011-01-01

    [Objective]To explore the method and efficacy of transpedicular screw fixation system for the treatment of traumatic axial dentoid process fracture complicated with atlantoaxial instability.[Methods]Twenty six adult cases of acute axial dentoid process fracture complicated with atlantoaxial instability from Dec.2005 to April 2010 were reviewed.Among all the cases, 18 cases were male and 8 cases were female.According to Anderson-D' Alonzo typing method modified by Grauer, 5 cases were type Ⅱ A, and 12 cases were type Ⅱ B, and 6 cases were type Ⅱ C, and 3 cases were type Ⅲ.Three cases were accompanied by spinal injury including 2 cases with type Ⅱ B and one case with type Ⅱ C.All cases were complicated with atlantoaxial instability.At first, all the cases underwent skull traction for atlantoaxial reduction, and then were fixed with atlantoaxial pedicle screw system by cervical posterior approach under general anesthesia.Of all cases, 19 cases underwent autologous iliac bone graft and 7 cases underwent atlantoaxial pedicle screw fixation.The surgical efficacy was assessed by JOA scores before and after operation.[Results]No vertebral artery or spinal injury occurred during operation.Mean time of follow-up was 12 months(8~25 months).Cervicobrachialgia in all patients was alleviated.Three cases with spinal injury had the recovery of neurological function to some ex tent.The imaging data of all cases showed that the atlantoaxial anatomic relationship recovered well and pedicle screws were in a proper position without postoperative loosening or breaking.The bony fusion was obtained in 19 cases undergoing bone graft at 6 months of follow up.The internal fixation system was removed in 7 ca ses without bone graft after one and a half years.Atlantoaxial rotational function was restored satisfactorily.[Conclusion]Atlantoaxial pedicle screw fixation for the treatment of traumatic axial dentoid process fracture complicated with atlantoaxial instability is a solid

  7. 前路减压植骨可吸收螺钉内固定治疗颈椎病%The anterior decompression and bone grafting with bio-absorbable screw fixation for cervical spondylosis

    Institute of Scientific and Technical Information of China (English)

    王栋; 贺西京; 李浩鹏; 张健; 徐思越; 杨平林; 王国毓

    2009-01-01

    Objective:To observe the early clinical effect of the cervical spendylosis treated by the fixation with bio-absorbable screw after cervical anterior decompression and bone grafting.Method:26 cases suffered from cervical spondylosis who were treated by anterior compression,bone grafting and fixating with 2 bio-ab-serbable screws from Mar. 2007 to Sep. 2008,including 16 males and 10 females with an average age of 49.4 years (38-70 years ).There were 11 cases with cervical spondylotic myelopathy,5 with cervical spendylofic radieulopathy and 10 with mixed type of cervical spondylosis.Clinical data of these patients was analyzed ret-rospectively.One intervertebral space involvement was in 8 cases,and two spaces involvement in 18 cases.All patients underwent anterior decompression and bone grafting,in which the grafted bone was fixated by 2 bio-absorptive screws (PLLA,diameter:2.7mm) from the midline of graft bone to the bone surface of upper and lower vertebrae in 45°.Cervical collar was commonly used for 4-6 weeks after operation.All cases were fol-lowed-up every month in outpatient department to observe the improvement of symptoms and evaluate the fu-sion of bone graft.Neurological function recovery was observed by JOA score.Result:Operations of all cases were finished and screws were placed successfully.The operative incisions healed well.The excellent and good rate of symptom improvement was 84.2%,the graft fusion time was 3.3±0.6 months (range,3.2-4.6 months).No obvious complications were found.Conclusion:The cervical spendylosis with one or two-level involvement can be effectively treated by anterior decompression and bone grafting with bio-absorbable screw fixation.This operative method is safe and can avoid the complications induced by metal implants.%目的:观察颈椎前路减压植骨可吸收螺钉内同定治疗颈椎病的初步临床疗效.方法:2007年3月~2008年9月我院应用颈椎前路减压植骨可吸收螺钉

  8. Biomechanics study of interal fixation with hollow compression screw and composite calcium phosphate cement of osteoporotic femoral neck%复合磷酸钙骨水泥强化骨质疏松股骨颈加压空心螺钉的生物力学研究

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To evaluate the biomechanics of hollow compression screw in the osteoporotic femoral neck with composite calcium phosphate cement (CCPC).Methods Sixteen femurs of superior segment were randomly divided into two groups: augmentation group and non augmentation group.CCPC was used in augmentation group.Result Augmentation with CCPC would improve the initial mobile force of hollow compression screw,the initial mobile force and the maximal axial pull out strength for augmentation group,non augmentation group increased from (192.7± 14.0)N and (202.8± 14.0)N to(328.5± 34.7)N and( 347.8± 31.2)N.There was significant difference of two groups(P< 0.01).Conclusion CCPC can enhance hollow compression screw fixation in osteoporotic femoral neck.

  9. Basis椎弓根螺钉固定加环形植骨融合治疗腰椎滑脱%Basis pedicle screw fixation and posterior instrumented circumferential fusion for the treatment of lumbar spondylolisthesis

    Institute of Scientific and Technical Information of China (English)

    董福龙; 申才良; 张建湘; 汤健; 杨庆国; 江曙

    2011-01-01

    Objective To summarize curative effects of the decompressive laminectomy by posterior approach, reduc tion of spondylolisthesis fixed with Basis pedicle screw and posterior instrumented circumferential fusion in the treat ment of lumbar spondylolisthesis. Methods Thirty-two patients with lumbar spondylolisthesis treated with posterior instrumented circumferential fusion were studied retrospectively. Results All the patients received follow-up for 4 ~ 25 months. Symptoms were disappeared after operations in all the patients. The postoperative X-ray films showed that 29 patients obtained complete reduction,3 partly reduction. This surgical methods produced satisfactory outcomes with the 100% osseous fusion. All the bone grafts were fusion, without screws loosening or breakage or internal fixation loosing was found. Based on Hou Shu-xun Criteria for therapeutical evalution, the efficacy was as follows: excellent in 23 cases,good in 7,and fair in 2,the rate of excellent and good was 94%. Conclusions Posterior instrumented cir cumferential fusion with Basis pedicle screw is an effective method for treating severe lumbar spondylolisthesis.%目的 探讨后路腰椎管减压、Basis椎弓根螺钉系统复位固定加环形植骨融合治疗腰椎滑脱症的疗效.方法 对32例腰椎滑脱症患者行后路腰椎管减压Basis椎弓根螺钉复位固定加环形植骨融合术.结果 32例均获随访,时间4~25个月.患者术后症状均消失,X线片示29例滑脱完全复位,3例部分复位.所有患者均达骨性融合,无椎弓根钉松动、断裂及再滑脱现象.根据侯树勋等疗效评定标准评定:优23例,良7例,可2例,优良率94%.结论 Basis椎弓根固定系统复位固定加环形植骨融合治疗腰椎滑脱症临床疗效满意,可作为治疗严重腰椎滑脱的首选方法.

  10. Clinical Effect of Percutaneous Sacroiliac Screws Fixation and Plate Fixation in Front of Sacroiliac Joints in Treating ;Unstable Pelvic Fractures%经皮骶髂螺钉与骶髂关节前方钢板固定治疗不稳定性骨盆骨折的临床疗效分析

    Institute of Scientific and Technical Information of China (English)

    刘洪; 唐长友; 贺健军

    2015-01-01

    Objective To investigate the clinical effect of plate fixation in front of sacroiliac joints and percutaneous sacroiliac screws fixation in treating unstable pelvic fractures. Methods 82 patients with unstable pelvic fractures treated in our hospital from March 2011 to March 2014 were selected and randomly divided into two groups. The control group (41 cases) was treated with plate fixation in front of sacroiliac joints, the observation group (41 cases) was treated with percutaneous sacroiliac screws fixation. The operation time, length of incision, bleeding volume during operation, hospitalization time, the treatment effects and complications were compared between two groups. Results The length of incision, operation time and hospitalization time of observation group were significantly shorter than those of control group, the bleeding volume during operation was significantly less than that of control group;the excellent and good rate of fracture reduction in observation group was 95.12%, significantly higher than 75.61%of control group;the incidence of complications of observation group was 4.88%, significantly lower than 19.51%of control group;all the difference was statistical (P<0.05). Conclusions In the treatment of unstable pelvic fractures, percutaneous sacroiliac screws fixation has the advantages of small trauma, quick recovery, better clinical effect and higher safety, which is worthy of promotion.%目的:探讨不稳定性骨盆骨折分别采用骶髂关节前方钢板固定与经皮骶髂螺钉固定治疗的临床效果。方法选取2011年3月至2014年3月我院收治的不稳定性骨盆骨折患者82例,随机分为两组各41例。对照组采用骶髂关节前方钢板固定治疗,观察组采用经皮骶髂螺钉固定治疗。比较两组的手术时间、切口长度、术中出血量、住院时间、治疗效果及并发症发生情况。结果观察组切口长度、手术时间及住院时间均明显短于对照组,术中出

  11. 可吸收螺钉结合外固定架治疗复杂性胫腓骨骨折%ABSORBABLE SCREWS WITH EXTERNAL TRESTLE FIXATION IN TREATING COMPLICATED FRACTURE OF TIBIA AND FIBULA

    Institute of Scientific and Technical Information of China (English)

    王占军; 吴洪增

    2011-01-01

    Objective To introduce a technique for treating the complicated fracture of tibia and fibula. Methods Fifty - four cases of opened and/or comminuted fracture of tibia and fibula were treated by internal absorbable screws fixation with external skeletal trestle fixation,at the same time underwent the conventional bone graft. Results There were 44 cases ( 81. 5% ) having anatomic reduction,and the others having approximately anatomic reduction,All the bone fracture healed good, the clinical healing time of bone fracture was 4 ~ 14 months( average time of 6. 5 months) . Fifty - four cases were followed - up for 10 ~ 24 months ( average time of 13 months). Accerding to Johner - Wruhs standard,51 cases were excellent,3 cases were good. Conclusion The method has many advantages such as mininal damage ,reliable effect, safety and low cost ,and it is worth promoting the application.%目的 介绍一种适合复杂性胫腓骨骨折的治疗方法.方法 本组54例开放性和(或)粉碎性胫腓骨骨折的病例,采用可吸收螺钉加外固定支架固定的方法治疗,同时常规行植骨术.结果 44例(81.5%)达到解剖复位,其余达到功能复位,骨折全部愈合,临床愈合时间4~14个月,平均6.5个月.随访10~24个月,平均13个月.按Johner-Wruhs评分标准,优51例,良3例.结论 该方法创伤小,固定可靠,安全经济,值得推广应用.

  12. Biomechanical analysis of short-segment pins Index-level screw fixation for low lumbar burst fractures%Index-level螺钉短节段固定治疗下腰椎爆裂压缩骨折的生物力学研究

    Institute of Scientific and Technical Information of China (English)

    王涛; 马剑雄; 王玉龙; 马信龙; 张晓林; 徐宝山; 杨强

    2013-01-01

    目的 通过对L4椎体爆裂骨折模型以及应用不同方法固定后的生物力学测试,探讨Index-level螺钉短节段固定方法在治疗下腰椎爆裂骨折中的意义.方法 选取10具新鲜尸体腰骶椎标本,通过截骨、切断部分韧带的方法制作L4椎体爆裂骨折模型,然后依序进行长节段固定、短节段固定以及短节段+ Index-level螺钉固定并进行生物力学测试,比较不同固定方法腰椎活动度(range of motion,ROM)的差异.结果 与短节段固定比较,短节段+Index-level螺钉固定在前屈、轴向旋转和侧屈时ROM降低,差异有统计学意义(P<0.05).在后伸位时短节段+Index-level固定稳定性提高,ROM降低32.7%,但差异无统计学意义.结论 Index-level螺钉短节段固定较单纯短节段内固定平均提高32.5%的即刻稳定性,而且比长节段固定保留更大范围ROM.%Objective To establish L4 vertebrae burst fractures and take a biomechanical test of different internal fixations so as to discuss the significance of internal fixation using short-segment plus Index-level screws in treatment of low lumbar burst fractures.Methods Ten fresh human lumbosacral vertebrae specimens were used to establish models of L4 vertebrae burst fractures by corpectomy and partial removal of ligament.Thereafter,the biomechanical test was performed in order as below:longsegment fixation,short-segment fixation and short-segment construction plus Index-level screw fixation.Differences of range of motion (ROM) of the lumbar after three different internal fixations were compared.Results Compared with short-segment fixation,short-segment plus Index-level screw fixation showed that ROM of the lumbar was decreased in front flexion,axial rotation and lateral bending (P < 0.05),but stability was improved and ROM of lumbar was decreased by 32.7% in back extension (P > 0.05).Conclusions Compared with short-segment fixation,the short-segment plus Index-level screw fixation can

  13. Application of percutaneous pedicle screw fixation for lumbar degenerative disease%应用经皮椎弓根螺钉技术治疗腰椎退行性疾病

    Institute of Scientific and Technical Information of China (English)

    吴浩; 陈永杰; 张璨; 陈赞; 菅凤增

    2014-01-01

    目的:评估在X线透视下经皮椎弓根螺钉微创内固定技术治疗腰椎退行性病变的安全性和准确性。方法回顾性分析首都医科大学宣武医院2012年3月至2013年10月采用X线透视下经皮椎弓根螺钉微创内固定技术,结合显微镜下微创经椎间孔入路椎间盘摘除、椎体间融合术(TLIF)治疗64例腰椎退行性疾病患者的临床资料,随访3个月或以上,统计术中出血量、住院时间、并发症、术前与术后采用视觉模拟量表(VAS)和Oswestry功能障碍指数(ODI)进行疗效评估,计算患者症状改善率;术后生活质量调查(SF-36);术后复查X线及腰椎CT平扫及腰椎核磁,评估螺钉位置及融合率。结果手术平均时间(3.4±0.9)h,术中出血平均(193±100)ml,住院平均时间(7±2)d,并发症发生率7.8%(5/64)。随访3个月显示,VAS和ODI改变差异有统计学意义(P<0.01)。临床症状改善显著,ODI改善率为50.8%,SF-36平均86.2%;64例患者共植入316颗螺钉,术后X线显示306颗螺钉位置良好,10颗螺钉位置可接受,无螺钉松动;螺钉植入成功率达100%,融合率达96%。结论X线透视下微创内固定技术完全可以获得准确、理想的螺钉植入位置,结合显微镜下微创TLIF治疗腰椎退行性疾病是安全、有效的方法。%Objective To evaluate the accuracy and safety of mini-invasive and percutaneous pedicle screw fixation with fluoroscopy for lumbar degenerative disease.Methods For this retrospective study, 64 cases of lumbar degenerative disease underwent mini-invasive transforaminal lumbar interbody fusion ( TLIF) under microscope plus percutaneous pedicle screw fixation with fluoroscopy of lumbar spine from March 2012 to October 2013.The parameters of operative duration , intraoperative blood loss volume , hospital stay and complications were recorded and analyzed.The clinical outcomes were assessed

  14. Platelet-rich plasma combined with closed reduction and hollow screw internal fixation for femoral neck fracture%PRP联合闭合复位空心螺钉内固定治疗股骨颈骨折

    Institute of Scientific and Technical Information of China (English)

    陈志军; 杨彪; 张大华

    2016-01-01

    目的:分析自体富血小板血浆( PRP)联合闭合复位空心螺钉内固定治疗股骨颈骨折的临床效果。方法回顾性分析2010年5月至2014年8月在我院治疗的200例股骨颈骨折患者的临床资料,分为PRP组和对照组,各100例。 PRP组采用PRP联合闭合复位空心螺钉内固定治疗,对照组单纯采用闭合复位空心螺钉内固定治疗,记录2组患者住院时间、骨折愈合时间、切口愈合情况、术后并发症、Harris评分及髋关节功能恢复情况。结果 PRP组住院时间、骨折愈合时间明显短于对照组,切口甲级愈合率高于对照组,术后合并股骨头坏死及骨折不愈合率明显低于对照组,差异均具有统计学意义(P<0.05)。 PRP组患者术后6个月、12个月Harris评分分别为87.35、90.82分,均高于对照组的81.37、84.32分,术后6个月、12个月髋关节功能优良率分别为86%、90%,高于对照组的67%和76%,差异均具有统计学意义(P<0.05)。结论 PRP联合闭合复位空心螺钉内固定治疗股骨颈骨折能明显缩短骨折愈合时间,减少术后并发症,提高患者髋关节功能及术后生活质量,安全性和有效性较高。%Objective To explore the clinical effect of autologous platelet-rich plasma ( PRP) combined with closed reduction and hol-low screw internal fixation for femoral neck fracture .Methods Totally 200 cases of femoral neck fracture were collected from May 2010 to August 2014 in our hospital .Randomly divided them into two groups , namely the PRP group and the control group , with 100 patients in each group.The PRP group were given autologous platelet-rich plasma ( PRP) combined with closed reduction and hollow screw internal fixation , while the control group were given closed reduction and hollow screw internal fixation merely .The length of stay , time of fracture healing , wound healing state , postoperative complications rate

  15. 后路椎弓根钉棒复位内固定+经伤椎椎弓根植骨治疗胸腰椎骨折%Posterior transpedicle vertebral bone grafting and screw fixation for thoracolumbar vertebral fracture

    Institute of Scientific and Technical Information of China (English)

    曹杰; 于海洋; 梁成民; 焦伟

    2016-01-01

    背景:胸腰椎骨折临床上常见,传统手术方案是后路椎弓根钉棒复位内固定+自体髂骨植骨,但术后胸腰段活动度受影响,且远期伤椎椎体前部仍会有椎体体积25%大小的骨缺损,即所谓的"蛋壳"效应,导致远期伤椎局部后凸再次增大、矫正丢失等并发症.后路椎弓根钉棒复位内固定+经伤椎椎弓根植骨可恢复椎体前中柱的抗压性,因而备受关注.目的:探讨后路椎弓根钉棒复位内固定+经伤椎椎弓根植骨治疗胸腰椎骨折的临床疗效.方法:2014年1月至2016年1月收治无需减压的胸腰椎骨折患者42例,男31例,女11例;年龄20~52岁,平均37.3±1.2岁;按Denis分型:DenisⅠ型(压缩型)31例,Ⅱ型(爆裂型)11例.分为2组,伤椎椎体后壁完整入选非融合组,后壁破损入选融合组,非融合组21例后路椎弓根钉棒复位内固定后在"C"型臂X线机透视引导下应用硫酸钙经伤椎椎弓根椎体内植骨治疗;融合组21例后路椎弓根钉棒复位内固定后取髂骨植骨融合治疗.比较两组患者的临床参数和影像学指标.结果:2组患者均顺利完成手术,术中未发生大出血、损伤神经等手术并发症,获得12~36个月随访,平均(23.5±1.8)个月.非融合组的术后胸腰段Cobb角(过屈位/过伸位)比值优于融合组(P<0.05),非融合组伤椎椎体的骨容量优于融合组,且非融合组术后伤椎均未出现"蛋壳"效应.结论:后路椎弓根钉棒复位内固定+经伤椎椎弓根植骨治疗胸腰椎骨折手术安全可靠,矫正效果满意,术后恢复快,不影响腰椎活动度,并有效防止伤椎出现"蛋壳"效应,能即时增加伤椎椎体的骨容量及前柱的抗压稳定性.%Background:Thoracolumbar fractures are common in clinic. The traditional operation scheme is posterior pedi-cle screw reduction and internal fixation plus iliac bone grafting, but thoracolumbar range of motion may be affected and there is still bone defect in anterior involved

  16. Cage Pedicle Screw Fixation for the Treatment of Lumbar Spondylolisthesis%Cage加椎弓根螺钉固定治疗腰椎滑脱症的临床疗效

    Institute of Scientific and Technical Information of China (English)

    桂曙光; 袁凌伟; 李得彬; 王建; 胡小东

    2015-01-01

    Objective:To research the clinical efficacy of posterior decompression and interbody cage fusion in the treatment of lumbar spondylolisthesis.Methods:From march 2009 to june 2013,I applied interbody fusion and pedicle screw in the treatment of 22 patients with lumbar spondylolisthesis, including 13 males and 9 females, aged 41-67 years, mean 48years old, type I spondylolisthesis 14cases t,ype II spondylolisthesis 7 cases, and III spondylolisthesis patients. All patients were followed up for 3 months to 32months , with an average of 28 months.Results:All the cases slippage were reseted. ,the fusion rate was 100%, the vertebral height and symptoms after operation improved significantly, the cage remain the normal position and the pedicle screw not be loosening and fracture. The excellent rate is 95.46%, ac-cording to the Zou Dewei rating criteria. Conclusion:The fixation with cage and pedicle screw in the treatment of lumbar spondylolisthesis is one of the good methods have the advantages of more safety , interbody fusion rate fixation , without fracture and loosening.%目的:评价后路减压固定加椎间cage融合术治疗腰椎滑脱症的临床疗效。方法:自2009年3月~2013年6月应用椎间cage加椎弓根螺钉固定技术治疗腰椎滑脱症患者22例,其中男13例,女9例,年龄41~67岁,平均48岁。其中Ⅰ度滑脱14例,Ⅱ度滑脱7例,Ⅲ度滑脱1例。对所有患者术后随访3个月~32个月,平均28个月。结果:所有滑脱基本复位,融合率100%,椎体间高度恢复,症状明显改善, cage位置正常,椎弓根螺钉无松动及断裂。根据邹德威等评分标准,优良率达95.46%。结论:采用cage加椎弓根螺钉固定治疗腰椎滑脱症临床效果好、安全,椎间融合率高,内固定物无断裂、松动,是较为理想的手术方法之一。

  17. Pedicle screw placement in the lumbar spine: effect of trajectory and screw design on acute biomechanical purchase.

    Science.gov (United States)

    Wray, Steven; Mimran, Ronnie; Vadapalli, Sasidhar; Shetye, Snehal S; McGilvray, Kirk C; Puttlitz, Christian M

    2015-05-01

    testing were statistically significant between the 3 screw/trajectory combinations. The incidence of cortical wall breach with the cortical or traditional pedicle screw trajectories was not significantly different. CONCLUSIONS The data demonstrated that the cortical trajectory provides denser bone that allows for utilization of smaller screws to obtain mechanical purchase that is equivalent to long pedicle screws placed in traditional pedicle screw trajectories for both normal- and low-quality bone. Overall, this biomechanical study in cadavers provides evidence that the cortical screw trajectory represents a good option to obtain fixation for the lumbar spine with low-quality bone.

  18. Comparison of the effects on percutaneous sacroiliac joint screw fixation and anterior sacroiliac joint plate fixation in the treatment of unstable pelvic fractures%经皮骶髂关节螺钉与骶髂关节前方钢板固定治疗不稳定型骨盆骨折的效果比较

    Institute of Scientific and Technical Information of China (English)

    丁涛

    2016-01-01

    Objective To investigate the efficacy of percutaneous sacroiliac joint screw fixation and anterior sacroiliac joint plate fixation in the treatment of unstable pelvic fractures. Methods Forty cases of patients with unstable pelvic fractures were divided into two groups according to odd and even numbers. The control group (odd numbers, 20 cases) was given anterior sacroiliac joint plated fixation, while the observation group (20 cases) was given percutaneous sacroiliac joint screw. The efficacy of the two groups were evaluated with perioperative indexes, Majeed scores and complications during 6 months follow-up. Results The operative time, blood loss and hospitalization time of the observation group were significantly superior to those of the control group (P<0.05); the excellent rate of the observation group was significantly higher than that of the control group (P<0.05); during follow-up, the complication rate of the observation group was lower than that of the control group (P<0.05). Conclusion Percutaneous sacroiliac joint screw fixation has a good therapeutic effect on unstable pelvic fracture, with less operation time and fewer complications, so as to promote the recovery of patients, which is worthy of clinical application.%目的:探讨经皮骶髂关节螺钉与骶髂关节前方钢板固定治疗不稳定型骨盆骨折的疗效。方法选取40例不稳定型骨盆骨折患者,按住院单双号分为两组。对照组(20例)给予骶髂关节前方钢板固定治疗,观察组(20例)给予经皮骶髂关节螺钉治疗,观察并记录两组围手术期指标、Majeed评分及随访6个月期间并发症发生情况。结果观察组手术时间、术中出血量、住院时间均明显优于对照组( P<0.05);观察组患者手术治疗的优良率明显高于对照组( P<0.05),随访期间,观察组患者并发症发生率明显低于对照组( P<0.05)。结论经皮骶髂关节螺钉手术对不稳定型骨盆骨折

  19. Comparison of fixation properties between coil-type and screw-type anchors for rotator cuff repair: A virtual pullout testing using 3-dimensional finite element method.

    Science.gov (United States)

    Sano, Hirotaka; Tokunaga, Masako; Noguchi, Moriyuki; Inawashiro, Takashi; Irie, Taichi; Abe, Hiroo; Abrassart, Sophie; Itoi, Eiji

    2016-07-01

    Pullout of inserted anchor constitutes one of the pathomechanisms of re-tearing after rotator cuff repair. The purpose of the present study was to investigate the fixation properties of suture anchors using 3-dimensional finite element method. The computer models of three types of anchors (TwinFix Ti, HEALICOIL PK and HEALICOIL RG) were inserted into the isotropic cube model that simulated cancellous bone. In the virtual pullout testing, a tensile load (500 N) along the long axis of the inserted anchor was applied to the site of suture thread attachment to simulate a traction force. The distribution of von Mises equivalent stress, the failure patterns of elements inside the cube and the anchor displacement were compared among the three anchors. In TwinFix Ti, the highest stress concentration was seen around the anchor threads close to the surface of the cube, which caused element failure at this site. On the other hand, both HEALICOIL PK and HEALICOIL RG demonstrated a high stress concentration as well as element failure around the anchor tip. Comparing the anchor displacement, HEALICOIL RG showed the smallest displacement among the three anchors. The tensile loads that required a 0.1-mm displacement for TwinFix Ti, HEALICOIL PK and HEALICOIL RG were 400 N, 370 N, and greater than 500 N, respectively. The bony structures close to the footprint surface may be damaged during surgery due to preparation for the bony bed as well as the insertion of anchors. Thus, we assumed that HEALICOIL RG represented the best initial fixation properties among the three anchors tested. Virtual pullout testing using 3-dimensional finite element method could reveal the detailed biomechanical characteristics of each suture anchor, which would be important for shoulder surgeons to improve the clinical outcomes of rotator cuff repair. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  20. The Curative Effect Analyze of Treatment Old Displacement Type Femoral Neck Fracture by Holl