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Sample records for distal radius-a biomechanical

  1. A Comprehensive Reanalysis of the Distal Iliotibial Band: Quantitative Anatomy, Radiographic Markers, and Biomechanical Properties.

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    Godin, Jonathan A; Chahla, Jorge; Moatshe, Gilbert; Kruckeberg, Bradley M; Muckenhirn, Kyle J; Vap, Alexander R; Geeslin, Andrew G; LaPrade, Robert F

    2017-09-01

    The qualitative anatomy of the distal iliotibial band (ITB) has previously been described. However, a comprehensive characterization of the quantitative anatomic, radiographic, and biomechanical properties of the Kaplan fibers of the deep distal ITB has not yet been established. It is paramount to delineate these characteristics to fully understand the distal ITB's contribution to rotational knee stability. Purpose/Hypothesis: There were 2 distinct purposes for this study: (1) to perform a quantitative anatomic and radiographic evaluation of the distal ITB's attachment sites and their relationships to pertinent osseous and soft tissue landmarks, and (2) to quantify the biomechanical properties of the deep (Kaplan) fibers of the distal ITB. It was hypothesized that the distal ITB has definable parameters concerning its anatomic attachments and consistent relationships to surgically pertinent landmarks with correlating plain radiographic findings. In addition, it was hypothesized that the biomechanical properties of the Kaplan fibers would support their role as important restraints against internal rotation. Descriptive laboratory study. Ten nonpaired, fresh-frozen human cadaveric knees (mean age, 61.1 years; range, 54-65 years) were dissected for anatomic and radiographic purposes. A coordinate measuring device quantified the attachment areas of the distal ITB to the distal femur, patella, and proximal tibia and their relationships to pertinent bony landmarks. A radiographic analysis was performed by inserting pins into the attachment sites of relevant anatomic structures to assess their location relative to pertinent bony landmarks with fluoroscopic guidance. A further biomechanical assessment of 10 cadaveric knees quantified the load to failure and stiffness of the Kaplan fibers' insertion on the distal femur after a preconditioning protocol. Two separate deep (Kaplan) fiber bundles were identified with attachments to 2 newly identified femoral bony prominences

  2. The distal semimembranosus complex: normal MR anatomy, variants, biomechanics and pathology

    International Nuclear Information System (INIS)

    Beltran, Javier; Jbara, Marlena; Maimon, Ron; Matityahu, Amir; Hwang, Ki; Padron, Mario; Mota, Javier; Beltran, Luis; Sundaram, Murali

    2003-01-01

    To describe the normal MR anatomy and variations of the distal semimembranosus tendinous arms and the posterior oblique ligament as seen in the three orthogonal planes, to review the biomechanics of this complex and to illustrate pathologic examples. The distal semimembranosus tendon divides into five tendinous arms named the anterior, direct, capsular, inferior and the oblique popliteal ligament. These arms intertwine with the branches of the posterior oblique ligament in the posterior medial aspect of the knee, providing stability. This tendon-ligamentous complex also acts synergistically with the popliteus muscle and actively pulls the posterior horn of the medial meniscus during knee flexion. Pathologic conditions involving this complex include complete and partial tears, insertional tendinosis, avulsion fractures and bursitis. (orig.)

  3. The distal semimembranosus complex: normal MR anatomy, variants, biomechanics and pathology

    Energy Technology Data Exchange (ETDEWEB)

    Beltran, Javier; Jbara, Marlena; Maimon, Ron [Department of Radiology, Maimonides Medical Center, 4802 Tenth Avenue, NY 11219, Brooklyn (United States); Matityahu, Amir; Hwang, Ki [Department of Orthopedic Surgery, Maimonides Medical Center, Brooklyn, NY (United States); Padron, Mario [Department of Radiology, Clinica CEMTRO, Madrid (Spain); Mota, Javier [Department of Radiology, Instituto Clinica Corachan, Barcelona (Spain); Beltran, Luis [New York Medical College, Valhalla, NY (United States); Sundaram, Murali [Department of Radiology, Mayo Clinic, Rochester, MN (United States)

    2003-08-01

    To describe the normal MR anatomy and variations of the distal semimembranosus tendinous arms and the posterior oblique ligament as seen in the three orthogonal planes, to review the biomechanics of this complex and to illustrate pathologic examples. The distal semimembranosus tendon divides into five tendinous arms named the anterior, direct, capsular, inferior and the oblique popliteal ligament. These arms intertwine with the branches of the posterior oblique ligament in the posterior medial aspect of the knee, providing stability. This tendon-ligamentous complex also acts synergistically with the popliteus muscle and actively pulls the posterior horn of the medial meniscus during knee flexion. Pathologic conditions involving this complex include complete and partial tears, insertional tendinosis, avulsion fractures and bursitis. (orig.)

  4. Single-row versus double-row repair of the distal Achilles tendon: a biomechanical comparison.

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    Pilson, Holly; Brown, Philip; Stitzel, Joel; Scott, Aaron

    2012-01-01

    Surgery for recalcitrant insertional Achilles tendinopathy often consists of partial or total release of the insertion site, debridement of the diseased portion of the tendon, calcaneal ostectomy, and reattachment of the Achilles to the calcaneus. Although single-row and double-row techniques exist for repair of the detached Achilles tendon, biomechanical data are lacking to support one technique over the other. Based on data extrapolated from the study of rotator cuff repairs, we hypothesized that a double-row construct would provide superior fixation strength over a single-row repair. Eighteen human cadaveric Achilles tendons (9 matched pairs) with attached calcanei were repaired with single-row or double-row techniques. Specimens were mounted in a servohydraulic materials testing machine, subjected to a preconditioning cycle, and loaded to failure. Failure was defined as suture breakage or pullout, midsubstance tendon rupture, or anchor pullout. Among the failures were 12 suture failures, 5 proximal-row anchor failures, and 1 distal-row anchor failure. No midsubstance tendon ruptures or testing apparatus failures were observed. There were no statistically significant differences in the peak load to failure between the single-row and double-row repairs (p = .46). Similarly, no significant differences were observed with regards to mean energy expenditure to failure (p = .069). The present study demonstrated no biomechanical advantages of the double-row repair over a single-row repair. Despite the lack of a clear biomechanical advantage, there may exist clinical advantages of a double-row repair, such as reduction in knot prominence and restoration of the Achilles footprint. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  5. Uncemented three-dimensional-printed prosthetic replacement for giant cell tumor of distal radius: a new design of prosthesis and surgical techniques.

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    Lu, Minxun; Min, Li; Xiao, Cong; Li, Yongjiang; Luo, Yi; Zhou, Yong; Zhang, Wenli; Tu, Chongqi

    2018-01-01

    Currently, it is challenging to treat giant cell tumor (GCT) of distal radius. For Campanacci grade III or recurrent GCTs, en bloc resection has been accepted as a better treatment option. Although numerous methods are available for reconstruction, all of them have some limitations in joint function and complications. In this study, our aims were to treat the GCT of distal radius with uncemented three-dimensional (3D)-printed prosthesis and to present and evaluate the surgical techniques and short-term outcomes. Between September 2015 and March 2017, 11 patients with distal radius GCTs were treated with personalized uncemented 3D-printed prosthesis. The preoperative/postoperative pain, range of motion, and grip strengths of all patients were evaluated. Oncological results, complications, and degenerative changes in the wrist joint were evaluated. Functional outcomes were assessed according to the disabilities of the arm, shoulder, and hand (DASH) questionnaire and Mayo wrist scoring systems. The average follow-up was 14.45 months (range, 8-18 months). There was a significant decrease in the mean postoperative visual analog scale score (2.33) compared with the preoperative score (5.22; p 3D-printed prosthesis can be alternative options to treat Campanacci grade III or recurrent GCTs of distal radius and can result in short-term oncologic salvage, good postoperative function, and low complication rate. However, a long-term follow-up is required to determine the outcome.

  6. Ipsilateral simultaneous fracture of the trochlea involving the lateral end clavicle and distal end radius: a rare combination and a unique mechanism of injury

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    Gupta RK

    2014-07-01

    Full Text Available 【Abstract】Isolated trochlea fracture in adults is a rare surgical entity as compared to its capitellar counterpart. It has been only mentioned sporadically in the literature as case reports. Fracture of the trochlea is accompanied by other elbow injuries like elbow dislocation, capitellum fracture, ulnar fracture and extraarticular condylar fracture. Here we report a unique case of isolated displaced trochlea fracture associated with fractures of the lateral end clavicle and the distal end radius. We propose a unique mechanism for this rare combination of injuries: typical triad of injury, i.e. fracture of the distal end radius with trochlea and fracture of the lateral end of the clavicle. Nonoperative treatment is recommended for undisplaced humeral trochlea fractures; but for displaced ones, anatomical reduction and internal fixation are essential to maintain the congruous trochleacoronoid articulation and hence to maintain the intrinsic stability of the elbow. Key words: Isolated trochlea fracture; Clavicle; Radius fractures

  7. Uncemented three-dimensional-printed prosthetic replacement for giant cell tumor of distal radius: a new design of prosthesis and surgical techniques

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    Lu MX

    2018-02-01

    Full Text Available Minxun Lu,* Li Min,* Cong Xiao, Yongjiang Li, Yi Luo, Yong Zhou, Wenli Zhang, Chongqi Tu Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China *These authors contributed equally to this work Introduction: Currently, it is challenging to treat giant cell tumor (GCT of distal radius. For Campanacci grade III or recurrent GCTs, en bloc resection has been accepted as a better treatment option. Although numerous methods are available for reconstruction, all of them have some limitations in joint function and complications. In this study, our aims were to treat the GCT of distal radius with uncemented three-dimensional (3D-printed prosthesis and to present and evaluate the surgical techniques and short-term outcomes. Methods: Between September 2015 and March 2017, 11 patients with distal radius GCTs were treated with personalized uncemented 3D-printed prosthesis. The preoperative/postoperative pain, range of motion, and grip strengths of all patients were evaluated. Oncological results, complications, and degenerative changes in the wrist joint were evaluated. Functional outcomes were assessed according to the disabilities of the arm, shoulder, and hand (DASH questionnaire and Mayo wrist scoring systems. Results: The average follow-up was 14.45 months (range, 8–18 months. There was a significant decrease in the mean postoperative visual analog scale score (2.33 compared with the preoperative score (5.22; p<0.001. The mean DASH score and Mayo wrist score of the wrist joint function were 18.7 and 72, respectively. There was no local recurrence or lung metastasis. No complication associated with prosthesis was observed, including aseptic loosening, subluxation, and breakage. Joint space narrowing, or disuse osteoporosis, was also not found in all cases. Conclusion: En bloc resection and reconstruction with a personalized uncemented 3D-printed prosthesis can be alternative options to

  8. Ipsilateral dislocation of the radial head associated with fracture of distal end of the radius: a case report and review of the literature

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    Gupta Vinay

    2013-06-01

    Full Text Available 【Abstract】Dislocation of the radial head in adults is uncommon. A simultaneous dislocation of the radial head and fracture of the ipsilateral distal end of radius with no other associated injuries is extremely rare. As far as we know, such an injury after an unusual mode of injury has been seldom reported in the English literature. We report such a case without any associated injuries or comorbidity. Closed reduction was performed within two hours after injury and results were satisfactory. Immobilisation was continued for 3 weeks. Gradual mobilisation was started after removal of the plaster under the supervision of a physiotherapist. At 6 months’ follow-up, the patient had no residual pain at the elbow with full flexion & extension. Almost full supination with a restriction of last 10 degrees of pronation was achieved. There was no evidence of instability of the elbow. Key words: Radial heads; Dislocations; Radius fractures

  9. Biomechanics of the Proximal Radius Following Drilling of the Bicipital Tuberosity to Mimic Cortical Button Distal Biceps Repair Technique.

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    Oak, Nikhil R; Lien, John R; Brunfeldt, Alexander; Lawton, Jeffrey N

    2018-05-01

    A fracture through the proximal radius is a theoretical concern after cortical button distal biceps fixation in an active patient. The permanent, nonossified cortical defect and medullary tunnel is at risk during a fall eliciting rotational and compressive forces. We hypothesized that during simulated torsion and compression, in comparison with unaltered specimens, the cortical button distal biceps repair model would have decreased torsional and compressive strength and would fracture in the vicinity of the bicipital tuberosity bone tunnel. Sixteen fourth-generation composite radius Sawbones models were used in this controlled laboratory study. A bone tunnel was created through the bicipital tuberosity to mimic the exact bone tunnel, 8 mm near cortex and 3.2 mm far cortex, made for the BicepsButton distal biceps tendon repair. The radius was then prepared and mounted on either a torsional or compression testing device and compared with undrilled control specimens. Compression tests resulted in average failure loads of 9015.2 N in controls versus 8253.25 N in drilled specimens ( P = .074). Torsional testing resulted in an average failure torque of 27.3 Nm in controls and 19.3 Nm in drilled specimens ( P = .024). Average fracture angle was 35.1° in controls versus 21.1° in drilled. Gross fracture patterns were similar in compression testing; however, in torsional testing all fractures occurred through the bone tunnel in the drilled group. There are weaknesses in the vicinity of the bone tunnel in the proximal radius during biomechanical stress testing which may not be clinically relevant in nature. In cortical button fixation, distal biceps repairs creates a permanent, nonossified cortical defect with tendon interposed in the bone tunnel, which can alter the biomechanical properties of the proximal radius during compressive and torsional loading.

  10. A Comparative Biomechanical Analysis of 2 Double-Row, Distal Triceps Tendon Repairs

    OpenAIRE

    Dorweiler, Matthew A.; Van Dyke, Rufus O.; Siska, Robert C.; Boin, Michael A.; DiPaola, Mathew J.

    2017-01-01

    Background: Triceps tendon ruptures are rare orthopaedic injuries that almost always require surgical repair. This study tests the biomechanical properties of an original anchorless double-row triceps repair against a previously reported knotless double-row repair. Hypothesis: The anchorless double-row triceps repair technique will yield similar biomechanical properties when compared with the knotless double-row repair technique. Study Design: Controlled laboratory study. Methods: Eighteen ca...

  11. Augmentation of Distal Biceps Repair With an Acellular Dermal Graft Restores Native Biomechanical Properties in a Tendon-Deficient Model.

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    Conroy, Christine; Sethi, Paul; Macken, Craig; Wei, David; Kowalsky, Marc; Mirzayan, Raffy; Pauzenberger, Leo; Dyrna, Felix; Obopilwe, Elifho; Mazzocca, Augustus D

    2017-07-01

    The majority of distal biceps tendon injuries can be repaired in a single procedure. In contrast, complete chronic tears with severe tendon substance deficiency and retraction often require tendon graft augmentation. In cases with extensive partial tears of the distal biceps, a human dermal allograft may be used as an alternative to restore tendon thickness and biomechanical integrity. Dermal graft augmentation will improve load to failure compared with nonaugmented repair in a tendon-deficient model. Controlled laboratory study. Thirty-six matched specimens were organized into 1 of 4 groups: native tendon, native tendon with dermal graft augmentation, tendon with an attritional defect, and tendon with an attritional defect repaired with a graft. To mimic a chronic attritional biceps lesion, a defect was created by a complete tear, leaving 30% of the tendon's width intact. The repair technique in all groups consisted of cortical button and interference screw fixation. All specimens underwent cyclical loading for 3000 cycles and were then tested to failure; gap formation and peak load at failure were documented. The mean (±SD) load to failure (320.9 ± 49.1 N vs 348.8 ± 77.6 N, respectively; P = .38) and gap formation (displacement) (1.8 ± 1.4 mm vs 1.6 ± 1.1 mm, respectively; P = .38) did not differ between the native tendon groups with and without graft augmentation. In the tendon-deficient model, the mean load to failure was significantly improved with graft augmentation compared with no graft augmentation (282.1 ± 83.8 N vs 199.7 ± 45.5 N, respectively; P = .04), while the mean gap formation was significantly reduced (1.2 ± 1.0 mm vs 2.7 ± 1.4 mm, respectively; P = .04). The mean load to failure of the deficient tendon with graft augmentation (282.1 N) compared with the native tendon (348.8 N) was not significantly different ( P = .12). This indicates that the native tendon did not perform differently from the grafted deficient tendon. In a tendon

  12. A Comparative Biomechanical Analysis of 2 Double-Row, Distal Triceps Tendon Repairs.

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    Dorweiler, Matthew A; Van Dyke, Rufus O; Siska, Robert C; Boin, Michael A; DiPaola, Mathew J

    2017-05-01

    Triceps tendon ruptures are rare orthopaedic injuries that almost always require surgical repair. This study tests the biomechanical properties of an original anchorless double-row triceps repair against a previously reported knotless double-row repair. The anchorless double-row triceps repair technique will yield similar biomechanical properties when compared with the knotless double-row repair technique. Controlled laboratory study. Eighteen cadaver arms were randomized into 2 groups. One group received the anchorless repair and the other received the knotless anchor repair. A materials testing system (MTS) machine was used to cycle the repaired arms from 0° to 90° with a 2.5-pound weight for 1500 cycles at 0.25 Hz. Real-time displacement of the tendon was measured during cycling using a probe. Load to failure was performed after completion of cyclic loading. The mean displacement with the anchorless technique was 0.77 mm (SD, 0.25 mm) at 0° (full elbow extension) and 0.76 mm (SD, 0.38 mm) at 90° (elbow flexion). The mean displacement with the anchored technique was 0.83 mm (SD, 0.57 mm) at 0° and 1.01 mm (SD, 0.62 mm) at 90°. There was no statistically significant difference for tendon displacement at 0º ( P = .75) or 90º ( P = .31). The mean load to failure with the anchorless technique was 618.9 N (SD, 185.6 N), while it was 560.5 N (SD, 154.1 N) with the anchored technique, again with no statistically significant difference ( P = .28). Our anchorless double-row triceps repair technique yields comparable biomechanical properties to previously described double-row triceps tendon repair techniques, with the added benefit of avoiding the cost of suture anchors. This anchorless double-row triceps tendon repair can be considered as an acceptable alternative to a knotless anchor repair for triceps tendon ruptures.

  13. Biomechanical evaluation of the locking titanium cable in the fixture of distal tibiofibular syndesmosis injury

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    Shu-zhi YAO

    2016-08-01

    Full Text Available Objective  The article aims at evaluating the biological properties of tibiofibular titanium cable fixation device in terms of both anti-separation and stress shielding by comparison to the interior fixation with lag screw based on experimental observation. Methods  Six corpse ankle specimens were first tested of pressure-separation and stress measurement, the data from which were compared to the normal group, and then a syndesmosis injury model was established. All the samples are randomly divided into 2 groups of 3 specimens each, which were treated with tibiofibula locked titanium cable and lag screw fixation respectively for syndesmosis injury. Then, the samples were tested for pressure-separation and stress measurement. The biomechanical properties as anti-separation ability and stress shielding were analyzed and compared between the two fixation method. Results  Both tibiofibula locked titanium cables and lag screws were able to provide enough strong lateral anti-separation ability, but strong fixation screws were inferior to tibiofibular titanium cable fixation device in fibular longitudinal stress transduction. Conclusion  Tibiofibular titanium cable fixation device not only provide sufficient lateral anti-separation, but also reduces the tibial and fibular longitudinal stress shielding, thus being superior to the traditional lag screw in biomechanical properties. DOI: 10.11855/j.issn.0577-7402.2016.07.09

  14. Biomechanical analysis of suture locations of the distal plantar fascia in partial foot.

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    Guo, Jun-Chao; Wang, Li-Zhen; Mo, Zhong-Jun; Chen, Wei; Fan, Yu-Bo

    2015-12-01

    The aim of this study was to evaluate the rationality of the suture locations of distal plantar fascia (DPF) after foot amputation to avoid the risk factors of re-amputation or plantar fasciitis. The tensile strain of plantar fascia (PF) in the different regions was measured by uni-axial tensile experiment. A three-dimensional (3D) finite element model was also developed to simulate tensile behaviour of PF in weight bearing conditions. The model includes 12 bones, ligaments, PF, cartilage and soft tissues. Four suture location models for the DPF were considered: the fourth and fifth DPF were sutured on the third metatarsal, the cuboid, and both the third metatarsal and the cuboid, and one un-sutured model. The peak tensile strain of the first, second and third PF was 0.134, 0.128 and 0.138 based on the mechanical test, respectively. The fourth and fifth DPF sutured at the cuboid and the third metatarsal could offer more favourable outcomes. The peak strain of 4.859 × 10(-2), 2.347 × 10(-2) and 1.364 × 10(-2) in the first, second and third PF showed the least outcomes in stance phase. Also, peak strain and stress of the residual PF reduced to 4.859 × 10(-2) and 1.834 MPa, respectively. The stress region was redistributed on the mid-shaft of the first and third PF and the peak stress of medial cuneiform bone evidently decreased. The fourth and fifth DPF suture at the third metatarsal and cuboid was appropriate for the partial foot. The findings are expected to suggest optimal surgical plan of the DPF suture and guide further therapeutic planning of partial foot patients.

  15. Synthetic Augmented Suture Anchor Reconstruction for a Complete Traumatic Distal Triceps Tendon Rupture in a Male Professional Bodybuilder with Postoperative Biomechanical Assessment

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    Maria-Elissavet Nikolaidou

    2014-01-01

    Full Text Available Bodybuilding is a high-risk sport for distal triceps tendon ruptures. Management, especially in high-demanding athletes, is operative with suture anchor refixation technique being frequently used. However, the rate of rerupture is high due to underlying poor tendon quality. Thus, additional augmentation could be useful. This case report presents a reconstruction technique for a complete traumatic distal triceps tendon rupture in a bodybuilder with postoperative biomechanical assessment. A 28-year-old male professional bodybuilder was treated with a synthetic augmented suture anchor reconstruction for a complete triceps tendon rupture of his right dominant elbow. Postoperative biomechanical assessment included isokinetic elbow strength and endurance testing by using multiple angular velocities to simulate the “off-season” and “precompetition” phases of training. Eighteen months postoperatively and after full return to training, the biomechanical assessment indicated that the strength and endurance of the operated elbow joint was fully restored with even higher ratings compared to the contralateral healthy arm. The described reconstruction technique can be considered as an advisable option in high-performance athletes with underlying poor tendon quality due to high tensile strength and lack of donor site morbidity, thus enabling them to restore preinjury status and achieve safe return to sports.

  16. Synthetic Augmented Suture Anchor Reconstruction for a Complete Traumatic Distal Triceps Tendon Rupture in a Male Professional Bodybuilder with Postoperative Biomechanical Assessment

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    Nikolaidou, Maria-Elissavet; Banke, Ingo J.; Laios, Thomas; Petsogiannis, Konstantinos; Mourikis, Anastasios

    2014-01-01

    Bodybuilding is a high-risk sport for distal triceps tendon ruptures. Management, especially in high-demanding athletes, is operative with suture anchor refixation technique being frequently used. However, the rate of rerupture is high due to underlying poor tendon quality. Thus, additional augmentation could be useful. This case report presents a reconstruction technique for a complete traumatic distal triceps tendon rupture in a bodybuilder with postoperative biomechanical assessment. A 28-year-old male professional bodybuilder was treated with a synthetic augmented suture anchor reconstruction for a complete triceps tendon rupture of his right dominant elbow. Postoperative biomechanical assessment included isokinetic elbow strength and endurance testing by using multiple angular velocities to simulate the “off-season” and “precompetition” phases of training. Eighteen months postoperatively and after full return to training, the biomechanical assessment indicated that the strength and endurance of the operated elbow joint was fully restored with even higher ratings compared to the contralateral healthy arm. The described reconstruction technique can be considered as an advisable option in high-performance athletes with underlying poor tendon quality due to high tensile strength and lack of donor site morbidity, thus enabling them to restore preinjury status and achieve safe return to sports. PMID:24711944

  17. Palmar reconstruction of the triangular fibrocartilage complex for instability of the distal radioulnar joint: a biomechanical study.

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    Kataoka, T; Moritomo, H; Omokawa, S; Iida, A; Wada, T; Aoki, M

    2013-06-01

    We developed a new triangular fibrocartilage complex reconstruction technique for distal radioulnar joint instability in which the palmar portion of the triangular fibrocartilage complex was predominantly reconstructed, and evaluated whether such reconstruction can restore stability of the distal radioulnar joint in seven fresh cadaver upper extremities. Distal radioulnar joint instability was induced by cutting all soft-tissue stabilizers around the distal ulna. Using a palmar approach, a palmaris longus tendon graft was sutured to the remnant of the palmar radioulnar and ulnocarpal ligaments. The graft was then passed through a bone tunnel created at the fovea and was sutured. Loads were applied to the radius, and dorsopalmar displacements of the radius relative to the ulna were measured using an electromagnetic tracking device in neutral rotation, 60° supination and 60° pronation. We compared the dorsopalmar displacements before sectioning, before reconstruction and after reconstruction. Dorsopalmar instability produced by sectioning significantly improved in all forearm positions after reconstruction.

  18. Impact of double-tiered subchondral support procedure with a polyaxial locking plate on the stability of distal radius fractures using fresh cadaveric forearms: Biomechanical and radiographic analyses.

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    Tsutsui, Sadaaki; Kawasaki, Keikichi; Yamakoshi, Ken-Ichi; Uchiyama, Eiichi; Aoki, Mitsuhiro; Inagaki, Katsunori

    2016-09-01

    The present study compared the changes in biomechanical and radiographic properties under cyclic axial loadings between the 'double-tiered subchondral support' (DSS) group (wherein two rows of screws were used) and the 'non-DSS' (NDSS) group (wherein only one row of distal screws was used) using cadaveric forearm models of radius fractures fixed with a polyaxial locking plate. Fifteen fresh cadaveric forearms were surgically operated to generate an Arbeitsgemeinschaft für Osteosynthesefragen (AO) type 23-C2 fracture model with the fixation of polyaxial volar locking plates. The model specimens were randomized into two groups: DSS (n = 7) and NDSS (n = 8). Both the groups received 4 locking screws in the most distal row, as is usually applied, whereas the DSS group received 2 additional screws in the second row inserted at an inclination of about 15° to support the dorsal aspect of the dorsal subchondral bone. Cyclic axial compression test was performed (3000 cycles; 0-250 N; 60 mm/min) to measure absolute rigidity and displacement, after 1, 1000, 2000 and 3000 cycles, and values were normalized relative to cycle 1. These absolute and normalized values were compared between those two groups. Radiographic images were taken before and after the cyclic loading to measure changes in volar tilt (ΔVT) and radial inclination (ΔRI). The DSS group maintained significantly higher rigidity and lower displacement values than the NDSS group during the entire loading period. Radiographic analysis indicated that the ΔVT values of the DSS group were lower than those of the NDSS group. In contrast, the fixation design did not influence the impact of loading on the ΔRI values. Biomechanical and radiographic analyses demonstrated that two rows of distal locking screws in the DSS procedure conferred higher stability than one row of distal locking screws. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  19. Implant Material, Type of Fixation at the Shaft, and Position of Plate Modify Biomechanics of Distal Femur Plate Osteosynthesis.

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    Kandemir, Utku; Augat, Peter; Konowalczyk, Stefanie; Wipf, Felix; von Oldenburg, Geert; Schmidt, Ulf

    2017-08-01

    To investigate whether (1) the type of fixation at the shaft (hybrid vs. locking), (2) the position of the plate (offset vs. contact) and (3) the implant material has a significant effect on (a) construct stiffness and (b) fatigue life in a distal femur extraarticular comminuted fracture model using the same design of distal femur periarticular locking plate. An extraarticular severely comminuted distal femoral fracture pattern (OTA/AO 33-A3) was simulated using artificial bone substitutes. Ten-hole distal lateral femur locking plates were used for fixation per the recommended surgical technique. At the distal metaphyseal fragment, all possible locking screws were placed. For the proximal diaphyseal fragment, different types of screws were used to create 4 different fixation constructs: (1) stainless steel hybrid (SSH), (2) stainless steel locked (SSL), (3) titanium locked (TiL), and (4) stainless steel locked with 5-mm offset at the diaphysis (SSLO). Six specimens of each construct configuration were tested. First, each specimen was nondestructively loaded axially to determine the stiffness. Then, each specimen was cyclically loaded with increasing load levels until failure. Construct Stiffness: The fixation construct with a stainless steel plate and hybrid fixation (SSH) had the highest stiffness followed by the construct with a stainless steel plate and locking screws (SSL) and were not statistically different from each other. Offset placement (SSLO) and using a titanium implant (TiL) significantly reduced construct stiffness. Fatigue Failure: The stainless steel with hybrid fixation group (SSH) withstood the most number of cycles to failure and higher loads, followed by the stainless steel plate and locking screw group (SSL), stainless steel plate with locking screws and offset group (SSLO), and the titanium plate and locking screws group (TiL) consecutively. Offset placement (SSLO) as well as using a titanium implant (TiL) reduced cycles to failure. Using the

  20. Anatomic relationships of the distal and proximal radioulnar joints articulating surface areas, and of the radius and ulna bone volumes – implications for biomechanical studies of the distal and proximal radioulnar joints and forearm bones

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    Paul S C Malone

    2016-07-01

    Full Text Available BackgroundPrevious work from this laboratory has evidenced the biomechanical role of forearm osseoligamentous structures in load transfer of applied forces. It has shown that transmitted forces across the distal radioulnar joint (DRUJ and proximal radioulnar joint (PRUJ are similar though not identical under axial loading conditions. The purpose of the study was to assess the articulating surface areas of the radioulnar joints and the volumes of the forearm bones addressing the hypothesis that there may be anatomic adaptations that reflect the biomechanical function of the integrated forearm unit.MethodsThe articulating surface areas of PRUJ and DRUJ were assessed using a laser scanner in 24 cadaver forearms. The articulating joint surfaces were additionally delineated from standardized photographs assessed by three observers. The surface areas of matched pairs of joints were compared on the null hypothesis that these were the same within a given forearm specimen. An additional 44 pairs of matched forearm bone volumes were measured using water displacement technique and again compared through statistical analysis (paired sample t-test, and Bland Altman analysis.ResultsThe findings of this study are that the articulating surface areas of the DRUJ and PRUJ as well as the bone volumes are significantly different and yet strongly correlated. The paired sample t-test showed a significant difference between the surface areas of the DRUJ and PRUJ (p<0.05. The PRUJ articulating surface area was marginally larger than the DRUJ with a PRUJ : DRUJ ratio of 1.02. Paired sample t-test showed a significant difference between the two bone volumes (p<0.01 with a radius to ulna bone volume ratio of 0.81. When the olecranon was disregarded, radius volume was on average 4% greater than ulna volume.ConclusionsThis study demonstrated defines the anatomical relationships between the two forearm bones and their articulating joints when matched for specimen. The data

  1. Full title: Biomechanical comparison between stainless steel, titanium and carbon-fiber reinforced polyetheretherketone volar locking plates for distal radius fractures.

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    Mugnai, Raffaele; Tarallo, Luigi; Capra, Francesco; Catani, Fabio

    2018-05-25

    As the popularity of volar locked plate fixation for distal radius fractures has increased, so have the number and variety of implants, including variations in plate design, the size and angle of the screws, the locking screw mechanism, and the material of the plates. carbon-fiber reinforced polyetheretherketone (CFR-PEEK) plate features similar biomechanical properties to metallic plates, representing, therefore, an optimal alternative for the treatment of distal radius fractures. three different materials-composed plates were evaluated: stainless steel volar lateral column (Zimmer); titanium DVR (Hand Innovations); CFR-PEEK DiPHOS-RM (Lima Corporate). Six plates for each type were implanted in sawbones and an extra-articular rectangular osteotomy was created. Three plates for each material were tested for load to failure and bending stiffness in axial compression. Moreover, 3 constructs for each plate were evaluated after dynamically loading for 6000 cycles of fatigue. the mean bending stiffness pre-fatigue was significantly higher for the stainless steel plate. The titanium plate yielded the higher load to failure both pre and post fatigue. After cyclic loading, the bending stiffness increased by a mean of 24% for the stainless steel plate; 33% for the titanium; and 17% for the CFR-PEEK plate. The mean load to failure post-fatigue increased by a mean of 10% for the stainless steel and 14% for CFR-PEEK plates, whereas it decreased (-16%) for the titanium plate. Statistical analysis between groups reported significant values (p plastic deformation, and lower load to failure. N/A. Copyright © 2018. Published by Elsevier Masson SAS.

  2. Commentary on Kataoka et al. Palmar reconstruction of the triangular fibrocartilage complex for instability of the distal radioulnar joint: a biomechanical study

    NARCIS (Netherlands)

    Bentohami, A.; Bijlsma, T. S.; Goslings, J. C.; de Reuver, P.; Kaufmann, L.; Schep, N. W. L.

    2013-01-01

    The purpose of this study was to assess the association between arm-specific disability measured with the QuickDASH questionaire and radiological criteria in patients with extra-articular distal radial fractures. A consecutive series of 385 patients were initially treated non-operatively for an

  3. A distal femoral supra-condylar plate: biomechanical comparison with condylar plate and first clinical application for treatment of supracondylar fracture.

    Science.gov (United States)

    Liang, Bowei; Ding, Zhenqi; Shen, Junguo; Zhai, Wenliang; Kang, Liangqi; Zhou, Liang; Sha, Mo; Liang, Dongzhu

    2012-08-01

    An anatomical supra-condylar plate is designed and analysed by biomechanical testing. The biomechanical properties of the supra-condylar and condylar plate were compared in six matched pairs of cadaveric femurs. A transverse osteotomy gap was created to simulate an OTA/AO type A3 supracondylar fracture. The left and right specimens were fitted with supra-condylar and condylar plate, respectively. Nondestructive axial compression, three-point bending and torsion tests were performed, and the peak load of the bone-implant construction was measured. The fracture site suitable for supra-condylar plate application and its correlation with femoral length were calculated. The gender influence on it was also discussed. The difference of stiffness between the supra-condylar and condyle groups were not significant (P > 0.05) at 363.4 and 362.5 N/mm for compression, 229.5 and 237.6 N/mm in the sagittal plane and 195.5 and 188.4 N/mm in the coronal plane for three-point bending, and 7.5 and 7.9 Nm/deg for axial torsion, respectively. The peak load was 4438 ± 136.15 N and 5215 ± 174.33 N, respectively, for the two groups. The average extent of the fracture site suitable for the application of the supra-condylar plate was 70.86 ± 4.61 mm. The femoral length and gender showed no influence on it. Despite the limited bone contact area provided by the supra-condylar plate, its construct stiffness is comparable to the condylar plate. The supra-condylar plate can be used to treat carefully-selected extra-articular supracondylar fractures.

  4. Biomechanical properties of orthogonal plate configuration versus parallel plate configuration using the same locking plate system for intra-articular distal humeral fractures under radial or ulnar column axial load.

    Science.gov (United States)

    Kudo, Toshiya; Hara, Akira; Iwase, Hideaki; Ichihara, Satoshi; Nagao, Masashi; Maruyama, Yuichiro; Kaneko, Kazuo

    2016-10-01

    Previous reports have questioned whether an orthogonal or parallel configuration is superior for distal humeral articular fractures. In previous clinical and biomechanical studies, implant failure of the posterolateral plate has been reported with orthogonal configurations; however, the reason for screw loosening in the posterolateral plate is unclear. The purpose of this study was to evaluate biomechanical properties and to clarify the causes of posterolateral plate loosening using a humeral fracture model under axial compression on the radial or ulnar column separately. And we changed only the plate set up: parallel or orthogonal. We used artificial bone to create an Association for the Study of Internal Fixation type 13-C2.3 intra-articular fracture model with a 1-cm supracondylar gap. We used an anatomically-preshaped distal humerus locking compression plate system (Synthes GmbH, Solothurn, Switzerland). Although this is originally an orthogonal plate system, we designed a mediolateral parallel configuration to use the contralateral medial plate instead of the posterolateral plate in the system. We calculated the stiffness of the radial and ulnar columns and anterior movement of the condylar fragment in the lateral view. The parallel configuration was superior to the orthogonal configuration regarding the stiffness of the radial column axial compression. There were significant differences between the two configurations regarding anterior movement of the capitellum during axial loading of the radial column. The posterolateral plate tended to bend anteriorly under axial compression compared with the medial or lateral plate. We believe that in the orthogonal configuration axial compression induced more anterior displacement of the capitellum than the trochlea, which eventually induced secondary fragment or screw dislocation on the posterolateral plate, or nonunion at the supracondylar level. In the parallel configuration, anterior movement of the capitellum or

  5. Influence of connection type on the biomechanical behavior of distal extension mandibular removable partial dentures supported by implants and natural teeth.

    Science.gov (United States)

    Xiao, Wei; Li, Zhiyong; Shen, Shiqian; Chen, Shaowu; Chen, Sulin; Wang, Jiawei

    2016-02-01

    Few studies are performed to evaluate the influence of connection type on the stress distribution of distal extension mandibular removable partial dentures (RPDs) supported by both implants and natural teeth. In this study, five three-dimensional finite element models were prepared to simulate mandibular bilateral partially edentulous arches. Four were RPDs supported by both implants and natural teeth, and the other one was RPDs supported only by natural teeth. The maximum equivalent (EQV) stress values of bone around implants, the abutments, and the mucosa displacements of the related supporting structures were measured. It was found that a non-rigid telescopic coping was more favorable to protect the implant than a rigid telescopic coping. Compared with other connection types, the easy resilient attachment (ERA) system seemed to be effective to associate implant without complications. However, the results obtained in the present study should be cautiously interpreted in the clinic.

  6. DISTAL MYOPATHIES

    Science.gov (United States)

    Dimachkie, Mazen M.; Barohn, Richard J.

    2014-01-01

    Over a century ago, Gowers described two young patients in whom distal muscles weakness involved the hand, foot, sternocleidomastoid, and facial muscles in the other case the shoulder and distal leg musculature. Soon after, , similar distal myopathy cases were reported whereby the absence of sensory symptoms and of pathologic changes in the peripheral nerves and spinal cord at postmortem examination allowed differentiation from Charcot-Marie-Tooth disease. In 1951, Welander described autosomal dominant (AD) distal arm myopathy in a large Scandanavian cohort. Since then the number of well-characterized distal myopathies has continued to grow such that the distal myopathies have formed a clinically and genetically heterogeneous group of disorders. Affected kindred commonly manifest weakness that is limited to foot and toe muscles even in advanced stages of the disease, with variable mild proximal leg, distal arm, neck and laryngeal muscle involvement in selected individuals. An interesting consequence of the molecular characterization of the distal myopathies has been the recognition that mutation in a single gene can lead to more than one clinical disorder. For example, Myoshi myopathy (MM) and limb girdle muscular dystrophy (LGMD) type 2B are allelic disorders due to defects in the gene that encodes dysferlin. The six well described distal myopathy syndromes are shown in Table 1. Table 2 lists advances in our understanding of the myofibrillar myopathy group and Table 3 includes more recently delineated and less common distal myopathies. In the same manner, the first section of this review pertains to the more traditional six distal myopathies followed by discussion of the myofibrillar myopathies. In the third section, we review other clinically and genetically distinctive distal myopathy syndromes usually based upon single or smaller family cohorts. The fourth section considers other neuromuscular disorders that are important to recognize as they display prominent

  7. Invertebrate biomechanics.

    Science.gov (United States)

    Patek, S N; Summers, A P

    2017-05-22

    Invertebrate biomechanics focuses on mechanical analyses of non-vertebrate animals, which at root is no different in aim and technique from vertebrate biomechanics, or for that matter the biomechanics of plants and fungi. But invertebrates are special - they are fabulously diverse in form, habitat, and ecology and manage this without the use of hard, internal skeletons. They are also numerous and, in many cases, tractable in an experimental and field setting. In this Primer, we will probe three axes of invertebrate diversity: worms (Phylum Annelida), spiders (Class Arachnida) and insects (Class Insecta); three habitats: subterranean, terrestrial and airborne; and three integrations with other fields: ecology, engineering and evolution. Our goal is to capture the field of invertebrate biomechanics, which has blossomed from having a primary focus on discoveries at the interface of physics and biology to being inextricably linked with integrative challenges that span biology, physics, mathematics and engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Computational biomechanics

    International Nuclear Information System (INIS)

    Ethier, C.R.

    2004-01-01

    Computational biomechanics is a fast-growing field that integrates modern biological techniques and computer modelling to solve problems of medical and biological interest. Modelling of blood flow in the large arteries is the best-known application of computational biomechanics, but there are many others. Described here is work being carried out in the laboratory on the modelling of blood flow in the coronary arteries and on the transport of viral particles in the eye. (author)

  9. Radiologic examination and measurement of the wrist and distal radio-ulnar joint

    International Nuclear Information System (INIS)

    Toernvall, A.H.; Ekenstam, F. af; Hagert, C.G.; Irstam, L.; Sahlgrenska Sjukhuset, Goeteborg; Uppsala Univ.

    1986-01-01

    Following fractures of the distal radius, a relatively high incidence of complications is caused by malalignment in the distal radio-ulnar (DRU) joint; recent anatomic and clinical investigations have shown a congruity of that joint to be of significant importance for restoring the function of the wrist. The radius forms a moderately arched bone, which moves around the ulna in pronation and supination. Biomechanically, the ulna may be regarded as the pillar around which the radius moves. In an anatomic investigation of 5 arm specimens, we have shown that the maximum cartilage contact in the DRU joint between the ulna head and the distal radius occurs in the neutral rotation position. A proposed routine examination method of the wrist and forearm includes a true antero-posterior and a lateral projection of the radius and the ulna, performed with the forearm and wrist in a neutral rotation, a neutral wrist deviation and with the elbow angled 90 degrees. Such an examination implies a standardized and reproducible method. In a radioanatomic investigation, a series of 50 healthy wrists and forearms were examined. A simple measuring technique is presented, applicable to the DRU joint and wrist favouring the ulna as the bone through which a reproducible long axis of the forearm/wrist may be drawn. It is suggested that the length of the radius should be judged relative to the ulna. Ulnar head inclination and radio-ulnar angle are new concepts, being major characteristics of the DRU joint. These angles of the right and left wrist were equal and no difference was found between the sexes. Minor alterations of the distal radius may be revealed when estimating these angles. (orig.)

  10. Radiologic examination and measurement of the wrist and distal radio-ulnar joint. New aspects

    Energy Technology Data Exchange (ETDEWEB)

    Toernvall, A.H.; Ekenstam, F. af; Hagert, C.G.; Irstam, L.

    Following fractures of the distal radius, a relatively high incidence of complications is caused by malalignment in the distal radio-ulnar (DRU) joint; recent anatomic and clinical investigations have shown a congruity of that joint to be of significant importance for restoring the function of the wrist. The radius forms a moderately arched bone, which moves around the ulna in pronation and supination. Biomechanically, the ulna may be regarded as the pillar around which the radius moves. In an anatomic investigation of 5 arm specimens, we have shown that the maximum cartilage contact in the DRU joint between the ulna head and the distal radius occurs in the neutral rotation position. A proposed routine examination method of the wrist and forearm includes a true antero-posterior and a lateral projection of the radius and the ulna, performed with the forearm and wrist in a neutral rotation, a neutral wrist deviation and with the elbow angled 90 degrees. Such an examination implies a standardized and reproducible method. In a radioanatomic investigation, a series of 50 healthy wrists and forearms were examined. A simple measuring technique is presented, applicable to the DRU joint and wrist favouring the ulna as the bone through which a reproducible long axis of the forearm/wrist may be drawn. It is suggested that the length of the radius should be judged relative to the ulna. Ulnar head inclination and radio-ulnar angle are new concepts, being major characteristics of the DRU joint. These angles of the right and left wrist were equal and no difference was found between the sexes. Minor alterations of the distal radius may be revealed when estimating these angles.

  11. [RESEARCH PROGRESS OF BIOMECHANICS OF PROXIMAL ROW CARPAL INSTABILITY].

    Science.gov (United States)

    Guo, Jinhai; Huang, Fuguo

    2015-01-01

    To review the research progress of the biomechanics of proximal row carpal instability (IPRC). The related literature concerning IPRC was extensively reviewed. The biomechanical mechanism of the surrounding soft tissue in maintaining the stability of the proximal row carpal (PRC) was analyzed, and the methods to repair or reconstruct the stability and function of the PRC were summarized from two aspects including basic biomechanics and clinical biomechanics. The muscles and ligaments of the PRC are critical to its stability. Most scholars have reached a consensus about biomechanical mechanism of the PRC, but there are still controversial conclusions on the biomechanics mechanism of the surrounding soft tissue to stability of distal radioulnar joint when the triangular fibrocartilage complex are damaged and the biomechanics mechanism of the scapholunate ligament. At present, there is no unified standard about the methods to repair or reconstruct the stability and function of the PRC. So, it is difficult for clinical practice. Some strides have been made in the basic biomechanical study on muscle and ligament and clinical biomechanical study on the methods to repair or reconstruct the stability and function of PRC, but it will be needed to further study the morphology of carpal articular surface and the adjacent articular surface, the pressure of distal carpals to proximal carpal and so on.

  12. Shoulder biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Lugo, Roberto; Kung, Peter; Ma, C. Benjamin [Sports Medicine and Shoulder Service, University of California, San Francisco, 500 Parnassus Avenue, MU 320W-0728 San Francisco, CA 914143 (United States)], E-mail: maben@orthosurg.ucsf.edu

    2008-10-15

    The biomechanics of the glenohumeral joint depend on the interaction of both static and dynamic-stabilizing structures. Static stabilizers include the bony anatomy, negative intra-articular pressure, the glenoid labrum, and the glenohumeral ligaments along with the joint capsule. The dynamic-stabilizing structures include the rotator cuff muscles and the other muscular structures surrounding the shoulder joint. The combined effect of these stabilizers is to support the multiple degrees of motion within the glenohumeral joint. The goal of this article is to review how these structures interact to provide optimal stability and how failure of some of these mechanisms can lead to shoulder joint pathology.

  13. Radiographic diagnosis of scapholunate dissociation among intra-articular fractures of the distal radius: interobserver reliability

    NARCIS (Netherlands)

    Gradl, Gertraud; Neuhaus, Valentin; Fuchsberger, Thomas; Guitton, Thierry G.; Prommersberger, Karl-Josef; Ring, David; Wahegaonkar, Abhijeet L.; Shafritz, Adam B.; Garcia, Aida E.; Caputo, Andrew E.; Terrono, Andrew L.; Spoor, Andy B.; Eschler, Anica; Vochteloo, Anne J. H.; Beumer, Annechien; Barquet, Antonio; Kristan, Anze; van der Zwan, Arnard L.; Berner, Arne; Ilyas, Asif; Jubel, Axel; Sutker, Ben; Nolan, Betsy M.; Petrisor, Brad; Cross, Brian J.; Wills, Brian P. D.; Barreto, Camilo J. R.; Fernandes, Carlos H.; Swigart, Carrie; Zalavras, Charalampos; Goldfarb, Charles A.; Cassidy, Charles; Eaton, Charles; Wilson, Chris; Cheng, Christine J.; Wall, Christopher J.; Walsh, Christopher J.; Jones, Christopher M.; Garnavos, Christos; Klostermann, Cyrus; Kirkpatrick, D. Kay; Eygendaal, Denise; Verbeek, Diederik O. F.; Beeres, Frank J. P.; Thomas, George; Ponsen, Kornelis J.; van den Bekerom, Michel P. J.; Schep, Niels; Kloen, Peter; Haverlag, Robert

    2013-01-01

    To evaluate the reliability and accuracy of diagnosis of scapholunate dissociation (SLD) among AO type C (compression articular) fractures of the distal radius. A total of 217 surgeons evaluated 21 sets of radiographs with type C fractures of the distal radius for which the status of the

  14. The role of imaging in diagnosing diseases of the distal radioulnar joint, triangular fibrocartilage complex, and distal ulna.

    Science.gov (United States)

    Squires, Judy H; England, Eric; Mehta, Kaushal; Wissman, Robert D

    2014-07-01

    The purpose of this article is to review the anatomy, biomechanics, and multimodality imaging findings of common and uncommon distal radioulnar joint (DRUJ), triangular fibrocartilage complex, and distal ulna abnormalities. The DRUJ is a common site for acute and chronic injuries and is frequently imaged to evaluate chronic wrist pain, forearm dysfunction, and traumatic forearm injury. Given the complex anatomy of the wrist, the radiologist plays a vital role in the diagnosis of wrist pain and dysfunction.

  15. Dinosaur biomechanics

    Science.gov (United States)

    Alexander, R. McNeill

    2006-01-01

    Biomechanics has made large contributions to dinosaur biology. It has enabled us to estimate both the speeds at which dinosaurs generally moved and the maximum speeds of which they may have been capable. It has told us about the range of postures they could have adopted, for locomotion and for feeding, and about the problems of blood circulation in sauropods with very long necks. It has made it possible to calculate the bite forces of predators such as Tyrannosaurus, and the stresses they imposed on its skull; and to work out the remarkable chewing mechanism of hadrosaurs. It has shown us how some dinosaurs may have produced sounds. It has enabled us to estimate the effectiveness of weapons such as the tail spines of Stegosaurus. In recent years, techniques such as computational tomography and finite element analysis, and advances in computer modelling, have brought new opportunities. Biomechanists should, however, be especially cautious in their work on animals known only as fossils. The lack of living specimens and even soft tissues oblige us to make many assumptions. It is important to be aware of the often wide ranges of uncertainty that result. PMID:16822743

  16. Distal renal tubular acidosis

    Science.gov (United States)

    ... this disorder. Alternative Names Renal tubular acidosis - distal; Renal tubular acidosis type I; Type I RTA; RTA - distal; Classical RTA Images Kidney anatomy Kidney - blood and urine flow References Bose A, Monk RD, Bushinsky DA. Kidney ...

  17. Biomechanics in Schools.

    Science.gov (United States)

    Vincent, J. F. V.

    1980-01-01

    Examines current usage of the term "biomechanics" and emphasizes the importance of differentiating between structure and material. Describes current prolects in biomechanics and lists four points about the educational significance of the field. (GS)

  18. Why National Biomechanics Day?

    Science.gov (United States)

    DeVita, Paul

    2018-04-11

    National Biomechanics Day (NBD) seeks to expand the influence and impact of Biomechanics on our society by expanding the awareness of Biomechanics among young people. NBD will manifest this goal through worldwide, synchronized and coordinated celebrations and demonstrations of all things Biomechanics with high school students. NBD invites all Biomechanists to participate in NBD 2018, http://nationalbiomechanicsday.asbweb.org/. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Research Techniques in Biomechanics.

    Science.gov (United States)

    Ward, Terry

    Biomechanics involves the biological human beings interacting with his/her mechanical environment. Biomechanics research is being done in connection with sport, physical education, and general motor behavior, and concerns mechanics independent of implements. Biomechanics research falls in the following two general categories: (1) that specific…

  20. FUNDAMENTALS OF BIOMECHANICS

    Directory of Open Access Journals (Sweden)

    Duane Knudson

    2007-09-01

    Full Text Available DESCRIPTION This book provides a broad and in-depth theoretical and practical description of the fundamental concepts in understanding biomechanics in the qualitative analysis of human movement. PURPOSE The aim is to bring together up-to-date biomechanical knowledge with expert application knowledge. Extensive referencing for students is also provided. FEATURES This textbook is divided into 12 chapters within four parts, including a lab activities section at the end. The division is as follows: Part 1 Introduction: 1.Introduction to biomechanics of human movement; 2.Fundamentals of biomechanics and qualitative analysis; Part 2 Biological/Structural Bases: 3.Anatomical description and its limitations; 4.Mechanics of the musculoskeletal system; Part 3 Mechanical Bases: 5.Linear and angular kinematics; 6.Linear kinetics; 7.Angular kinetics; 8.Fluid mechanics; Part 4 Application of Biomechanics in Qualitative Analysis :9.Applying biomechanics in physical education; 10.Applying biomechanics in coaching; 11.Applying biomechanics in strength and conditioning; 12.Applying biomechanics in sports medicine and rehabilitation. AUDIENCE This is an important reading for both student and educators in the medicine, sport and exercise-related fields. For the researcher and lecturer it would be a helpful guide to plan and prepare more detailed experimental designs or lecture and/or laboratory classes in exercise and sport biomechanics. ASSESSMENT The text provides a constructive fundamental resource for biomechanics, exercise and sport-related students, teachers and researchers as well as anyone interested in understanding motion. It is also very useful since being clearly written and presenting several ways of examples of the application of biomechanics to help teach and apply biomechanical variables and concepts, including sport-related ones

  1. Biomechanics principles and practices

    CERN Document Server

    Peterson, Donald R

    2014-01-01

    Presents Current Principles and ApplicationsBiomedical engineering is considered to be the most expansive of all the engineering sciences. Its function involves the direct combination of core engineering sciences as well as knowledge of nonengineering disciplines such as biology and medicine. Drawing on material from the biomechanics section of The Biomedical Engineering Handbook, Fourth Edition and utilizing the expert knowledge of respected published scientists in the application and research of biomechanics, Biomechanics: Principles and Practices discusses the latest principles and applicat

  2. Distal digital replantation.

    Science.gov (United States)

    Jazayeri, Leila; Klausner, Jill Q; Chang, James

    2013-11-01

    Hand surgeons have been hesitant to perform distal digital replantation because of the technical challenges and the perception of a high cost-to-benefit ratio. Recent studies, however, have shown high survival rates and excellent functional and aesthetic results, providing renewed enthusiasm for distal replantation. The authors reviewed the literature and summarize key points regarding the surgical treatment, perioperative care, and outcomes of distal digital replantation. They describe specific techniques and considerations for surgical repair in each of four distal zones as described by Sebastin and Chung. Zone 1A replantation involves an artery-only anastomosis of a longitudinal pulp artery. Venous anastomosis first becomes possible in zone 1B. Zone 1C involves periarticular amputations where arthrodesis of the distal interphalangeal joint is usually indicated. Repair of the artery, vein, and nerve is technically optimal in zone 1D, where venous anastomosis should be performed. Overall, survival rates for distal digital replantation are similar to those reported for more proximal replantation. The literature reports good outcomes regarding nail salvage, fingertip sensibility, and range of motion, with restoration of length and aesthetic appearance. Distal replantation performed at institutions that specialize in microsurgery and specifically tailored to the level of injury is associated with good survival, function, and patient satisfaction and superior aesthetic outcome. More prospective data are needed to evaluate the cost of treatment, psychological outcomes, and functional outcomes of distal replantation compared with revision amputation.

  3. Gingival Recessions and Biomechanics

    DEFF Research Database (Denmark)

    Laursen, Morten Godtfredsen

    Gingival recessions and biomechanics “Tissue is the issue, but bone sets the tone.“ A tooth outside the cortical plate can result in loss of bone and development of a gingival recession. The presentation aims to show biomechanical considerations in relation to movement of teeth with gingival...... by moving the root back in the alveolus. The tooth movement is accompanied by bone gain and thus increase the success rate for soft tissue augmentation. The choice of biomechanical system influences the treatment outcome. If a standard straight wire appliance is used, a biomechanical dilemma can arise...

  4. Functional anatomy of the distal radioulnar joint in health and disease.

    Science.gov (United States)

    Lees, V C

    2013-04-01

    The distal radioulnar joint (DRUJ) is critical to the function of the forearm as a mechanical unit. This paper is concerned with the concepts and observations that have changed understanding of the function of the DRUJ, notably with respect to the biomechanics of this joint. The DRUJ has been shown to be important in acting to distribute load and removal of the ulna head leads to the biomechanical equivalent of a one-bone forearm. The soft tissues with topographical relations to the distal forearm and DRUJ have also been investigated in our experimental series with findings including the description of a clinical disorder termed subluxation-related ulna neuropathy syndrome.

  5. Biomechanics of the brain

    CERN Document Server

    Miller, Karol

    2011-01-01

    With contributions from scientists at major institutions, this book presents an introduction to brain anatomy for engineers and scientists. It provides, for the first time, a comprehensive resource in the field of brain biomechanics.

  6. Computational modeling in biomechanics

    CERN Document Server

    Mofrad, Mohammad

    2010-01-01

    This book provides a glimpse of the diverse and important roles that modern computational technology is playing in various areas of biomechanics. It includes unique chapters on ab initio quantum mechanical, molecular dynamic and scale coupling methods..

  7. Biomechanics of Spider Silks

    Science.gov (United States)

    2006-03-02

    water and deformation conditions. Such fibres [Nexia ’ biosteel ’ silk ] were spun from recombinant silk ’cloned’ from Spidroin II and indeed show 67...SUBTITLE 5. FUNDING NUMBERS Biomechanics of Spider Silks F49620-03-1-0111 6. AUTHOR(S) Fritz Vollrath 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...Perform Pro, WHSIDIOR, Oct 94 COVER SHEET FINAL (3rd Year) Report to AFOSR on: BIOMECHANICS OF SPIDER SILKS Fritz Vollrath, Oxford University, England

  8. Biomechanics and tennis.

    Science.gov (United States)

    Elliott, B

    2006-05-01

    Success in tennis requires a mix of player talent, good coaching, appropriate equipment, and an understanding of those aspects of sport science pertinent to the game. This paper outlines the role that biomechanics plays in player development from sport science and sport medicine perspectives. Biomechanics is a key area in player development because all strokes have a fundamental mechanical structure and sports injuries primarily have a mechanical cause.

  9. [Distal clavicle fracture].

    Science.gov (United States)

    Seppel, G; Lenich, A; Imhoff, A B

    2014-06-01

    Reposition and fixation of unstable distal clavicle fractures with a low profile locking plate (Acumed, Hempshire, UK) in conjunction with a button/suture augmentation cerclage (DogBone/FibreTape, Arthrex, Naples, FL, USA). Unstable fractures of the distal clavicle (Jäger and Breitner IIA) in adults. Unstable fractures of the distal clavicle (Jäger and Breitner IV) in children. Distal clavicle fractures (Jäger and Breitner I, IIB or III) with marked dislocation, injury of nerves and vessels, or high functional demand. Patients in poor general condition. Fractures of the distal clavicle (Jäger and Breitner I, IIB or III) without marked dislocation or vertical instability. Local soft-tissue infection. Combination procedure: Initially the lateral part of the clavicle is exposed by a 4 cm skin incision. After reduction of the fracture, stabilization is performed with a low profile locking distal clavicle plate. Using a special guiding device, a transclavicular-transcoracoidal hole is drilled under arthroscopic view. Additional vertical stabilization is arthroscopically achieved by shuttling the DogBone/FibreTape cerclage from the lateral portal cranially through the clavicular plate. The two ends of the FibreTape cerclage are brought cranially via adjacent holes of the locking plate while the DogBone button is placed under the coracoid process. Thus, plate bridging is achieved. Finally reduction is performed and the cerclage is secured by surgical knotting. Use of an arm sling for 6 weeks. Due to the fact that the described technique is a relatively new procedure, long-term results are lacking. In the short term, patients postoperatively report high subjective satisfaction without persistent pain.

  10. Biomechanically acquired foot types

    International Nuclear Information System (INIS)

    Weissman, S.D.

    1989-01-01

    Over the years, orthopedics of the foot has gone through many stages and phases, each of which has spawned a whole vocabulary of its own. According the author, today we are in the biomechanical age, which represents a step forward in understanding the mechanisms governing the functions of the lower extremity. A great deal of scientific research on the various foot types and pathological entities is now being performed. This paper discusses how, from a radiographic point of view, a knowledge of certain angular relationships must be achieved before one can perform a biomechanical evaluation. In order to validate the gross clinical findings, following an examination of a patient, a biomechanical evaluation can be performed on the radiographs taken. It must be remembered, however, that x-rays are never the sole means of making a diagnosis. They are just one of many findings that must be put together to arrive at a pertinent clinical assessment or diagnosis

  11. Dr Dapertutto's biomechanics

    Directory of Open Access Journals (Sweden)

    Stojmenović Dragan

    2015-01-01

    Full Text Available The subject matter of the research is the basic models of Meyerhold's biomechanics, which were used to define its theoretical principles. Professor Meyerhold, the theatrical leader of an eccentric stream, with which he changed the modern understanding of the theatre, established the technique of biomechanics by analysing the calculated type of movement. The analysis determines the answers to the questions: What kind of influence does Taylor's 'scientific management of work' have on defining the principles of Meyerhold's techniques of biomechanics? Which aesthetic models of stage movement were some of the basic subjects of Meyerhold's research? Meyerhold's theatrical work has been researched by a number of theatre theorists. However, how much does his work influence the film medium?.

  12. Distal finger replantation.

    Science.gov (United States)

    Scheker, Luis R; Becker, Giles W

    2011-03-01

    Reconstruction of the fingertip distal to the flexor tendon insertion by replantation remains controversial and technically challenging, but the anatomy of the fingertip has been well described and provides help in surgical planning. The open-book surgical technique is described with potential complications and is illustrated with clinical cases. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  13. Distal radioulnar joint injuries

    Directory of Open Access Journals (Sweden)

    Binu P Thomas

    2012-01-01

    Full Text Available Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint , forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments.The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis.

  14. CURRENT CONCEPTS IN BIOMECHANICAL INTERVENTIONS FOR PATELLOFEMORAL PAIN

    Science.gov (United States)

    Meira, Erik P.

    2016-01-01

    Patellofemoral pain (PFP) has historically been a complex and enigmatic issue. Many of the factors thought to relate to PFP remain after patients' symptoms have resolved making their clinical importance difficult to determine. The tissue homeostasis model proposed by Dye in 2005 can assist with understanding and implementing biomechanical interventions for PFP. Under this model, the goal of interventions for PFP should be to re-establish patellofemoral joint (PFJ) homeostasis through a temporary alteration of load to the offended tissue, followed by incrementally restoring the envelope of function to the baseline level or higher. High levels of PFJ loads, particularly in the presence of an altered PFJ environment, are thought to be a factor in the development of PFP. Clinical interventions often aim to alter the biomechanical patterns that are thought to result in elevated PFJ loads while concurrently increasing the load tolerance capabilities of the tissue through therapeutic exercise. Biomechanics may play a role in PFJ load modification not only when addressing proximal and distal components, but also when considering the involvement of more local factors such as the quadriceps musculature. Biomechanical considerations should consider the entire kinetic chain including the hip and the foot/ankle complex, however the beneficial effects of these interventions may not be the result of long-term biomechanical changes. Biomechanical alterations may be achieved through movement retraining, but the interventions likely need to be task-specific to alter movement patterns. The purpose of this commentary is to describe biomechanical interventions for the athlete with PFP to encourage a safe and complete return to sport. Level of Evidence 5 PMID:27904791

  15. Mathematical foundations of biomechanics.

    Science.gov (United States)

    Niederer, Peter F

    2010-01-01

    The aim of biomechanics is the analysis of the structure and function of humans, animals, and plants by means of the methods of mechanics. Its foundations are in particular embedded in mathematics, physics, and informatics. Due to the inherent multidisciplinary character deriving from its aim, biomechanics has numerous connections and overlapping areas with biology, biochemistry, physiology, and pathophysiology, along with clinical medicine, so its range is enormously wide. This treatise is mainly meant to serve as an introduction and overview for readers and students who intend to acquire a basic understanding of the mathematical principles and mechanics that constitute the foundation of biomechanics; accordingly, its contents are limited to basic theoretical principles of general validity and long-range significance. Selected examples are included that are representative for the problems treated in biomechanics. Although ultimate mathematical generality is not in the foreground, an attempt is made to derive the theory from basic principles. A concise and systematic formulation is thereby intended with the aim that the reader is provided with a working knowledge. It is assumed that he or she is familiar with the principles of calculus, vector analysis, and linear algebra.

  16. Biomechanical pulping of kenaf

    Science.gov (United States)

    Aziz Ahmed; Masood Akhtar; Gary C. Myers; Gary M. Scott

    1999-01-01

    The objective of this study was to investigate the effect of fungal pretreatment of whole kenaf prior to refining on refiner electrical energy consumption, paper strength, and optical properties. We also explored the suitability of whole kenaf biomechanical pulp for making newsprint in terms of ISO brightness and strength properties. Kenaf was sterilized by autoclaving...

  17. Biomechanics of footwear.

    Science.gov (United States)

    Snijders, C J

    1987-07-01

    This article discusses biomechanical principles that indicate a number of basic design criteria for shoes and the properties of good footwear in terms of normal daily activities at home, at school, and at work. These properties also apply to normal occupational footwear and safety footwear.

  18. Applications of biomechanics for prevention of work-related musculoskeletal disorders.

    Science.gov (United States)

    Garg, Arun; Kapellusch, Jay M

    2009-01-01

    This paper summarises applications of biomechanical principles and models in industry to control musculoskeletal disorders of the low back and upper extremity. Applications of 2-D and 3-D biomechanical models to estimate compressive force on the low back, the strength requirements of jobs, application of guidelines for overhead work and application of strain index and threshold limit value to address distal upper extremity musculoskeletal disorders are presented. Several case studies applied in the railroad industry, manufacturing, healthcare and warehousing are presented. Finally, future developments needed for improved biomechanical applications in industry are discussed. The information presented will be of value to practising ergonomists to recognise how biomechanics has played a significant role in identifying causes of musculoskeletal disorders and controlling them in the workplace. In particular, the information presented will help practising ergonomists with how physical stresses can be objectively quantified.

  19. Distal corporoplasty for distal cylinders extrusion after penile prosthesis implantation.

    Science.gov (United States)

    Carrino, Maurizio; Chiancone, Francesco; Battaglia, Gaetano; Pucci, Luigi; Fedelini, Paolo

    2017-02-03

    Distal extrusion of cylinders is a potential complication of the penile prosthesis implantation. Several methods have been proposed for repairing a distal penile erosion. We present our preliminary experience in "Distal corporoplasty" technique. We enrolled 18 consecutive patients whose underwent a distal corporoplasty with simultaneous reimplantation of an "AMS 700 inflatable penile prosthesis (LGX)" from January 2013 to November 2015 at our hospital. All procedures were performed by a single surgical team. Intraoperative and postoperative complications have been classified and reported according to Satava6 and Clavien-Dindo (CD) system.7 Mean values with standard deviations (±SD) were computed and reported for all items. Mean age of the patients was 53.61 (±11.90) years. Mean body max index (BMI) was 24.22 (±2.51). Mean operative time was 85.2 (±13.1) minutes. Blood losses were minimal. No intraoperative complications are reported according to Satava classification. Four out of 18 patients (22.22%) experienced postoperative complications according to CD system. All patients had sexual intercourse for the first time postsurgery after a mean of 59.11 ± 2.08 days. Mean follow-up was 22.11 (±9.95). Distal extrusion of cylinders is a potential complication of the penile prosthesis implantation. Distal corporoplasty was first described by Mulcahy. He reported a series of 14 patients with a follow-up of about 2 years with optimal functional outcomes. Moreover, distal corporoplasty resulted in shorter operative time, better function, less pain, and fewer recurrences than Gortex windsock repair.10 In our experience, distal corporoplasty is a simple and safe procedure in the treatment of distal cylinders extrusion when the prosthetic material is not exposed to the exterior.

  20. Reverse Distal Transverse Palmar Arch in Distal Digital Replantation.

    Science.gov (United States)

    Wei, Ching-Yueh; Orozco, Oscar; Vinagre, Gustavo; Shafarenko, Mark

    2017-11-01

    Refinements in microsurgery have made distal finger replantation an established technique with high success rates and good functional and aesthetic outcomes. However, it still represents a technically demanding procedure due to the small vessel caliber and frequent lack of vessel length, requiring the use of interpositional venous grafts in some instances. We describe a new technique for anastomosis in fingertip replantation, whereby the need for venous grafts is eliminated. Applying the reverse distal transverse palmar arch technique, 11 cases of distal digital replantation were performed between January 2011 and July 2016. The described procedure was used for arterial anastomosis in 10 cases and arteriovenous shunting for venous drainage in 1 case. A retrospective case review was conducted. The technical description and clinical outcome evaluations are presented. Ten of the 11 replanted digits survived, corresponding to an overall success rate of 91%. One replant failed due to venous insufficiency. Blood transfusions were not required for any of the patients. Follow-up (range, 1.5-5 months) revealed near-normal range of motion and good aesthetic results. All of the replanted digits developed protective sensation. The average length of hospital admission was 5 days. All patients were satisfied with the results and were able to return to their previous work. The use of the reverse distal transverse palmar arch is a novel and reliable technique in distal digital replantation when an increase in vessel length is required, allowing for a tension-free arterial repair without the need for vein grafts.

  1. Systems biomechanics of the cell

    CERN Document Server

    Maly, Ivan V

    2013-01-01

    Systems Biomechanics of the Cell attempts to outline systems biomechanics of the cell as an emergent and promising discipline. The new field owes conceptually to cell mechanics, organism-level systems biomechanics, and biology of biochemical systems. Its distinct methodology is to elucidate the structure and behavior of the cell by analyzing the unintuitive collective effects of elementary physical forces that interact within the heritable cellular framework. The problematics amenable to this approach includes the variety of cellular activities that involve the form and movement of the cell body and boundary (nucleus, centrosome, microtubules, cortex, and membrane). Among the elementary system effects in the biomechanics of the cell, instability of symmetry, emergent irreversibility, and multiperiodic dissipative motion can be noted. Research results from recent journal articles are placed in this unifying framework. It is suggested that the emergent discipline has the potential to expand the spectrum of ques...

  2. Scale-Independent Biomechanical Optimization

    National Research Council Canada - National Science Library

    Schutte, J. F; Koh, B; Reinbolt, J. A; Haftka, R. T; George, A; Fregly, B. J

    2003-01-01

    ...: the Particle Swarm Optimizer (PSO). They apply this method to the biomechanical system identification problem of finding positions and orientations of joint axes in body segments through the processing of experimental movement data...

  3. Biomechanics: basic and applied research

    International Nuclear Information System (INIS)

    Bergmann, G.; Rohlmann, A.; Koelbel, R.

    1987-01-01

    This volume presents the state of the art in biomechanics. The most recent achievements of biomechanical research in the fields of orthopaedics, dynamics of the musculoskeletal system, hard and soft tissues, rehabilitation, sports, cardiovascular problems and research methodology have been selected and edited by a distinguished panel of reviewers. The material is such that the volume will serve as a reference for many years for bioengineers, sports scientists, clinicians and clinical researchers in rehabilitation, orthopaedics and cardiovascular surgery

  4. Intraarticular arthrofibrosis of the knee alters patellofemoral contact biomechanics.

    Science.gov (United States)

    Mikula, Jacob D; Slette, Erik L; Dahl, Kimi D; Montgomery, Scott R; Dornan, Grant J; O'Brien, Luke; Turnbull, Travis Lee; Hackett, Thomas R

    2017-12-19

    Arthrofibrosis in the suprapatellar pouch and anterior interval can develop after knee injury or surgery, resulting in anterior knee pain. These adhesions have not been biomechanically characterized. The biomechanical effects of adhesions in the suprapatellar pouch and anterior interval during simulated quadriceps muscle contraction from 0 to 90° of knee flexion were assessed. Adhesions of the suprapatellar pouch and anterior interval were hypothesized to alter the patellofemoral contact biomechanics and increase the patellofemoral contact force compared to no adhesions. Across all flexion angles, suprapatellar adhesions increased the patellofemoral contact force compared to no adhesions by a mean of 80 N. Similarly, anterior interval adhesions increased the contact force by a mean of 36 N. Combined suprapatellar and anterior interval adhesions increased the mean patellofemoral contact force by 120 N. Suprapatellar adhesions resulted in a proximally translated patella from 0 to 60°, and anterior interval adhesions resulted in a distally translated patella at all flexion angles other than 15° (p patellofemoral contact forces were significantly increased by simulated adhesions in the suprapatellar pouch and anterior interval. Anterior knee pain and osteoarthritis may result from an increase in patellofemoral contact force due to patellar and quadriceps tendon adhesions. For these patients, arthroscopic lysis of adhesions may be beneficial.

  5. Biomechanical Characteristics and Determinants of Instep Soccer Kick

    Science.gov (United States)

    Kellis, Eleftherios; Katis, Athanasios

    2007-01-01

    Good kicking technique is an important aspect of a soccer player. Therefore, understanding the biomechanics of soccer kicking is particularly important for guiding and monitoring the training process. The purpose of this review was to examine latest research findings on biomechanics of soccer kick performance and identify weaknesses of present research which deserve further attention in the future. Being a multiarticular movement, soccer kick is characterised by a proximal-to-distal motion of the lower limb segments of the kicking leg. Angular velocity is maximized first by the thigh, then by the shank and finally by the foot. This is accomplished by segmental and joint movements in multiple planes. During backswing, the thigh decelerates mainly due to a motion-dependent moment from the shank and, to a lesser extent, by activation of hip muscles. In turn, forward acceleration of the shank is accomplished through knee extensor moment as well as a motion-dependent moment from the thigh. The final speed, path and spin of the ball largely depend on the quality of foot-ball contact. Powerful kicks are achieved through a high foot velocity and coefficient of restitution. Preliminary data indicate that accurate kicks are achieved through slower kicking motion and ball speed values. Key pointsSoccer kick is achieved through segmental and joint rotations in multiple planes and via the proximal-to-distal sequence of segmental angular velocities until ball impact. The quality of ball - foot impact and the mechanical behavior of the foot are also important determinants of the final speed, path and spin of the ball.Ball speed values during the maximum instep kick range from 18 to 35 msec-1 depending on various factors, such as skill level, age, approach angle and limb dominance.The main bulk of biomechanics research examined the biomechanics of powerful kicks, mostly under laboratory conditions. A powerful kick is characterized by the achievement of maximal ball speed. However

  6. Traumatic Distal Ulnar Artery Thrombosis

    Directory of Open Access Journals (Sweden)

    Ahmet A. Karaarslan

    2014-01-01

    Full Text Available This paper is about a posttraumatic distal ulnar artery thrombosis case that has occurred after a single blunt trauma. The ulnar artery thrombosis because of chronic trauma is a frequent condition (hypothenar hammer syndrome but an ulnar artery thrombosis because of a single direct blunt trauma is rare. Our patient who has been affected by a single blunt trauma to his hand and developed ulnar artery thrombosis has been treated by resection of the thrombosed ulnar artery segment. This report shows that a single blunt trauma can cause distal ulnar artery thrombosis in the hand and it can be treated merely by thrombosed segment resection in suitable cases.

  7. MR morphology of triangular fibrocartilage complex: correlation with quantitative MR and biomechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Won C.; Chang, Eric Y.; Chung, Christine B. [VA San Diego Healthcare System, Radiology Service, San Diego, CA (United States); University of California-San Diego, Department of Radiology, San Diego, CA (United States); Ruangchaijatuporn, Thumanoon [Mahidol University, Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine Ramathibodi Hospital, Rachathewi, Bangkok (Thailand); Biswas, Reni; Du, Jiang; Statum, Sheronda [University of California-San Diego, Department of Radiology, San Diego, CA (United States)

    2016-04-15

    To evaluate pathology of the triangular fibrocartilage complex (TFCC) using high-resolution morphologic magnetic resonance (MR) imaging, and compare with quantitative MR and biomechanical properties. Five cadaveric wrists (22-70 years) were imaged at 3 T using morphologic (proton density weighted spin echo, PD FS, and 3D spoiled gradient echo, 3D SPGR) and quantitative MR sequences to determine T2 and T1rho properties. In eight geographic regions, morphology of TFC disc and laminae were evaluated for pathology and quantitative MR values. Samples were disarticulated and biomechanical indentation testing was performed on the distal surface of the TFC disc. On morphologic PD SE images, TFC disc pathology included degeneration and tears, while that of the laminae included degeneration, degeneration with superimposed tear, mucinous transformation, and globular calcification. Punctate calcifications were highly visible on 3D SPGR images and found only in pathologic regions. Disc pathology occurred more frequently in proximal regions of the disc than distal regions. Quantitative MR values were lowest in normal samples, and generally higher in pathologic regions. Biomechanical testing demonstrated an inverse relationship, with indentation modulus being high in normal regions with low MR values. The laminae studied were mostly pathologic, and additional normal samples are needed to discern quantitative changes. These results show technical feasibility of morphologic MR, quantitative MR, and biomechanical techniques to characterize pathology of the TFCC. Quantitative MRI may be a suitable surrogate marker of soft tissue mechanical properties, and a useful adjunct to conventional morphologic MR techniques. (orig.)

  8. MR morphology of triangular fibrocartilage complex: correlation with quantitative MR and biomechanical properties

    International Nuclear Information System (INIS)

    Bae, Won C.; Chang, Eric Y.; Chung, Christine B.; Ruangchaijatuporn, Thumanoon; Biswas, Reni; Du, Jiang; Statum, Sheronda

    2016-01-01

    To evaluate pathology of the triangular fibrocartilage complex (TFCC) using high-resolution morphologic magnetic resonance (MR) imaging, and compare with quantitative MR and biomechanical properties. Five cadaveric wrists (22-70 years) were imaged at 3 T using morphologic (proton density weighted spin echo, PD FS, and 3D spoiled gradient echo, 3D SPGR) and quantitative MR sequences to determine T2 and T1rho properties. In eight geographic regions, morphology of TFC disc and laminae were evaluated for pathology and quantitative MR values. Samples were disarticulated and biomechanical indentation testing was performed on the distal surface of the TFC disc. On morphologic PD SE images, TFC disc pathology included degeneration and tears, while that of the laminae included degeneration, degeneration with superimposed tear, mucinous transformation, and globular calcification. Punctate calcifications were highly visible on 3D SPGR images and found only in pathologic regions. Disc pathology occurred more frequently in proximal regions of the disc than distal regions. Quantitative MR values were lowest in normal samples, and generally higher in pathologic regions. Biomechanical testing demonstrated an inverse relationship, with indentation modulus being high in normal regions with low MR values. The laminae studied were mostly pathologic, and additional normal samples are needed to discern quantitative changes. These results show technical feasibility of morphologic MR, quantitative MR, and biomechanical techniques to characterize pathology of the TFCC. Quantitative MRI may be a suitable surrogate marker of soft tissue mechanical properties, and a useful adjunct to conventional morphologic MR techniques. (orig.)

  9. MR morphology of triangular fibrocartilage complex: correlation with quantitative MR and biomechanical properties.

    Science.gov (United States)

    Bae, Won C; Ruangchaijatuporn, Thumanoon; Chang, Eric Y; Biswas, Reni; Du, Jiang; Statum, Sheronda; Chung, Christine B

    2016-04-01

    To evaluate pathology of the triangular fibrocartilage complex (TFCC) using high-resolution morphologic magnetic resonance (MR) imaging, and compare with quantitative MR and biomechanical properties. Five cadaveric wrists (22-70 years) were imaged at 3 T using morphologic (proton density weighted spin echo, PD FS, and 3D spoiled gradient echo, 3D SPGR) and quantitative MR sequences to determine T2 and T1rho properties. In eight geographic regions, morphology of TFC disc and laminae were evaluated for pathology and quantitative MR values. Samples were disarticulated and biomechanical indentation testing was performed on the distal surface of the TFC disc. On morphologic PD SE images, TFC disc pathology included degeneration and tears, while that of the laminae included degeneration, degeneration with superimposed tear, mucinous transformation, and globular calcification. Punctate calcifications were highly visible on 3D SPGR images and found only in pathologic regions. Disc pathology occurred more frequently in proximal regions of the disc than distal regions. Quantitative MR values were lowest in normal samples, and generally higher in pathologic regions. Biomechanical testing demonstrated an inverse relationship, with indentation modulus being high in normal regions with low MR values. The laminae studied were mostly pathologic, and additional normal samples are needed to discern quantitative changes. These results show technical feasibility of morphologic MR, quantitative MR, and biomechanical techniques to characterize pathology of the TFCC. Quantitative MRI may be a suitable surrogate marker of soft tissue mechanical properties, and a useful adjunct to conventional morphologic MR techniques.

  10. Functional anatomy and biomechanics of the carpus

    International Nuclear Information System (INIS)

    Schmitt, R.

    2006-01-01

    The wrist is an exceedingly complex structure composed of several joints and a dedicated ligamentous system. Its functional principles allow a wide range of carpal motion and make the wrist remarkably resistant to external stress forces: The proximal carpal row serves as an intercalated link interposed between the static elements of both the forearm and the distal carpal row. Like a flexible placeholder, the proximal row synchronously adapts to the spatial and temporal requirements of the wrist. There are synergistic movement patterns including simultaneous flexion of the proximal row as the wrist is deviated radially and simultaneous extension during ulnar deviation. Together with pronosupination of the radioulnar joints, the combined radial/ulnar inclination and flexion/extension enable spherical, out-of-plane movements of the hand. Carpal function is best explained by the ''model of a ring under tension.'' This review addresses the anatomy and the biomechanics of the wrist and illustrates systematic image analysis by using carpal lines and angles as well as indices of carpal height. (orig.) [de

  11. A PROSPECTIVE STUDY OF DISTAL TIBIAL FRACTURES BY MIPO (LCP

    Directory of Open Access Journals (Sweden)

    Chandra Sekharam Naidu

    2015-05-01

    contact . 9 MIPO promoted by AO group emphasis on indirect reduction, axial alignment and s table fixation without disturbing the fracture environment and thus preserving most of the vascularization and fracture haematoma, containing all necessary growth factors for bony healing. Technique of closed reduction and MIPPO with LCP has emerged as an alternative treatment option for distal dia - metaphyseal tibia fracture. When applied subcutaneously, LCP does not endanger periosteal blood supply, respect fracture heamtoma and also provides biomechanically stable construct. Several clinical studies have established MIPO with LCP as a biologically friendly and technically sound method of fixation for distal meta - diaphyseal tibial fracture.

  12. Distal protection in cardiovascular medicine: current status.

    Science.gov (United States)

    Ali, Onn Akbar; Bhindi, Ravinay; McMahon, Aisling C; Brieger, David; Kritharides, Leonard; Lowe, Harry C

    2006-08-01

    Iatrogenic and spontaneous downstream microembolization of atheromatous material is increasingly recognized as a source of cardiovascular morbidity and mortality. Devising ways of reducing this distal embolization using a variety of mechanical means--distal protection--is currently under intense and diverse investigation. This review therefore summarizes the present status of distal protection. It examines the problem of distal embolization, describes the available distal protection devices, reviews those areas of cardiovascular medicine where distal protection devices are being investigated, and discusses potential future developments.

  13. Biomechanical analysis of rollator walking

    DEFF Research Database (Denmark)

    Alkjaer, T; Larsen, Peter K; Pedersen, Gitte

    2006-01-01

    The rollator is a very popular walking aid. However, knowledge about how a rollator affects the walking patterns is limited. Thus, the purpose of the study was to investigate the biomechanical effects of walking with and without a rollator on the walking pattern in healthy subjects.......The rollator is a very popular walking aid. However, knowledge about how a rollator affects the walking patterns is limited. Thus, the purpose of the study was to investigate the biomechanical effects of walking with and without a rollator on the walking pattern in healthy subjects....

  14. Simulations of Biomechanical Phenomena

    Science.gov (United States)

    Gonzalez, Jose Cruz

    Recent studies have published breakthroughs in the application of finite element (FEA) studies in the design and analysis of advanced orthodontics. However, FEA has not captured bone remodeling responses to advanced orthodontics. The results of these simulations report unrealistic displacement around the nasal bridge, which impeded correlation with clinical data. Bone remodeling has been previously documented in FEA and has shown bone response to mechanical stimulus in femur bone models. However, the relationship between mechanical stimulus and bone remodeling has not been reported in orthodontic studies due to the complexity of the skull. In the current study, strain energy is used as the mechanical stimulus to control remodeling, from which density and modulus evolve. Due to the localization of forces in orthodontics, current remodeling algorithms have limited application. In turn, we developed an algorithm that dynamically collects, sorts, and bins stresses in all elements for regional remodeling based on the proximity of the element to the load. The results demonstrate that bone response to orthodontic appliances is different than that of an FEA without bone remodeling, due to load path changes based upon evolution of the bone properties. It was also found that density and moduli proximal to the load application site exhibit faster remodeling than those located remotely. Modeling another biomechanical phenomena, a 3D simulation was created to simulate recent experimental results that discovered a difference in impact mitigation properties of dense-polymer/foam bilayer structure based on the orientation of the dense-polymer with respect to the impact site. The impact energy transmitted varied in time of arrival and amplitude depending on the orientation of the structure (thin layer up or down). By creating a 3D explicit dynamic FEA simulation, it is expected to reduce costly experiments and time consumed in set up, and offer opportunities for optimization for

  15. Cycling biomechanics: a literature review.

    Science.gov (United States)

    Wozniak Timmer, C A

    1991-01-01

    Submitted in partial fulfillment for a Master of Science degree at the University of Pittsburgh, School of Health Related Professions, Pittsburgh, PA 1.5213 This review of current literature on cycling biomechanics emphasizes lower extremity muscle actions and joint excursions, seat height, pedal position, pedaling rate, force application, and pedaling symmetry. Guidelines are discussed for optimal seat height, pedal position, and pedaling rate. Force application in the power and recovery phases of cycling and the relationship of force application to pedaling symmetry are discussed. The need for a biomechanical approach to cycling exists since a great deal of the literature is primarily physiologic in nature. The purpose of this review is to make cyclists and their advisors aware of the biomechanics of cycling and guidelines to follow. This approach is also important because cycling is a very common form of exercise prescribed by physical therapists for clinic or home programs. Biomechanical aspects of cycling should be considered by cyclists at any level of participation and by physical therapists in order for goal-oriented, efficient cycling to occur. J Orthop Sports Phys Ther 1991;14(3):106-113.

  16. Clinical applications of biomechanics cinematography.

    Science.gov (United States)

    Woodle, A S

    1986-10-01

    Biomechanics cinematography is the analysis of movement of living organisms through the use of cameras, image projection systems, electronic digitizers, and computers. This article is a comparison of cinematographic systems and details practical uses of the modality in research and education.

  17. The biomechanics of seed germination.

    Science.gov (United States)

    Steinbrecher, Tina; Leubner-Metzger, Gerhard

    2017-02-01

    From a biomechanical perspective, the completion of seed (and fruit) germination depends on the balance of two opposing forces: the growth potential of the embryonic axis (radicle-hypocotyl growth zone) and the restraint of the seed-covering layers (endosperm, testa, and pericarp). The diverse seed tissues are composite materials which differ in their dynamic properties based on their distinct cell wall composition and water uptake capacities. The biomechanics of embryo cell growth during seed germination depend on irreversible cell wall loosening followed by water uptake due to the decreasing turgor, and this leads to embryo elongation and eventually radicle emergence. Endosperm weakening as a prerequisite for radicle emergence is a widespread phenomenon among angiosperms. Research into the biochemistry and biomechanics of endosperm weakening has demonstrated that the reduction in puncture force of a seed's micropylar endosperm is environmentally and hormonally regulated and involves tissue-specific expression of cell wall remodelling proteins such as expansins, diverse hydrolases, and the production of directly acting apoplastic reactive oxygen. The endosperm-weakening biomechanics and its underlying cell wall biochemistry differ between the micropylar (ME) and chalazal (CE) endosperm domains. In the ME, they involve cell wall loosening, cell separation, and programmed cell death to provide decreased and localized ME tissue resistance, autolysis, and finally the formation of an ME hole required for radicle emergence. Future work will further unravel the molecular mechanisms, environmental regulation, and evolution of the diverse biomechanical cell wall changes underpinning the control of germination by endosperm weakening. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. Biomechanical consequences of adding plantar fascia release to metatarsal osteotomies: Changes in forefoot plantar pressures.

    Science.gov (United States)

    Aydogan, Umur; Roush, Evan P; Moore, Blake E; Andrews, Seth H; Lewis, Gregory S

    2017-04-01

    Destruction of the normal metatarsal arch by a long metatarsal is often a cause for metatarsalgia. When surgery is warranted, distal oblique, or proximal dorsiflexion osteotomies of the long metatarsal bones are commonly used. The plantar fascia has anatomical connection to all metatarsal heads. There is controversial scientific evidence on the effect of plantar fascia release on forefoot biomechanics. In this cadaveric biomechanical study, we hypothesized that plantar fascia release would augment the plantar metatarsal pressure decreasing effects of two common second metatarsal osteotomy techniques. Six matched pairs of foot and ankle specimens were mounted on a pressure mat loading platform. Two randomly assigned surgery groups, which had received either distal oblique, or proximal dorsiflexion osteotomy of the second metatarsal, were evaluated before and after plantar fasciectomy. Specimens were loaded up to a ground reaction force of 400 N at varying Achilles tendon forces. Average pressures, peak pressures, and contact areas were analyzed. Supporting our hypothesis, average pressures under the second metatarsal during 600 N Achilles load were decreased by plantar fascia release following proximal osteotomy (p plantar fascia release following modified distal osteotomy, under multiple Achilles loading conditions (p Plantar fasciotomy should not be added to distal metatarsal osteotomy in the treatment of metatarsalgia. If proximal dorsiflexion osteotomy would be preferred, plantar fasciotomy should be approached cautiously not to disturb the forefoot biomechanics. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:800-804, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  19. Spleen-preserving distal pancreatectomy in trauma.

    Science.gov (United States)

    Schellenberg, Morgan; Inaba, Kenji; Cheng, Vincent; Bardes, James M; Lam, Lydia; Benjamin, Elizabeth; Matsushima, Kazuhide; Demetriades, Demetrios

    2018-01-01

    Traumatic injuries to the distal pancreas are infrequent. Universally accepted recommendations about the need for routine splenectomy with distal pancreatectomy do not exist. The aims of this study were to compare outcomes after distal pancreatectomy and splenectomy versus spleen-preserving distal pancreatectomy, and to define the appropriate patient population for splenic preservation. All patients who underwent distal pancreatectomy (January 1, 2007, to December 31, 2014) were identified from the National Trauma Data Bank. Patients with concomitant splenic injury and those who underwent partial splenectomy were excluded. Demographics, clinical data, procedures, and outcomes were collected. Study groups were defined by surgical procedure: distal pancreatectomy and splenectomy versus spleen-preserving distal pancreatectomy. Baseline characteristics between groups were compared with univariate analysis. Multivariate analysis was performed with logistic and linear regression to examine differences in outcomes. Over the 8-year study period, 2,223 patients underwent distal pancreatectomy. After excluding 1,381 patients with concomitant splenic injury (62%) and 8 (pancreatectomy and splenectomy, those who underwent spleen-preserving distal pancreatectomy were younger (p pancreatectomy (p = 0.017). Complications, mortality, and intensive care unit LOS were not significantly different. In young patients after blunt trauma who are not severely injured, a spleen-preserving distal pancreatectomy should be considered to allow for conservation of splenic function and a shorter hospital LOS. In all other patients, the surgeon should not hesitate to remove the spleen with the distal pancreas. Therapy, level IV.

  20. A literature review of the effects of computer input device design on biomechanical loading and musculoskeletal outcomes during computer work.

    Science.gov (United States)

    Bruno Garza, J L; Young, J G

    2015-01-01

    Extended use of conventional computer input devices is associated with negative musculoskeletal outcomes. While many alternative designs have been proposed, it is unclear whether these devices reduce biomechanical loading and musculoskeletal outcomes. To review studies describing and evaluating the biomechanical loading and musculoskeletal outcomes associated with conventional and alternative input devices. Included studies evaluated biomechanical loading and/or musculoskeletal outcomes of users' distal or proximal upper extremity regions associated with the operation of alternative input devices (pointing devices, mice, other devices) that could be used in a desktop personal computing environment during typical office work. Some alternative pointing device designs (e.g. rollerbar) were consistently associated with decreased biomechanical loading while other designs had inconsistent results across studies. Most alternative keyboards evaluated in the literature reduce biomechanical loading and musculoskeletal outcomes. Studies of other input devices (e.g. touchscreen and gestural controls) were rare, however, those reported to date indicate that these devices are currently unsuitable as replacements for traditional devices. Alternative input devices that reduce biomechanical loading may make better choices for preventing or alleviating musculoskeletal outcomes during computer use, however, it is unclear whether many existing designs are effective.

  1. The forearm complex: anatomy, biomechanics and clinical considerations.

    Science.gov (United States)

    LaStayo, Paul C; Lee, Michael J

    2006-01-01

    The forearm complex is comprised of the proximal radioulnar joint, middle radioulnar joint/interosseous membrane, and the distal radioulnar joint. These three areas function in a coordinated manner to rotate the hand in space and allow performance of functional tasks. If a structure or structures in one of these three areas is disrupted, this can adversely affect the function at any of the other two remaining areas. Surgical intervention focuses on restoring anatomical alignment to preserve the function of the forearm complex. Rehabilitation is guided by the relationships between the three areas of the forearm complex and the awareness of clinical signs, symptoms, and complications. The purposes of this paper are to 1) describe the anatomy and biomechanical function of the forearm complex and 2) discuss clinical correlates pertaining to select forearm injuries (excluding peripheral nerve injuries) that may affect forearm function.

  2. The Biomechanics of Cervical Spondylosis

    Directory of Open Access Journals (Sweden)

    Lisa A. Ferrara

    2012-01-01

    Full Text Available Aging is the major risk factor that contributes to the onset of cervical spondylosis. Several acute and chronic symptoms can occur that start with neck pain and may progress into cervical radiculopathy. Eventually, the degenerative cascade causes desiccation of the intervertebral disc resulting in height loss along the ventral margin of the cervical spine. This causes ventral angulation and eventual loss of lordosis, with compression of the neural and vascular structures. The altered posture of the cervical spine will progress into kyphosis and continue if the load balance and lordosis is not restored. The content of this paper will address the physiological and biomechanical pathways leading to cervical spondylosis and the biomechanical principles related to the surgical correction and treatment of kyphotic progression.

  3. Confidence crisis of results in biomechanics research.

    Science.gov (United States)

    Knudson, Duane

    2017-11-01

    Many biomechanics studies have small sample sizes and incorrect statistical analyses, so reporting of inaccurate inferences and inflated magnitude of effects are common in the field. This review examines these issues in biomechanics research and summarises potential solutions from research in other fields to increase the confidence in the experimental effects reported in biomechanics. Authors, reviewers and editors of biomechanics research reports are encouraged to improve sample sizes and the resulting statistical power, improve reporting transparency, improve the rigour of statistical analyses used, and increase the acceptance of replication studies to improve the validity of inferences from data in biomechanics research. The application of sports biomechanics research results would also improve if a larger percentage of unbiased effects and their uncertainty were reported in the literature.

  4. Biomechanical forces promote embryonic haematopoiesis

    Science.gov (United States)

    Adamo, Luigi; Naveiras, Olaia; Wenzel, Pamela L.; McKinney-Freeman, Shannon; Mack, Peter J.; Gracia-Sancho, Jorge; Suchy-Dicey, Astrid; Yoshimoto, Momoko; Lensch, M. William; Yoder, Mervin C.; García-Cardeña, Guillermo; Daley, George Q.

    2009-01-01

    Biomechanical forces are emerging as critical regulators of embryogenesis, particularly in the developing cardiovascular system1,2. After initiation of the heartbeat in vertebrates, cells lining the ventral aspect of the dorsal aorta, the placental vessels, and the umbilical and vitelline arteries initiate expression of the transcription factor Runx1 (refs 3–5), a master regulator of haematopoiesis, and give rise to haematopoietic cells4. It remains unknown whether the biomechanical forces imposed on the vascular wall at this developmental stage act as a determinant of haematopoietic potential6. Here, using mouse embryonic stem cells differentiated in vitro, we show that fluid shear stress increases the expression of Runx1 in CD41+c-Kit+ haematopoietic progenitor cells7,concomitantly augmenting their haematopoietic colony-forming potential. Moreover, we find that shear stress increases haematopoietic colony-forming potential and expression of haematopoietic markers in the paraaortic splanchnopleura/aorta–gonads–mesonephros of mouse embryos and that abrogation of nitric oxide, a mediator of shear-stress-induced signalling8, compromises haematopoietic potential in vitro and in vivo. Collectively, these data reveal a critical role for biomechanical forces in haematopoietic development. PMID:19440194

  5. Qualitative biomechanical principles for application in coaching.

    Science.gov (United States)

    Knudson, Duane

    2007-01-01

    Many aspects of human movements in sport can be readily understood by Newtonian rigid-body mechanics. Many of these laws and biomechanical principles, however, are counterintuitive to a lot of people. There are also several problems in the application of biomechanics to sports, so the application of biomechanics in the qualitative analysis of sport skills by many coaches has been limited. Biomechanics scholars have long been interested in developing principles that facilitate the qualitative application of biomechanics to improve movement performance and reduce the risk of injury. This paper summarizes the major North American efforts to establish a set of general biomechanical principles of movement, and illustrates how principles can be used to improve the application of biomechanics in the qualitative analysis of sport technique. A coach helping a player with a tennis serve is presented as an example. The standardization of terminology for biomechanical principles is proposed as an important first step in improving the application ofbiomechanics in sport. There is also a need for international cooperation and research on the effectiveness of applying biomechanical principles in the coaching of sport techniques.

  6. A review of biomechanics of the shoulder and biomechanical concepts of rotator cuff repair

    Directory of Open Access Journals (Sweden)

    Nobuyuki Yamamoto

    2015-01-01

    Full Text Available In this article, we describe the basic knowledge about shoulder biomechanics, which is thought to be useful for surgeons. Some clinical reports have described that the excellent outcome after cuff repair without acromioplasty and a limited acromioplasty might be enough for subacromial decompression. It was biomechanically demonstrated that a 10-mm medial shift of the tendon repair site has a minimum effect on biomechanics. Many biomechanical studies reported that the transosseous equivalent repair was superior to other techniques, although the tendon may lose its inherent elasticity. We herein introduce our recent experiment data and latest information on biomechanics.

  7. Posttraumatic osteolysis of the distal clavicula end

    International Nuclear Information System (INIS)

    Hermanns, P.H.; Beeger, R.; Koetter, D.; Hamburg Univ.

    1981-01-01

    Posttraumatic osteolysis of bone is rare. Its etiology is unknown. A case of posttraumatic osteolysis of the distal clavicle end is reported. Differentialdiagnostical and ethiological relations are discussed. The literature of posttraumatic osteolysis especially of distal clavicle osteolysis is reported. (orig.) [de

  8. Contemporary Management of Primary Distal Urethral Cancer

    NARCIS (Netherlands)

    Traboulsi, S.L.; Witjes, J.A.; Kassouf, W.

    2016-01-01

    Primary urethral cancer is one of the rare urologic tumors. Distal urethral tumors are usually less advanced at diagnosis compared with proximal tumors and have a good prognosis if treated appropriately. Low-stage distal tumors can be managed successfully with a surgical approach in men or radiation

  9. Applied Biomechanics in an Instructional Setting

    Science.gov (United States)

    Hudson, Jackie L.

    2006-01-01

    Biomechanics is the science of how people move better, meaning more skillfully and more safely. This article places more emphasis on skill rather than safety, though there are many parallels between them. It shares a few features of the author's paradigm of applied biomechanics and discusses an integrated approach toward a middle school football…

  10. Biomechanical properties of bone allografts

    International Nuclear Information System (INIS)

    Pelker, R.R.; Friedlaender, G.E.; Markham, T.C.

    1983-01-01

    The biomechanical properties of allograft bone can be altered by the methods chosen for its preservation and storage. These effects are minimal with deep-freezing or low-level radiation. Freeze-drying, however, markedly diminishes the torsional and bending strength of bone allografts but does not deleteriously affect the compressive or tensile strength. Irradiation of bone with more than 3.0 megarad or irradiation combined with freeze-drying appears to cause a significant reduction in breaking strength. These factors should be considered when choosing freeze-dried or irradiated allogeneic bone that will be subjected to significant loads following implantation

  11. Problems of Sport Biomechanics and Robotics

    Directory of Open Access Journals (Sweden)

    Wlodzimierz S. Erdmann

    2013-02-01

    Full Text Available This paper presents many common areas of interest of different specialists. There are problems described from sport, biomechanics, sport biomechanics, sport engineering, robotics, biomechanics and robotics, sport biomechanics and robotics. There are many approaches to sport from different sciences and engineering. Robotics is a relatively new area and has had moderate attention from sport specialists. The aim of this paper is to present several areas necessary to develop sport robots based on biomechanics and also to present different types of sport robots: serving balls, helping to provide sports training, substituting humans during training, physically participating in competitions, physically participating in competitions against humans, serving as models of real sport performance, helping organizers of sport events and robot toys. Examples of the application of robots in sports communities are also given.

  12. ES-2 Dummy Biomechanical Responses.

    Science.gov (United States)

    Byrnes, Katie; Abramczyk, Joseph; Berliner, Jeff; Irwin, Annette; Jensen, Jack; Kowsika, Murthy; Mertz, Harold J; Rouhana, Stephen W; Scherer, Risa; Shi, Yibing; Sutterfield, Aleta; Xu, Lan; Tylko, Suzanne; Dalmotas, Dainius

    2002-11-01

    This technical paper presents the results of biomechanical testing conducted on the ES-2 dummy by the Occupant Safety Research Partnership and Transport Canada. The ES-2 is a production dummy, based on the EuroSID-1 dummy, that was modified to further improve testing capabilities as recommended by users of the EuroSID-1 dummy. Biomechanical response data were obtained by completing a series of drop, pendulum, and sled tests that are outlined in the International Organization of Standardization Technical Report 9790 that describes biofidelity requirements for the midsize adult male side impact dummy. A few of the biofidelity tests were conducted on both sides of the dummy to evaluate the symmetry of its responses. Full vehicle crash tests were conducted to verify if the changes in the EuroSID-1, resulting in the ES-2 design, did improve the dummy's testing capability. In addition to the biofidelity testing, the ES-2 dummy repeatability, reproducibility and durability are discussed. Finally, this technical paper will compare the biofidelity ratings of the current adult side impact dummies with the ES-2 dummy, which received an overall dummy biofidelity rating of 4.6.

  13. Toward characterization of craniofacial biomechanics.

    Science.gov (United States)

    Szwedowski, Tomasz D; Whyne, Cari M; Fialkov, Jeffrey A

    2010-01-01

    Surgical reconstruction of craniofacial deformities has advanced significantly in recent years. However, unlike orthopedic surgery of the appendicular skeleton, the biomechanical characterization of the human craniofacial skeleton (CFS) has yet to be elucidated. Attempts to simplify facial skeletal structure into straightforward mechanical device analogies have been insufficient in delineating craniofacial biomechanics. Advanced computational engineering analysis methods offer the potential to accurately and completely define the internal mechanical environment of the CFS. This study developed a finite element (FE) model in the I-deas 10 FEM software package of a preserved cadaveric human CFS and compared the predictions of this model against in vitro strain measurement of simulated occlusal loading forces from a single masseter muscle. The FE model applied shell element modeling to capture the behavior of the thin cortical bone that may play an important role in stabilizing the facial structures against functional loads. In vitro testing included strain measurements at 12 locations for a total of 16 independent channels with less than 150 N of tensile force applied through the masseter muscle into the zygomatic arch origin at 4 different orientations, with 3 trials of 500 recorded data points for each loading orientation. Linear regression analysis yielded a moderate prediction (r = 0.57) between the model and experimentally measured strains. Exclusion of strain comparisons in regions that required greater modeling assumptions greatly improved the correlation (r = 0.70). Future validation studies will benefit from improved placement of strain gauges as guided by FE model predicted strain patterns.

  14. Three Dimensional Finite Element Analysis of Distal Abutment Stresses of Removable Partial Dentures with Different Retainer Designs

    Science.gov (United States)

    Zarrati, Simindokht; Heidari, Fatemeh; Kashani, Jamal

    2015-01-01

    Objectives: This finite element method study aimed to compare the amount of stress on an isolated mandibular second premolar in two conventional reciprocal parallel interface designs of removable partial dentures (RPDs) and the same RPD abutment tooth (not isolated). Materials and Methods: A Kennedy Class 1, modification 1 RPD framework was simulated on a 3D model of mandible with three different designs: an isolated tooth with a mesial rest, an isolated tooth with mesial and distal rests and an abutment with a mesial rest (which was not isolated); 26 N occlusal forces were exerted bilaterally on the first molar sites. Stress on the abutment teeth was analyzed using Cosmos Works 2009 Software. Results: In all designs, the abutment tooth stress concentration was located in the buccal alveolar crest. In the first model, the von Mises stress distribution in the contact area of I-bar clasp and cervical portion of the tooth was 19 MPa and the maximum stress was 30 MPa. In the second model, the maximum von Mises stress distribution was 15 MPa in the cervical of the tooth. In the third model, the maximum von Mises stress was located in the cervical of the tooth and the distal proximal plate. Conclusion: We recommend using both mesial and distal rests on the distal abutment teeth of distal extension RPDs. The abutment of an extension base RPD, which is not isolated in presence of its neighboring more anterior tooth, may have a better biomechanical prognosis. PMID:26884772

  15. Three Dimensional Finite Element Analysis of Distal Abutment Stresses of Removable Partial Dentures with Different Retainer Designs.

    Science.gov (United States)

    Zarrati, Simindokht; Bahrami, Mehran; Heidari, Fatemeh; Kashani, Jamal

    2015-06-01

    This finite element method study aimed to compare the amount of stress on an isolated mandibular second premolar in two conventional reciprocal parallel interface designs of removable partial dentures (RPDs) and the same RPD abutment tooth (not isolated). A Kennedy Class 1, modification 1 RPD framework was simulated on a 3D model of mandible with three different designs: an isolated tooth with a mesial rest, an isolated tooth with mesial and distal rests and an abutment with a mesial rest (which was not isolated); 26 N occlusal forces were exerted bilaterally on the first molar sites. Stress on the abutment teeth was analyzed using Cosmos Works 2009 Software. In all designs, the abutment tooth stress concentration was located in the buccal alveolar crest. In the first model, the von Mises stress distribution in the contact area of I-bar clasp and cervical portion of the tooth was 19 MPa and the maximum stress was 30 MPa. In the second model, the maximum von Mises stress distribution was 15 MPa in the cervical of the tooth. In the third model, the maximum von Mises stress was located in the cervical of the tooth and the distal proximal plate. We recommend using both mesial and distal rests on the distal abutment teeth of distal extension RPDs. The abutment of an extension base RPD, which is not isolated in presence of its neighboring more anterior tooth, may have a better biomechanical prognosis.

  16. Biomechanical Remodeling of the Diabetic Gastrointestinal Tract

    DEFF Research Database (Denmark)

    Zhao, Jingbo; Liao, Donghua; Yang, Jian

    2010-01-01

    several years, several studies demonstrated that experimental diabetes induces GI morphological and biomechanical remodeling. Following the development of diabetes, the GI wall becomes thicker and the stiffness of the GI wall increases in a time-dependent manner. It is well known that mechanosensitive...... the biomechanical environment of the mechanosensitive nerve endings, therefore, the structure as well as the tension, stress and strain distribution in the GI wall is important for the sensory and motor function. Biomechanical remodeling of diabetic GI tract including alterations of residual strain and increase...

  17. Proximal versus distal control of two-joint planar reaching movements in the presence of neuromuscular noise.

    Science.gov (United States)

    Nguyen, Hung P; Dingwell, Jonathan B

    2012-06-01

    Determining how the human nervous system contends with neuro-motor noise is vital to understanding how humans achieve accurate goal-directed movements. Experimentally, people learning skilled tasks tend to reduce variability in distal joint movements more than in proximal joint movements. This suggests that they might be imposing greater control over distal joints than proximal joints. However, the reasons for this remain unclear, largely because it is not experimentally possible to directly manipulate either the noise or the control at each joint independently. Therefore, this study used a 2 degree-of-freedom torque driven arm model to determine how different combinations of noise and/or control independently applied at each joint affected the reaching accuracy and the total work required to make the movement. Signal-dependent noise was simultaneously and independently added to the shoulder and elbow torques to induce endpoint errors during planar reaching. Feedback control was then applied, independently and jointly, at each joint to reduce endpoint error due to the added neuromuscular noise. Movement direction and the inertia distribution along the arm were varied to quantify how these biomechanical variations affected the system performance. Endpoint error and total net work were computed as dependent measures. When each joint was independently subjected to noise in the absence of control, endpoint errors were more sensitive to distal (elbow) noise than to proximal (shoulder) noise for nearly all combinations of reaching direction and inertia ratio. The effects of distal noise on endpoint errors were more pronounced when inertia was distributed more toward the forearm. In contrast, the total net work decreased as mass was shifted to the upper arm for reaching movements in all directions. When noise was present at both joints and joint control was implemented, controlling the distal joint alone reduced endpoint errors more than controlling the proximal joint

  18. Conceptualizing distal drivers in land use competition

    DEFF Research Database (Denmark)

    Niewhöner, Jörg; Nielsen, Jonas Ø; Gasparri, Gasparri

    2016-01-01

    This introductory chapter explores the notion of ‘distal drivers’ in land use competition. Research has moved beyond proximate causes of land cover and land use change to focus on the underlying drivers of these dynamics. We discuss the framework of telecoupling within human–environment systems...... as a first step to come to terms with the increasingly distal nature of driving forces behind land use practices. We then expand the notion of distal as mainly a measure of Euclidian space to include temporal, social, and institutional dimensions. This understanding of distal widens our analytical scope...... for the analysis of land use competition as a distributed process to consider the role of knowledge and power, technology, and different temporalities within a relational or systemic analysis of practices of land use competition. We conclude by pointing toward the historical and social contingency of land use...

  19. Distal technologies and type 1 diabetes management.

    Science.gov (United States)

    Duke, Danny C; Barry, Samantha; Wagner, David V; Speight, Jane; Choudhary, Pratik; Harris, Michael A

    2018-02-01

    Type 1 diabetes requires intensive self-management to avoid acute and long-term health complications. In the past two decades, substantial advances in technology have enabled more effective and convenient self-management of type 1 diabetes. Although proximal technologies (eg, insulin pumps, continuous glucose monitors, closed-loop and artificial pancreas systems) have been the subject of frequent systematic and narrative reviews, distal technologies have received scant attention. Distal technologies refer to electronic systems designed to provide a service remotely and include heterogeneous systems such as telehealth, mobile health applications, game-based support, social platforms, and patient portals. In this Review, we summarise the empirical literature to provide current information about the effectiveness of available distal technologies to improve type 1 diabetes management. We also discuss privacy, ethics, and regulatory considerations, issues of global adoption, knowledge gaps in distal technology, and recommendations for future directions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Genetics Home Reference: distal arthrogryposis type 1

    Science.gov (United States)

    ... 1 is a disorder characterized by joint deformities (contractures) that restrict movement in the hands and feet. ... distal arthrogryposis type 1 . However, researchers speculate that contractures may be related to problems with muscle contraction ...

  1. Potassium secretion in mammalian distal colon

    DEFF Research Database (Denmark)

    Sørensen, Mads Vaarby

    2009-01-01

    Epithelial organs adjust the „inner milieu“ of the body and are crucial for all homeostatic processes. Epithelial transport of different solutes and water is regulated phenomena. The regulation processes include both long term hormonal regulation and short term local agonist mediated regulation....... This research project is the summary of 3 original papers addressing the functional role of different regulating factors on ion transport in mouse distal colon. The first paper addresses the effect of luminal nucleotides on electrogenic Na+ absorption. The distal colon, like the distal nephron is an aldosterone......-sensitive tissue and participates in the regulation of Na+ excretion. In the distal nephron it was found that luminal nucleotides inhibit ENaC-mediated Na+ absorption. Here it was addressed whether luminal nucleotides regulate Na+ absorption and if so, which of the known luminal P2 receptors are involved. Using...

  2. Biomechanical aspects of playing surfaces.

    Science.gov (United States)

    Nigg, B M; Yeadon, M R

    1987-01-01

    The purpose of this paper is to discuss some biomechanical aspects of playing surfaces with special focus on (a) surface induced injuries, (b) methodologies used to assess surfaces and (c) findings from various sports. The paper concentrates primarily on questions related to load on the athlete's body. Data from epidemiological studies suggest strongly that the surface is an important factor in the aetiology of injuries. Injury frequencies are reported to be significantly different for different surfaces in several sports. The methodologies used to assess surfaces with respect to load or performance include material tests and tests using experimental subjects. There is only little correlation between the results of these two approaches. Material tests used in many standardized test procedures are not validated which suggests that one should exercise restraint in the interpretation of these results. Point elastic surfaces are widely studied while area elastic surfaces have received little attention to date. Questions of energy losses on sport surfaces have rarely been studied scientifically.

  3. Normal distal pulmonary vein anatomy

    Directory of Open Access Journals (Sweden)

    Wiesława Klimek-Piotrowska

    2016-01-01

    Full Text Available Background. It is well known that the pulmonary veins (PVs, especially their myocardial sleeves play a critical role in the initiation and maintenance of atrial fibrillation. Understanding the PV anatomy is crucial for the safety and efficacy of all procedures performed on PVs. The aim of this study was to present normal distal PV anatomy and to create a juxtaposition of all PV ostium variants.Methods. A total of 130 randomly selected autopsied adult human hearts (Caucasian were examined. The number of PVs ostia was evaluated and their diameter was measured. The ostium-to-last-tributary distance and macroscopic presence of myocardial sleeves were also evaluated.Results. Five hundred forty-one PV ostia were identified. Four classical PV ostia patterns (two left and two right PVs were observed in 70.8% of all cases. The most common variant was the classical pattern with additional middle right PV (19.2%, followed by the common ostium for the left superior and the inferior PVs (4.44%. Mean diameters of PV ostia (for the classical pattern were: left superior = 13.8 ± 2.9 mm; left inferior = 13.3 ± 3.4 mm; right superior = 14.3 ± 2.9 mm; right inferior = 13.7 ± 3.3 mm. When present, the additional middle right PV ostium had the smallest PV ostium diameter in the heart (8.2 ± 4.1 mm. The mean ostium-to-last-tributary (closest to the atrium distances were: left superior = 15.1 ± 4.6 mm; left inferior = 13.5 ± 4.0 mm; right superior = 11.8 ± 4.0 mm; right inferior = 11.0 ± 3.7 mm. There were no statistically significant differences between sexes in ostia diameters and ostium-to-last-tributary distances.Conclusion. Only 71% of the cases have four standard pulmonary veins. The middle right pulmonary vein is present in almost 20% of patients. Presented data can provide useful information for the clinicians during interventional procedures or radiologic examinations of PVs.

  4. Biomechanics of the Optic Nerve Sheath in VIIP Syndrome

    Science.gov (United States)

    Ethier, C. Ross; Raykin, Julia; Gleason, Rudy; Mulugeta, Lealem; Myers, Jerry; Nelson, Emily; Samuels, Brian C.

    2014-01-01

    Long-duration space flight carries the risk of developing Visual Impairment and Intracranial Pressure (VIIP) syndrome, a spectrum of ophthalmic changes including posterior globe flattening, choroidal folds, distension of the optic nerve sheath (ONS), optic nerve kinking and potentially permanent degradation of visual function. The slow onset of VIIP, its chronic nature, and certain clinical features strongly suggest that biomechanical factors acting on the ONS play a role in VIIP. Here we measure several relevant ONS properties needed to model VIIP biomechanics. The ONS (meninges) of fresh porcine eyes (n7) was reflected, the nerve proper was truncated near the sclera, and the meninges were repositioned to create a hollow cylinder of meningeal connective tissue attached to the posterior sclera. The distal end was cannulated, sealed, and pressure clamped (mimicking cerebrospinal fluid [CSF] pressure), while the eye was also cannulated for independent control of intraocular pressure (IOP). The meninges were inflated (CSF pressure cycling 7-50 mmHg) while ONS outer diameter was imaged. In another set of experiments (n4), fluid permeation rate across the meninges was recorded by observing the drainage of an elevated fluid reservoir (30 mmHg) connected to the meninges. The ONS showed behavior typical of soft tissues: viscoelasticity, with hysteresis in early preconditioning cycles and repeatable behavior after 4 cycles, and nonlinear stiffening, particularly at CSF pressures 15 mmHg (Figure). Tangent moduli measured from the loading curve were 372 101, 1199 358, and 2050 379 kPa (mean SEM) at CSF pressures of 7, 15 and 30 mmHg, respectively. Flow rate measurements through the intact meninges at 30mmHg gave a permeability of 1.34 0.46 lmincm2mmHg (mean SEM). The ONS is a tough, strain-stiffening connective tissue that is surprisingly permeable. The latter observation suggests that there could be significant CSF drainage through the ONS into the orbit, likely important

  5. THE CENTER FOR MILITARY BIOMECHANICS RESEARCH

    Data.gov (United States)

    Federal Laboratory Consortium — The Center for Military Biomechanics Research is a 7,500 ft2 dedicated laboratory outfitted with state-of-the-art equipment for 3-D analysis of movement, measurement...

  6. Recent software developments for biomechanical assessment

    Science.gov (United States)

    Greaves, John O. B.

    1990-08-01

    While much of the software developed in research laboratories is narrow in focus and suited for a specific experiment, some of it is broad enough and of high enough quality to be useful to others in solving similar problems. Several biomechanical assessment packages are now beginning to emerge, including: * 3D research biomechanics (5- and 6-DOF) with kinematics, kinetics, 32-channel analog data subsystem, and project management. * 3D full-body gait analysis with kinematics, kinetics, EMG charts, and force plate charts. * 2D dynamic rear-foot assessment. * 2D occupational biomechanics lifting task and personnel assessments. * 2D dynamic gait analysis. * Multiple 2D dynamic spine assessments. * 2D sport and biomechanics assessments with kinematics and kinetics. * 2D and 3D equine gait assessments.

  7. Biomechanical aspects of bone microstructure in vertebrates ...

    Indian Academy of Sciences (India)

    Prakash

    2009-10-29

    Oct 29, 2009 ... Biomechanical or biophysical principles can be applied to study biological structures in their modern or .... Accounting for the flow in a horizontal pipe, z1 = z2, and ..... OH, USA for providing financial assistance and academic.

  8. Lingual biomechanics, case selection and success

    Directory of Open Access Journals (Sweden)

    Sanjay Labh

    2016-01-01

    Full Text Available Deeper understanding of lingual biomechanics is prerequisite for success with lingual appliance. The difference between labial and lingual force system must be understood and kept in mind during treatment planning, especially anchorage planning, and extraction decision-making. As point of application of force changes, it completely changes the force system in all planes. This article describes lingual biomechanics, anchorage planning, diagnostic considerations, treatment planning, and case selection criteria in lingual orthodontics.

  9. Biomechanical analysis of clavicle hook plate implantation with different hook angles in the acromioclavicular joint.

    Science.gov (United States)

    Hung, Li-Kun; Su, Kuo-Chih; Lu, Wen-Hsien; Lee, Cheng-Hung

    2017-08-01

    A clavicle hook plate is a simple and effective method for treating acromioclavicular dislocation and distal clavicle fractures. However, subacromial osteolysis and peri-implant fractures are complicated for surgeons to manage. This study uses finite element analysis (FEA) to investigate the post-implantation biomechanics of clavicle hook plates with different hook angles. This FEA study constructed a model with a clavicle, acromion, clavicle hook plate, and screws to simulate the implantation of clavicle hook plates at different hook angles (90°, 95°, 100°, 105°, and 110°) for treating acromioclavicular joint dislocations. This study investigated the biomechanics of the acromion, clavicle, hook plate, and screws. A smaller hook angle increases the stress on the middle third of the clavicle. A larger hook angle increases the force exerted by the clavicle hook plate on the acromion. The screw at the most medial position on the plate generated the highest stress. The highest stress on the implanted clavicle hook plate was on the turning corner of the hook. A clavicle hook plate with different hook angles may induce different biomechanical behaviors in the clavicle and acromion. Orthopedic surgeons must select a suitable clavicle hook plate based on the anatomical structure of each patient.

  10. Brillouin microscopy: assessing ocular tissue biomechanics.

    Science.gov (United States)

    Yun, Seok Hyun; Chernyak, Dimitri

    2018-07-01

    Assessment of corneal biomechanics has been an unmet clinical need in ophthalmology for many years. Many researchers and clinicians have identified corneal biomechanics as source of variability in refractive procedures and one of the main factors in keratoconus. However, it has been difficult to accurately characterize corneal biomechanics in patients. The recent development of Brillouin light scattering microscopy heightens the promise of bringing biomechanics into the clinic. The aim of this review is to overview the progress and discuss prospective applications of this new technology. Brillouin microscopy uses a low-power near-infrared laser beam to determine longitudinal modulus or mechanical compressibility of tissue by analyzing the return signal spectrum. Human clinical studies have demonstrated significant difference in the elastic properties of normal corneas versus corneas diagnosed with mild and severe keratoconus. Clinical data have also shown biomechanical changes after corneal cross-linking treatment of keratoconus patients. Brillouin measurements of the crystalline lens and sclera have also been demonstrated. Brillouin microscopy is a promising technology under commercial development at present. The technique enables physicians to characterize the biomechanical properties of ocular tissues.

  11. Biomechanical and morphological properties of the multiparous ovine vagina and effect of subsequent pregnancy.

    Science.gov (United States)

    Rynkevic, Rita; Martins, Pedro; Hympanova, Lucie; Almeida, Henrique; Fernandes, Antonio A; Deprest, Jan

    2017-05-24

    Pelvic floor soft tissues undergo changes during the pregnancy. However, the degree and nature of this process is not completely characterized. This study investigates the effect of subsequent pregnancy on biomechanical and structural properties of ovine vagina. Vaginal wall from virgin, pregnant (in their third pregnancy) and parous (one year after third vaginal delivery) Swifter sheep (n=5 each) was harvested. Samples for biomechanics and histology, were cut in longitudinal axis (proximal and distal regions). Outcome measurements describing Young's modulus, ultimate stress and elongation were obtained from stress-strain curves. For histology samples were stained with Miller's Elastica staining. Collagen, elastin and muscle cells and myofibroblasts contents were estimated, using image processing techniques. Statistical analyses were performed in order to determine significant differences among experimental groups. Significant regional differences were identified. The proximal vagina was stiffer than distal, irrespective the reproductive status. During the pregnancy proximal vagina become more compliant than in parous (+47.45%) or virgin sheep (+64.35%). This coincided with lower collagen (-15 to -21%), higher elastin (+30 to +60%), and more smooth muscle cells (+17 to +37%). Vaginal tissue from parous ewes was weaker than of virgins, coinciding with lower collagen (-10%), higher elastin (+50%), more smooth muscle cells (+20%). It could be proposed that after pregnancy biomechanical properties of vagina do not recover to those of virgins. Since elastin has a significant influence on the compliance of soft tissues and collagen is the main "actor" regarding strength, histological analysis performed in this study justifies the mechanical behavior observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. ANATOMIC AND PHYSIOLOGICAL FEATURES OF DISTAL LOWER LEG AND THEIR INFLUENCE ON THE PROCESS OF OSTEOGENESIS

    Directory of Open Access Journals (Sweden)

    Desimir Mladenović

    2010-06-01

    Full Text Available Osteogenesis is the process of bone tissue forming, i.e. bone or callus regeneration. This process is influenced by many factors, and the degree of bone fragments’ stability and vascularization in the fracture area are the basic local factors which determine the nature of reparative process. Regenerative process of all bone structures increases with increasing of blood supply.The distal lower leg has its specific biomechanical features, and plays an important role in the transfer of body weight to foot. The distal part of tibia has a small diameter, which as a consequence has reduced diameter in medullar cave. Through this anatomic feature, the medullar network in the lower tibia part is also reduced.As for anatomic aspect, vascularization in the lower end of tibia is poor. It primarily depends on periosteal vascularization, because medullar vascularization is reduced. Fasciae, tendons and skin cover the lower part of the leg, and there is no muscle mass. These tissues have poor vascular network and that is why the extraosseous blood circulation in tibia is poor, and does not participate in the osteogenesis process. For these reasons, distal lower leg represents a predelection site for delayed osteogenesis and pseudoarthrosys development.Osteosynthesis causes secondary damage to bone and soft tissue circulation. The screw plate damages the periosteal circulation – in the lower part of tibia it is the main source of vascularization, and for this reason, this method of osteosynthesis should not be applied. The external fixator has a sparing role regarding vascularization, and that is the reason why this method is recommended for fracture stabilization at the level of distal lower leg.

  13. A nondestructive, reproducible method of measuring joint reaction force at the distal radioulnar joint.

    Science.gov (United States)

    Canham, Colin D; Schreck, Michael J; Maqsoodi, Noorullah; Doolittle, Madison; Olles, Mark; Elfar, John C

    2015-06-01

    To develop a nondestructive method of measuring distal radioulnar joint (DRUJ) joint reaction force (JRF) that preserves all periarticular soft tissues and more accurately reflects in vivo conditions. Eight fresh-frozen human cadaveric limbs were obtained. A threaded Steinmann pin was placed in the middle of the lateral side of the distal radius transverse to the DRUJ. A second pin was placed into the middle of the medial side of the distal ulna colinear to the distal radial pin. Specimens were mounted onto a tensile testing machine using a custom fixture. A uniaxial distracting force was applied across the DRUJ while force and displacement were simultaneously measured. Force-displacement curves were generated and a best-fit polynomial was solved to determine JRF. All force-displacement curves demonstrated an initial high slope where relatively large forces were required to distract the joint. This ended with an inflection point followed by a linear area with a low slope, where small increases in force generated larger amounts of distraction. Each sample was measured 3 times and there was high reproducibility between repeated measurements. The average baseline DRUJ JRF was 7.5 N (n = 8). This study describes a reproducible method of measuring DRUJ reaction forces that preserves all periarticular stabilizing structures. This technique of JRF measurement may also be suited for applications in the small joints of the wrist and hand. Changes in JRF can alter native joint mechanics and lead to pathology. Reliable methods of measuring these forces are important for determining how pathology and surgical interventions affect joint biomechanics. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  14. Biomechanics of far cortical locking.

    Science.gov (United States)

    Bottlang, Michael; Feist, Florian

    2011-02-01

    The development of far cortical locking (FCL) was motivated by a conundrum: locked plating constructs provide inherently rigid stabilization, yet they should facilitate biologic fixation and secondary bone healing that relies on flexible fixation to stimulate callus formation. Recent studies have confirmed that the high stiffness of standard locked plating constructs can suppress interfragmentary motion to a level that is insufficient to reliably promote secondary fracture healing by callus formation. Furthermore, rigid locking screws cause an uneven stress distribution that may lead to stress fracture at the end screw and stress shielding under the plate. This review summarizes four key features of FCL constructs that have been shown to enhance fixation and healing of fractures: flexible fixation, load distribution, progressive stiffening, and parallel interfragmentary motion. Specifically, flexible fixation provided by FCL reduces the stiffness of a locked plating construct by 80% to 88% to actively promote callus proliferation similar to an external fixator. Load is evenly distributed between FCL screws to mitigate stress risers at the end screw. Progressive stiffening occurs by near cortex support of FCL screws and provides additional support under elevated loading. Finally, parallel interfragmentary motion by the S-shaped flexion of FCL screws promotes symmetric callus formation. In combination, these features of FCL constructs have been shown to induce more callus and to yield significantly stronger and more consistent healing compared with standard locked plating constructs. As such, FCL constructs function as true internal fixators by replicating the biomechanical behavior and biologic healing response of external fixators.

  15. Biomechanical analysis of the effect of occlusal force on osteosynthesis following sagittal split ramus osteotomy

    International Nuclear Information System (INIS)

    Okuda, Katsuya; Nakajima, Masahiro; Kakudo, Kenji

    2009-01-01

    Relapse is sometimes observed during the postoperative course following sagittal split ramus osteotomy which is widely used to correct jaw deformities. Relapse may be caused by biomechanical factors such as the postoperative occlusal force. We evaluated serial changes in the stress distribution associated with postoperative occlusal force and jaw-closing pressure on the mandible and osteosynthesis plate using three-dimensional finite element analysis. Based on CT data, we produced mandibular models 1, 3, 6, and 12 months after sagittal split ramus osteotomy, and subjected them to simulated occlusal force and jaw-closing pressure. Changes in equivalent stress in the proximal and distal segments, at the osteosynthesis site, and the fixation plate were evaluated by three-dimensional finite element analysis. The equivalent stresses in the proximal and distal segments slightly increased over time from 1 to 12 months after the operation. In particular, marked stress concentration was observed at the anterior border of the ramus at each measurement area. Stress at the osteosynthesis site increased from 1 to 6 months after the operation, but decreased after 12 months. As a result of postoperative occlusal forces and jaw-closing pressure, stress was concentrated at the anterior border of the ramus in the proximal segment. Between 3 and 6 months after the operation, tensile stress was concentrated at the upper and lower ends of the osteotomy line at the osteosynthesis site. These biomechanical findings indicate the application of clockwise stress on the distal segment up to 6 months after the operation. We concluded that sagittal split ramus osteotomy runs the risk of relapse between 3 and 6 months after the operation. (author)

  16. Fractures of the distal phalanx and associated soft tissue and osseous abnormalities in 22 horses with ossified sclerotic ungual cartilages diagnosed with magnetic resonance imaging.

    Science.gov (United States)

    Selberg, Kurt; Werpy, Natasha

    2011-01-01

    Ungual cartilage ossification in the forelimb is a common finding in horses. Subtle abnormalities associated with the ungual cartilages can be difficult to identify on radiographs. Magnetic resonance (MR) imaging findings of 22 horses (23 forelimbs) with a fracture of the distal phalanx and ossified ungual cartilage were characterized and graded. All horses had a forelimb fracture. Eleven involved a left forelimb (seven medial; four lateral), and 12 involved a right forelimb (five medial; seven lateral). All fractures were nonarticular, simple in configuration, and nondisplaced. The fractures were oriented in an axial proximal to abaxial distal and palmar to dorsal direction, and extended from the base of the ossified ungual cartilage into the distal phalanx. The fracture involved the fossa of the collateral ligament on the distal phalanx in 17 of 23 limbs. The palmar process and ossified ungual cartilage was abnormally mineralized in all horses. Ligaments and soft tissues adjacent to the ossified ungual cartilages were affected in all horses. The routine site of fracture in this study at the base of the ossified ungual cartilage extending into the distal phalanx suggests a biomechanical cause or focal stress point from cycling. The ligamentous structures associated with the ungual cartilages were often affected, showed altered signal intensity as well as enlargement and were thought to be contributing to the lameness. In conclusion, ossified ungual cartilages may lead to fracture of the palmar process of the distal phalanx and injury of the ungual cartilage ligaments. © 2011 Veterinary Radiology & Ultrasound.

  17. Biomechanics of the classic metaphyseal lesion: finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Andy; Kleinman, Paul K. [Boston Children' s Hospital, Department of Radiology, Harvard Medical School, Boston, MA (United States); Coats, Brittany [University of Utah, Department of Mechanical Engineering, Salt Lake City, UT (United States)

    2017-11-15

    The classic metaphyseal lesion (CML) is strongly associated with infant abuse, but the biomechanics responsible for this injury have not been rigorously studied. Radiologic and CT-pathological correlates show that the distal tibial CML always involves the cortex near the subperiosteal bone collar, with variable extension of the fracture into the medullary cavity. Therefore, it is reasonable to assume that the primary site of bone failure is cortical, rather than intramedullary. This study focuses on the strain patterns generated from finite element modeling to identify loading scenarios and regions of the cortex that are susceptible to bone failure. A geometric model was constructed from a normal 3-month-old infant's distal tibia and fibula. The model's boundary conditions were set to mimic forceful manipulation of the ankle with eight load modalities (tension, compression, internal rotation, external rotation, dorsiflexion, plantar flexion, valgus bending and varus bending). For all modalities except internal and external rotation, simulations showed increased cortical strains near the subperiosteal bone collar. Tension generated the largest magnitude of cortical strain (24%) that was uniformly distributed near the subperiosteal bone collar. Compression generated the same distribution of strain but to a lesser magnitude overall (15%). Dorsiflexion and plantar flexion generated high (22%) and moderate (14%) localized cortical strains, respectively, near the subperiosteal bone collar. Lower cortical strains resulted from valgus bending, varus bending, internal rotation and external rotation (8-10%). The highest valgus and varus bending cortical strains occurred medially. These simulations suggest that the likelihood of the initial cortical bone failure of the CML is higher along the margin of the subperiosteal bone collar when the ankle is under tension, compression, valgus bending, varus bending, dorsiflexion and plantar flexion, but not under internal

  18. Biomechanics of the classic metaphyseal lesion: finite element analysis

    International Nuclear Information System (INIS)

    Tsai, Andy; Kleinman, Paul K.; Coats, Brittany

    2017-01-01

    The classic metaphyseal lesion (CML) is strongly associated with infant abuse, but the biomechanics responsible for this injury have not been rigorously studied. Radiologic and CT-pathological correlates show that the distal tibial CML always involves the cortex near the subperiosteal bone collar, with variable extension of the fracture into the medullary cavity. Therefore, it is reasonable to assume that the primary site of bone failure is cortical, rather than intramedullary. This study focuses on the strain patterns generated from finite element modeling to identify loading scenarios and regions of the cortex that are susceptible to bone failure. A geometric model was constructed from a normal 3-month-old infant's distal tibia and fibula. The model's boundary conditions were set to mimic forceful manipulation of the ankle with eight load modalities (tension, compression, internal rotation, external rotation, dorsiflexion, plantar flexion, valgus bending and varus bending). For all modalities except internal and external rotation, simulations showed increased cortical strains near the subperiosteal bone collar. Tension generated the largest magnitude of cortical strain (24%) that was uniformly distributed near the subperiosteal bone collar. Compression generated the same distribution of strain but to a lesser magnitude overall (15%). Dorsiflexion and plantar flexion generated high (22%) and moderate (14%) localized cortical strains, respectively, near the subperiosteal bone collar. Lower cortical strains resulted from valgus bending, varus bending, internal rotation and external rotation (8-10%). The highest valgus and varus bending cortical strains occurred medially. These simulations suggest that the likelihood of the initial cortical bone failure of the CML is higher along the margin of the subperiosteal bone collar when the ankle is under tension, compression, valgus bending, varus bending, dorsiflexion and plantar flexion, but not under internal

  19. Distal splenorenal shunt with partial spleen resection

    Directory of Open Access Journals (Sweden)

    Gajin Predrag

    2007-01-01

    Full Text Available Introduction: Hypersplenism is a common complication of portal hypertension. Cytopenia in hypersplenism is predominantly caused by splenomegaly. Distal splenorenal shunt (Warren with partial spleen resection is an original surgical technique that regulates cytopenia by reduction of the enlarged spleen. Objective. The aim of our study was to present the advantages of distal splenorenal shunt (Warren with partial spleen resection comparing morbidity and mortality in a group of patients treated by distal splenorenal shunt with partial spleen resection with a group of patients treated only by a distal splenorenal shunt. Method. From 1995 to 2003, 41 patients with portal hypertension were surgically treated due to hypersplenism and oesophageal varices. The first group consisted of 20 patients (11 male, mean age 42.3 years who were treated by distal splenorenal shunt with partial spleen resection. The second group consisted of 21 patients (13 male, mean age 49.4 years that were treated by distal splenorenal shunt only. All patients underwent endoscopy and assessment of oesophageal varices. The size of the spleen was evaluated by ultrasound, CT or by scintigraphy. Angiography was performed in all patients. The platelet and white blood cell count and haemoglobin level were registered. Postoperatively, we noted blood transfusion, complications and total hospital stay. Follow-up period was 12 months, with first checkup after one month. Results In the first group, only one patient had splenomegaly postoperatively (5%, while in the second group there were 13 patients with splenomegaly (68%. Before surgery, the mean platelet count in the first group was 51.6±18.3x109/l, to 118.6±25.4x109/l postoperatively. The mean platelet count in the second group was 67.6±22.8x109/l, to 87.8±32.1x109/l postoperatively. Concerning postoperative splenomegaly, statistically significant difference was noted between the first and the second group (p<0.05. Comparing the

  20. Contemporary Management of Primary Distal Urethral Cancer.

    Science.gov (United States)

    Traboulsi, Samer L; Witjes, Johannes Alfred; Kassouf, Wassim

    2016-11-01

    Primary urethral cancer is one of the rare urologic tumors. Distal urethral tumors are usually less advanced at diagnosis compared with proximal tumors and have a good prognosis if treated appropriately. Low-stage distal tumors can be managed successfully with a surgical approach in men or radiation therapy in women. There are no clear-cut indications for the choice of the most appropriate treatment modality. Organ-preserving modalities have shown effective and should be used whenever they do not compromise the oncological safety to decrease the physical and psychological trauma of dismemberment or loss of sexual/urinary function. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Spontaneous distal rupture of the plantar fascia.

    Science.gov (United States)

    Gitto, Salvatore; Draghi, Ferdinando

    2018-07-01

    Spontaneous ruptures of the plantar fascia are uncommon injuries. They typically occur at its calcaneal insertion and usually represent a complication of plantar fasciitis and local treatment with steroid injections. In contrast, distal ruptures commonly result from traumatic injuries. We describe the case of a spontaneous distal rupture of the plantar fascia in a 48-year-old woman with a low level of physical activity and no history of direct injury to the foot, plantar fasciitis, or steroid injections. © 2017 Wiley Periodicals, Inc.

  2. Torsion of wandering spleen and distal pancreas

    International Nuclear Information System (INIS)

    Sheflin, J.R.; Lee, C.M.; Kretchmar, K.A.

    1984-01-01

    Wandering spleen is the term applied to the condition in which a long pedicle allows the spleen to lie in an abnormal location. Torsion of a wandering spleen is an unusual cause of an acute abdomen and is rarely diagnosed preoperatively. Associated torsion of the distal pancreas is even more uncommon. The authors describe a patient with torsion of a wandering spleen and distal pancreas, who was correctly diagnosed, and define the merits of the imaging methods used. The initial examination should be 99 /sup m/Tc-sulfur colloid liner-spleen scanning

  3. Role of Aquaporin 0 in lens biomechanics

    International Nuclear Information System (INIS)

    Sindhu Kumari, S.; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G.; Menon, Anil G.; Mathias, Richard T.; Varadaraj, Kulandaiappan

    2015-01-01

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5 −/− ), AQP0 KO (heterozygous KO: AQP0 +/− ; homozygous KO: AQP0 −/− ; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0 +/− lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to

  4. Biomechanics and mechanobiology in functional tissue engineering

    Science.gov (United States)

    Guilak, Farshid; Butler, David L.; Goldstein, Steven A.; Baaijens, Frank P.T.

    2014-01-01

    The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical function. Furthermore, it is now clear that mechanobiological interactions between cells and scaffolds can critically influence cell behavior, even in tissues and organs that do not serve an overt biomechanical role. Over the past decade, the field of “functional tissue engineering” has grown as a subfield of tissue engineering to address the challenges and questions on the role of biomechanics and mechanobiology in tissue engineering. Originally posed as a set of principles and guidelines for engineering of load-bearing tissues, functional tissue engineering has grown to encompass several related areas that have proven to have important implications for tissue repair and regeneration. These topics include measurement and modeling of the in vivo biomechanical environment; quantitative analysis of the mechanical properties of native tissues, scaffolds, and repair tissues; development of rationale criteria for the design and assessment of engineered tissues; investigation of the effects biomechanical factors on native and repair tissues, in vivo and in vitro; and development and application of computational models of tissue growth and remodeling. Here we further expand this paradigm and provide examples of the numerous advances in the field over the past decade. Consideration of these principles in the design process will hopefully improve the safety, efficacy, and overall success of engineered tissue replacements. PMID:24818797

  5. Computational biomechanics for medicine from algorithms to models and applications

    CERN Document Server

    Joldes, Grand; Nielsen, Poul; Doyle, Barry; Miller, Karol

    2017-01-01

    This volume comprises the latest developments in both fundamental science and patient-specific applications, discussing topics such as: cellular mechanics; injury biomechanics; biomechanics of heart and vascular system; medical image analysis; and both patient-specific fluid dynamics and solid mechanics simulations. With contributions from researchers world-wide, the Computational Biomechanics for Medicine series of titles provides an opportunity for specialists in computational biomechanics to present their latest methodologies and advancements.

  6. 4th International Plant Biomechanics Conference Proceedings (Abstracts)

    Energy Technology Data Exchange (ETDEWEB)

    Frank W. Telewski; Lothar H. Koehler; Frank W. Ewers

    2003-07-20

    The 4th International Plant Biomechanics Conference facilitated an interdisciplinary exchange between scientists, engineers, and educators addressing the major questions encountered in the field of Plant Biomechanics. Subjects covered by the conference include: Evolution; Ecology; Mechanoreception; Cell Walls; Genetic Modification; Applied Biomechanics of Whole Plants, Plant Products, Fibers & Composites; Fluid Dynamics; Wood & Trees; Fracture Mechanics; Xylem Pressure & Water Transport; Modeling; and Introducing Plant Biomechanics in Secondary School Education.

  7. Endovascular treatment of ruptured distal posterior inferior ...

    African Journals Online (AJOL)

    2014-03-01

    Mar 1, 2014 ... there are lots of reports regarding the interventional therapy of the artery aneurysms (including proximal and distal), all of which are considered to be safe and effective. All the incidences of interventional-related complications are below 10% and there is no report of injury of lower cranial nerves [11, 12].

  8. Urethral mobilization and advancement for distal hypospadias ...

    African Journals Online (AJOL)

    Background/purpose Despite the existence of numerous techniques for the repair of distal penile hypospadias, none of them is completely satisfactory. Advancing the urethra without mobilization for repair of glanular hypospadias has the advantage of avoiding a common problem occurring with other techniques: ...

  9. Sixth Computational Biomechanics for Medicine Workshop

    CERN Document Server

    Nielsen, Poul MF; Miller, Karol; Computational Biomechanics for Medicine : Deformation and Flow

    2012-01-01

    One of the greatest challenges for mechanical engineers is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, biomedical sciences, and medicine. This book is an opportunity for computational biomechanics specialists to present and exchange opinions on the opportunities of applying their techniques to computer-integrated medicine. Computational Biomechanics for Medicine: Deformation and Flow collects the papers from the Sixth Computational Biomechanics for Medicine Workshop held in Toronto in conjunction with the Medical Image Computing and Computer Assisted Intervention conference. The topics covered include: medical image analysis, image-guided surgery, surgical simulation, surgical intervention planning, disease prognosis and diagnostics, injury mechanism analysis, implant and prostheses design, and medical robotics.

  10. Multiscale modeling in biomechanics and mechanobiology

    CERN Document Server

    Hwang, Wonmuk; Kuhl, Ellen

    2015-01-01

    Presenting a state-of-the-art overview of theoretical and computational models that link characteristic biomechanical phenomena, this book provides guidelines and examples for creating multiscale models in representative systems and organisms. It develops the reader's understanding of and intuition for multiscale phenomena in biomechanics and mechanobiology, and introduces a mathematical framework and computational techniques paramount to creating predictive multiscale models.   Biomechanics involves the study of the interactions of physical forces with biological systems at all scales – including molecular, cellular, tissue and organ scales. The emerging field of mechanobiology focuses on the way that cells produce and respond to mechanical forces – bridging the science of mechanics with the disciplines of genetics and molecular biology. Linking disparate spatial and temporal scales using computational techniques is emerging as a key concept in investigating some of the complex problems underlying these...

  11. Influence of Physical Exercise and Food Restriction on the Biomechanical Properties of the Femur of Ageing Male Rats

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Skalicky, Monika; Viidik, Andrus

    2008-01-01

    BACKGROUND: Voluntary running in wheels as well as food reduction increase the life spans of rats. Disparate parameters such as the collagen biomarker of ageing and the development of kidney pathologies are decreased by voluntary exercise. There are few reports on the influence of physical exercise...... were used: baseline (BL), voluntarily running in wheels (RW), food restriction to attain pair weight with RW animals (PW), forced running in treadmills (TM), and sedentary controls (SE). The biomechanical properties of femoral neck, diaphysis, and distal metaphysis were measured. RESULTS: While...

  12. Role of Aquaporin 0 in lens biomechanics.

    Science.gov (United States)

    Sindhu Kumari, S; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G; Menon, Anil G; Mathias, Richard T; Varadaraj, Kulandaiappan

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5(-/-)), AQP0 KO (heterozygous KO: AQP0(+/-); homozygous KO: AQP0(-/-); all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0(+/-) lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to confer

  13. Tennis elbow: a biomechanical and therapeutic approach.

    Science.gov (United States)

    Schnatz, P; Steiner, C

    1993-07-01

    Lateral epicondylitis, one of the most common lesions of the arm, affects some 50% of tennis players. This condition poses a problem in clinical management because treatment is dependent not only on proper medical therapy but also on correction of the improper on-court biomechanics. The most common flaw is a late contact on the backhand groundstroke, forcing the player to extend the wrist with the extensor muscles. This action predisposes to trauma of the tendon fibers at the lateral epicondyle. Understanding the biomechanics will better prepare the physician to advise the patient and to communicate with a tennis teaching professional to facilitate long-term relief.

  14. Mechanism of distal radius fracture as analyzed by 3D finite element model

    International Nuclear Information System (INIS)

    Tomizawa, Kazuo

    2007-01-01

    The purpose of this study is to see the difference of distal radius fracture between normal and osteoporotic bones and in its patterns due to limb position at injury through simulation and analysis of the biomechanics using three-dimensional (3D) finite element model. CT images were taken with SIEMENS machine, of right wrist joints of 32 and 76 years old, normal healthy man and osteoporotic woman, respectively. The wrist joint angles at CT were 70 degrees both at dorsiflexion and at palmerflexion for simulating fracture at tumbling down. The 3D bone model reconstructed from CT images with Forge software (Studio PON) was trimmed to remain the distal radial-ulnar portion and proximal carpal bones to make simulation easer, and the simplified 3D model was divided to 56,622 elements and 13,274 nodal points (normal bone) or 51,760 and 12,940 (osteoporosis), respectively, in 3 areas of different bone densities calculated with Scion Image processor. This 3D finite element model was analyzed with the software ANSYS LS-DYNA 10.0 for simulating the fracture (the defined yield stress attained) by impacting the elements of carpal bones to the radial bone joint surface with a measure of Mises stress. In osteoporotic bone, fracture was found to occur at dorsal cortex closer to the joint surface. Fracture occurred at dorsal and palmer cortex at dorsiflexion and palmerflexion, respectively. (R.T.)

  15. Examination of Skill Acquisition and Grader Bias in a Distal Radius Fracture Fixation Model.

    Science.gov (United States)

    Putnam, Matthew D; Adams, Julie E; Lender, Paul; Van Heest, Ann E; Shanedling, Janet R; Nuckley, David J; Bechtold, Joan E

    2018-03-01

    Primary: Assess the ability of faculty graders to predict the objectively measured strength of distal radius fracture fixation. Secondary: Compare resident skill variation and retention related to other knowable training data. Residents were allowed 60 minutes to stabilize a standardized distal radius fracture using an assigned fixed-angle volar plate. Faculty observed and subjectively graded the residents without providing real-time feedback. Objective biomechanical evaluation (construct strength and stiffness) was compared to subjective grades. Resident-specific characteristics (sex, PGY, and ACGME case log) were also used to compare the objective data. A simulated operating room in our laboratory. Post-graduate year 2, 3, 4, and 5 orthopedic residents. Primary: Faculty were not successful at predicting objectively measured fixation, and their subjective scoring suggests confirmation bias as PGY increased. Secondary: Resident year-in-training alone did not predict objective measures (p = 0.53), but was predictive of subjective scores (p external faculty unfamiliar with tested residents, might alter these results. Copyright © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  16. Biomechanics of Pediatric Manual Wheelchair Mobility.

    Science.gov (United States)

    Slavens, Brooke A; Schnorenberg, Alyssa J; Aurit, Christine M; Tarima, Sergey; Vogel, Lawrence C; Harris, Gerald F

    2015-01-01

    Currently, there is limited research of the biomechanics of pediatric manual wheelchair mobility. Specifically, the biomechanics of functional tasks and their relationship to joint pain and health is not well understood. To contribute to this knowledge gap, a quantitative rehabilitation approach was applied for characterizing upper extremity biomechanics of manual wheelchair mobility in children and adolescents during propulsion, starting, and stopping tasks. A Vicon motion analysis system captured movement, while a SmartWheel simultaneously collected three-dimensional forces and moments occurring at the handrim. A custom pediatric inverse dynamics model was used to evaluate three-dimensional upper extremity joint motions, forces, and moments of 14 children with spinal cord injury (SCI) during the functional tasks. Additionally, pain and health-related quality of life outcomes were assessed. This research found that joint demands are significantly different amongst functional tasks, with greatest demands placed on the shoulder during the starting task. Propulsion was significantly different from starting and stopping at all joints. We identified multiple stroke patterns used by the children, some of which are not standard in adults. One subject reported average daily pain, which was minimal. Lower than normal physical health and higher than normal mental health was found in this population. It can be concluded that functional tasks should be considered in addition to propulsion for rehabilitation and SCI treatment planning. This research provides wheelchair users and clinicians with a comprehensive, biomechanical, mobility assessment approach for wheelchair prescription, training, and long-term care of children with SCI.

  17. Expose Mechanical Engineering Students to Biomechanics Topics

    Science.gov (United States)

    Shen, Hui

    2011-01-01

    To adapt the focus of engineering education to emerging new industries and technologies nationwide and in the local area, a biomechanics module has been developed and incorporated into a mechanical engineering technical elective course to expose mechanical engineering students at ONU (Ohio Northern University) to the biomedical engineering topics.…

  18. Neck muscle biomechanics and neural control.

    Science.gov (United States)

    Fice, Jason Bradley; Siegmund, Gunter P; Blouin, Jean-Sebastien

    2018-04-18

    The mechanics, morphometry, and geometry of our joints, segments and muscles are fundamental biomechanical properties intrinsic to human neural control. The goal of our study was to investigate if the biomechanical actions of individual neck muscles predicts their neural control. Specifically, we compared the moment direction & variability produced by electrical stimulation of a neck muscle (biomechanics) to their preferred activation direction & variability (neural control). Subjects sat upright with their head fixed to a 6-axis load cell and their torso restrained. Indwelling wire electrodes were placed into the sternocleidomastoid (SCM), splenius capitis (SPL), and semispinalis capitis (SSC) muscles. The electrically stimulated direction was defined as the moment direction produced when a current (2-19mA) was passed through each muscle's electrodes. Preferred activation direction was defined as the vector sum of the spatial tuning curve built from RMS EMG when subjects produced isometric moments at 7.5% and 15% of their maximum voluntary contraction (MVC) in 26 3D directions. The spatial tuning curves at 15% MVC were well-defined (unimodal, pbiomechanics but, as activation increases, biomechanical constraints in part dictate the activation of synergistic neck muscles.

  19. Biomechanics of the pelvic floor musculature

    NARCIS (Netherlands)

    Janda, S.

    2006-01-01

    The present thesis was motivated by two main goals. The first research goal of the thesis was to understand the complex biomechanical behaviour of the pelvic floor muscles. The second goal was to study the mechanism of the pelvic organ prolapse (genital prolapse). The pelvic floor in humans is a

  20. Biomechanical aspects of bone microstructure in vertebrates

    Indian Academy of Sciences (India)

    2009-10-29

    Oct 29, 2009 ... Biomechanical or biophysical principles can be applied to study biological structures in their modern or fossil form. Bone is an important tissue in paleontological studies as it is a commonly preserved element in most fossil vertebrates, and can often allow its microstructures such as lacuna and canaliculi to ...

  1. Biomechanical analysis of drop and countermovement jumps

    NARCIS (Netherlands)

    Bobbert, M. F.; Mackay, M.T.; Schinkelshoek, D.; Huijing, P. A.; van Ingen Schenau, G. J.

    For 13 subjects the performance of drop jumps from a height of 40 cm (DJ) and of countermovement jumps (CMJ) was analysed and compared. From force plate and cine data biomechanical variables including forces, moments, power output and amount of work done were calculated for hip, knee and ankle

  2. Biomechanics and mechanobiology in functional tissue engineering

    NARCIS (Netherlands)

    Guilak, F.; Butler, D.L.; Goldstein, S.A.; Baaijens, F.P.T.

    2014-01-01

    The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical

  3. Biomechanics Scholar Citations across Academic Ranks

    Directory of Open Access Journals (Sweden)

    Knudson Duane

    2015-11-01

    Full Text Available Study aim: citations to the publications of a scholar have been used as a measure of the quality or influence of their research record. A world-wide descriptive study of the citations to the publications of biomechanics scholars of various academic ranks was conducted.

  4. Interdisciplinary Vertical Integration: The Future of Biomechanics

    Science.gov (United States)

    Gregor, Robert J.

    2008-01-01

    The field of biomechanics has grown rapidly in the past 30 years in both size and complexity. As a result, the term might mean different things to different people. This article addresses the issues facing the field in the form of challenges biomechanists face in the future. Because the field is so diverse, strength within the different areas of…

  5. Biomechanical comparison of transoral and transbuccal lateral ...

    African Journals Online (AJOL)

    Objectives: The purpose of this experimental study was to compare the biomechanical behaviors of two different types of osteosynthesis that are used in the treatment of mandibular angle fractures. Materials and Methods: Twenty synthetic polyurethane human mandible replicas, with medullar and cortical portions, were ...

  6. The Value of Biomechanical Research in Dance.

    Science.gov (United States)

    Ranney, D. A.

    Simple observation of dance movement, while very useful, can lead to misconceptions, about the physical realities of dance movement, that make learning difficult. This gap between reality and understanding can be reduced by the application of biomechanical techniques such as cinematography, electromyography, and force-plate analysis. Biomechanical…

  7. Distal displacement of the maxilla and the upper first molar.

    Science.gov (United States)

    Baumrind, S; Molthen, R; West, E E; Miller, D M

    1979-06-01

    Data from a sample of 198 Class II cases treated with various appliances which deliver distally directed forces to the maxilla were examined to determine the frequency of absolute distal displacement of the upper first molar and of the maxilla. Analysis revealed that such distal displacement is possible and that it is, in fact, a frequent finding following treatment. Long-range stability of distal displacement was not assessed.

  8. Distal radioulnar joint: functional anatomy, including pathomechanics.

    Science.gov (United States)

    Haugstvedt, J R; Langer, M F; Berger, R A

    2017-05-01

    The distal radioulnar joint allows the human to rotate the forearm to place the hand in a desired position to perform different tasks, without interfering with the grasping function of the hand. The ulna is the stable part of the forearm around which the radius rotates; the stability of the distal radioulnar joint is provided by the interaction between ligaments, muscles and bones. The stabilizing structures are the triangular fibrocartilage complex, the ulnocarpal ligament complex, the extensor carpi ulnaris tendon and tendon sheath, the pronator quadratus, the interosseous membrane and ligament, the bone itself and the joint capsule. The purpose of this review article is to present and illustrate the current understanding of the functional anatomy and pathomechanics of this joint.

  9. Distal radius plate of CFR-PEEK has minimal effect compared to titanium plates on bone parameters in high-resolution peripheral quantitative computed tomography: a pilot study.

    Science.gov (United States)

    de Jong, Joost J A; Lataster, Arno; van Rietbergen, Bert; Arts, Jacobus J; Geusens, Piet P; van den Bergh, Joop P W; Willems, Paul C

    2017-02-27

    Carbon-fiber-reinforced poly-ether-ether-ketone (CFR-PEEK) has superior radiolucency compared to other orthopedic implant materials, e.g. titanium or stainless steel, thus allowing metal-artifact-free postoperative monitoring by computed tomography (CT). Recently, high-resolution peripheral quantitative CT (HRpQCT) proved to be a promising technique to monitor the recovery of volumetric bone mineral density (vBMD), micro-architecture and biomechanical parameters in stable conservatively treated distal radius fractures. When using HRpQCT to monitor unstable distal radius fractures that require volar distal radius plating for fixation, radiolucent CFR-PEEK plates may be a better alternative to currently used titanium plates to allow for reliable assessment. In this pilot study, we assessed the effect of a volar distal radius plate made from CFR-PEEK on bone parameters obtained from HRpQCT in comparison to two titanium plates. Plates were instrumented in separate cadaveric human fore-arms (n = 3). After instrumentation and after removal of the plates duplicate HRpQCT scans were made of the region covered by the plate. HRpQCT images were visually checked for artifacts. vBMD, micro-architectural and biomechanical parameters were calculated, and compared between the uninstrumented and instrumented radii. No visible image artifacts were observed in the CFR-PEEK plate instrumented radius, and errors in bone parameters ranged from -3.2 to 2.6%. In the radii instrumented with the titanium plates, severe image artifacts were observed and errors in bone parameters ranged between -30.2 and 67.0%. We recommend using CFR-PEEK plates in longitudinal in vivo studies that monitor the healing process of unstable distal radius fractures treated operatively by plating or bone graft ingrowth.

  10. Distal Stressors and Depression among Homeless Men

    OpenAIRE

    Coohey, Carol; Easton, Scott D.

    2016-01-01

    Depression is a common problem among homeless men that may interfere with functional tasks, such as securing stable housing, obtaining employment, and accessing health services. Previous research on depression among homeless men has largely focused on current psychosocial resources, substance abuse, and past victimization. Guided by Ensel and Lin’s life course stress process model, the authors examined whether distal stressors, including victimization and exposure to parent problems in childh...

  11. Three Dimensional Finite Element Analysis of Distal Abutment Stresses of Removable Partial Dentures with Different Retainer Designs

    Directory of Open Access Journals (Sweden)

    Simindokht Zarrati

    2015-11-01

    Full Text Available Objectives: This finite element method study aimed to compare the amount of stress on an isolated mandibular second premolar in two conventional reciprocal parallel interface designs of removable partial dentures (RPDs and the same RPD abutment tooth (not isolated.Materials and Methods: A Kennedy Class 1, modification 1 RPD framework was simulated on a 3D model of mandible with three different designs: an isolated tooth with a mesial rest, an isolated tooth with mesial and distal rests and an abutment with a mesial rest (which was not isolated; 26 N occlusal forces were exerted bilaterally on the first molar sites. Stress on the abutment teeth was analyzed using Cosmos Works 2009 Software.Results: In all designs, the abutment tooth stress concentration was located in the buccal alveolar crest. In the first model, the von Mises stress distribution in the contact area of I-bar clasp and cervical portion of the tooth was 19 MPa and the maximum stress was 30 MPa. In the second model, the maximum von Mises stress distribution was 15 MPa in the cervical of the tooth. In the third model, the maximum von Mises stress was located in the cervical of the tooth and the distal proximal plate.Conclusion: We recommend using both mesial and distal rests on the distal abutment teeth of distal extension RPDs. The abutment of an extension base RPD, which is not isolated in presence of its neighboring more anterior tooth, may have a better biomechanical prognosis.      

  12. Fractures of the distal phalanx in the horse

    International Nuclear Information System (INIS)

    Yovich, J.V.

    1989-01-01

    Fractures of the distal phalanx are an important cause of lameness referable to the foot. Depending on the fracture configuration and articular involvement, conservative or surgical treatment may be required. Fractures of the distal phalanx have been divided into six categories based on fracture configuration. Discussion of clinical features, management, and prognosis for horses with distal phalangeal fractures is presented for each fracture type

  13. Nonunions of the distal tibia treated by reamed intramedullary nailing

    NARCIS (Netherlands)

    Richmond, Jeffrey; Colleran, Kevin; Borens, Olivier; Kloen, Peter; Helfet, David L.

    2004-01-01

    The purpose of this study is to determine the efficacy of reamed intramedullary nailing in the treatment of nonunions of the distal one-fourth of the tibia. Nonunions of the distal tibia are particularly difficult to treat given the short distal segment, the proximity to the ankle joint, and the

  14. Management and treatment of distal ulcerative colitis

    Directory of Open Access Journals (Sweden)

    Andrea Calafiore

    2013-12-01

    Full Text Available Ulcerative colitis (UC is a chronic inflammatory condition that is confined to the colonic mucosa. Its main symptoms include diarrhea, rectal bleeding and abdominal pain. Approximately two-thirds of UC patients have disease confined distal to the splenic flexure, which can be treated effectively with topical therapy. This means the active drug can be delivered directly to the site of inflammation, limiting the systemic absorption and potential side effects. Topical treatment with aminosalicylates is the most effective approach in the treatment of these forms, provided that the formulation reaches the upper margin of the disease. Given this, the suppository formulation is the treatment of choice for proctitis and distal sigmoiditis. Thanks to their proximal spread, enemas, foams and gels represent the treatment of choice for proctosigmoiditis and for distal ulcerative colitis. Oral aminosalicylates are less effective than topical therapies in patients with active disease, while the combination of topical and oral treatment is more effective in patients refractory to topical or oral mono-therapy. Topically administered aminosalicylates play an important role in the maintenance of remission, but the long-term adhesion to therapy is poor. For this reason, the oral formulation is the first-line therapy in the maintenance of remission. Refractory patients can be treated with topical steroids or systemic steroids and TNF-alpha inhibitors in severe forms.

  15. Distal Embolic Protection for Renal Arterial Interventions

    International Nuclear Information System (INIS)

    Dubel, Gregory J.; Murphy, Timothy P.

    2008-01-01

    Distal or embolic protection has intuitive appeal for its potential to prevent embolization of materials generated during interventional procedures. Distal protection devices (DPDs) have been most widely used in the coronary and carotid vascular beds, where they have demonstrated the ability to trap embolic materials and, in some cases, to reduce complications. Given the frequency of chronic kidney disease in patients with renal artery stenosis undergoing stent placement, it is reasonable to propose that these devices may play an important role in limiting distal embolization in the renal vasculature. Careful review of the literature reveals that atheroembolization does occur during renal arterial interventions, although it often goes undetected. Early experience with DPDs in the renal arteries in patients with suitable anatomy suggests retrieval of embolic materials in approximately 71% of cases and renal functional improvement/stabilization in 98% of cases. The combination of platelet inhibition and a DPD may provide even greater benefit. Given the critical importance of renal functional preservation, it follows that everything that can be done to prevent atheroembolism should be undertaken including the use of DPDs when anatomically feasible. The data available at this time support a beneficial role for these devices

  16. Maxillary molar distalization with the dual-force distalizer supported by mini-implants: a clinical study.

    Science.gov (United States)

    Oberti, Giovanni; Villegas, Carlos; Ealo, Martha; Palacio, John Camilo; Baccetti, Tiziano

    2009-03-01

    The objective of this prospective study was to describe the clinical effects of a bone-supported molar distalizing appliance, the dual-force distalizer. The study group included 16 patients (mean age, 14.3 years) with Class II molar relationships. Study models and lateral cephalograms were taken before and after the distalizing movement to record significant dental and skeletal changes (Wilcoxon test). The average distalization time was 5 months, with a movement rate of 1.2 mm per month; the distalization amounts were 5.9 +/- 1.72 mm at the crown level and 4.4 +/- 1.41 mm at the furcation level. The average molar inclination was 5.6 degrees +/- 3.7 degrees ; this was less than the amount of inclination generated by bone-supported appliances that use single distalizing forces. The correlation between inclination and distalization was not significant, indicating predominantly bodily movement. The teeth anterior to the first molar moved distally also; the second premolars distalized an average of 4.26 mm, and the incisors retruded by 0.53 mm. The dual-force distalizer is a valid alternative distalizing appliance that generates controlled molar distalization with a good rate of movement and no loss of anchorage.

  17. Robotic distal pancreatectomy versus conventional laparoscopic distal pancreatectomy: a comparative study for short-term outcomes.

    Science.gov (United States)

    Lai, Eric C H; Tang, Chung Ngai

    2015-09-01

    Robotic system has been increasingly used in pancreatectomy. However, the effectiveness of this method remains uncertain. This study compared the surgical outcomes between robot-assisted laparoscopic distal pancreatectomy and conventional laparoscopic distal pancreatectomy. During a 15-year period, 35 patients underwent minimally invasive approach of distal pancreatectomy in our center. Seventeen of these patients had robot-assisted laparoscopic approach, and the remaining 18 had conventional laparoscopic approach. Their operative parameters and perioperative outcomes were analyzed retrospectively in a prospective database. The mean operating time in the robotic group (221.4 min) was significantly longer than that in the laparoscopic group (173.6 min) (P = 0.026). Both robotic and conventional laparoscopic groups presented no significant difference in spleen-preservation rate (52.9% vs. 38.9%) (P = 0.505), operative blood loss (100.3 ml vs. 268.3 ml) (P = 0.29), overall morbidity rate (47.1% vs. 38.9%) (P = 0.73), and post-operative hospital stay (11.4 days vs. 14.2 days) (P = 0.46). Both groups also showed no perioperative mortality. Similar outcomes were observed in robotic distal pancreatectomy and conventional laparoscopic approach. However, robotic approach tended to have the advantages of less blood loss and shorter hospital stay. Further studies are necessary to determine the clinical position of robotic distal pancreatectomy.

  18. An innovative technique to distalize maxillary molar using microimplant supported rapid molar distalizer

    Directory of Open Access Journals (Sweden)

    Meenu Goel

    2013-01-01

    Full Text Available Introduction: In recent years, enhancements in implants have made their use possible as a mode of absolute anchorage in orthodontic patients. In this paper, the authors have introduced an innovative technique to unilaterally distalize the upper left 1 st molar to obtain an ideal Class I molar relationship from a Class II existing molar relationship with an indigenous designed distalizer. Clinical Innovation: For effective unilateral diatalization of molar, a novel cantilever sliding jig assembly was utilized with coil spring supported by a buccally placed single micro implant. The results showed 3 mm of bodily distalization with 1 mm of intrusion and 2° of distal tipping of upper left 1 st molar in 1.5 months. Discussion: This appliance is relatively easy to insert, well-tolerated, and requires minimal patient cooperation compared to other present techniques of molar distalization. Moreover, it is particularly useful in cases that are Class II on one side and Class I on the other, with a minor midline discrepancy and nominal overjet. Patient acceptance level was reported to be within patients physiological and comfort limits.

  19. Role of Aquaporin 0 in lens biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Sindhu Kumari, S.; Gupta, Neha [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Shiels, Alan [Washington University School of Medicine, St. Louis, MO (United States); FitzGerald, Paul G. [Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA (United States); Menon, Anil G. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Mathias, Richard T. [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States)

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5{sup −/−}), AQP0 KO (heterozygous KO: AQP0{sup +/−}; homozygous KO: AQP0{sup −/−}; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0{sup +/−} lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and

  20. [New anterolateral approach of distal femur for treatment of distal femoral fractures].

    Science.gov (United States)

    Zhang, Bin; Dai, Min; Zou, Fan; Luo, Song; Li, Binhua; Qiu, Ping; Nie, Tao

    2013-11-01

    To assess the effectiveness of the new anterolateral approach of the distal femur for the treatment of distal femoral fractures. Between July 2007 and December 2009, 58 patients with distal femoral fractures were treated by new anterolateral approach of the distal femur in 28 patients (new approach group) and by conventional approach in 30 patients (conventional approach group). There was no significant difference in gender, age, cause of injury, affected side, type of fracture, disease duration, complication, or preoperative intervention (P > 0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy frequency, hospitalization days, and Hospital for Special Surgery (HSS) score of knee were recorded. Operation was successfully completed in all patients of 2 groups, and healing of incision by first intention was obtained; no vascular and nerves injuries occurred. The operation time and intraoperative fluoroscopy frequency of new approach group were significantly less than those of conventional approach group (P 0.05). All patients were followed up 12-36 months (mean, 19.8 months). Bone union was shown on X-ray films; the fracture healing time was (12.62 +/- 2.34) weeks in the new approach group and was (13.78 +/- 1.94) weeks in the conventional approach group, showing no significant difference (t=2.78, P=0.10). The knee HSS score at last follow-up was 94.4 +/- 4.2 in the new approach group, and was 89.2 +/- 6.0 in the conventional approach group, showing significant difference between 2 groups (t=3.85, P=0.00). New anterolateral approach of the distal femur for distal femoral fractures has the advantages of exposure plenitude, minimal tissue trauma, and early function rehabilitation training so as to enhance the function recovery of knee joint.

  1. Distal protection filter device efficacy with carotid artery stenting: comparison between a distal protection filter and a distal protection balloon.

    Science.gov (United States)

    Iko, Minoru; Tsutsumi, Masanori; Aikawa, Hiroshi; Matsumoto, Yoshihisa; Go, Yoshinori; Nii, Kouhei; Abe, Gorou; Ye, Iwae; Nomoto, Yasuyuki; Kazekawa, Kiyoshi

    2013-01-01

    This retrospective study aimed to compare the effectiveness of the embolization prevention mechanism of two types of embolic protection device (EPD)-a distal protection balloon (DPB) and a distal protection filter (DPF). Subjects were 164 patients scheduled to undergo carotid artery stenting: a DPB was used in 82 cases (DPB group) from April 2007 until June 2010, and a DPF was used in 82 cases (DPF group) from July 2010 to July 2011. Rates of positive findings on postoperative diffusion-weighted imaging (DWI) and stroke incidence were compared. Positive postoperative DWI results were found in 34 cases in the DPB group (41.4 %), but in only 22 cases in the DPF group (26.8 %), and there was only a small significant difference within the DPF group. In the DPB group, there was one case of transient ischemic attack (TIA) (1.2 %) and four cases of brain infarction (2 minor strokes, 2 major strokes; 4.9 %), compared to the DFP group with one case of TIA (1.2 %) and no cases of minor or major strokes. In this study, significantly lower rates of occurrence of DWI ischemic lesions and intraoperative embolization were associated with use of the DPF compared to the DPB.

  2. Biomedical Imaging and Computational Modeling in Biomechanics

    CERN Document Server

    Iacoviello, Daniela

    2013-01-01

    This book collects the state-of-art and new trends in image analysis and biomechanics. It covers a wide field of scientific and cultural topics, ranging from remodeling of bone tissue under the mechanical stimulus up to optimizing the performance of sports equipment, through the patient-specific modeling in orthopedics, microtomography and its application in oral and implant research, computational modeling in the field of hip prostheses, image based model development and analysis of the human knee joint, kinematics of the hip joint, micro-scale analysis of compositional and mechanical properties of dentin, automated techniques for cervical cell image analysis, and iomedical imaging and computational modeling in cardiovascular disease.   The book will be of interest to researchers, Ph.D students, and graduate students with multidisciplinary interests related to image analysis and understanding, medical imaging, biomechanics, simulation and modeling, experimental analysis.

  3. Cervical spondylosis anatomy: pathophysiology and biomechanics.

    Science.gov (United States)

    Shedid, Daniel; Benzel, Edward C

    2007-01-01

    Cervical spondylosis is the most common progressive disorder in the aging cervical spine. It results from the process of degeneration of the intervertebral discs and facet joints of the cervical spine. Biomechanically, the disc and the facets are the connecting structures between the vertebrae for the transmission of external forces. They also facilitate cervical spine mobility. Symptoms related to myelopathy and radiculopathy are caused by the formation of osteophytes, which compromise the diameter of the spinal canal. This compromise may also be partially developmental. The developmental process, together with the degenerative process, may cause mechanical pressure on the spinal cord at one or multiple levels. This pressure may produce direct neurological damage or ischemic changes and, thus, lead to spinal cord disturbances. A thorough understanding of the biomechanics, the pathology, the clinical presentation, the radiological evaluation, as well as the surgical indications of cervical spondylosis, is essential for the management of patients with cervical spondylosis.

  4. Biomechanical implications of lumbar spinal ligament transection.

    Science.gov (United States)

    Von Forell, Gregory A; Bowden, Anton E

    2014-11-01

    Many lumbar spine surgeries either intentionally or inadvertently damage or transect spinal ligaments. The purpose of this work was to quantify the previously unknown biomechanical consequences of isolated spinal ligament transection on the remaining spinal ligaments (stress transfer), vertebrae (bone remodelling stimulus) and intervertebral discs (disc pressure) of the lumbar spine. A finite element model of the full lumbar spine was developed and validated against experimental data and tested in the primary modes of spinal motion in the intact condition. Once a ligament was removed, stress increased in the remaining spinal ligaments and changes occurred in vertebral strain energy, but disc pressure remained similar. All major biomechanical changes occurred at the same spinal level as the transected ligament, with minor changes at adjacent levels. This work demonstrates that iatrogenic damage to spinal ligaments disturbs the load sharing within the spinal ligament network and may induce significant clinically relevant changes in the spinal motion segment.

  5. Biomechanical study of percutaneous lumbar diskectomy

    International Nuclear Information System (INIS)

    Li Yuan; Huang Xianglong; Shen Tianzhen; Hu Zhou; Hong Shuizong; Mei Haiying

    2003-01-01

    Objective: To investigate the stiffness of lumbar spine after the injury caused by percutaneous diskectomy and evaluate the efficiency of percutaneous lumbar diskectomy by biomechanical study. Methods: Four fresh lumbar specimens were used to analyse load-displacement curves in the intact lumbar spine and vertical disc-injured lumbar spine. The concepts of average flexibility coefficient (f) and standardized average flexibility coefficient (fs) were also introduced. Results: The load-displacement curves showed a good stabilization effect of the intact lumbar spine and disc-injured lumbar spine in flexion, extension, right and left bending. The decrease of anti-rotation also can be detected (P<0.05). Conclusion: In biomechanical study, percutaneous lumbar diskectomy is one of the efficiency methods to treat lumbar diac hernia

  6. Biomechanics/risk management (Working Group 2)

    DEFF Research Database (Denmark)

    Sanz, Mariano; Naert, Ignace; Gotfredsen, Klaus

    2009-01-01

    INTRODUCTION: The remit of this workgroup was to update the existing knowledge base in biomechanical factors, navigation systems and medications that may affect the outcome of implant therapy. MATERIAL AND METHODS: The literature was systematically searched and critically reviewed. Five manuscripts...... were produced in five specific topics identified as areas where innovative approaches have been developed in biomechanical factors, navigation systems and medications that may affect the outcome of implant therapy. RESULTS: The results and conclusions of the review process are presented...... survival and complications of implant supported restorations? * A systematic review on the accuracy and the clinical outcome of computer-guided template based implant dentistry. * What is the impact of systemic bisphosphonates on patients undergoing oral implant therapy? * What is the impact...

  7. Biomechanical considerations in mandibular incisor extraction cases.

    Science.gov (United States)

    Rachala, Madhukar Reddy; Aileni, Kaladhar Reddy; Dasari, Arun Kumar; Sinojiya, Jay

    2015-01-01

    Mandibular incisor extraction can be regarded as a valuable treatment option in certain malocclusions to obtain excellence in orthodontic results in terms of function, aesthetics and stability. This treatment alternative is indicated in clinical situations like mild to moderate class III malocclusion, mild anterior mandibular tooth size excess, periodontally compromised teeth, ectopic eruption of mandibular incisor and minimal openbite tendencies. Unlike in premolar extraction cases, space closure in mandibular incisor extraction cases is unique in which the extraction space will be in the middle of the arch. The end result of space closure in these cases should be well aligned, upright, anterior teeth with parallel roots and the goal can be achieved with the bodily tooth movement through proper application of biomechanics. The purpose of this article is to explain the biomechanics of space closure in mandibular incisor extraction cases.

  8. Mini-implant-supported Molar Distalization

    Directory of Open Access Journals (Sweden)

    Amit Goyal

    2012-01-01

    Full Text Available Temporary anchorage devices popularly called mini-implants or miniscrews are the latest addition to an orthodontist′s armamentarium. The following case report describes the treatment of a 16-year-old girl with a pleasant profile, moderate crowding and Angle′s Class II molar relationship. Maxillary molar distalization was planned and mini-implants were used to preserve the anterior anchorage. After 13 months of treatment, Class I molar and canine relation was achieved bilaterally and there was no anterior proclination. Thus, mini-implants provide a viable option to the clinician to carry out difficult tooth movements without any side effects.

  9. Periosteal osteoblastoma of the distal femur

    Energy Technology Data Exchange (ETDEWEB)

    Nakatani, Tetsuya; Yamamoto, Tetsuji; Akisue, Toshihiro; Marui, Takashi; Hitora, Toshiaki; Kawamoto, Teruya; Nagira, Keiko; Yoshiya, Shinichi; Kurosaka, Masahiro [Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe (Japan); Fujita, Ikuo; Matsumoto, Keiji [Department of Orthopaedic Surgery, Hyogo Medical Center for Adults, Akashi, Hyogo (Japan)

    2004-02-01

    Osteoblastomas located on the surface of the cortical bone, so-called periosteal osteoblastomas, are extremely rare. We report on a case of periosteal osteoblastoma arising from the posterior surface of the right distal femur in a 17-year-old man. Roentgenographic, computed tomographic, magnetic resonance imaging, and histologic features of the case are presented. Periosteal osteoblastoma should be radiologically and histologically differentiated from myositis ossificans, avulsive cortical irregularity syndrome, osteoid osteoma, parosteal osteosarcoma, periosteal osteosarcoma, and high-grade surface osteosarcoma. Although periosteal osteoblastoma is rare, this tumor should be included in the differential diagnosis of surface-type bone tumors. (orig.)

  10. Numerical Simulation of Some Biomechanical Problems

    Czech Academy of Sciences Publication Activity Database

    Nedoma, Jiří; Klézl, Z.; Fousek, J.; Kestřánek, Zdeněk; Stehlík, J.

    2003-01-01

    Roč. 61, 3-6 (2003), s. 283-295 ISSN 0378-4754. [MODELLING 2001. IMACS Conference on Mathematical Modelling and Computational Methods in Mechanics, Physics , Biomechanics and Geodynamics /2./. Pilsen, 19.06.2001-25.06.2001] Institutional research plan: AV0Z1030915 Keywords : non-linear elasticity * contact problems * variational inequality * finite element method * wrist * spine * fracture Subject RIV: BA - General Mathematics Impact factor: 0.558, year: 2003

  11. Analysis of Biomechanical Factors in Bend Running

    OpenAIRE

    Bing Zhang; Xinping You; Feng Li

    2013-01-01

    Sprint running is the demonstration of comprehensive abilities of technology and tactics, under various conditions. However, whether it is just to allocate the tracks for short-distance athletes from different racetracks has been the hot topic. This study analyzes its forces, differences in different tracks and winding influences, in the aspects of sport biomechanics. The results indicate, many disadvantages exist in inner tracks, middle tracks are the best and outer ones are inferior to midd...

  12. Biomechanical Factors in Tibial Stress Fracture

    Science.gov (United States)

    2001-08-01

    Relationship between Loading Rates and Tibial Accelerometry in Forefoot Strike Runners. Presented at the Annual American Society of Biomechanics Mtg...of the APTA, Seattle, WA, 2/99. McClay, IS, Williams, DS, and Manal, KT. Lower Extremity Mechanics of Runners with a Converted Forefoot Strike ...Management, Inc, 1998-1999 The Effect of Different Orthotic Devices on Lower Extremity Mechanics of Rearfoot and Forefoot Strikers, $3,500. Foot Management

  13. Injury Biomechanics of C2 Dens Fractures

    OpenAIRE

    Yoganandan, Narayan; Pintar, Frank; Baisden, Jamie; Gennarelli, Thomas; Maiman, Dennis

    2004-01-01

    The objective of this study is to analyze the biomechanics of dens fractures of the second cervical vertebra in the adult population due to motor vehicle crashes. Case-by-case records from the Crash Injury Research and Engineering Network (CIREN) and National Automotive Sampling System (NASS) databases were used. Variables such as change in velocity, impact direction and body habitus were extracted. Results indicated that similarities exist in the two databases despite differences in sampling...

  14. Computational Biomechanics Theoretical Background and BiologicalBiomedical Problems

    CERN Document Server

    Tanaka, Masao; Nakamura, Masanori

    2012-01-01

    Rapid developments have taken place in biological/biomedical measurement and imaging technologies as well as in computer analysis and information technologies. The increase in data obtained with such technologies invites the reader into a virtual world that represents realistic biological tissue or organ structures in digital form and allows for simulation and what is called “in silico medicine.” This volume is the third in a textbook series and covers both the basics of continuum mechanics of biosolids and biofluids and the theoretical core of computational methods for continuum mechanics analyses. Several biomechanics problems are provided for better understanding of computational modeling and analysis. Topics include the mechanics of solid and fluid bodies, fundamental characteristics of biosolids and biofluids, computational methods in biomechanics analysis/simulation, practical problems in orthopedic biomechanics, dental biomechanics, ophthalmic biomechanics, cardiovascular biomechanics, hemodynamics...

  15. [Cement augmentation on the spine : Biomechanical considerations].

    Science.gov (United States)

    Kolb, J P; Weiser, L; Kueny, R A; Huber, G; Rueger, J M; Lehmann, W

    2015-09-01

    Vertebral compression fractures are the most common osteoporotic fractures. Since the introduction of vertebroplasty and screw augmentation, the management of osteoporotic fractures has changed significantly. The biomechanical characteristics of the risk of adjacent fractures and novel treatment modalities for osteoporotic vertebral fractures, including pure cement augmentation by vertebroplasty, and cement augmentation of screws for posterior instrumentation, are explored. Eighteen human osteoporotic lumbar spines (L1-5) adjacent to vertebral bodies after vertebroplasty were tested in a servo-hydraulic machine. As augmentation compounds we used standard cement and a modified low-strength cement. Different anchoring pedicle screws were tested with and without cement augmentation in another cohort of human specimens with a simple pull-out test and a fatigue test that better reflects physiological conditions. Cement augmentation in the osteoporotic spine leads to greater biomechanical stability. However, change in vertebral stiffness resulted in alterations with the risk of adjacent fractures. By using a less firm cement compound, the risk of adjacent fractures is significantly reduced. Both screw augmentation techniques resulted in a significant increase in the withdrawal force compared with the group without cement. Augmentation using perforated screws showed the highest stability in the fatigue test. The augmentation of cement leads to a significant change in the biomechanical properties. Differences in the stability of adjacent vertebral bodies increase the risk of adjacent fractures, which could be mitigated by a modified cement compound with reduced strength. Screws that were specifically designed for cement application displayed greatest stability in the fatigue test.

  16. Advanced Computational Methods in Bio-Mechanics.

    Science.gov (United States)

    Al Qahtani, Waleed M S; El-Anwar, Mohamed I

    2018-04-15

    A novel partnership between surgeons and machines, made possible by advances in computing and engineering technology, could overcome many of the limitations of traditional surgery. By extending surgeons' ability to plan and carry out surgical interventions more accurately and with fewer traumas, computer-integrated surgery (CIS) systems could help to improve clinical outcomes and the efficiency of healthcare delivery. CIS systems could have a similar impact on surgery to that long since realised in computer-integrated manufacturing. Mathematical modelling and computer simulation have proved tremendously successful in engineering. Computational mechanics has enabled technological developments in virtually every area of our lives. One of the greatest challenges for mechanists is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, the biomedical sciences, and medicine. Biomechanics has significant potential for applications in orthopaedic industry, and the performance arts since skills needed for these activities are visibly related to the human musculoskeletal and nervous systems. Although biomechanics is widely used nowadays in the orthopaedic industry to design orthopaedic implants for human joints, dental parts, external fixations and other medical purposes, numerous researches funded by billions of dollars are still running to build a new future for sports and human healthcare in what is called biomechanics era.

  17. Scleral Biomechanics in the Aging Monkey Eye

    Science.gov (United States)

    Girard, Michaël J. A.; Suh, J-K. Francis; Bottlang, Michael; Burgoyne, Claude F.; Downs, J. Crawford

    2010-01-01

    Purpose To investigate the age-related differences in the inhomogeneous, anisotropic, nonlinear biomechanical properties of posterior sclera from old (22.9 ± 5.3 years) and young (1.5 ± 0.7 years) rhesus monkeys. Methods The posterior scleral shell of each eye was mounted on a custom-built pressurization apparatus, then intraocular pressure (IOP) was elevated from 5 to 45 mmHg while the 3D displacements of the scleral surface were measured using speckle interferometry. Each scleral shell geometry was digitally reconstructed from data generated by a 3D digitizer (topography) and 20 MHz ultrasounds (thickness). An inverse finite element (FE) method incorporating a fiber-reinforced constitutive model was used to extract a unique set of biomechanical properties for each eye. Displacements, thickness, stress, strain, tangent modulus, structural stiffness, and preferred collagen fiber orientation were mapped for each posterior sclera. Results The model yielded 3-D deformations of posterior sclera that matched well with those observed experimentally. The posterior sclera exhibited inhomogeneous, anisotropic, nonlinear mechanical behavior. The sclera was significantly thinner (p = 0.038), and tangent modulus and structural stiffness were significantly higher in old monkeys (p biomechanics, and potentially contribute to age-related susceptibility to glaucomatous vision loss. PMID:19494203

  18. Current Biomechanical Concepts for Rotator Cuff Repair

    Science.gov (United States)

    2013-01-01

    For the past few decades, the repair of rotator cuff tears has evolved significantly with advances in arthroscopy techniques, suture anchors and instrumentation. From the biomechanical perspective, the focus in arthroscopic repair has been on increasing fixation strength and restoration of the footprint contact characteristics to provide early rehabilitation and improve healing. To accomplish these objectives, various repair strategies and construct configurations have been developed for rotator cuff repair with the understanding that many factors contribute to the structural integrity of the repaired construct. These include repaired rotator cuff tendon-footprint motion, increased tendon-footprint contact area and pressure, and tissue quality of tendon and bone. In addition, the healing response may be compromised by intrinsic factors such as decreased vascularity, hypoxia, and fibrocartilaginous changes or aforementioned extrinsic compression factors. Furthermore, it is well documented that torn rotator cuff muscles have a tendency to atrophy and become subject to fatty infiltration which may affect the longevity of the repair. Despite all the aforementioned factors, initial fixation strength is an essential consideration in optimizing rotator cuff repair. Therefore, numerous biomechanical studies have focused on elucidating the strongest devices, knots, and repair configurations to improve contact characteristics for rotator cuff repair. In this review, the biomechanical concepts behind current rotator cuff repair techniques will be reviewed and discussed. PMID:23730471

  19. An introduction to biomechanics solids and fluids, analysis and design

    CERN Document Server

    Humphrey, Jay D

    2004-01-01

    Designed to meet the needs of undergraduate students, Introduction to Biomechanics takes the fresh approach of combining the viewpoints of both a well-respected teacher and a successful student. With an eye toward practicality without loss of depth of instruction, this book seeks to explain the fundamental concepts of biomechanics. With the accompanying web site providing models, sample problems, review questions and more, Introduction to Biomechanics provides students with the full range of instructional material for this complex and dynamic field.

  20. Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations

    Science.gov (United States)

    2016-06-01

    AWARD NUMBER: W81XWH-13-2-0043 TITLE: Lumbar Spine Musculoskeletal Physiology and Biomechanics During Simulated Military Operations PRINCIPAL...31May2016 4. TITLE AND SUBTITLE Lumbar Spine Musculoskeletal Physiology and Biomechanics 5a. CONTRACT NUMBER During Simulated Military Operations 5b... Biomechanics , Cincinnati, 2015. § Website(s) or other Internet site(s) § Nothing to report § Technologies or techniques § Nothing to report

  1. Radiographic anatomy of the distal dural SAC

    International Nuclear Information System (INIS)

    Larsen, J.L.; Olsen, K.O.

    1991-01-01

    A radio-anatomical study was performed of the distal dural sac (DS) in 121 patients subjected to myelography. In 83.4% the termination of the DS was located from the upper half of the S1-segment to the lower half of the S2-segment. In the remaining patients the dural terminations were more distally located. The average location of the DS-termination was higher than that found in a previous anatomic study. The inference is that in patients with low-back pain and sciatica, the DS tends to terminate at a higher spinal level than in a non-selected anatomic material. The caudal reduction in sagittal diameter of the DS was less than that of the frontal diameter of the sac. The linear diminution in cross-sectional area of the DS from the level of L3 towards the lumbosacral junction was not correlated with the degree of caudal extension of the DS into the sacrum. Thus the length of the DS and its transverse diameters are independent of each other. These results supported the view that the location of the termination of the DS (and hence that of the spinal cord) is not related to stenosis of the central spinal canal. (orig.)

  2. Maxillary molar distalization with first class appliance.

    Science.gov (United States)

    Ramesh, Namitha; Palukunnu, Biswas; Ravindran, Nidhi; Nair, Preeti P

    2014-02-27

    Non-extraction treatment has gained popularity for corrections of mild-to-moderate class II malocclusion over the past few decades. The distalization of maxillary molars is of significant value for treatment of cases with minimal arch discrepancy and mild class II molar relation associated with a normal mandibular arch and acceptable profile. This paper describes our experience with a 16-year-old female patient who reported with irregularly placed upper front teeth and unpleasant smile. The patient was diagnosed to have angles class II malocclusion with moderate maxillary anterior crowding, deep bite of 4 mm on a skeletal class II base with an orthognathic maxilla and retrognathic mandible and normal growth pattern. She presented an ideal profile and so molar distalization was planned with the first-class appliance. Molars were distalised by 8 mm on the right and left quadrants and class I molar relation achieved within 4 months. The space gained was utilised effectively to align the arch and establish a class I molar and canine relation.

  3. Dermal pocketing following distal finger replantation.

    Science.gov (United States)

    Puhaindran, Mark E; Paavilainen, Pasi; Tan, David M K; Peng, Yeong Pin; Lim, Aymeric Y T

    2010-08-01

    Replantation is an ideal technique for reconstruction following fingertip amputation as it provides 'like for like' total reconstruction of the nail complex, bone pulp tissue and skin with no donor-site morbidity. However, fingertips are often not replanted because veins cannot be found or are thought to be too small to repair. Attempts at 'cap-plasty' or pocketing of replanted tips with and without microvascular anastomosis have been done in the past with varying degrees of success. We prospectively followed up a group of patients who underwent digital replantation and dermal pocketing in the palm to evaluate the outcome of this procedure. There were 10 patients with 14 amputated digits (two thumbs, five index, four middle, two ring and one little) who underwent dermal pocketing of the amputated digit following replantation. Among the 14 digits that were treated with dermal pocketing, 11 survived completely, one had partial atrophy and two were completely lost. Complications encountered included finger stiffness (two patients) and infection of the replanted fingertip with osteomyelitis of the distal phalanx (one patient). We believe that this technique can help increase the chance of survival for distal replantation with an acceptable salvage rate of 85% in our series. Copyright 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  4. Osteoid osteoma of the distal clavicle

    Directory of Open Access Journals (Sweden)

    Bernardo Barcellos Terra

    Full Text Available ABSTRACT The osteoid osteoma is a bone tumor that accounts for 10% of benign tumors. It was described in 1935 by Jaffe, as a tumor that affects the young adult population, with a predominance of males. This study aims to present a case of late diagnosis of a patient with osteoid osteoma of the distal clavicle region. Female patient, 44 years old, non-professional volleyball player, reported pain in the anterior and superior region of the shoulder girdle, specifically in the acromioclavicular joint, which worsened at night and had been treated for nine months as tendinitis of the rotator cuff and acromioclavicular joint arthritis. After confirming the diagnosis, the patient underwent open surgery with resection of the distal clavicle. At two years of follow-up, the patient presents without local pain. In the radiographic evaluation, coracoclavicular distance is preserved and there are no signs of recurrence. Tumors of the shoulder girdle are rare and are often diagnosed late. A high degree of suspicion for the diagnosis of tumors of the shoulder girdle is needed in order to avoid late diagnosis.

  5. Biotin absorption by distal rat intestine

    International Nuclear Information System (INIS)

    Bowman, B.B.; Rosenberg, I.H.

    1987-01-01

    We used the in vivo intestinal loop approach, with short (10-min) and long (3-h) incubations, to examine biotin absorption in proximal jejunum, distal ileum, cecum and proximal colon. In short-term studies, luminal biotin disappearance from rat ileum was about half that observed in the jejunum, whereas absorption by proximal colon was about 12% of that in the jejunum. In 3-h closed-loop studies, the absorption of 1.0 microM biotin varied regionally. Biotin absorption was nearly complete in the small intestine after 3 h; however, only about 15% of the dose had been absorbed in the cecum and 27% in the proximal colon after 3 h. Independent of site of administration, the major fraction of absorbed biotin was recovered in the liver; measurable amounts of radioactive biotin were also present in kidney and plasma. The results support the potential nutritional significance for the rat of biotin synthesized by bacteria in the distal intestine, by demonstrating directly an absorptive capability of mammalian large bowel for this vitamin

  6. [Distal ureteral lithiasis. ESWL versus ambulatory URS].

    Science.gov (United States)

    Miján Ortiz, J L; Gutiérrez Tejero, F; López Carmona, F; Nogueras Ocaña, M; Arrabal Martín, M; Zuluaga Gómez, A

    2001-11-01

    To present the results achieved in the treatment of 1802 distal ureteral stones treated at the Lithotripsy Unit of the San Cecilio University Hospital over the last 10 years (1990-2000). Stones were treated by extracorporeal shock wave lithotripsy (ESWL) or ureteroscopy (URS). ESWL was the initial treatment in 81% of the cases (1460 calculi) and URS in the remaining 19% (342 stones). URS was performed for complication or failed ESWL (102 stones) and ESWL was performed for failed URS, basically due to stone migration (24 stones). Ureterolithotomy was required on 7 occasions. Sedation-analgesia with fentanyl and midazolam was routinely used in URS. Sedation was required in only 55% of the ESWL procedures. Elective ESWL resolved 93% of the cases, a percentage which is similar to that achieved with URS as first treatment. The ESWL retreatment rate was 1.3. URS was successful in 98% of the cases of failed ESWL. There are two treatment modalities for stones in the distal ureter: ESWL and URS. We advocate the use of outpatient URS with sedation preferably in the female patient, impacted stones, obstructive uropathy, stones larger than 2 cm and radiotransparent stones.

  7. A STUDY OF SURGICAL MANAGEMENT OF DISTAL FEMORAL FRACTURES BY DISTAL FEMORAL LOCKING COMPRESSION PLATE OSTEOSYNTHESIS

    Directory of Open Access Journals (Sweden)

    Dema Rajaiah

    2016-08-01

    Full Text Available AIMS AND OBJECTIVES To study the fractures of distal end of femur and the mechanism of injury in distal end femur fractures, the advantages and disadvantages of open reduction and internal fixation of distal end femur fractures by distal femoral locking compression plate osteosynthesis and to analyse the outcome in terms of range of Knee motion, time to union, and limb shortening. RESULTS The mean age of patient is 44 years, 85% are males, road traffic accidents account for majority (80%, right side involved in 70%, Muller’s type C fracture is common, good range of movements is seen 90% of cases and union occurred in 95% in 5 months. The results were assessed using Neer’s score, seven (35% patients had excellent results, eight (40% patients had good results, four (20% patients had fair results and one (5% patient had poor result. CONCLUSION From our study, we conclude that DF-LCP is a safe and reliable implant and has shown excellent to satisfactory results in majority of intra-articular fractures (AO type C. Fixation with locking compression plate showed more effectiveness in severely osteoporotic bones, shorter operative stay, faster recovery, faster union rates and excellent functional outcome.

  8. Biomechanics of subcellular structures by non-invasive Brillouin microscopy

    Science.gov (United States)

    Antonacci, Giuseppe; Braakman, Sietse

    2016-11-01

    Cellular biomechanics play a pivotal role in the pathophysiology of several diseases. Unfortunately, current methods to measure biomechanical properties are invasive and mostly limited to the surface of a cell. As a result, the mechanical behaviour of subcellular structures and organelles remains poorly characterised. Here, we show three-dimensional biomechanical images of single cells obtained with non-invasive, non-destructive Brillouin microscopy with an unprecedented spatial resolution. Our results quantify the longitudinal elastic modulus of subcellular structures. In particular, we found the nucleoli to be stiffer than both the nuclear envelope (p biomechanics and its role in pathophysiology.

  9. An Evidence-Based Videotaped Running Biomechanics Analysis.

    Science.gov (United States)

    Souza, Richard B

    2016-02-01

    Running biomechanics play an important role in the development of injuries. Performing a running biomechanics analysis on injured runners can help to develop treatment strategies. This article provides a framework for a systematic video-based running biomechanics analysis plan based on the current evidence on running injuries, using 2-dimensional (2D) video and readily available tools. Fourteen measurements are proposed in this analysis plan from lateral and posterior video. Identifying simple 2D surrogates for 3D biomechanic variables of interest allows for widespread translation of best practices, and have the best opportunity to impact the highly prevalent problem of the injured runner. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Harnessing biomechanics to develop cartilage regeneration strategies.

    Science.gov (United States)

    Athanasiou, Kyriacos A; Responte, Donald J; Brown, Wendy E; Hu, Jerry C

    2015-02-01

    As this review was prepared specifically for the American Society of Mechanical Engineers H.R. Lissner Medal, it primarily discusses work toward cartilage regeneration performed in Dr. Kyriacos A. Athanasiou's laboratory over the past 25 years. The prevalence and severity of degeneration of articular cartilage, a tissue whose main function is largely biomechanical, have motivated the development of cartilage tissue engineering approaches informed by biomechanics. This article provides a review of important steps toward regeneration of articular cartilage with suitable biomechanical properties. As a first step, biomechanical and biochemical characterization studies at the tissue level were used to provide design criteria for engineering neotissues. Extending this work to the single cell and subcellular levels has helped to develop biochemical and mechanical stimuli for tissue engineering studies. This strong mechanobiological foundation guided studies on regenerating hyaline articular cartilage, the knee meniscus, and temporomandibular joint (TMJ) fibrocartilage. Initial tissue engineering efforts centered on developing biodegradable scaffolds for cartilage regeneration. After many years of studying scaffold-based cartilage engineering, scaffoldless approaches were developed to address deficiencies of scaffold-based systems, resulting in the self-assembling process. This process was further improved by employing exogenous stimuli, such as hydrostatic pressure, growth factors, and matrix-modifying and catabolic agents, both singly and in synergistic combination to enhance neocartilage functional properties. Due to the high cell needs for tissue engineering and the limited supply of native articular chondrocytes, costochondral cells are emerging as a suitable cell source. Looking forward, additional cell sources are investigated to render these technologies more translatable. For example, dermis isolated adult stem (DIAS) cells show potential as a source of

  11. Closed loop problems in biomechanics. Part II--an optimization approach.

    Science.gov (United States)

    Vaughan, C L; Hay, J G; Andrews, J G

    1982-01-01

    A closed loop problem in biomechanics may be defined as a problem in which there are one or more closed loops formed by the human body in contact with itself or with an external system. Under certain conditions the problem is indeterminate--the unknown forces and torques outnumber the equations. Force transducing devices, which would help solve this problem, have serious drawbacks, and existing methods are inaccurate and non-general. The purposes of the present paper are (1) to develop a general procedure for solving closed loop problems; (2) to illustrate the application of the procedure; and (3) to examine the validity of the procedure. A mathematical optimization approach is applied to the solution of three different closed loop problems--walking up stairs, vertical jumping and cartwheeling. The following conclusions are drawn: (1) the method described is reasonably successful for predicting horizontal and vertical reaction forces at the distal segments although problems exist for predicting the points of application of these forces; (2) the results provide some support for the notion that the human neuromuscular mechanism attempts to minimize the joint torques and thus, to a certain degree, the amount of muscular effort; (3) in the validation procedure it is desirable to have a force device for each of the distal segments in contact with a fixed external system; and (4) the method is sufficiently general to be applied to all classes of closed loop problems.

  12. Limited arthrodesis of the wrist for treatment of giant cell tumor of the distal radius.

    Science.gov (United States)

    Flouzat-Lachaniette, Charles-Henri; Babinet, Antoine; Kahwaji, Antoine; Anract, Philippe; Biau, David-Jean

    2013-08-01

    To present the functional results of a technique of radiocarpal arthrodesis and reconstruction with a structural nonvascularized autologous bone graft after en bloc resection of giant cell tumors of the distal radius. A total of 13 patients with a mean age of 37 years with aggressive giant cell tumor (Campanacci grade III) of distal radius were managed with en bloc resection and reconstruction with a structural nonvascularized bone graft. The primary outcome measure was the disability evaluated by the Musculoskeletal Tumor Society rating score of limb salvage. Secondary outcomes included survival of the reconstruction measured from the date of the operation to revision procedure for any reason (mechanical, infectious, or oncologic). Other outcomes included active wrist motion and ability to resume work. Mean follow-up period was 6 years (range, 2-14 y). The median arc of motion at the midcarpal joint was 40°, median wrist flexion was 20°, and median extension was 10°. The median Musculoskeletal Tumor Society score based on the analysis of factors pertinent to the patient as a whole (pain, functional activities, and emotional acceptance) and specific to the upper limb (positioning of the hand, manual dexterity, and lifting ability) was 86%. Five patients underwent a second surgical procedure. The cumulative probability of reoperation for mechanical reason was 31% at similar follow-up times at 2, 5, and 10 years. This technique provided a stable wrist and partially restored wrist motion with limited pain. However, further surgical procedures may be necessary to reach this goal. Therapeutic IV. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  13. Distal Communication by Chimpanzees (Pan troglodytes): Evidence for Common Ground?

    Science.gov (United States)

    Leavens, David A; Reamer, Lisa A; Mareno, Mary Catherine; Russell, Jamie L; Wilson, Daniel; Schapiro, Steven J; Hopkins, William D

    2015-01-01

    van der Goot et al. (2014) proposed that distal, deictic communication indexed the appreciation of the psychological state of a common ground between a signaler and a receiver. In their study, great apes did not signal distally, which they construed as evidence for the human uniqueness of a sense of common ground. This study exposed 166 chimpanzees to food and an experimenter, at an angular displacement, to ask, "Do chimpanzees display distal communication?" Apes were categorized as (a) proximal or (b) distal signalers on each of four trials. The number of chimpanzees who communicated proximally did not statistically differ from the number who signaled distally. Therefore, contrary to the claim by van der Goot et al., apes do communicate distally. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

  14. Distal intersection tenosynovitis of the wrist: a lesser-known extensor tendinopathy with characteristic MR imaging features

    International Nuclear Information System (INIS)

    Parellada, Antoni J.; Gopez, Angela G.; Morrison, William B.; Sweet, Stephanie; Leinberry, Charles F.; Reiter, Sean B.; Kohn, Mark

    2007-01-01

    To present the MRI imaging findings of extensor tenosynovitis at the distal intersection or crossover between the second (extensor carpi radialis longus (ECRL) and brevis (ECRB)) and third (extensor pollicis longus (EPL)) extensor compartment tendons, and the anatomical details that may play a role in the pathogenesis of this condition. The imaging studies and clinical records of five patients (three females and two males, with ages ranging between 22 and 78 years; mean age, 49 years) presenting with pain on the dorsal and radial aspect of the wrist were reviewed by two musculoskeletal radiologists in consensus. Three cases were identified serendipitously during routine clinical reading sessions; a follow-up computerized database search for additional cases reported in the prior two years yielded two additional cases. The overall number of cases screened was 1,031. The diagnosis of tendinopathy affecting the second and third compartment extensor tendons was made on the basis of MRI findings and clinical follow-up, or synovectomy. All patients showed signs of tenosynovitis: in four patients both the tendons of the second and third extensor compartments were affected; the fifth patient showed signs of tenosynovitis of the EPL tendon, and tendinosis of the extensor carpi radialis tendons. Three patients showed tenosynovitis proximal and distal to the point of intersection; and in two of them, a discrete point of constriction was appreciated at the crossover site in relation to the extensor retinaculum. Two patients showed tenosynovitis limited to the segment distal to the point of decussation. Tendinosis tended to follow the presence of tenosynovitis. In one of the patients, subtendinous reactive marrow edema in Lister's tubercle was noted. Distal intersection tenosynovitis may be related to the biomechanical pulley effect exerted by Lister's tubercle on the EPL tendon as it leaves the third compartment and crosses over the extensor carpi radialis tendons, as well as

  15. Distal intersection tenosynovitis of the wrist: a lesser-known extensor tendinopathy with characteristic MR imaging features

    Energy Technology Data Exchange (ETDEWEB)

    Parellada, Antoni J. [DII - Diagnostic Imaging, Inc., Philadelphia, PA (United States); Frankford Hospitals - Torresdale Campus, Department of Radiology, Philadelphia, PA (United States); Gopez, Angela G.; Morrison, William B. [Thomas Jefferson University, Department of Radiology, Philadelphia, PA (United States); Sweet, Stephanie [Thomas Jefferson University, Philadelphia Hand Center, Philadelphia, PA (United States); Leinberry, Charles F. [Thomas Jefferson University, Department of Orthopedic Surgery - Hand Surgery, Philadelphia, PA (United States); Reiter, Sean B.; Kohn, Mark [DII - Diagnostic Imaging, Inc., Philadelphia, PA (United States)

    2007-03-15

    To present the MRI imaging findings of extensor tenosynovitis at the distal intersection or crossover between the second (extensor carpi radialis longus (ECRL) and brevis (ECRB)) and third (extensor pollicis longus (EPL)) extensor compartment tendons, and the anatomical details that may play a role in the pathogenesis of this condition. The imaging studies and clinical records of five patients (three females and two males, with ages ranging between 22 and 78 years; mean age, 49 years) presenting with pain on the dorsal and radial aspect of the wrist were reviewed by two musculoskeletal radiologists in consensus. Three cases were identified serendipitously during routine clinical reading sessions; a follow-up computerized database search for additional cases reported in the prior two years yielded two additional cases. The overall number of cases screened was 1,031. The diagnosis of tendinopathy affecting the second and third compartment extensor tendons was made on the basis of MRI findings and clinical follow-up, or synovectomy. All patients showed signs of tenosynovitis: in four patients both the tendons of the second and third extensor compartments were affected; the fifth patient showed signs of tenosynovitis of the EPL tendon, and tendinosis of the extensor carpi radialis tendons. Three patients showed tenosynovitis proximal and distal to the point of intersection; and in two of them, a discrete point of constriction was appreciated at the crossover site in relation to the extensor retinaculum. Two patients showed tenosynovitis limited to the segment distal to the point of decussation. Tendinosis tended to follow the presence of tenosynovitis. In one of the patients, subtendinous reactive marrow edema in Lister's tubercle was noted. Distal intersection tenosynovitis may be related to the biomechanical pulley effect exerted by Lister's tubercle on the EPL tendon as it leaves the third compartment and crosses over the extensor carpi radialis tendons

  16. Distal renal tubular acidosis and hepatic lipidosis in a cat.

    Science.gov (United States)

    Brown, S A; Spyridakis, L K; Crowell, W A

    1986-11-15

    Clinical and laboratory evidence of hepatic failure was found in a chronically anorectic cat. Simultaneous blood and urine pH determinations established a diagnosis of distal renal tubular acidosis. The cat did not respond to treatment. Necropsy revealed distal tubular nephrosis and hepatic lipidosis. The finding of distal renal tubular acidosis in a cat with hepatic lipidosis emphasizes the importance of complete evaluation of acid-base disorders in patients.

  17. Proximal humerus fractures: a comparative biomechanical analysis of intra and extramedullary implants.

    Science.gov (United States)

    Füchtmeier, B; May, R; Hente, R; Maghsudi, M; Völk, M; Hammer, J; Nerlich, M; Prantl, L

    2007-08-01

    The biomechanical stability of a newly developed humerus nail (Sirustrade mark) for the treatment of fractures of the proximal humerus was analyzed in comparison to established systems. In total, three randomized groups were formed (n = 4 pairs) from 12 matched pairs of human cadaver humeri. All intact bones were mechanically characterized by five subsequent load cycles under bending and torsional loading. The bending moment at the osteotomy was 7.5 N m the torsional moment was 8.3 N m over the hole specimen length. Loading was consistently initiated at the distal epiphysis and the deformation at the distal epiphysis was continuously recorded. Prior to implant reinforcement, a defect of 5 mm was created to simulate an unstable subcapital humerus fracture. For paired comparison, one humerus of each pair was stabilized with the Sirus proximal humerus nail while the counterpart was stabilized by a reference implant. In detail, the following groups were created: Sirus versus Proximal humerus nail (PHN) with spiral blade (group I); Sirus versus PHILOS plate (group II); Sirus versus 4.5 mm AO T-plate (group III). The Sirus nail demonstrated significantly higher stiffness values compared to the reference implants for both bending and torsional loading. The following distal epiphyseal displacements were recorded for a bending moment of 7.5 N m at the osteotomy: Sirus I: 8.8 mm, II: 8.4 mm, III: 7.7 mm (range 6.9-10.9), PHN 21.1 mm (range 15.7-25.2) (P = 0.005), PHILOS plate 27.5 mm (range 21.6-35.8) (P model presented here. Supplementary, the Sirus Nail showed higher stiffness values than the PHN. However, the latter are gaining in importance due to the possibility of minimal invasive implantation. Whether this will be associated with functional advantages requires further clinical investigation.

  18. Post-transplant distal limb syndrome

    Directory of Open Access Journals (Sweden)

    María Florencia Borghi Torzillo

    2017-02-01

    Full Text Available The post-transplant distal limb syndrome is a not well known entity, with a prevalence of 5% in patients with renal transplant. Its diagnosis is based on clinical symptoms, bone scintigraphy and MRI, it has a benign course and the patient recovers without sequel. We present the case of a 37-year-old male, with medical history of hypertension, Berger's disease in 1999 that required dialysis three times a week for four years (2009-2013 and renal transplant in 2013. The patient consults on January 2014 referring severe pain in both feet, with sudden onset; he remembers the exact date of the beginning of the pain and denies trauma, pain prevents ambulation. The bone scintigraphy shows pathological uptake in both feet with no difference between the two. Although there is no treatment for this disease, it has a benign course

  19. Modelling biomechanics of bark patterning in grasstrees.

    Science.gov (United States)

    Dale, Holly; Runions, Adam; Hobill, David; Prusinkiewicz, Przemyslaw

    2014-09-01

    Bark patterns are a visually important characteristic of trees, typically attributed to fractures occurring during secondary growth of the trunk and branches. An understanding of bark pattern formation has been hampered by insufficient information regarding the biomechanical properties of bark and the corresponding difficulties in faithfully modelling bark fractures using continuum mechanics. This study focuses on the genus Xanthorrhoea (grasstrees), which have an unusual bark-like structure composed of distinct leaf bases connected by sticky resin. Due to its discrete character, this structure is well suited for computational studies. A dynamic computational model of grasstree development was created. The model captures both the phyllotactic pattern of leaf bases during primary growth and the changes in the trunk's width during secondary growth. A biomechanical representation based on a system of masses connected by springs is used for the surface of the trunk, permitting the emergence of fractures during secondary growth to be simulated. The resulting fracture patterns were analysed statistically and compared with images of real trees. The model reproduces key features of grasstree bark patterns, including their variability, spanning elongated and reticulate forms. The patterns produced by the model have the same statistical character as those seen in real trees. The model was able to support the general hypothesis that the patterns observed in the grasstree bark-like layer may be explained in terms of mechanical fractures driven by secondary growth. Although the generality of the results is limited by the unusual structure of grasstree bark, it supports the hypothesis that bark pattern formation is primarily a biomechanical phenomenon.

  20. Head Impact Biomechanics in Women's College Soccer.

    Science.gov (United States)

    Lynall, Robert C; Clark, Michael D; Grand, Erin E; Stucker, Jaclyn C; Littleton, Ashley C; Aguilar, Alain J; Petschauer, Meredith A; Teel, Elizabeth F; Mihalik, Jason P

    2016-09-01

    There are limited nonlaboratory soccer head impact biomechanics data. This is surprising given soccer's global popularity. Epidemiological data suggest that female college soccer players are at a greater concussion injury risk than their male counterparts. Therefore, the purposes of our study were to quantify head impact frequency and magnitude during women's soccer practices and games in the National Collegiate Athletic Association and to characterize these data across event type, playing position, year on the team, and segment of game (first and second halves). Head impact biomechanics were collected from female college soccer players (n = 22; mean ± SD age = 19.1 ± 0.1 yr, height = 168.0 ± 3.5 cm, mass = 63.7 ± 6.0 kg). We employed a helmetless head impact measurement device (X2 Biosystems xPatch) before each competition and practice across a single season. Peak linear and rotational accelerations were categorized based on impact magnitude and subsequently analyzed using appropriate nonparametric analyses. Overall, women's college soccer players experience approximately seven impacts per 90 min of game play. The overwhelming majority (~90%) of all head impacts were categorized into our mildest linear acceleration impact classification (10g-20g). Interestingly, a higher percentage of practice impacts in the 20g-40g range compared with games (11% vs 7%) was observed. Head impact biomechanics studies have provided valuable insights into understanding collision sports and for informing evidence-based rule and policy changes. These have included changing the football kickoff, ice hockey body checking ages, and head-to-head hits in both sports. Given soccer's global popularity, and the growing public concern for the potential long-term neurological implications of collision and contact sports, studying soccer has the potential to impact many athletes and the sports medicine professionals caring for them.

  1. Biomechanical studies: science (f)or common sense?

    NARCIS (Netherlands)

    Mellema, Jos J.; Doornberg, Job N.; Guitton, Thierry G.; Ring, David; van der Zwan, A. L.; Spoor, A. B.; van Vugt, A. B.; Armstrong, A. D.; Shrivastava, A.; Wahegaonkar, A. L.; Shafritz, A. B.; Adams, J.; Ilyas, A.; Vochteloo, A. J. H.; Castillo, A. P.; Basak, A.; Andreas, P.; Barquet, A.; Kristan, A.; Berner, A.; Ranade, A. B.; Ashish, S.; Terrono, A. L.; Jubel, A.; Frieman, B.; Bamberger, H. B.; van den Bekerom, M. P. J.; Belangero, W. D.; Hearon, B. F.; Boler, J. M.; Walter, F. L.; Boyer, M.; Wills, B. P. D.; Broekhuyse, H.; Buckley, R.; Watkins, B.; Sears, B. W.; Calfee, R. P.; Ekholm, C.; Fernandes, C. H.; Swigart, C.; Cassidy, C.; Wilson, C. J.; Bainbridge, L. C.; Wilson, C.; Eygendaal, D.; Goslings, J. C.; Schep, N.; Kloen, P.; Haverlag, R.

    2014-01-01

    It is our impression that many biomechanical studies invest substantial resources studying the obvious: that more and larger metal is stronger. The purpose of this study is to evaluate if a subset of biomechanical studies comparing fixation constructs just document common sense. Using a web-based

  2. Biomechanical factors associated with the development of tibiofemoral knee osteoarthritis

    DEFF Research Database (Denmark)

    van Tunen, Joyce A C; Dell'Isola, Andrea; Juhl, Carsten

    2016-01-01

    INTRODUCTION: Altered biomechanics, increased joint loading and tissue damage, might be related in a vicious cycle within the development of knee osteoarthritis (KOA). We have defined biomechanical factors as joint-related factors that interact with the forces, moments and kinematics in and aroun...... publications in peer-reviewed journals and presentations at (inter)national conferences. TRIAL REGISTRATION NUMBER: CRD42015025092....

  3. Biomechanical factors associated with the risk of knee injury when ...

    African Journals Online (AJOL)

    Objectives. To systematically assess the literature investigating biomechanical knee injury risk factors when an individual lands from a jump. Data sources. Four electronic databases were searched for peer-reviewed English journals containing landing biomechanical studies published over 14 years (1990 - 2003).

  4. Factors Related to Students' Learning of Biomechanics Concepts

    Science.gov (United States)

    Hsieh, ChengTu; Smith, Jeremy D.; Bohne, Michael; Knudson, Duane

    2012-01-01

    The purpose of this study was to replicate and expand a previous study to identify the factors that affect students' learning of biomechanical concepts. Students were recruited from three universities (N = 149) located in the central and western regions of the United States. Data from 142 students completing the Biomechanics Concept Inventory…

  5. [The development of an oral biomechanical testing instrument].

    Science.gov (United States)

    Zhang, X H; Sun, X D; Lin, Z

    2000-03-01

    An oral biomechanical testing instrument, which is portable, powered with batteries and controlled by single chip microcomputer, was described. The instrument was characterized by its multichannel, high accuracy, low power dissipation, wide rage of force measurement and stable performance. It can be used for acquisiting, displaying and storing data. And it may be expected to be an ideal instrument for oral biomechanical measurements.

  6. Dance band on the Titanic: biomechanical signaling in cardiac hypertrophy.

    Science.gov (United States)

    Sussman, Mark A; McCulloch, Andrew; Borg, Thomas K

    2002-11-15

    Biomechanical signaling is a complex interaction of both intracellular and extracellular components. Both passive and active components are involved in the extracellular environment to signal through specific receptors to multiple signaling pathways. This review provides an overview of extracellular matrix, specific receptors, and signaling pathways for biomechanical stimulation in cardiac hypertrophy.

  7. The Undergraduate Biomechanics Experience at Iowa State University.

    Science.gov (United States)

    Francis, Peter R.

    This paper discusses the objectives of a program in biomechanics--the analysis of sports skills and movement--and the evolution of the biomechanics program at Iowa State University. The primary objective of such a course is to provide the student with the basic tools necessary for adequate analysis of human movement, with special emphasis upon…

  8. Biomechanics, Exercise Physiology, and the 75th Anniversary of RQES

    Science.gov (United States)

    Hamill, Joseph; Haymes, Emily M.

    2005-01-01

    The purpose of this paper is to review the biomechanics and exercise physiology studies published in the Research Quarterly for Exercise and Sport (RQES) over the past 75 years. Studies in biomechanics, a relatively new subdiscipline that evolved from kinesiology, first appeared in the journal about 40 years ago. Exercise physiology studies have…

  9. Comparison of standard laparoscopic distal pancreatectomy with minimally invasive distal pancreatectomy using the da Vinci S system.

    Science.gov (United States)

    Ito, Masahiro; Asano, Yukio; Shimizu, Tomohiro; Uyama, Ichiro; Horiguchi, Akihiko

    2014-01-01

    Minimally invasive procedures for pancreatic pathologies are increasingly being used, including distal pancreatectomy. This study aimed to assess the indications for and outcomes of the da Vinci distal pancreatectomy procedure. We reviewed the medical records of patients who underwent pancreatic head resection from April 2009 to September 2013. Four patients (mean age, 52.7 years) underwent da Vinci distal pancreatectomy and 10 (mean age, 68.0 +/- 12.1 years) underwent laparoscopic distal pancreatectomy. The mean surgical duration was 292 +/- 153 min and 306 +/- 29 min, the mean blood loss was 153 +/- 71 mL and 61.7 +/- 72 mL, and the mean postoperative length of stay was 24 +/- 11 days and 14 +/- 3 days in the da Vinci distal pancreatectomy and laparoscopic distal pancreatectomy groups, respectively. One patient who underwent da Vinci distal pancreatectomy developed a pancreatic fistula, while 2 patients in the laparoscopic distal pancreatectomy group developed splenic ischemia and gastric torsion, respectively. Laparoscopic and robotic pancreatic resection were both safe and feasible in selected patients with distal pancreatic pathologies. Further studies are necessary to clarify the role of robotic surgery in the advanced laparoscopic era.

  10. High resolution extremity CT for biomechanics modeling

    International Nuclear Information System (INIS)

    Ashby, A.E.; Brand, H.; Hollerbach, K.; Logan, C.M.; Martz, H.E.

    1995-01-01

    With the advent of ever more powerful computing and finite element analysis (FEA) capabilities, the bone and joint geometry detail available from either commercial surface definitions or from medical CT scans is inadequate. For dynamic FEA modeling of joints, precise articular contours are necessary to get appropriate contact definition. In this project, a fresh cadaver extremity was suspended in parafin in a lucite cylinder and then scanned with an industrial CT system to generate a high resolution data set for use in biomechanics modeling

  11. Biomechanical evaluation of the Nice knot

    OpenAIRE

    Hill, Shannon W.; Chapman, Christopher R.; Adeeb, Samer; Duke, Kajsa; Beaupre, Lauren; Bouliane, Martin J.

    2016-01-01

    Background: The Nice knot is a bulky double-stranded knot. Biomechanical data supporting its use as well as the number of half hitches required to ensure knot security is lacking. Materials and Methods: Nice knots with, one, two, or three half-hitches were compared with the surgeon′s and Tennessee slider knots with three half hitches. Each knot was tied 10 times around a fixed diameter using four different sutures: FiberWire (Arthrex, Naples, FL), Ultrabraid (Smith and Nephew, Andover, MA...

  12. Anatomy, normal variants, and basic biomechanics

    International Nuclear Information System (INIS)

    Berquist, T.H.; Johnson, K.A.

    1989-01-01

    This paper reports on the anatomy and basic functions of the foot and ankle important to physicians involved in imaging procedures, clinical medicine, and surgery. New radiographic techniques especially magnetic resonance imaging, provide more diagnostic information owing to improved tissue contrast and the ability to obtain multiple image planes (axial, sagittal, coronal, oblique). Therefore, a thorough knowledge of skeletal and soft tissue anatomy is even more essential. Normal variants must also be understood in order to distinguish normal from pathologic changes in the foot and ankle. A basic understanding of biomechanics is also essential for selecting the proper diagnostic techniques

  13. High resolution extremity CT for biomechanics modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, A.E.; Brand, H.; Hollerbach, K.; Logan, C.M.; Martz, H.E.

    1995-09-23

    With the advent of ever more powerful computing and finite element analysis (FEA) capabilities, the bone and joint geometry detail available from either commercial surface definitions or from medical CT scans is inadequate. For dynamic FEA modeling of joints, precise articular contours are necessary to get appropriate contact definition. In this project, a fresh cadaver extremity was suspended in parafin in a lucite cylinder and then scanned with an industrial CT system to generate a high resolution data set for use in biomechanics modeling.

  14. BIOMECHANICS AND PATHOMECHANICS OF THE PATELLOFEMORAL JOINT

    Science.gov (United States)

    2016-01-01

    The patellofemoral joint is a joint that can be an area of concern for athletes of various sports and ages. The joint is somewhat complex with multiple contact points and numerous tissues that attach to the patella. Joint forces are variable and depend on the degree of knee flexion and whether the foot is in contact with the ground. The sports medicine specialist must have a good working knowledge of the anatomy and biomechanics of the patellofemoral joint in order to treat it effectively. PMID:27904787

  15. [Comparison of laparoscopic distal pancreatectomy and open distal pancreatectomy in pancreatic ductal adenocarcinoma].

    Science.gov (United States)

    Xu, K; Su, J J; Su, M; Yan, L; Feng, J; Xin, X L; Chen, Y L

    2017-10-23

    Objective: To compare and evaluate the curative effect of laparoscopic distal pancreatectomy(LDP) and traditional open distal pancreatectomy(ODP) in pancreatic ductal adenocarcinoma. Methods: The clinical data of 15 patients treated by LDP and 87 contemporaneous cases treated by ODP from January 2010 to November 2015 was collected, and the curative effect and prognosis of these patients were retrospectively analyzed. Results: The operation time of LDP group was (286.5±48.1) min, significantly longer than that of OPD group(226.6±56.8) min ( P 0.05). In both LDP group and ODP group, none occurred percutaneous drainage, re-admissions, second operation or perioperative death. Conclusions: Compared to ODP, LDP is much safer and more steady in perioperative periodand operation. Patients of pancreatic ductal adenocarcinoma received LDP can acquire more benefit and recovery sooner, and LDP is a safe and effective operative method.

  16. Biomechanics in dermatology: Recent advances and future directions.

    Science.gov (United States)

    Lewinson, Ryan T; Haber, Richard M

    2017-02-01

    Biomechanics is increasingly being recognized as an important research area in dermatology. To highlight only a few examples, biomechanics has contributed to the development of novel topical therapies for aesthetic and medical purposes, enhanced our understanding of the pathogenesis of plantar melanoma, and provided insight into the epidemiology of psoriatic disease. This article summarizes the findings from recent studies to demonstrate the important role that biomechanics may have in dermatologic disease and therapy and places these biomechanical findings in a clinical context for the practicing physician. In addition, areas for future biomechanics research and development in dermatology are discussed. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  17. A Biomechanical Approach to Assessing Hip Fracture Risk

    Science.gov (United States)

    Ellman, Rachel

    2009-01-01

    Bone loss in microgravity is well documented, but it is difficult to quantify how declines in bone mineral density (BMD) contribute to an astronaut's overall risk of fracture upon return. This study uses a biomechanical approach to assessing hip fracture risk, or Factor of Risk (Phi), which is defined as the ratio of applied load to bone strength. All long-duration NASA astronauts from Expeditions 1-18 were included in this study (n=25), while crewmembers who flew twice (n=2) were treated as separate subjects. Bone strength was estimated based on an empirical relationship between areal BMD at the hip, as measured by DXA, and failure load, as determined by mechanical testing of cadaver femora. Fall load during a sideways fall was calculated from a previously developed biomechanical model, which takes into account body weight, height, gender, and soft tissue thickness overlying the lateral aspect of the hip that serves to attenuate the impact force. While no statistical analyses have been performed yet, preliminary results show that males in this population have a higher FOR than females, with a post- flight Phi of 0.87 and 0.36, respectively. FOR increases 5.1% from preflight to postflight, while only one subject crossed the fracture "threshold" of Phi = 1, for a total of 2 subjects with a postflight Phi > 1. These results suggest that men may be at greater risk for hip fracture due largely in part to their relatively thin soft tissue padding as compared to women, since soft tissue thickness has the highest correlation (R(exp 2)= .53) with FOR of all subject-specific parameters. Future work will investigate changes in FOR during recovery to see if baseline risk levels are restored upon return to 1-g activity. While dual x-ray absorptiometry (DXA) is the most commonly used clinical measure of bone health, it fails to provide compartment-specific information that is useful in assessing changes to bone quality as a result of microgravity exposure. Peripheral

  18. Young Children's Sibling Relationship Quality: Distal and Proximal Correlates

    Science.gov (United States)

    Kretschmer, Tina; Pike, Alison

    2009-01-01

    Background: Relationships within families are interdependent and related to distal environmental factors. Low socioeconomic status (SES) and high household chaos (distal factors) have been linked to less positive marital and parent-child relationships, but have not yet been examined with regard to young children's sibling relationships. The…

  19. Distal clavicular osteolysis: MR evidence for subchondral fracture

    Energy Technology Data Exchange (ETDEWEB)

    Kassarjian, Ara; Palmer, William E. [Massachusetts General Hospital, Department of Radiology, Division of Musculoskeletal Radiology, Yawkey Center, Boston, MA (United States); Llopis, Eva [Hospital de la Ribera, Department of Radiology, Valencia (Spain)

    2007-01-15

    To investigate the association between distal clavicular osteolysis and subchondral fractures of the distal clavicle at MRI. This study was approved by the hospital human research committee, which waived the need for informed consent. Three radiologists retrospectively analyzed 36 shoulder MR examinations in 36 patients with imaging findings of distal clavicular osteolysis. The presence of a subchondral fracture of the distal clavicle, abnormalities of the acromioclavicular joint, rotator cuff tears and labral tears were assessed by MRI. These cases were then compared with 36 age-matched controls. At MRI, 31 of 36 patients (86%) had a subchondral line within the distal clavicular edema, consistent with a subchondral fracture. Of the 36 patients, 32 (89%) had fluid in the acromioclavicular joint, while 27 of 36 patients (75%) had cysts or erosions in the distal clavicle. There were 13 patients (36%) with associated labral tears, while eight patients (22%) had partial-thickness rotator cuff tears. In the control group one of 36 (3%) had a subchondral line (P<0.05), while ten of 36 (28%) had rotator cuff tears and 13 of 36 (36%) had labral tears. These latter two were not statistically significant between the groups. A distal clavicular subchondral fracture is a common finding in patients with imaging evidence of distal clavicular osteolysis. These subchondral fractures may be responsible for the propensity of findings occurring on the clavicular side of the acromioclavicular joint. (orig.)

  20. Distal clavicular osteolysis: MR evidence for subchondral fracture

    International Nuclear Information System (INIS)

    Kassarjian, Ara; Palmer, William E.; Llopis, Eva

    2007-01-01

    To investigate the association between distal clavicular osteolysis and subchondral fractures of the distal clavicle at MRI. This study was approved by the hospital human research committee, which waived the need for informed consent. Three radiologists retrospectively analyzed 36 shoulder MR examinations in 36 patients with imaging findings of distal clavicular osteolysis. The presence of a subchondral fracture of the distal clavicle, abnormalities of the acromioclavicular joint, rotator cuff tears and labral tears were assessed by MRI. These cases were then compared with 36 age-matched controls. At MRI, 31 of 36 patients (86%) had a subchondral line within the distal clavicular edema, consistent with a subchondral fracture. Of the 36 patients, 32 (89%) had fluid in the acromioclavicular joint, while 27 of 36 patients (75%) had cysts or erosions in the distal clavicle. There were 13 patients (36%) with associated labral tears, while eight patients (22%) had partial-thickness rotator cuff tears. In the control group one of 36 (3%) had a subchondral line (P<0.05), while ten of 36 (28%) had rotator cuff tears and 13 of 36 (36%) had labral tears. These latter two were not statistically significant between the groups. A distal clavicular subchondral fracture is a common finding in patients with imaging evidence of distal clavicular osteolysis. These subchondral fractures may be responsible for the propensity of findings occurring on the clavicular side of the acromioclavicular joint. (orig.)

  1. Intra-articular osteotomy for distal humerus malunion

    NARCIS (Netherlands)

    Marti, René K.; Doornberg, Job

    2009-01-01

    Intra-articular osteotomy is considered in the rare case of malunion after a fracture of the distal humerus to restore humeral alignment and gain a functional arc of elbow motion. Traumatic and iatrogenic disruption of the limited blood flow to the distal end of the humerus resulting in avascular

  2. Clinical relevance of distal biceps insertional and footprint anatomy

    NARCIS (Netherlands)

    van den Bekerom, Michel P J; Kodde, Izaäk F.; Aster, Asir; Bleys, Ronald L A W; Eygendaal, Denise

    2016-01-01

    Purpose: The aim of this review was to present an overview, based on a literature search, of surgical anatomy for distal biceps tendon repairs, based on the current literature. Methods: A narrative review was performed using Pubmed/Medline using key words: Search terms were distal biceps,

  3. Distal tibiofibular synostosis in a Nigerian: A case report | Owoeye ...

    African Journals Online (AJOL)

    X-ray of the bones showed an oblique fracture in the distal end of the shaft of fibula which is suggestive of post traumatic tibiofibular synostosis (TFS). Knowledge of distal TFS is important in resolving the puzzle of chronic shin pain of unknown origin and in accurate diagnosis of causes of ankle deformity and malformations.

  4. Radiographic study of distal radial physeal closure in thoroughbred horses

    International Nuclear Information System (INIS)

    Vulcano, L.C.; Mamprim, M.J.; Muniz, L.M.R.; Moreira, A.F.; Luna, S.P.L.

    1997-01-01

    Monthly radiography was performed to study distal radial physeal closure in ten male and ten female Throughbred horses. The height, thoracic circumference and metacarpus circumference were also measured, Distal radial physeal closure time was sooner in females than males, and took 701 +/- 37 and 748 +/- 55 days respectively

  5. Alterations of bone density, microstructure, and strength of the distal radius in male patients with rheumatoid arthritis: a case-control study with HR-pQCT.

    Science.gov (United States)

    Zhu, Tracy Y; Griffith, James F; Qin, Ling; Hung, Vivian W; Fong, Tsz-Ning; Au, Sze-Ki; Li, Martin; Lam, Yvonne Yi-On; Wong, Chun-Kwok; Kwok, Anthony W; Leung, Ping-Chung; Li, Edmund K; Tam, Lai-Shan

    2014-09-01

    In this cross-sectional study, we investigated volumetric bone mineral density (vBMD), bone microstructure, and biomechanical competence of the distal radius in male patients with rheumatoid arthritis (RA). The study cohort comprised 50 male RA patients of average age of 61.1 years and 50 age-matched healthy males. Areal BMD (aBMD) of the hip, lumbar spine, and distal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius provided measures of cortical and trabecular vBMD, microstructure, and biomechanical indices. aBMD of the hip but not the lumbar spine or ultradistal radius was significantly lower in RA patients than controls after adjustment for body weight. Total, cortical, and trabecular vBMD at the distal radius were, on average, -3.9% to -23.2% significantly lower in RA patients, and these differences were not affected by adjustment for body weight, testosterone level, or aBMD at the ultradistal radius. Trabecular microstructure indices were, on average, -8.1% (trabecular number) to 28.7% (trabecular network inhomogeneity) significantly inferior, whereas cortical pore volume and cortical porosity index were, on average, 80.3% and 63.9%, respectively, significantly higher in RA patients. RA patients also had significantly lower whole-bone stiffness, modulus, and failure load, with lower and more unevenly distributed cortical and trabecular stress. Density and microstructure indices significantly correlated with disease activity, severity, and levels of pro-inflammatory cytokines (interleukin [IL] 12p70, tumor necrosis factor, IL-6 and IL-1β). Ten RA patients had focal periosteal bone apposition most prominent at the ulnovolar aspect of the distal radius. These patients had shorter disease duration and significantly higher cortical porosity. In conclusion, HR-pQCT reveals significant alterations of bone density, microstructure, and strength of the distal radius in

  6. Adaptive sports technology and biomechanics: wheelchairs.

    Science.gov (United States)

    Cooper, Rory A; De Luigi, Arthur Jason

    2014-08-01

    Wheelchair sports are an important tool in the rehabilitation of people with severe chronic disabilities and have been a driving force for innovation in technology and practice. In this paper, we will present an overview of the adaptive technology used in Paralympic sports with a special focus on wheeled technology and the impact of design on performance (defined as achieving the greatest level of athletic ability and minimizing the risk of injury). Many advances in manual wheelchairs trace their origins to wheelchair sports. Features of wheelchairs that were used for racing and basketball 25 or more years ago have become integral to the manual wheelchairs that people now use every day; moreover, the current components used on ultralight wheelchairs also have benefitted from technological advances developed for sports wheelchairs. For example, the wheels now used on chairs for daily mobility incorporate many of the components first developed for sports chairs. Also, advances in manufacturing and the availability of aerospace materials have driven current wheelchair design and manufacture. Basic principles of sports wheelchair design are universal across sports and include fit; minimizing weight while maintaining high stiffness; minimizing rolling resistance; and optimizing the sports-specific design of the chair. However, a well-designed and fitted wheelchair is not sufficient for optimal sports performance: the athlete must be well trained, skilled, and use effective biomechanics because wheelchair athletes face some unique biomechanical challenges. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  7. Integrative Structural Biomechanical Concepts of Ankylosing Spondylitis

    Directory of Open Access Journals (Sweden)

    Alfonse T. Masi

    2011-01-01

    Full Text Available Ankylosing spondylitis (AS is not fully explained by inflammatory processes. Clinical, epidemiological, genetic, and course of disease features indicate additional host-related risk processes and predispositions. Collectively, the pattern of predisposition to onset in adolescent and young adult ages, male preponderance, and widely varied severity of AS is unique among rheumatic diseases. However, this pattern could reflect biomechanical and structural differences between the sexes, naturally occurring musculoskeletal changes over life cycles, and a population polymorphism. During juvenile development, the body is more flexible and weaker than during adolescent maturation and young adulthood, when strengthening and stiffening considerably increase. During middle and later ages, the musculoskeletal system again weakens. The novel concept of an innate axial myofascial hypertonicity reflects basic mechanobiological principles in human function, tissue reactivity, and pathology. However, these processes have been little studied and require critical testing. The proposed physical mechanisms likely interact with recognized immunobiological pathways. The structural biomechanical processes and tissue reactions might possibly precede initiation of other AS-related pathways. Research in the combined structural mechanobiology and immunobiology processes promises to improve understanding of the initiation and perpetuation of AS than prevailing concepts. The combined processes might better explain characteristic enthesopathic and inflammatory processes in AS.

  8. Integrated biomechanical and topographical surface characterization (IBTSC)

    Energy Technology Data Exchange (ETDEWEB)

    Löberg, Johanna, E-mail: Johanna.Loberg@dentsply.com [Dentsply Implants, Box 14, SE-431 21 Mölndal (Sweden); Mattisson, Ingela [Dentsply Implants, Box 14, SE-431 21 Mölndal (Sweden); Ahlberg, Elisabet [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-41296 Gothenburg (Sweden)

    2014-01-30

    In an attempt to reduce the need for animal studies in dental implant applications, a new model has been developed which combines well-known surface characterization methods with theoretical biomechanical calculations. The model has been named integrated biomechanical and topographical surface characterization (IBTSC), and gives a comprehensive description of the surface topography and the ability of the surface to induce retention strength with bone. IBTSC comprises determination of 3D-surface roughness parameters by using 3D-scanning electron microscopy (3D-SEM) and atomic force microscopy (AFM), and calculation of the ability of different surface topographies to induce retention strength in bone by using the local model. Inherent in this integrated approach is the use of a length scale analysis, which makes it possible to separate different size levels of surface features. The IBTSC concept is tested on surfaces with different level of hierarchy, induced by mechanical as well as chemical treatment. Sequential treatment with oxalic and hydrofluoric acid results in precipitated nano-sized features that increase the surface roughness and the surface slope on the sub-micro and nano levels. This surface shows the highest calculated shear strength using the local model. The validity, robustness and applicability of the IBTSC concept are demonstrated and discussed.

  9. A FUNCTIONAL EVALUATION STUDY OF DISTAL FEMORAL FRACTURES FIXED WITH DISTAL FEMORAL LOCKING PLATE

    Directory of Open Access Journals (Sweden)

    Manikumar C. J

    2017-04-01

    Full Text Available BACKGROUND Fractures of the distal femur present considerable challenges in management. Older patients especially women sustain fractures due to osteoporosis. Supracondylar fractures of femur have a bimodal distribution. They account for 6% of all femur fractures and 31% if hip fractures were excluded. Nearly, 50% of distal femur intra-articular fractures are open fractures. Before 1970, most supracondylar fractures were treated nonoperatively; however, difficulties were often encountered including persistent angulatory deformity, knee joint incongruity, loss of knee motion and delayed mobilisation. The trend of open reduction and internal fixation has become evident in recent years with good results being obtained with AO blade plate, dynamic condylar screw, intramedullary supracondylar nail and locking compression plate. Elderly patients and osteoporosis pose difficulty in treating intra-articular fractures of the lower end of femur. Loss of stable fixation is of great concern in these cases. Hence, locking compression plate use has an advantage in these patients. MATERIALS AND METHODS In this study, 20 patients with closed fracture of distal femur were studied. All the cases were treated at the Department of Orthopaedics, Rangaraya Medical College/Government General Hospital, Kakinada, Andhra Pradesh, between November 2013 and November 2015. The method used for fracture fixation was open reduction and internal fixation with distal femoral locking plate. The duration of follow up ranged from 3 months to 24 months. All the fractures in this series were posttraumatic. The patients were functionally evaluated with Neer’s scoring system. 1 RESULTS Twenty distal femoral fractures were treated with distal femoral locking plates. 15 patients were males and 5 patients were females. The median age was 47 years ranging from 28-70 years. 16 of the fractures were caused by road traffic accidents and 2 were due to fall, 2 were due to assault. 12 patients

  10. Rehabilitation for distal radial fractures in adults.

    Science.gov (United States)

    Handoll, Helen H G; Elliott, Joanne

    2015-09-25

    Fracture of the distal radius is a common clinical problem, particularly in older people with osteoporosis. There is considerable variation in the management, including rehabilitation, of these fractures. This is an update of a Cochrane review first published in 2002 and last updated in 2006. To examine the effects of rehabilitation interventions in adults with conservatively or surgically treated distal radial fractures. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL 2014; Issue 12), MEDLINE, EMBASE, CINAHL, AMED, PEDro, OTseeker and other databases, trial registers, conference proceedings and reference lists of articles. We did not apply any language restrictions. The date of the last search was 12 January 2015. Randomised controlled trials (RCTs) or quasi-RCTs evaluating rehabilitation as part of the management of fractures of the distal radius sustained by adults. Rehabilitation interventions such as active and passive mobilisation exercises, and training for activities of daily living, could be used on their own or in combination, and be applied in various ways by various clinicians. The review authors independently screened and selected trials, and reviewed eligible trials. We contacted study authors for additional information. We did not pool data. We included 26 trials, involving 1269 mainly female and older patients. With few exceptions, these studies did not include people with serious fracture or treatment-related complications, or older people with comorbidities and poor overall function that would have precluded trial participation or required more intensive treatment. Only four of the 23 comparisons covered by these 26 trials were evaluated by more than one trial. Participants of 15 trials were initially treated conservatively, involving plaster cast immobilisation. Initial treatment was surgery (external fixation or internal fixation) for all participants

  11. Distal Stressors and Depression among Homeless Men.

    Science.gov (United States)

    Coohey, Carol; Easton, Scott D

    2016-05-01

    Depression is a common problem among homeless men that may interfere with functional tasks, such as securing stable housing, obtaining employment, and accessing health services. Previous research on depression among homeless men has largely focused on current psychosocial resources, substance abuse, and past victimization. Guided by Ensel and Lin's life course stress process model, the authors examined whether distal stressors, including victimization and exposure to parent problems in childhood, contributed to men's depression above and beyond current (or proximal) stressors, such as substance abuse and health problems, and social resources. The sample consisted of 309 homeless men who had entered a federally funded emergency shelter. Using the Burns Depression Checklist, the authors found that one out of three men met the threshold for moderate to severe depression during the past week. The logistic regression showed that past exposure to parent problems was related to depression after accounting for current stressors and social resources (number of close adult relationships and whether their emotional support needs were met). Past victimization was not related to depression. To address men's depression, workers should concurrently provide services that meet men's basic needs (for example, housing) and address their relationship needs, including their need for emotional support.

  12. Movement of the distal carpal row during narrowing and widening of the carpal arch width.

    Science.gov (United States)

    Gabra, Joseph N; Domalain, Mathieu; Li, Zong-Ming

    2012-10-01

    Change in carpal arch width (CAW) is associated with wrist movement, carpal tunnel release, or therapeutic tunnel manipulation. This study investigated the angular rotations of the distal carpal joints as the CAW was adjusted. The CAW was narrowed and widened by 2 and 4 mm in seven cadaveric specimens while the bone positions were tracked by a marker-based motion capture system. The joints mainly pronated during CAW narrowing and supinated during widening. Ranges of motion about the pronation axis for the hamate-capitate (H-C), capitate-trapezoid (C-Td), and trapezoid-trapezium (Td-Tm) joints were 8.1 ± 2.3 deg, 5.3 ± 1.3 deg, and 5.5 ± 3.5 deg, respectively. Differences between the angular rotations of the joints were found at ΔCAW = -4 mm about the pronation and ulnar-deviation axes. For the pronation axis, angular rotations of the H-C joint were larger than that of the C-Td and Td-Tm joints. Statistical interactions among the factors of joint, rotation axis, and ΔCAW indicated complex joint motion patterns. The complex three-dimensional motion of the bones can be attributed to several anatomical constraints such as bone arrangement, ligament attachments, and articular congruence. The results of this study provide insight into the mechanisms of carpal tunnel adaptations in response to biomechanical alterations of the structural components.

  13. Teaching undergraduate biomechanics with Just-in-Time Teaching.

    Science.gov (United States)

    Riskowski, Jody L

    2015-06-01

    Biomechanics education is a vital component of kinesiology, sports medicine, and physical education, as well as for many biomedical engineering and bioengineering undergraduate programmes. Little research exists regarding effective teaching strategies for biomechanics. However, prior work suggests that student learning in undergraduate physics courses has been aided by using the Just-in-Time Teaching (JiTT). As physics understanding plays a role in biomechanics understanding, the purpose of study was to evaluate the use of a JiTT framework in an undergraduate biomechanics course. This two-year action-based research study evaluated three JiTT frameworks: (1) no JiTT; (2) mathematics-based JiTT; and (3) concept-based JiTT. A pre- and post-course assessment of student learning used the biomechanics concept inventory and a biomechanics concept map. A general linear model assessed differences between the course assessments by JiTT framework in order to evaluate learning and teaching effectiveness. The results indicated significantly higher learning gains and better conceptual understanding in a concept-based JiTT course, relative to a mathematics-based JiTT or no JiTT course structure. These results suggest that a course structure involving concept-based questions using a JiTT strategy may be an effective method for engaging undergraduate students and promoting learning in biomechanics courses.

  14. Artificial intelligence in sports biomechanics: new dawn or false hope?

    Science.gov (United States)

    Bartlett, Roger

    2006-12-15

    This article reviews developments in the use of Artificial Intelligence (AI) in sports biomechanics over the last decade. It outlines possible uses of Expert Systems as diagnostic tools for evaluating faults in sports movements ('techniques') and presents some example knowledge rules for such an expert system. It then compares the analysis of sports techniques, in which Expert Systems have found little place to date, with gait analysis, in which they are routinely used. Consideration is then given to the use of Artificial Neural Networks (ANNs) in sports biomechanics, focusing on Kohonen self-organizing maps, which have been the most widely used in technique analysis, and multi-layer networks, which have been far more widely used in biomechanics in general. Examples of the use of ANNs in sports biomechanics are presented for javelin and discus throwing, shot putting and football kicking. I also present an example of the use of Evolutionary Computation in movement optimization in the soccer throw in, which predicted an optimal technique close to that in the coaching literature. After briefly overviewing the use of AI in both sports science and biomechanics in general, the article concludes with some speculations about future uses of AI in sports biomechanics. Key PointsExpert Systems remain almost unused in sports biomechanics, unlike in the similar discipline of gait analysis.Artificial Neural Networks, particularly Kohonen Maps, have been used, although their full value remains unclear.Other AI applications, including Evolutionary Computation, have received little attention.

  15. MINIMAL INVASIVE PLATE OSTEOSYNTHESIS- AN EFFECTIVE TREATMENT METHOD FOR DISTAL TIBIA INTRAARTICULAR (PILON FRACTURES- AN 18 MONTHS FOLLOW UP

    Directory of Open Access Journals (Sweden)

    Saket Jati

    2016-12-01

    Full Text Available BACKGROUND Tibial pilon fracture though requires operative treatment is difficult to manage. Conventional osteosynthesis is not suitable, because distal tibia is subcutaneous bone with poor vascularity. Closed reduction and Minimally Invasive Plate Osteosynthesis (MIPO for distal tibia has emerged as an alternative treatment option because it respects fracture biology and haematoma and also provides biomechanically stable construct. The aim of the study is to evaluate the results of minimally invasive plate osteosynthesis using locking plates in treating tibial pilon fractures in terms of fracture union, restoration of ankle function and complications. MATERIALS AND METHODS 30 patients with closed tibial pilon fractures (Ruedi and Allgower type I (14, type II (13, type III (3 treated with MIPO with Locking Compression Plates (LCP were prospectively followed for average duration of 18 months. RESULTS Average duration of injury-hospital and injury-surgery interval was as 12.05 hrs. and 3.50 days, respectively. All fractures got united with an average duration of 20.8 weeks (range 14-28 weeks. Olerud and Molander score was used for evaluation at 3 months, 6 months and 18 months. One patient had union with valgus angulation of 15 degrees, but no nonunion was found. CONCLUSION The present study shows that MIPO with LCP is an effective treatment method in terms of union time and complications rate for tibial pilon fracture promoting early union and early weight bearing.

  16. Biomechanical and Hemodynamic Measures of Right Ventricular Diastolic Function: Translating Tissue Biomechanics to Clinical Relevance.

    Science.gov (United States)

    Jang, Sae; Vanderpool, Rebecca R; Avazmohammadi, Reza; Lapshin, Eugene; Bachman, Timothy N; Sacks, Michael; Simon, Marc A

    2017-09-12

    Right ventricular (RV) diastolic function has been associated with outcomes for patients with pulmonary hypertension; however, the relationship between biomechanics and hemodynamics in the right ventricle has not been studied. Rat models of RV pressure overload were obtained via pulmonary artery banding (PAB; control, n=7; PAB, n=5). At 3 weeks after banding, RV hemodynamics were measured using a conductance catheter. Biaxial mechanical properties of the RV free wall myocardium were obtained to extrapolate longitudinal and circumferential elastic modulus in low and high strain regions (E 1 and E 2 , respectively). Hemodynamic analysis revealed significantly increased end-diastolic elastance (E ed ) in PAB (control: 55.1 mm Hg/mL [interquartile range: 44.7-85.4 mm Hg/mL]; PAB: 146.6 mm Hg/mL [interquartile range: 105.8-155.0 mm Hg/mL]; P =0.010). Longitudinal E 1 was increased in PAB (control: 7.2 kPa [interquartile range: 6.7-18.1 kPa]; PAB: 34.2 kPa [interquartile range: 18.1-44.6 kPa]; P =0.018), whereas there were no significant changes in longitudinal E 2 or circumferential E 1 and E 2 . Last, wall stress was calculated from hemodynamic data by modeling the right ventricle as a sphere: stress=Pressure×radius2×thickness. RV pressure overload in PAB rats resulted in an increase in diastolic myocardial stiffness reflected both hemodynamically, by an increase in E ed , and biomechanically, by an increase in longitudinal E 1 . Modest increases in tissue biomechanical stiffness are associated with large increases in E ed . Hemodynamic measurements of RV diastolic function can be used to predict biomechanical changes in the myocardium. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  17. A comparison between robotic-assisted laparoscopic distal pancreatectomy versus laparoscopic distal pancreatectomy.

    Science.gov (United States)

    Goh, Brian K P; Chan, Chung Yip; Soh, Hui-Ling; Lee, Ser Yee; Cheow, Peng-Chung; Chow, Pierce K H; Ooi, London L P J; Chung, Alexander Y F

    2017-03-01

    This study aims to compare the early perioperative outcomes of robotic-assisted laparoscopic distal pancreatectomy (RDP) versus laparoscopic distal pancreatectomy (LDP). The clinicopathologic features of 45 consecutive patients who underwent minimally-invasive distal pancreatectomy from 2006 to 2015 were retrospectively reviewed. Thirty-nine patients who met our study criteria were included. Eight patients underwent RDP and 31 had LDP. There were 10 (25.6%) open conversions. Six (15.4%) patients had major (> grade 2) morbidities and there was no in-hospital mortality. There were 14 (35.9%) grade A and 9 (23.1%) grade B pancreatic fistulas. Comparison between RDP and LDP demonstrated no significant difference between the patients' baseline characteristics except there was increased frequency of spleen-preserving pancreatectomies (3 (37.5%) vs 25 (80.6%), P=0.016) and splenic-vessel preservation (5 (62.5%) vs 4 (12.9%), P=0.003) in RDP. Comparison between outcomes demonstrated that RDP was associated with a longer median operation time (452.5 (range, 300-685) vs 245 min (range, 85-430), P=0.001) and increased frequency of the procedure completed purely laparoscopically (8 (100%) vs 18 (58.1%), P=0.025). RDP can be safely adopted and is equivalent to LDP in most perioperative outcomes. It is also associated with a decreased frequency of the need for hand-assistance laparoscopic surgery or open conversion but needed a longer operation time. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Unilateral maxillary molar distalization with zygoma-gear appliance.

    Science.gov (United States)

    Kilkis, Dogan; Bayram, Mehmet; Celikoglu, Mevlut; Nur, Metin

    2012-08-01

    The aim of this study was to present the orthodontic treatment of a 15-year-old boy with a unilateral maxillary molar distalization system, called the zygoma-gear appliance. It consisted of a zygomatic anchorage miniplate, an inner bow, and a Sentalloy closed coil spring (GAC International, Bohemia, NY). A distalizing force of 350 g was used during the distalization period. The unilateral Class II malocclusion was corrected in 5 months with the zygoma-gear appliance. The maxillary left first molar showed distalization of 4 mm with an inclination of 3°. The maxillary premolars moved distally with the help of the transseptal fibers. In addition, there were slight decreases in overjet (-0.5 mm) and maxillary incisor inclination (-1°), indicating no anchorage loss from the zygoma-gear appliance. Preadjusted fixed appliances (0.022 × 0.028-in, MBT system; 3M Unitek, Monrovia, Calif) were placed in both arches to achieve leveling and alignment. After 14 months of unilateral distalization with the zygoma-gear appliance and fixed appliances, Class I molar and canine relationships were established with satisfactory interdigitation of the posterior teeth. Acceptable overjet and overbite were also achieved. This article shows that this new system, the zygoma-gear appliance, can be used for unilateral maxillary molar distalization without anchorage loss. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  19. Biomechanical ToolKit: Open-source framework to visualize and process biomechanical data.

    Science.gov (United States)

    Barre, Arnaud; Armand, Stéphane

    2014-04-01

    C3D file format is widely used in the biomechanical field by companies and laboratories to store motion capture systems data. However, few software packages can visualize and modify the integrality of the data in the C3D file. Our objective was to develop an open-source and multi-platform framework to read, write, modify and visualize data from any motion analysis systems using standard (C3D) and proprietary file formats (used by many companies producing motion capture systems). The Biomechanical ToolKit (BTK) was developed to provide cost-effective and efficient tools for the biomechanical community to easily deal with motion analysis data. A large panel of operations is available to read, modify and process data through C++ API, bindings for high-level languages (Matlab, Octave, and Python), and standalone application (Mokka). All these tools are open-source and cross-platform and run on all major operating systems (Windows, Linux, MacOS X). Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Potassium transport across guinea pig distal colon

    International Nuclear Information System (INIS)

    Rechkemmer, G.; Halm, D.R.; Frizzell, R.A.

    1986-01-01

    Active absorption and secretion of K was studied by measuring bidirectional 42 K fluxes across short-circuited guinea pig distal colon. Tissues were pretreated with mucosal (m) and serosal (s) indomethacin (1 μM) and amiloride (0.1 mM, m) to suppress spontaneous, electrogenic Cl secretion and Na absorption. Under these conditions, the short-circuit current (I/sub sc/) was 0.4 μeq/cm 2 h while electroneutral K absorption was 2.8 μeq/cm 2 h. Epinephrine (5 μM, s) stimulated electrogenic K secretion, reducing net K absorption to 1.3 μeq/cm 2 h. Bumetanide (0.1 mM, s) abolished this K secretion and restored K absorption to control values, suggesting mechanistic similarities between K and Cl secretion. K absorption was inhibited 40% by the gastric H/K ATPase inhibitor, omeprazole (0.1 mM, m), and was abolished by ouabain (0.1 mM, m). Neutral K absorption does not appear to be mediated by an apical membrane Na/K pump since: the effect of mucosal ouabain on K absorption does not require the presence of mucosal or serosal Na, unidirectional Na fluxes are not influenced by mucosal ouabain, and K absorption is not affected when Na absorption is abolished by amiloride. Net K transport is determined by the balance between electroneutral K absorption and electrogenic K secretion. The ouabain sensitivity of K absorption suggests that colonic H/K ATPase differs from its gastric counterpart

  1. Histology of the distal dural ring.

    Science.gov (United States)

    Graffeo, Christopher S; Perry, Avital; Copeland, William R; Raghunathan, Aditya; Link, Michael J

    2017-09-01

    The distal dural ring (DDR) is a conserved intracranial anatomic structure marking the boundary point at which the internal carotid artery (ICA) exits the cavernous sinus (CS) and enters the subarachnoid space. Although the CS has been well described in a range of anatomic studies, to our knowledge no prior study has analyzed the histologic relationship between the ICA and DDR. Correspondingly, our objective was to assess the relationship of the DDR to the ICA and determine whether the DDR can be dissected from the ICA and thus divided, or can only be circumferentially trimmed around the artery. The authors examined ten fresh-frozen, adult cadaveric specimens. A standard frontotemporal craniotomy, orbito-optic osteotomy, and extradural anterior clinoidectomy was performed bilaterally. The cavernous ICA, DDR, and supraclinoid ICA were harvested as an en bloc specimen. Specimens formalin-fixed and paraffin-embedded prior to routine histochemical staining with hematoxylin and eosin and Masson trichrome. In all specimens, marked microscopic investment of the DDR throughout the ICA adventitia was noted. Dural collagen fibers extensively permeated the arterial layers superficial to the muscularis propria, with no evidence of a clear separation between the DDR and arterial adventitia. Histologic analysis suggests that the ICA and DDR are highly interrelated, continuous structures, and therefore attempted intraoperative dissection between these structures may carry an elevated risk of injury to the ICA. We correspondingly recommend careful circumferential trimming of the DDR in lieu of direct dissection in cases requiring mobilization of the clinoidal ICA. Clin. Anat. 30:742-746, 2017. © 2017Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Research in biomechanics of occupant protection.

    Science.gov (United States)

    King, A I; Yang, K H

    1995-04-01

    This paper discusses the biomechanical bases for occupant protection against frontal and side impact. Newton's Laws of Motion are used to illustrate the effect of a crash on restrained and unrestrained occupants, and the concept of ride down is discussed. Occupant protection through the use of energy absorbing materials is described, and the mechanism of injury of some of the more common injuries is explained. The role of the three-point belt and the airbag in frontal protection is discussed along with the potential injuries that can result from the use of these restraint systems. Side impact protection is more difficult to attain but some protection can be derived from the use of padding or a side impact airbag. It is concluded that the front seat occupants are adequately protected against frontal impact if belts are worn in an airbag equipped vehicle. Side impact protection may not be uniform in all vehicles.

  3. Patellofemoral anatomy and biomechanics: current concepts

    Science.gov (United States)

    ZAFFAGNINI, STEFANO; DEJOUR, DAVID; GRASSI, ALBERTO; BONANZINGA, TOMMASO; MUCCIOLI, GIULIO MARIA MARCHEGGIANI; COLLE, FRANCESCA; RAGGI, FEDERICO; BENZI, ANDREA; MARCACCI, MAURILIO

    2013-01-01

    The patellofemoral joint, due to its particular bone anatomy and the numerous capsuloligamentous structures and muscles that act dynamically on the patella, is considered one of the most complex joints in the human body from the biomechanical point of view. The medial patellofemoral ligament (MPFL) has been demonstrated to contribute 60% of the force that opposes lateral displacement of the patella, and MPFL injury results in an approximately 50% reduction in the force needed to dislocate the patella laterally with the knee extended. For this reason, recent years have seen a growing interest in the study of this important anatomical structure, whose aponeurotic nature has thus been demonstrated. The MPFL acts as a restraint during motion, playing an active role under conditions of laterally applied stress, but an only marginal role during natural knee flexion. However, it remains extremely difficult to clearly define the anatomy of the MPFL and its relationships with other anatomical structures. PMID:25606512

  4. Integrative Role Of Cinematography In Biomechanics Research

    Science.gov (United States)

    Zernicke, Ronald F.; Gregor, Robert J.

    1982-02-01

    Cinematography is an integral element in the interdisciplinary biomechanics research conducted in the Department of Kinesiology at the University of California, Los Angeles. For either an isolated recording of a movement phenomenon or as a recording component which is synchronized with additional transducers and recording equipment, high speed motion picture film has been effectively incorporated into resr'arch projects ranging from two and three dimensional analyses of human movements, locomotor mechanics of cursorial mammals and primates, to the structural responses and dynamic geometries of skeletal muscles, tendons, and ligaments. The basic equipment used in these studies includes three, 16 mm high speed, pin-registered cameras which have the capacity for electronic phase-locking. Crystal oscillators provide the generator pulses to synchronize the timing lights of the cameras and the analog-to-digital recording equipment. A rear-projection system with a sonic digitizer permits quantification of film coordinates which are stored on computer disks. The capacity for synchronizing the high speed films with additional recording equipment provides an effective means of obtaining not only position-time data from film, but also electromyographic, force platform, tendon force transducer, and strain gauge recordings from tissues or moving organisms. During the past few years, biomechanics research which comprised human studies has used both planar and three-dimensional cinematographic techniques. The studies included planar analyses which range from the gait characteristics of lower extremity child amputees to the running kinematics and kinetics of highly skilled sprinters and long-distance runners. The dynamics of race cycling and kinetics of gymnastic maneuvers were studied with cinematography and either a multi-dimensional force platform or a bicycle pedal with strain gauges to determine the time histories of the applied forces. The three-dimensional technique

  5. Biomechanics trends in modeling and simulation

    CERN Document Server

    Ogden, Ray

    2017-01-01

    The book presents a state-of-the-art overview of biomechanical and mechanobiological modeling and simulation of soft biological tissues. Seven well-known scientists working in that particular field discuss topics such as biomolecules, networks and cells as well as failure, multi-scale, agent-based, bio-chemo-mechanical and finite element models appropriate for computational analysis. Applications include arteries, the heart, vascular stents and valve implants as well as adipose, brain, collagenous and engineered tissues. The mechanics of the whole cell and sub-cellular components as well as the extracellular matrix structure and mechanotransduction are described. In particular, the formation and remodeling of stress fibers, cytoskeletal contractility, cell adhesion and the mechanical regulation of fibroblast migration in healing myocardial infarcts are discussed. The essential ingredients of continuum mechanics are provided. Constitutive models of fiber-reinforced materials with an emphasis on arterial walls ...

  6. Two-wave propagation in in vitro swine distal ulna

    Science.gov (United States)

    Mano, Isao; Horii, Kaoru; Matsukawa, Mami; Otani, Takahiko

    2015-07-01

    Ultrasonic transmitted waves were obtained in an in vitro swine distal ulna specimen, which mimics a human distal radius, that consists of interconnected cortical bone and cancellous bone. The transmitted waveforms appeared similar to the fast waves, slow waves, and overlapping fast and slow waves measured in the specimen after removing the surface cortical bone (only cancellous bone). In addition, the circumferential waves in the cortical bone and water did not affect the fast and slow waves. This suggests that the fast-and-slow-wave phenomenon can be observed in an in vivo human distal radius.

  7. Intra-Articular Osteotomy for Distal Humerus Malunion

    Directory of Open Access Journals (Sweden)

    René K. Marti

    2009-01-01

    Full Text Available Intra-articular osteotomy is considered in the rare case of malunion after a fracture of the distal humerus to restore humeral alignment and gain a functional arc of elbow motion. Traumatic and iatrogenic disruption of the limited blood flow to the distal end of the humerus resulting in avascular necrosis of capitellum or trochlea is a major pitfall of the this technically challenging procedure. Two cases are presented which illustrate the potential problems of intra-articular osteotomy for malunion of the distal humerus.

  8. A biomechanical model of mammographic compressions.

    Science.gov (United States)

    Chung, J H; Rajagopal, V; Nielsen, P M F; Nash, M P

    2008-02-01

    A number of biomechanical models have been proposed to improve nonrigid registration techniques for multimodal breast image alignment. A deformable breast model may also be useful for overcoming difficulties in interpreting 2D X-ray projections (mammograms) of 3D volumes (breast tissues). If a deformable model could accurately predict the shape changes that breasts undergo during mammography, then the model could serve to localize suspicious masses (visible in mammograms) in the unloaded state, or in any other deformed state required for further investigations (such as biopsy or other medical imaging modalities). In this paper, we present a validation study that was conducted in order to develop a biomechanical model based on the well-established theory of continuum mechanics (finite elasticity theory with contact mechanics) and demonstrate its use for this application. Experimental studies using gel phantoms were conducted to test the accuracy in predicting mammographic-like deformations. The material properties of the gel phantom were estimated using a nonlinear optimization process, which minimized the errors between the experimental and the model-predicted surface data by adjusting the parameter associated with the neo-Hookean constitutive relation. Two compressions (the equivalent of cranio-caudal and medio-lateral mammograms) were performed on the phantom, and the corresponding deformations were recorded using a MRI scanner. Finite element simulations were performed to mimic the experiments using the estimated material properties with appropriate boundary conditions. The simulation results matched the experimental recordings of the deformed phantom, with a sub-millimeter root-mean-square error for each compression state. Having now validated our finite element model of breast compression, the next stage is to apply the model to clinical images.

  9. WorldSID Prototype Dummy Biomechanical Responses.

    Science.gov (United States)

    Cesari, D; Compigne, S; Scherer, R; Xu, L; Takahashi, N; Page, M; Asakawa, K; Kostyniuk, G; Hautmann, E; Bortenschlager, K; Sakurai, M; Harigae, T

    2001-11-01

    The results of biomechanical testing of the WorldSID prototype dummy are presented in this paper. The WorldSID dummy is a new, advanced Worldwide Side Impact Dummy that has the anthropometry of a mid-sized adult male. The first prototype of this dummy has been evaluated by the WorldSID Task Group against previously established corridors for its critical body regions. The response corridors are defined in the International Organization of Standardization (ISO) Technical Report 9790. The prototype is the first version of the WorldSID dummy to be built and tested. This dummy has been subjected to a rigorous program of testing to evaluate, first and foremost its biofidelity, but also its repeatability. Following this initial evaluation, any required modifications will be incorporated into a pre-production version of the WorldSID dummy so that it rates "good" to "excellent" on the ISO dummy biofidelity scale - a rating exceeding that of all current side impact dummies. Also, the overall WorldSID repeatability must not exceed a coefficient of variation of 7% at injury assessment level and this has to be verified for the different body regions. The dummy's head, neck, thorax, abdomen and pelvis were evaluated against the ISO technical report requirements. Testing included drop tests, pendulum impacts, and sled tests. The biofidelity rating of the WorldSID prototype was calculated using the weighted biomechanical test response procedure developed by ISO. The paper presents the results of the testing, which give a very positive indication of the dummy's potential. Based on this evaluation of the dummy biofidelity, the WorldSID prototype dummy exhibits a biofidelity rating of 6.15 that corresponds to an ISO biofidelity classification of "fair". In addition, the dummy shows good repeatability with a global coefficient of variation of 3.30% for the pendulum and rigid sled tests.

  10. Biomechanical implications of walking with indigenous footwear.

    Science.gov (United States)

    Willems, Catherine; Stassijns, Gaetane; Cornelis, Wim; D'Août, Kristiaan

    2017-04-01

    This study investigates biomechanical implications of walking with indigenous "Kolhapuri" footwear compared to barefoot walking among a population of South Indians. Ten healthy adults from South India walked barefoot and indigenously shod at voluntary speed on an artificial substrate. The experiment was repeated outside, on a natural substrate. Data were collected from (1) a heel-mounted 3D-accelerometer recording peak impact at heel contact, (2) an ankle-mounted 3D-goniometer (plantar/dorsiflexion and inversion/eversion), and (3) sEMG electrodes at the m. tibialis anterior and the m. gastrocnemius medialis. Data show that the effect of indigenous footwear on the measured variables, compared to barefoot walking, is relatively small and consistent between substrates (even though subjects walked faster on the natural substrate). Walking barefoot, compared to shod walking yields higher impact accelerations, but the differences are small and only significant for the artificial substrate. The main rotations of the ankle joint are mostly similar between conditions. Only the shod condition shows a faster ankle rotation over the rapid eversion motion on the natural substrate. Maximal dorsiflexion in late stance differs between the footwear conditions on an artificial substrate, with the shod condition involving a less dorsiflexed ankle, and the plantar flexion at toe-off is more extreme when shod. Overall the activity pattern of the external foot muscles is similar. The indigenous footwear studied (Kolhapuri) seems to alter foot biomechanics only in a subtle way. While offering some degree of protection, walking in this type of footwear resembles barefoot gait and this type of indigenous footwear might be considered "minimal". © 2017 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

  11. The biomechanical consequences of rod reduction on pedicle screws: should it be avoided?

    Science.gov (United States)

    Paik, Haines; Kang, Daniel G; Lehman, Ronald A; Gaume, Rachel E; Ambati, Divya V; Dmitriev, Anton E

    2013-11-01

    Rod contouring is frequently required to allow for appropriate alignment of pedicle screw-rod constructs. When residual mismatch is still present, a rod persuasion device is often used to achieve further rod reduction. Despite its popularity and widespread use, the biomechanical consequences of this technique have not been evaluated. To evaluate the biomechanical fixation strength of pedicle screws after attempted reduction of a rod-pedicle screw mismatch using a rod persuasion device. Fifteen 3-level, human cadaveric thoracic specimens were prepared and scanned for bone mineral density. Osteoporotic (n=6) and normal (n=9) specimens were instrumented with 5.0-mm-diameter pedicle screws; for each pair of comparison level tested, the bilateral screws were equal in length, and the screw length was determined by the thoracic level and size of the vertebra (35 to 45 mm). Titanium 5.5-mm rods were contoured and secured to the pedicle screws at the proximal and distal levels. For the middle segment, the rod on the right side was intentionally contoured to create a 5-mm residual gap between the inner bushing of the pedicle screw and the rod. A rod persuasion device was then used to engage the setscrew. The left side served as a control with perfect screw/rod alignment. After 30 minutes, constructs were disassembled and vertebrae individually potted. The implants were pulled in-line with the screw axis with peak pullout strength (POS) measured in Newton (N). For the proximal and distal segments, pedicle screws on the right side were taken out and reinserted through the same trajectory to simulate screw depth adjustment as an alternative to rod reduction. Pedicle screws reduced to the rod generated a 48% lower mean POS (495±379 N) relative to the controls (954±237 N) (p.05). In circumstances where a rod is not fully seated within the pedicle screw, the use of a rod persuasion device decreases the overall POS and work energy to failure of the screw or results in outright

  12. Soft Tissue Biomechanical Modeling for Computer Assisted Surgery

    CERN Document Server

    2012-01-01

      This volume focuses on the biomechanical modeling of biological tissues in the context of Computer Assisted Surgery (CAS). More specifically, deformable soft tissues are addressed since they are the subject of the most recent developments in this field. The pioneering works on this CAS topic date from the 1980's, with applications in orthopaedics and biomechanical models of bones. More recently, however, biomechanical models of soft tissues have been proposed since most of the human body is made of soft organs that can be deformed by the surgical gesture. Such models are much more complicated to handle since the tissues can be subject to large deformations (non-linear geometrical framework) as well as complex stress/strain relationships (non-linear mechanical framework). Part 1 of the volume presents biomechanical models that have been developed in a CAS context and used during surgery. This is particularly new since most of the soft tissues models already proposed concern Computer Assisted Planning, with ...

  13. The increasing importance of the biomechanics of impact trauma

    Indian Academy of Sciences (India)

    Like most engineering subjects, impact biomechanics has evolved from early ... show that the primary deceleration forces acting in the majority of car ... the natural history of falls in old age' showed how the routine observations of a practicing.

  14. The Impact of Biomechanics in Tissue Engineering and Regenerative Medicine

    Science.gov (United States)

    Butler, David L.; Goldstein, Steven A.; Guo, X. Edward; Kamm, Roger; Laurencin, Cato T.; McIntire, Larry V.; Mow, Van C.; Nerem, Robert M.; Sah, Robert L.; Soslowsky, Louis J.; Spilker, Robert L.; Tranquillo, Robert T.

    2009-01-01

    Biomechanical factors profoundly influence the processes of tissue growth, development, maintenance, degeneration, and repair. Regenerative strategies to restore damaged or diseased tissues in vivo and create living tissue replacements in vitro have recently begun to harness advances in understanding of how cells and tissues sense and adapt to their mechanical environment. It is clear that biomechanical considerations will be fundamental to the successful development of clinical therapies based on principles of tissue engineering and regenerative medicine for a broad range of musculoskeletal, cardiovascular, craniofacial, skin, urinary, and neural tissues. Biomechanical stimuli may in fact hold the key to producing regenerated tissues with high strength and endurance. However, many challenges remain, particularly for tissues that function within complex and demanding mechanical environments in vivo. This paper reviews the present role and potential impact of experimental and computational biomechanics in engineering functional tissues using several illustrative examples of past successes and future grand challenges. PMID:19583462

  15. Emulating facial biomechanics using multivariate partial least squares surrogate models.

    Science.gov (United States)

    Wu, Tim; Martens, Harald; Hunter, Peter; Mithraratne, Kumar

    2014-11-01

    A detailed biomechanical model of the human face driven by a network of muscles is a useful tool in relating the muscle activities to facial deformations. However, lengthy computational times often hinder its applications in practical settings. The objective of this study is to replace precise but computationally demanding biomechanical model by a much faster multivariate meta-model (surrogate model), such that a significant speedup (to real-time interactive speed) can be achieved. Using a multilevel fractional factorial design, the parameter space of the biomechanical system was probed from a set of sample points chosen to satisfy maximal rank optimality and volume filling. The input-output relationship at these sampled points was then statistically emulated using linear and nonlinear, cross-validated, partial least squares regression models. It was demonstrated that these surrogate models can mimic facial biomechanics efficiently and reliably in real-time. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Biomechanical comparison of osteosynthesis with poly‑L‑lactic acid ...

    African Journals Online (AJOL)

    2015-01-21

    Jan 21, 2015 ... Fractures of the mandibular condylar process are common fractures affecting the ... mandible replicas are having a medullar and a cortical portion (Synbone ... Based on the biomechanical simulations they performed Neff et al ...

  17. Recent microfluidic devices for studying gamete and embryo biomechanics.

    Science.gov (United States)

    Lai, David; Takayama, Shuichi; Smith, Gary D

    2015-06-25

    The technical challenges of biomechanic research such as single cell analysis at a high monetary cost, labor, and time for just a small number of measurements is a good match to the strengths of microfluidic devices. New scientific discoveries in the fertilization and embryo development process, of which biomechanics is a major subset of interest, is crucial to fuel the continual improvement of clinical practice in assisted reproduction. The following review will highlight some recent microfluidic devices tailored for gamete and embryo biomechanics where biomimicry arises as a major theme of microfluidic device design and function, and the application of fundamental biomechanic principles are used to improve outcomes of cryopreservation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Low-Back Biomechanics and Static Stability During Isometric Pushing

    Science.gov (United States)

    Granata, Kevin P.; Bennett, Bradford C.

    2006-01-01

    Pushing and pulling tasks are increasingly prevalent in industrial workplaces. Few studies have investigated low-back biomechanical risk factors associated with pushing, and we are aware of none that has quantified spinal stability during pushing exertions. Data recorded from 11 healthy participants performing isometric pushing exertions demonstrated that trunk posture, vector force direction of the applied load, and trunk moment were influenced (p pushing task, and foot position. A biomechanical model was used to analyze the posture and hand force data gathered from the pushing exertions. Model results indicate that pushing exertions provide significantly (p pushing exertions. If one maintains stability by means of cocontraction, additional spinal load is thereby created, increasing the risk of overload injury. Thus it is important to consider muscle cocontraction when evaluating the biomechanics of pushing exertions. Potential applications of this research include improved assessment of biomechanical risk factors for the design of industrial pushing tasks. PMID:16435695

  19. Combined open proximal and stent-graft distal repair for distal arch aneurysms: an alternative to total debranching.

    Science.gov (United States)

    Zierer, Andreas; Sanchez, Luis A; Moon, Marc R

    2009-07-01

    We present herein a novel, combined, simultaneous open proximal and stent-graft distal repair for complex distal aortic arch aneurysms involving the descending aorta. In the first surgical step, the transverse arch is opened during selective antegrade cerebral perfusion, and a Dacron graft (DuPont, Wilmington, DE) is positioned down the descending aorta in an elephant trunk-like fashion with its proximal free margin sutured circumferentially to the aorta just distal to the left subclavian or left common carotid artery. With the graft serving as the new proximal landing zone, subsequent endovascular repair is performed antegrade during rewarming through the ascending aorta.

  20. early functional outcome of distal femoral fractures at kenyatta

    African Journals Online (AJOL)

    The leading cause was RTA, followed by falls from a height. ... Distal femoral fractures cause considerable morbidity .... as means and standard deviations. .... Anaesthesia. Spinal. 37 (80). General Anaesthesia (GA). 9 (20). Transfusion.

  1. Subtrochanteric and Distal Femur Fractures in a Patient with ...

    African Journals Online (AJOL)

    This study reports the surgical management for this rare case and the treatment ... car accident and presented closed femoral shaft fracture associated with a ... to fix the distal femur fracture, enhancing the construction stability [Figures 4 and 5].

  2. Minimally invasive percutaneous plate fixation of distal tibia fractures.

    LENUS (Irish Health Repository)

    Bahari, Syah

    2007-10-01

    We report a series of 42 patients reviewed at a mean of 19.6 months after treatment of distal tibial and pilon fractures using the AO distal tibia locking plate with a minimally invasive percutaneous plate osteosynthesis (MIPPO) technique. Mean time to union was 22.4 weeks. All fractures united with acceptable alignment and angulation. Two cases of superficial infection were noted, with one case of deep infection. Mean SF36 score was 85 and mean AOFAS score was 90 at a mean of 19 months follow-up. We report satisfactory outcomes with the use of the AO distal tibia locking plate in treatment of unstable distal tibial fractures. Eighty-nine percent of the patients felt that they were back to their pre injury status and 95% back to their previous employment.

  3. Surgical treatment of distal biceps tendon rupture: a case report

    Directory of Open Access Journals (Sweden)

    Cristina N. Cozma

    2017-11-01

    Full Text Available Objectives. Distal biceps tendon rupture affects the functional upperextremity movement, impairing supination and flexion strength. According to age, profession and additional risks treatment might be nonoperative or surgical. Methods. We describe the case of a 43 years old male patient who sustained an injury to his right distal biceps and was diagnosed with acute right distal biceps rupture. Surgical treatment was decided and biceps tendon was reinserted to the radius tuberosity using a combination of a cortical button fixation associated with an interference screw. Results. Postoperative functional result was favorable with no complications and with no movement limitation after one month. Conclusions. When possible, distal biceps tendon repair should be realized surgically because this permits restoring of the muscle strength to near normal levels with no loss of motion. Nerve complications are common; therefore the surgery should be realized by experienced upper extremity surgeons.

  4. Biomechanical interpretation of a free-breathing lung motion model

    International Nuclear Information System (INIS)

    Zhao Tianyu; White, Benjamin; Lamb, James; Low, Daniel A; Moore, Kevin L; Yang Deshan; Mutic, Sasa; Lu Wei

    2011-01-01

    The purpose of this paper is to develop a biomechanical model for free-breathing motion and compare it to a published heuristic five-dimensional (5D) free-breathing lung motion model. An ab initio biomechanical model was developed to describe the motion of lung tissue during free breathing by analyzing the stress–strain relationship inside lung tissue. The first-order approximation of the biomechanical model was equivalent to a heuristic 5D free-breathing lung motion model proposed by Low et al in 2005 (Int. J. Radiat. Oncol. Biol. Phys. 63 921–9), in which the motion was broken down to a linear expansion component and a hysteresis component. To test the biomechanical model, parameters that characterize expansion, hysteresis and angles between the two motion components were reported independently and compared between two models. The biomechanical model agreed well with the heuristic model within 5.5% in the left lungs and 1.5% in the right lungs for patients without lung cancer. The biomechanical model predicted that a histogram of angles between the two motion components should have two peaks at 39.8° and 140.2° in the left lungs and 37.1° and 142.9° in the right lungs. The data from the 5D model verified the existence of those peaks at 41.2° and 148.2° in the left lungs and 40.1° and 140° in the right lungs for patients without lung cancer. Similar results were also observed for the patients with lung cancer, but with greater discrepancies. The maximum-likelihood estimation of hysteresis magnitude was reported to be 2.6 mm for the lung cancer patients. The first-order approximation of the biomechanical model fit the heuristic 5D model very well. The biomechanical model provided new insights into breathing motion with specific focus on motion trajectory hysteresis.

  5. Interpreting locomotor biomechanics from the morphology of human footprints.

    Science.gov (United States)

    Hatala, Kevin G; Wunderlich, Roshna E; Dingwall, Heather L; Richmond, Brian G

    2016-01-01

    Fossil hominin footprints offer unique direct windows to the locomotor behaviors of our ancestors. These data could allow a clearer understanding of the evolution of human locomotion by circumventing issues associated with indirect interpretations of habitual locomotor patterns from fossil skeletal material. However, before we can use fossil hominin footprints to understand better the evolution of human locomotion, we must first develop an understanding of how locomotor biomechanics are preserved in, and can be inferred from, footprint morphologies. In this experimental study, 41 habitually barefoot modern humans created footprints under controlled conditions in which variables related to locomotor biomechanics could be quantified. Measurements of regional topography (depth) were taken from 3D models of those footprints, and principal components analysis was used to identify orthogonal axes that described the largest proportions of topographic variance within the human experimental sample. Linear mixed effects models were used to quantify the influences of biomechanical variables on the first five principal axes of footprint topographic variation, thus providing new information on the biomechanical variables most evidently expressed in the morphology of human footprints. The footprint's overall depth was considered as a confounding variable, since biomechanics may be linked to the extent to which a substrate deforms. Three of five axes showed statistically significant relationships with variables related to both locomotor biomechanics and substrate displacement; one axis was influenced only by biomechanics and another only by the overall depth of the footprint. Principal axes of footprint morphological variation were significantly related to gait type (walking or running), kinematics of the hip and ankle joints and the distribution of pressure beneath the foot. These results provide the first quantitative framework for developing hypotheses regarding the

  6. Advances in Proximal Interphalangeal Joint Arthroplasty: Biomechanics and Biomaterials.

    Science.gov (United States)

    Zhu, Andy F; Rahgozar, Paymon; Chung, Kevin C

    2018-05-01

    Proximal interphalangeal (PIP) joint arthritis is a debilitating condition. The complexity of the joint makes management particularly challenging. Treatment of PIP arthritis requires an understanding of the biomechanics of the joint. PIP joint arthroplasty is one treatment option that has evolved over time. Advances in biomaterials have improved and expanded arthroplasty design. This article reviews biomechanics and arthroplasty design of the PIP joint. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Biomechanics of compensatory mechanisms in spinal-pelvic complex

    Science.gov (United States)

    Ivanov, D. V.; Hominets, V. V.; Kirillova, I. V.; Kossovich, L. Yu; Kudyashev, A. L.; Teremshonok, A. V.

    2018-04-01

    3D geometric solid computer model of spinal-pelvic complex was constructed on the basis of computed tomography and full body X-ray in standing position data. The constructed model was used for biomechanical analysis of compensatory mechanisms arising in the spine with anteversion and retroversion of the pelvis. The results of numerical biomechanical 3D modeling are in good agreement with the clinical data.

  8. Emulating facial biomechanics using multivariate partial least squares surrogate models

    OpenAIRE

    Martens, Harald; Wu, Tim; Hunter, Peter; Mithraratne, Kumar

    2014-01-01

    This is the author’s final, accepted and refereed manuscript to the article. Locked until 2015-05-06 A detailed biomechanical model of the human face driven by a network of muscles is a useful tool in relating the muscle activities to facial deformations. However, lengthy computational times often hinder its applications in practical settings. The objective of this study is to replace precise but computationally demanding biomechanical model by a much faster multivariate meta-mode...

  9. Enclavado endomedular en fracturas del tercio distal de la tibia

    OpenAIRE

    Arroquy, Damian; Chahla, Jorge; Gomez Rodriguez, Gustavo; Cid Casteulani, Alberto; Svarzchtein, Santiago; Gomez, Diego; Pesciallo, Cesar

    2015-01-01

    Objetivo: Describir los resultados obtenidos con el enclavado endomedular acerrojado en pacientes con fractura del tercio distal de la tibia. Materiales y Métodos: Se incluyeron pacientes con fracturas desplazadas del tercio distal de la tibia, tratadas con clavo endomedular. La muestra incluyo 35 pacientes. El tiempo de seguimiento posoperatorio fue de 29.2 meses. Se evaluaron el tiempo de consolidacion, la consolidacion viciosa y las complicaciones. Los resultados funcionales se determinaro...

  10. Fractures of the Distal Tibia Treated with Polyaxial Locking Plating

    OpenAIRE

    Gao, Hong; Zhang, Chang-Qing; Luo, Cong-Feng; Zhou, Zu-Bin; Zeng, Bing-Fang

    2008-01-01

    We evaluated the healing rate, complications, and functional outcomes in 32 adult patients with very short metaphyseal fragments in fractures of the distal tibia treated with a polyaxial locking system. The average distance from the distal extent of the fracture to the tibial plafond was 11 mm. All fractures healed and the average time to union was 14 weeks. Six patients (19%) reported occasional local disturbance over the medial malleolus. There were two cases of postoperative superficial in...

  11. A comparative biomechanical analysis of implants for the stabilization of proximal humerus fractures.

    Science.gov (United States)

    Füchtmeier, B; May, R; Fierlbeck, J; Hammer, J; Nerlich, M

    2006-01-01

    A new humerus nail (Sirus) has become available for the treatment of fractures of the proximal humerus. The aim of the study was the biomechanical comparison of this implant with established systems. 12 matched pairs of human humeri were employed for testing. Three randomized groups were formed (n = 4 pairs). A bending moment of 7.5 Nm and a torsional moment of 8.3 Nm were applied in a test of five loading cycles to all intact bones. Loading was consistently initiated at the distal epiphysis. The consequent deformation at the distal epiphysis was continuously recorded. Then an osteotomy with a defect of 5 mm was created to simulate an unstable subcapital humerus fracture. For paired comparison, one of each pair was stabilized with the Sirus proximal humerus nail. The other side was fixed with a reference implant. The following groups were created.: Group I: Sirus versus Proximal humerus nail (PHN) with spiral blade. Group II: Sirus versus PHILOS plate. Group III: Sirus versus 4.5 mm AO T-plate. The proximal humerus nail (Sirus) demonstrated significantly higher stiffness values than the reference implants for both bending and torsional load. The following values were recorded at a bending moment of 7.5 Nm: Sirus 14.2 mm, PHN 20.7 mm, PHILOS plate 28.1 mm, 4.5 AO T-plate 29.3 mm p model presented here. Supplementary, the Sirus Nail showed higher stiffness values than the PHN. However, the latter are gaining in importance due to the possibility of minimal invasive implantation. Whether this will be associated with functional advantages requires further clinical investigation.

  12. Gait biomechanics in the era of data science.

    Science.gov (United States)

    Ferber, Reed; Osis, Sean T; Hicks, Jennifer L; Delp, Scott L

    2016-12-08

    Data science has transformed fields such as computer vision and economics. The ability of modern data science methods to extract insights from large, complex, heterogeneous, and noisy datasets is beginning to provide a powerful complement to the traditional approaches of experimental motion capture and biomechanical modeling. The purpose of this article is to provide a perspective on how data science methods can be incorporated into our field to advance our understanding of gait biomechanics and improve treatment planning procedures. We provide examples of how data science approaches have been applied to biomechanical data. We then discuss the challenges that remain for effectively using data science approaches in clinical gait analysis and gait biomechanics research, including the need for new tools, better infrastructure and incentives for sharing data, and education across the disciplines of biomechanics and data science. By addressing these challenges, we can revolutionize treatment planning and biomechanics research by capitalizing on the wealth of knowledge gained by gait researchers over the past decades and the vast, but often siloed, data that are collected in clinical and research laboratories around the world. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Biomechanics of occlusion--implications for oral rehabilitation.

    Science.gov (United States)

    Peck, C C

    2016-03-01

    The dental occlusion is an important aspect of clinical dentistry; there are diverse functional demands ranging from highly precise tooth contacts to large crushing forces. Further, there are dogmatic, passionate and often diverging views on the relationship between the dental occlusion and various diseases and disorders including temporomandibular disorders, non-carious cervical lesions and tooth movement. This study provides an overview of the biomechanics of the masticatory system in the context of the dental occlusion's role in function. It explores the adaptation and precision of dental occlusion, its role in bite force, jaw movement, masticatory performance and its influence on the oro-facial musculoskeletal system. Biomechanics helps us better understand the structure and function of biological systems and consequently an understanding of the forces on, and displacements of, the dental occlusion. Biomechanics provides insight into the relationships between the dentition, jaws, temporomandibular joints, and muscles. Direct measurements of tooth contacts and forces are difficult, and biomechanical models have been developed to better understand the relationship between the occlusion and function. Importantly, biomechanical research will provide knowledge to help correct clinical misperceptions and inform better patient care. The masticatory system demonstrates a remarkable ability to adapt to a changing biomechanical environment and changes to the dental occlusion or other components of the musculoskeletal system tend to be well tolerated. © 2015 John Wiley & Sons Ltd.

  14. ARTIFICIAL INTELLIGENCE IN SPORTS BIOMECHANICS: NEW DAWN OR FALSE HOPE?

    Directory of Open Access Journals (Sweden)

    Roger Bartlett

    2006-12-01

    Full Text Available This article reviews developments in the use of Artificial Intelligence (AI in sports biomechanics over the last decade. It outlines possible uses of Expert Systems as diagnostic tools for evaluating faults in sports movements ('techniques' and presents some example knowledge rules for such an expert system. It then compares the analysis of sports techniques, in which Expert Systems have found little place to date, with gait analysis, in which they are routinely used. Consideration is then given to the use of Artificial Neural Networks (ANNs in sports biomechanics, focusing on Kohonen self-organizing maps, which have been the most widely used in technique analysis, and multi-layer networks, which have been far more widely used in biomechanics in general. Examples of the use of ANNs in sports biomechanics are presented for javelin and discus throwing, shot putting and football kicking. I also present an example of the use of Evolutionary Computation in movement optimization in the soccer throw in, which predicted an optimal technique close to that in the coaching literature. After briefly overviewing the use of AI in both sports science and biomechanics in general, the article concludes with some speculations about future uses of AI in sports biomechanics.

  15. Biomechanically Excited SMD Model of a Walking Pedestrian

    DEFF Research Database (Denmark)

    Zhang, Mengshi; Georgakis, Christos T.; Chen, Jun

    2016-01-01

    Through their biomechanical properties, pedestrians interact with the structures they occupy. Although this interaction has been recognized by researchers, pedestrians' biomechanical properties have not been fully addressed. In this paper, a spring-mass-damper (SMD) system, with a pair of biomech......Through their biomechanical properties, pedestrians interact with the structures they occupy. Although this interaction has been recognized by researchers, pedestrians' biomechanical properties have not been fully addressed. In this paper, a spring-mass-damper (SMD) system, with a pair...... produced the pedestrian's center of mass (COM) trajectories from the captured motion markers. The vertical COM trajectory was approximated to be the pedestrian SMD dynamic responses under the excitation of biomechanical forces. SMD model parameters of a pedestrian for a specific walking frequency were...... estimated from a known walking frequency and the pedestrian's weight, assuming that pedestrians always walk in displacement resonance and retain a constant damping ratio of 0.3. Thus, biomechanical forces were extracted using the measured SMD dynamic responses and the estimated SMD parameters. Extracted...

  16. DYNAMIC MAGNIFICATION OF BIOMECHANICAL SYSTEM MOTION

    Directory of Open Access Journals (Sweden)

    A. E. Pokatilov

    2017-01-01

    Full Text Available Methods for estimation of dynamic magnification pertaining to motion in biomechanics have been developed and approbаted in the paper. It has been ascertained that widely-used characteristics for evaluation of motion influence on mechanisms and machinery such as a dynamic coefficient and acceleration capacity factor become irrelevant while investigating human locomotion under elastic support conditions. The reason is an impossibility to compare human motion in case when there is a contact with elastic and rigid supports because while changing rigidity of the support exercise performing technique is also changing. In this case the technique still depends on a current state of a specific sportsman. Such situation is observed in sports gymnastics. Structure of kinematic and dynamic models for human motion has been investigated in the paper. It has been established that properties of an elastic support are reflected in models within two aspects: in an explicit form, when models have parameters of dynamic deformation for a gymnastic apparatus, and in an implicit form, when we have numerically changed parameters of human motion. The first part can be evaluated quantitatively while making comparison with calculations made in accordance with complete models. For this reason notions of selected and complete models have been introduced in the paper. It has been proposed to specify models for support and models of biomechanical system that represent models pertaining only to human locomotor system. It has been revealed that the selected models of support in kinematics and dynamics have structural difference. Kinematics specifies only parameters of elastic support deformation and dynamics specifies support parameters in an explicit form and additionally in models of human motion in an explicit form as well. Quantitative estimation of a dynamic motion magnification in kinematics and dynamics models has been given while using computing experiment for grand

  17. Volar plating for distal radius fractures--do not trust the image intensifier when judging distal subchondral screw length.

    Science.gov (United States)

    Park, Derek H; Goldie, Boyd S

    2012-09-01

    The use of the volar plate to treat distal radius fractures is increasing but despite the theoretical advantages of a volar approach there have been reports of extensor tendon ruptures due to prominent screw tips protruding past the dorsal cortex. The valley in the intermediate column between Lister tubercle and the sigmoid notch of the distal radius makes it difficult to rely on fluoroscopy to judge screw length. Our aim was to quantify the dimensions of this valley and to demonstrate the danger of relying on intraoperative image intensification fluoroscopy to determine lengths of distal screws. We measured the depth of this valley in the intermediate column of the distal radius in 33 patients with computed tomographic (9 patients) or magnetic resonance image (24 patients) scans of the wrist. There was a consistent valley in all images examined [average 1.8 mm (95% confidence interval, 1.6-2.0 mm)]. Thirty-nine percent of wrists had a valley depth of at least 2 mm. Standard lateral views or rotation of the forearm to obtain oblique views does not identify prominent screw tips; and whatever the rotation of the forearm, screw tips protruding beyond dorsal cortex may look as if it is within the bone when in fact it is out. When drilling we suggest noting the depth at which the drill bit just penetrates dorsal cortex and routinely downsize the distal screw length by 2 mm. We caution against relying on flourosocopy when judging the length of the distal subchondral screws.

  18. Arthroplasty of the distal ulna distal in managing patients with post-traumatic disorders of the distal radioulnar joint: measurement of quality of life

    Directory of Open Access Journals (Sweden)

    Marcio Aurélio Aita

    2015-12-01

    Full Text Available ABSTRACT OBJECTIVE: To measure the quality of life and clinical-functional results from patients diagnosed with osteoarthrosis of the distal radioulnar joint who underwent surgical treatment using the technique of total arthroplasty of the ulna, with a total or partial Ascension(r prosthesis of the distal ulna. METHODS: Ten patients were evaluated after 12 months of follow-up subsequent to total or partial arthroplasty of the distal ulna. All of them presented post-traumatic osteoarthrosis and/or chronic symptomatic instability of the distal radioulnar joint. The study was prospective. Seven patients had previously undergone wrist procedures (two cases with Darrach, three with Sauvé-Kapandji and two with ligament reconstruction of the fibrocartilage complex and three presented fractures of the distal ulna that evolved with pain, instability and osteoarthrosis of the distal radioulnar joint. The following were assessed: quality of life (DASH scale; percentage degree of palm grip strength (kgf and pronosupination range of motion in relation to the unaffected side; pain (VAS; return to work; subjective evaluation of radiography; and complications. RESULTS: The patients presented a mean range of motion of 174.5° (normal side: 180°. Quality of life was analyzed by applying the DASH questionnaire and the mean value found was 5.9. The mean pain score using the VAS was 2.3. The mean degree of palm grip strength (kgf was 50.7, which represented 90.7% of the strength on the unaffected side. The complication rate was 10%: this patient presented slight dorsal instability of the ulna and persistent pain, and did not return to work. This patient is still being followed up in the outpatient clinic and occupational therapy sector, with little improvement. He does not wish to undergo a new procedure. The mean length of follow-up was 16.8 months, with a minimum of 10 and maximum of 36 months. CONCLUSION: This concept is subject to the test of time

  19. Biomechanical comments about Triassic dinosaurs from Brazil

    Directory of Open Access Journals (Sweden)

    Rafael Delcourt

    2012-01-01

    Full Text Available Triassic dinosaurs of Brazil are found in Santa Maria and Caturrita formations, Rio Grande do Sul state, Brazil. There are three species known from the Santa Maria Formation (Staurikosaurus pricei, Saturnalia tupiniquim and Pampadromaeus barberenai, and two from Caturrita Formation (Guaibasaurus candelariensis and Unaysaurus tolentinoi. These dinosaur materials are, for the most part, well preserved and allow for descriptions of musculature and biomechanical studies. The lateral rotation of the Saturnalia femur is corroborated through calculations of muscle moment arms. The enhanced supracetabular crest of Saturnalia, Guaibasaurus, Staurikosaurus, Herrerasaurus ischigualastensis, Efraasia minor and Chormogisaurus novasi suggests that basal dinosaurs may have maintained an inclination of the trunk at least 20º on the horizontal axis. The pectoral girdle articulation of basal sauropodomorphs (Saturnalia and Unaysaurus was established using a new method, the Clavicular Ring, and the scapular blade remains near 60º on the horizontal axis. This is a plesiomorphic condition among sauropodomorphs and is also seen in the articulated plateosauridae Seitaad ruessi. The Brazilian basal dinosaurs were lightweight with a body mass estimated around 18.5 kg for Staurikosaurus, 6.5 kg for Saturnalia, and 17 kg for Guaibasaurus. Pampadromaeus probably weighed 2.5 kg, but measures of its femur are necessary to confirm this hypothesis. The Triassic dinosaurs from Brazil were diversified but shared some functional aspects that were important in an evolutionary context.

  20. Patient-specific models of cardiac biomechanics

    Science.gov (United States)

    Krishnamurthy, Adarsh; Villongco, Christopher T.; Chuang, Joyce; Frank, Lawrence R.; Nigam, Vishal; Belezzuoli, Ernest; Stark, Paul; Krummen, David E.; Narayan, Sanjiv; Omens, Jeffrey H.; McCulloch, Andrew D.; Kerckhoffs, Roy C. P.

    2013-07-01

    Patient-specific models of cardiac function have the potential to improve diagnosis and management of heart disease by integrating medical images with heterogeneous clinical measurements subject to constraints imposed by physical first principles and prior experimental knowledge. We describe new methods for creating three-dimensional patient-specific models of ventricular biomechanics in the failing heart. Three-dimensional bi-ventricular geometry is segmented from cardiac CT images at end-diastole from patients with heart failure. Human myofiber and sheet architecture is modeled using eigenvectors computed from diffusion tensor MR images from an isolated, fixed human organ-donor heart and transformed to the patient-specific geometric model using large deformation diffeomorphic mapping. Semi-automated methods were developed for optimizing the passive material properties while simultaneously computing the unloaded reference geometry of the ventricles for stress analysis. Material properties of active cardiac muscle contraction were optimized to match ventricular pressures measured by cardiac catheterization, and parameters of a lumped-parameter closed-loop model of the circulation were estimated with a circulatory adaptation algorithm making use of information derived from echocardiography. These components were then integrated to create a multi-scale model of the patient-specific heart. These methods were tested in five heart failure patients from the San Diego Veteran's Affairs Medical Center who gave informed consent. The simulation results showed good agreement with measured echocardiographic and global functional parameters such as ejection fraction and peak cavity pressures.

  1. Physiological and biomechanical aspects of orienteering.

    Science.gov (United States)

    Creagh, U; Reilly, T

    1997-12-01

    Orienteering is an endurance running event which differs from other running sports both in its cognitive element and in the type of terrain encountered. The demands of overcoming this terrain are not manifest in significant differences between orienteers and road runners in somatotype, though elite female orienteers have consistently been shown to have higher levels of adiposity (> 19%) than elite road runners. High aerobic power in orienteers (up to 63 and 76 ml/kg/min in women and men, respectively) is coupled with lower anaerobic performance. While leg strength is generally not high when compared with other athletic specialties, female orienteers have relatively good leg flexion strength. The energy cost of running is greatly increased in rough terrain. Oxygen cost was 26% higher while running in a forest when compared with road running. Biomechanical differences in stride pattern contribute towards this increased demand. Despite the high energy demands during competition, orienteers pace themselves such that their mean heart rate remains within the range of 167 to 172 beats/min, despite large fluctuations. The rough terrain encountered in orienteering results not only in a high energy cost but also in a higher incidence of sport-specific injuries, particularly to the ankle. Minor injuries such as cuts and bruises are common during competition.

  2. Biomechanical influences on balance recovery by stepping.

    Science.gov (United States)

    Hsiao, E T; Robinovitch, S N

    1999-10-01

    Stepping represents a common means for balance recovery after a perturbation to upright posture. Yet little is known regarding the biomechanical factors which determine whether a step succeeds in preventing a fall. In the present study, we developed a simple pendulum-spring model of balance recovery by stepping, and used this to assess how step length and step contact time influence the effort (leg contact force) and feasibility of balance recovery by stepping. We then compared model predictions of step characteristics which minimize leg contact force to experimentally observed values over a range of perturbation strengths. At all perturbation levels, experimentally observed step execution times were higher than optimal, and step lengths were smaller than optimal. However, the predicted increase in leg contact force associated with these deviations was substantial only for large perturbations. Furthermore, increases in the strength of the perturbation caused subjects to take larger, quicker steps, which reduced their predicted leg contact force. We interpret these data to reflect young subjects' desire to minimize recovery effort, subject to neuromuscular constraints on step execution time and step length. Finally, our model predicts that successful balance recovery by stepping is governed by a coupling between step length, step execution time, and leg strength, so that the feasibility of balance recovery decreases unless declines in one capacity are offset by enhancements in the others. This suggests that one's risk for falls may be affected more by small but diffuse neuromuscular impairments than by larger impairment in a single motor capacity.

  3. Comparative biomechanics: life's physical world (second edition)

    CERN Document Server

    Vogel, Steven

    2013-01-01

    Why do you switch from walking to running at a specific speed? Why do tall trees rarely blow over in high winds? And why does a spore ejected into air at seventy miles per hour travel only a fraction of an inch? Comparative Biomechanics is the first and only textbook that takes a comprehensive look at the mechanical aspects of life--covering animals and plants, structure and movement, and solids and fluids. An ideal entry point into the ways living creatures interact with their immediate physical world, this revised and updated edition examines how the forms and activities of animals and plants reflect the materials available to nature, considers rules for fluid flow and structural design, and explores how organisms contend with environmental forces. Drawing on physics and mechanical engineering, Steven Vogel looks at how animals swim and fly, modes of terrestrial locomotion, organism responses to winds and water currents, circulatory and suspension-feeding systems, and the relationship between size and mech...

  4. Adaptive sports technology and biomechanics: prosthetics.

    Science.gov (United States)

    De Luigi, Arthur Jason; Cooper, Rory A

    2014-08-01

    With the technologic advances in medicine and an emphasis on maintaining physical fitness, the population of athletes with impairments is growing. It is incumbent upon health care practitioners to make every effort to inform these individuals of growing and diverse opportunities and to encourage safe exercise and athletic participation through counseling and education. Given the opportunities for participation in sports for persons with a limb deficiency, the demand for new, innovative prosthetic designs is challenging the clinical and technical expertise of the physician and prosthetist. When generating a prosthetic prescription, physicians and prosthetists should consider the needs and preferences of the athlete with limb deficiency, as well as the functional demands of the chosen sporting activity. The intent of this article is to provide information regarding the current advancements in the adaptive sports technology and biomechanics in the field of prosthetics, and to assist clinicians and their patients in facilitating participation in sporting activities. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  5. Injury biomechanics of C2 dens fractures.

    Science.gov (United States)

    Yoganandan, Narayan; Pintar, Frank; Baisden, Jamie; Gennarelli, Thomas; Maiman, Dennis

    2004-01-01

    The objective of this study is to analyze the biomechanics of dens fractures of the second cervical vertebra in the adult population due to motor vehicle crashes. Case-by-case records from the Crash Injury Research and Engineering Network (CIREN) and National Automotive Sampling System (NASS) databases were used. Variables such as change in velocity, impact direction and body habitus were extracted. Results indicated that similarities exist in the two databases despite differences in sampling methods between the two sources (e.g., CIREN is not population based). Trauma is predominantly associated with the frontal mode of impact. Majority of injuries occur with change in velocities below current federal guideline thresholds. No specific bias exists with respect to variables such as age, height, weight, and gender. Because similar conclusions can be drawn with regard to vehicle model years, design changes during these years may have had little effect on this injury. To ameliorate trauma, emphasis should be placed on the frontal impact mode and entire adult population. Because of clinical implications in the fracture type (II being most critical) and lack of specific coding, CIREN data demonstrates the need to improve injury coding in the AIS and application in the NASS to enhance occupant safety and treatment in the field of automotive medicine.

  6. Feeding in billfishes: inferring the role of the rostrum from a biomechanical standpoint.

    Science.gov (United States)

    Habegger, Maria L; Dean, Mason N; Dunlop, John W C; Mullins, Gray; Stokes, Michael; Huber, Daniel R; Winters, Daniel; Motta, Philip J

    2015-03-01

    Perhaps the most striking feature of billfishes is the extreme elongation of the premaxillary bones forming their rostra. Surprisingly, the exact role of this structure in feeding is still controversial. The goal of this study is to investigate the use of the rostrum from a functional, biomechanical and morphological standpoint to ultimately infer its possible role during feeding. Using beam theory, experimental and theoretical loading tests were performed on the rostra from two morphologically different billfish, the blue marlin (Makaira nigricans) and the swordfish (Xiphias gladius). Two loading regimes were applied (dorsoventral and lateral) to simulate possible striking behaviors. Histological samples and material properties of the rostra were obtained along their lengths to further characterize structure and mechanical performance. Intraspecific results show similar stress distributions for most regions of the rostra, suggesting that this structure may be designed to withstand continuous loadings with no particular region of stress concentration. Although material stiffness increased distally, flexural stiffness increased proximally owing to higher second moment of area. The blue marlin rostrum was stiffer and resisted considerably higher loads for both loading planes compared with that of the swordfish. However, when a continuous load along the rostrum was considered, simulating the rostrum swinging through the water, swordfish exhibited lower stress and drag during lateral loading. Our combined results suggest that the swordfish rostrum is suited for lateral swiping to incapacitate their prey, whereas the blue marlin rostrum is better suited to strike prey from a wider variety of directions. © 2015. Published by The Company of Biologists Ltd.

  7. Advantages of the Ilizarov external fixation in the management of intra-articular fractures of the distal tibia

    Directory of Open Access Journals (Sweden)

    Kaspiris Angelos

    2009-09-01

    Full Text Available Abstract Background Treatment of distal tibial intra-articular fractures is challenging due to the difficulties in achieving anatomical reduction of the articular surface and the instability which may occur due to ligamentous and soft tissue injury. The purpose of this study is to present an algorithm in the application of external fixation in the management of intra-articular fractures of the distal tibia either from axial compression or from torsional forces. Materials and methods Thirty two patients with intra-articular fractures of the distal tibia have been studied. Based on the mechanism of injury they were divided into two groups. Group I includes 17 fractures due to axial compression and group II 15 fractures due to torsional force. An Ilizarov external fixation was used in 15 patients (11 of group I and 4 of group II. In 17 cases (6 of group I and 11 of group II a unilateral hinged external fixator was used. In 7 out of 17 fractures of group I an additional fixation of the fibula was performed. Results All fractures were healed. The mean time of removal of the external fixator was 11 weeks for group I and 10 weeks for group II. In group I, 5 patients had radiological osteoarthritic lesions (grade III and IV but only 2 were symptomatic. Delayed union occurred in 3 patients of group I with fixed fibula. Other complications included one patient of group II with subluxation of the ankle joint after removal of the hinged external fixator, in 2 patients reduction found to be insufficient during the postoperative follow up and were revised and 6 patients had a residual pain. The range of ankle joint motion was larger in group II. Conclusion Intra-articular fractures of the distal tibia due to axial compression are usually complicated with cartilaginous problems and are requiring anatomical reduction of the articular surface. Fractures due to torsional forces are complicated with ankle instability and reduction should be augmented with ligament

  8. Advantages of the Ilizarov external fixation in the management of intra-articular fractures of the distal tibia

    Science.gov (United States)

    Vasiliadis, Elias S; Grivas, Theodoros B; Psarakis, Spyridon A; Papavasileiou, Evangelos; Kaspiris, Angelos; Triantafyllopoulos, Georgios

    2009-01-01

    Background Treatment of distal tibial intra-articular fractures is challenging due to the difficulties in achieving anatomical reduction of the articular surface and the instability which may occur due to ligamentous and soft tissue injury. The purpose of this study is to present an algorithm in the application of external fixation in the management of intra-articular fractures of the distal tibia either from axial compression or from torsional forces. Materials and methods Thirty two patients with intra-articular fractures of the distal tibia have been studied. Based on the mechanism of injury they were divided into two groups. Group I includes 17 fractures due to axial compression and group II 15 fractures due to torsional force. An Ilizarov external fixation was used in 15 patients (11 of group I and 4 of group II). In 17 cases (6 of group I and 11 of group II) a unilateral hinged external fixator was used. In 7 out of 17 fractures of group I an additional fixation of the fibula was performed. Results All fractures were healed. The mean time of removal of the external fixator was 11 weeks for group I and 10 weeks for group II. In group I, 5 patients had radiological osteoarthritic lesions (grade III and IV) but only 2 were symptomatic. Delayed union occurred in 3 patients of group I with fixed fibula. Other complications included one patient of group II with subluxation of the ankle joint after removal of the hinged external fixator, in 2 patients reduction found to be insufficient during the postoperative follow up and were revised and 6 patients had a residual pain. The range of ankle joint motion was larger in group II. Conclusion Intra-articular fractures of the distal tibia due to axial compression are usually complicated with cartilaginous problems and are requiring anatomical reduction of the articular surface. Fractures due to torsional forces are complicated with ankle instability and reduction should be augmented with ligament repair, in order to

  9. A New Orthodontic Appliance with a Mini Screw for Upper Molar Distalization.

    Science.gov (United States)

    Ozkalayci, Nurhat; Yetmez, Mehmet

    2016-01-01

    The aim of this study is to present a new upper molar distalization appliance called Cise distalizer designed as intraoral device supported with orthodontic mini screw for upper permanent molar distalization. The new appliance consists of eight main components. In order to understand the optimum force level, the appliance under static loading is tested by using strain gage measurement techniques. Results show that one of the open coils produces approximately 300 gr distalization force. Cise distalizer can provide totally 600 gr distalization force. This range of force level is enough for distalization of upper first and second molar teeth.

  10. A New Orthodontic Appliance with a Mini Screw for Upper Molar Distalization

    Directory of Open Access Journals (Sweden)

    Nurhat Ozkalayci

    2016-01-01

    Full Text Available The aim of this study is to present a new upper molar distalization appliance called Cise distalizer designed as intraoral device supported with orthodontic mini screw for upper permanent molar distalization. The new appliance consists of eight main components. In order to understand the optimum force level, the appliance under static loading is tested by using strain gage measurement techniques. Results show that one of the open coils produces approximately 300 gr distalization force. Cise distalizer can provide totally 600 gr distalization force. This range of force level is enough for distalization of upper first and second molar teeth.

  11. Limited distal organelles and synaptic function in extensive monoaminergic innervation.

    Science.gov (United States)

    Tao, Juan; Bulgari, Dinara; Deitcher, David L; Levitan, Edwin S

    2017-08-01

    Organelles such as neuropeptide-containing dense-core vesicles (DCVs) and mitochondria travel down axons to supply synaptic boutons. DCV distribution among en passant boutons in small axonal arbors is mediated by circulation with bidirectional capture. However, it is not known how organelles are distributed in extensive arbors associated with mammalian dopamine neuron vulnerability, and with volume transmission and neuromodulation by monoamines and neuropeptides. Therefore, we studied presynaptic organelle distribution in Drosophila octopamine neurons that innervate ∼20 muscles with ∼1500 boutons. Unlike in smaller arbors, distal boutons in these arbors contain fewer DCVs and mitochondria, although active zones are present. Absence of vesicle circulation is evident by proximal nascent DCV delivery, limited impact of retrograde transport and older distal DCVs. Traffic studies show that DCV axonal transport and synaptic capture are not scaled for extensive innervation, thus limiting distal delivery. Activity-induced synaptic endocytosis and synaptic neuropeptide release are also reduced distally. We propose that limits in organelle transport and synaptic capture compromise distal synapse maintenance and function in extensive axonal arbors, thereby affecting development, plasticity and vulnerability to neurodegenerative disease. © 2017. Published by The Company of Biologists Ltd.

  12. Fractures of the distal radius in children: A retrospective evaluation

    Directory of Open Access Journals (Sweden)

    Selma Yazıcı

    2012-06-01

    Full Text Available Objectives: This study designed to evaluate the resultsof treatment, closed reduction and percutaneous wires, ofthe distal radius fractures in children.Materials and methods: A retrospective analysis wascarried out in children aged between 5-15 years who presentedwith a displaced fracture of the distal radius to ourhospital. They were initially treated with closed reductionand cast immobilization. If the fractures redisplaced treatedby percutaneous Kirschner (K- wire with scope undera general anaesthesia.Results: Totally 104 patients, who have distal radius fractureswere treated by closed reduction and immobilizationin a plaster cast. 13 patient who have distal radiusfractures were treated by closed reduction under generalanaesthesia and fixed by percutaneous Kirschner (K-wire. Patients with impaired the alignment of the fracturein late period were usually completely displaced fractures.(n=5, 4,3%, in early period, completely displaced fractures(n=5, 4,3% are superior to partial displaced fractures(n=2, 1,7%.Conclusion: In our study, when children with distal radiusfracture first come, they were treated by closed reductionand immobilization in a plaster cast. We thought that inredisplaced fractures patients were suitable for the closedreduction with percutaneous wire treatment.

  13. Biomechanics of the thorax - research evidence and clinical expertise.

    Science.gov (United States)

    Lee, Diane Gail

    2015-07-01

    Understanding the biomechanics of the thorax is critical for understanding its role in multiple conditions since the thorax is part of many integrated systems including the musculoskeletal, respiratory, cardiac, digestive and urogynecological. The thorax is also an integrated system within itself and an element of the whole body/person. Therefore, understanding the biomechanics of the thorax is fundamental to all forms of treatment for multiple conditions. The interpretation of movement examination findings depends on one's view of optimal biomechanics and the influential factors. This article will provide a synopsis of the current state of research evidence as well as observations from clinical experience pertaining to the biomechanics of the thorax in order to help clinicians organise this knowledge and facilitate evidence-based and informed management of the, often complex, patient with or without thoracic pain and impairment. The integrated systems model (ISM) will be introduced as a way to determine when the noted biomechanical findings are relevant to a patient's clinical presentation.

  14. Optic nerve head biomechanics in aging and disease.

    Science.gov (United States)

    Downs, J Crawford

    2015-04-01

    This nontechnical review is focused upon educating the reader on optic nerve head biomechanics in both aging and disease along two main themes: what is known about how mechanical forces and the resulting deformations are distributed in the posterior pole and ONH (biomechanics) and what is known about how the living system responds to those deformations (mechanobiology). We focus on how ONH responds to IOP elevations as a structural system, insofar as the acute mechanical response of the lamina cribrosa is confounded with the responses of the peripapillary sclera, prelaminar neural tissues, and retrolaminar optic nerve. We discuss the biomechanical basis for IOP-driven changes in connective tissues, blood flow, and cellular responses. We use glaucoma as the primary framework to present the important aspects of ONH biomechanics in aging and disease, as ONH biomechanics, aging, and the posterior pole extracellular matrix (ECM) are thought to be centrally involved in glaucoma susceptibility, onset and progression. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Biomechanics of the thorax – research evidence and clinical expertise

    Science.gov (United States)

    Lee, Diane Gail

    2015-01-01

    Understanding the biomechanics of the thorax is critical for understanding its role in multiple conditions since the thorax is part of many integrated systems including the musculoskeletal, respiratory, cardiac, digestive and urogynecological. The thorax is also an integrated system within itself and an element of the whole body/person. Therefore, understanding the biomechanics of the thorax is fundamental to all forms of treatment for multiple conditions. The interpretation of movement examination findings depends on one's view of optimal biomechanics and the influential factors. This article will provide a synopsis of the current state of research evidence as well as observations from clinical experience pertaining to the biomechanics of the thorax in order to help clinicians organise this knowledge and facilitate evidence-based and informed management of the, often complex, patient with or without thoracic pain and impairment. The integrated systems model (ISM) will be introduced as a way to determine when the noted biomechanical findings are relevant to a patient's clinical presentation. PMID:26309383

  16. Biomechanics Strategies for Space Closure in Deep Overbite

    Directory of Open Access Journals (Sweden)

    Harryanto Wijaya

    2013-07-01

    Full Text Available Space closure is an interesting aspect of orthodontic treatment related to principles of biomechanics. It should be tailored individually based on patient’s diagnosis and treatment plan. Understanding the space closure biomechanics basis leads to achieve the desired treatment objective. Overbite deepening and losing posterior anchorage are the two most common unwanted side effects in space closure. Conventionally, correction of overbite must be done before space closure resulted in longer treatment. Application of proper space closure biomechanics strategies is necessary to achieve the desired treatment outcome. This cases report aimed to show the space closure biomechanics strategies that effectively control the overbite as well as posterior anchorage in deep overbite patients without increasing treatment time. Two patients who presented with class II division 1 malocclusion were treated with fixed orthodontic appliance. The primary strategies included extraction space closure on segmented arch that employed two-step space closure, namely single canine retraction simultaneously with incisors intrusion followed by enmasse retraction of four incisors by using differential moment concept. These strategies successfully closed the space, corrected deep overbite and controlled posterior anchorage simultaneously so that the treatment time was shortened. Biomechanics strategies that utilized were effective to achieve the desired treatment outcome.

  17. Laparoscopic versus open distal pancreatectomy for pancreatic cancer.

    Science.gov (United States)

    Riviere, Deniece; Gurusamy, Kurinchi Selvan; Kooby, David A; Vollmer, Charles M; Besselink, Marc G H; Davidson, Brian R; van Laarhoven, Cornelis J H M

    2016-04-04

    Surgical resection is currently the only treatment with the potential for long-term survival and cure of pancreatic cancer. Surgical resection is provided as distal pancreatectomy for cancers of the body and tail of the pancreas. It can be performed by laparoscopic or open surgery. In operations on other organs, laparoscopic surgery has been shown to reduce complications and length of hospital stay as compared with open surgery. However, concerns remain about the safety of laparoscopic distal pancreatectomy compared with open distal pancreatectomy in terms of postoperative complications and oncological clearance. To assess the benefits and harms of laparoscopic distal pancreatectomy versus open distal pancreatectomy for people undergoing distal pancreatectomy for pancreatic ductal adenocarcinoma of the body or tail of the pancreas, or both. We used search strategies to search the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index Expanded and trials registers until June 2015 to identify randomised controlled trials (RCTs) and non-randomised studies. We also searched the reference lists of included trials to identify additional studies. We considered for inclusion in the review RCTs and non-randomised studies comparing laparoscopic versus open distal pancreatectomy in patients with resectable pancreatic cancer, irrespective of language, blinding or publication status.. Two review authors independently identified trials and independently extracted data. We calculated odds ratios (ORs), mean differences (MDs) or hazard ratios (HRs) along with 95% confidence intervals (CIs) using both fixed-effect and random-effects models with RevMan 5 on the basis of intention-to-treat analysis when possible. We found no RCTs on this topic. We included in this review 12 non-randomised studies that compared laparoscopic versus open distal pancreatectomy (1576 participants: 394 underwent laparoscopic distal pancreatectomy and 1182

  18. Femoral Component External Rotation Affects Knee Biomechanics: A Computational Model of Posterior-stabilized TKA.

    Science.gov (United States)

    Kia, Mohammad; Wright, Timothy M; Cross, Michael B; Mayman, David J; Pearle, Andrew D; Sculco, Peter K; Westrich, Geoffrey H; Imhauser, Carl W

    2018-01-01

    The correct amount of external rotation of the femoral component during TKA is controversial because the resulting changes in biomechanical knee function associated with varying degrees of femoral component rotation are not well understood. We addressed this question using a computational model, which allowed us to isolate the biomechanical impact of geometric factors including bony shapes, location of ligament insertions, and implant size across three different knees after posterior-stabilized (PS) TKA. Using a computational model of the tibiofemoral joint, we asked: (1) Does external rotation unload the medial collateral ligament (MCL) and what is the effect on lateral collateral ligament tension? (2) How does external rotation alter tibiofemoral contact loads and kinematics? (3) Does 3° external rotation relative to the posterior condylar axis align the component to the surgical transepicondylar axis (sTEA) and what anatomic factors of the femoral condyle explain variations in maximum MCL tension among knees? We incorporated a PS TKA into a previously developed computational knee model applied to three neutrally aligned, nonarthritic, male cadaveric knees. The computational knee model was previously shown to corroborate coupled motions and ligament loading patterns of the native knee through a range of flexion. Implant geometries were virtually installed using hip-to-ankle CT scans through measured resection and anterior referencing surgical techniques. Collateral ligament properties were standardized across each knee model by defining stiffness and slack lengths based on the healthy population. The femoral component was externally rotated from 0° to 9° relative to the posterior condylar axis in 3° increments. At each increment, the knee was flexed under 500 N compression from 0° to 90° simulating an intraoperative examination. The computational model predicted collateral ligament forces, compartmental contact forces, and tibiofemoral internal/external and

  19. Giant Cell Tumour of the Distal Ulna: A Rare Presentation

    Directory of Open Access Journals (Sweden)

    Ruben Jaya Kumar

    2011-07-01

    Full Text Available Giant-cell tumour (GCT of bone, a primary yet locally aggressive benign tumour, commonly affects patients between the ages of 20 and 40 years, with the peak incidence occurring in the third decade. Women are affected slightly more than men. The distal end of the ulna is an extremely uncommon site for primary bone tumours in general and giant cell tumours in particular. Wide resection of the distal ulna is the recommended treatment for GCT in such locations. Radio-ulna convergence and dorsal displacement of the ulna stump are known complications following ulna resection proximal to the insertion of the pronator quadratus. This leads to reduction in grip power and forearm rotatory motion. Stabilization of the ulna stump with extensor carpi ulnaris (ECU tendon after wide resection of the tumour has been described in the literature. We report a case of GCT of distal end of ulna treated with wide resection and stabilization with ECU tendon.

  20. Segmental reversal of distal small intestine in short bowel syndrome

    DEFF Research Database (Denmark)

    Grave, Pernille Kock; Thomsen, Sabrina Valentin; Clark, Pia Susanne

    2018-01-01

    were the influence on cell proliferation and mucosal architecture shown by histological analysis. Methods: Sixteen piglets underwent a 60% resection of the distal small intestine and were randomized into two groups. Group 1 short bowel syndrome alone (SBS) (n = 8) and group 2 with reversal of a distal...... small intestinal segment (SBS-RS) (n = 8). Body weight was measured daily and the pigs were euthanized after 1 month. Crypt depths, villus heights and muscle layers thicknesses were measured. For the evaluation of microvilli of the brush border of the epithelium and cell proliferation...... was found in the SBS group and increase in the thickness of the circular and longitudinal muscle layers in the SBS-RS group. In the distal ileal segment the longitudinal muscle layer thicknesses were increased in the SBS group. Otherwise, no significant changes were found. Conclusion: Reversal of a 20-cm...

  1. Fractures of the distal tibia treated with polyaxial locking plating.

    Science.gov (United States)

    Gao, Hong; Zhang, Chang-Qing; Luo, Cong-Feng; Zhou, Zu-Bin; Zeng, Bing-Fang

    2009-03-01

    We evaluated the healing rate, complications, and functional outcomes in 32 adult patients with very short metaphyseal fragments in fractures of the distal tibia treated with a polyaxial locking system. The average distance from the distal extent of the fracture to the tibial plafond was 11 mm. All fractures healed and the average time to union was 14 weeks. Six patients (19%) reported occasional local disturbance over the medial malleolus. There were two cases of postoperative superficial infections and evidence of delayed wound healing. Using the American Orthopaedic Foot and Ankle Society ankle score, the average functional score was 87.3 points (of 100 total possible points). Our results show the polyaxial locking plates, which offer more fixation versatility, may be a reasonable treatment option for distal tibia fractures with very short metaphyseal segments.

  2. Biomechanical and clinical evaluation of posterior malleolar fractures. A systematic review of the literature

    NARCIS (Netherlands)

    van den Bekerom, Michel P. J.; Haverkamp, Daniel; Kloen, Peter

    2009-01-01

    INTRODUCTION: Ankle fractures often have involvement of the posterior malleolus. Treatment guidelines exist based on limited biomechanical evidence and still is considered controversial. The objective of this article is to review the biomechanical literature concerning changes in tibiotalar contract

  3. Validation of 2 noninvasive, markerless reconstruction techniques in biplane high-speed fluoroscopy for 3-dimensional research of bovine distal limb kinematics.

    Science.gov (United States)

    Weiss, M; Reich, E; Grund, S; Mülling, C K W; Geiger, S M

    2017-10-01

    Lameness severely impairs cattle's locomotion, and it is among the most important threats to animal welfare, performance, and productivity in the modern dairy industry. However, insight into the pathological alterations of claw biomechanics leading to lameness and an understanding of the biomechanics behind development of claw lesions causing lameness are limited. Biplane high-speed fluoroscopic kinematography is a new approach for the analysis of skeletal motion. Biplane high-speed videos in combination with bone scans can be used for 3-dimensional (3D) animations of bones moving in 3D space. The gold standard, marker-based animation, requires implantation of radio-opaque markers into bones, which impairs the practicability for lameness research in live animals. Therefore, the purpose of this study was to evaluate the comparative accuracy of 2 noninvasive, markerless animation techniques (semi-automatic and manual) in 3D animation of the bovine distal limb. Tantalum markers were implanted into each of the distal, middle, and proximal phalanges of 5 isolated bovine distal forelimbs, and biplane high-speed x-ray videos of each limb were recorded to capture the simulation of one step. The limbs were scanned by computed tomography to create bone models of the 6 digital bones, and 3D animation of the bones' movements were subsequently reconstructed using the marker-based, the semi-automatic, and the manual animation techniques. Manual animation translational bias and precision varied from 0.63 ± 0.26 mm to 0.80 ± 0.49 mm, and rotational bias and precision ranged from 2.41 ± 1.43° to 6.75 ± 4.67°. Semi-automatic translational values for bias and precision ranged from 1.26 ± 1.28 mm to 2.75 ± 2.17 mm, and rotational values varied from 3.81 ± 2.78° to 11.7 ± 8.11°. In our study, we demonstrated the successful application of biplane high-speed fluoroscopic kinematography to gait analysis of bovine distal limb. Using the manual animation technique, kinematics

  4. Minimally Invasive Distal Pancreatectomy: Review of the English Literature.

    Science.gov (United States)

    Wang, Kai; Fan, Ying

    2017-02-01

    Recently, the superiority of the minimally invasive approach, which results in a better cosmetic result, faster recovery, and shorter length of hospital stay, is a technique that has been progressively recognized as it has developed. And the minimally invasive approach has been applied to distal pancreatectomy (DP), which is a standard method for the treatment of benign, borderline, and part of malignant lesions of the pancreatic body and tail. This article aims to analyze the types, postoperative recovery, and outcomes of laparoscopic distal pancreatectomy (LDP). A systematic search of the scientific literature was performed using PubMed, EMBASE, online journals, and the Internet for all publications on LDP. Articles were selected if the abstract contained patients who underwent LDP for pancreatic diseases. All selected articles were reviewed and analyzed. If there were no contraindications for LDP, this operation is suitable for benign, borderline, or malignant tumors of the pancreatic body and tail, which should try to be performed with preservation of the spleen. LDP is safe and feasible under some conditions to experienced surgeon. Single-incision laparoscopic distal pancreatectomy (S-LDP) and robotic laparoscopic distal pancreatectomy (R-LDP) perioperative outcomes are similar with conventional multi-incision laparoscopic distal pancreatectomy (C-LDP). And the advantages of S-LDP and R-LDP require further exploration. With the application of enhanced recovery program (ERP), length of hospital stay and costs are reduced. LDP is safe and feasible under some conditions. Compared with open distal pancreatectomy, LDP has a lot of advantages; a trend was observed for LDP to replace traditional open surgery. LDP combined with ERP is expected to become standard in the treatment of pancreatic body and tail lesions.

  5. Laparoscopic distal pancreatectomy for adenocarcinoma: safe and reasonable?

    Science.gov (United States)

    Postlewait, Lauren M.

    2015-01-01

    As a result of technological advances during the past two decades, surgeons now use minimally invasive surgery (MIS) approaches to pancreatic resection more frequently, yet the role of these approaches for pancreatic ductal adenocarcinoma resections remains uncertain, given the aggressive nature of this malignancy. Although there are no controlled trials comparing MIS technique to open surgical technique, laparoscopic distal pancreatectomy for pancreatic adenocarcinoma is performed with increasing frequency. Data from retrospective studies suggest that perioperative complication profiles between open and laparoscopic distal pancreatectomy are similar, with perhaps lower blood loss and fewer wound infections in the MIS group. Concerning oncologic outcomes, there appear to be no differences in the rate of achieving negative margins or in the number of lymph nodes (LNs) resected when compared to open surgery. There are limited recurrence and survival data on laparoscopic compared to open distal pancreatectomy for pancreatic adenocarcinoma, but in the few studies that assess long term outcomes, recurrence rates and survival outcomes appear similar. Recent studies show that though laparoscopic distal pancreatectomy entails a greater operative cost, the associated shorter length of hospital stay leads to decreased overall cost compared to open procedures. Multiple new technologies are emerging to improve resection of pancreatic cancer. Robotic pancreatectomy is feasible, but there are limited data on robotic resection of pancreatic adenocarcinoma, and outcomes appear similar to laparoscopic approaches. Additionally fluorescence-guided surgery represents a new technology on the horizon that could improve oncologic outcomes after resection of pancreatic adenocarcinoma, though published data thus far are limited to animal models. Overall, MIS distal pancreatectomy appears to be a safe and reasonable approach to treating selected patients with pancreatic ductal

  6. Biomechanical analysis using Kinovea for sports application

    Science.gov (United States)

    Muaza Nor Adnan, Nor; Patar, Mohd Nor Azmi Ab; Lee, Hokyoo; Yamamoto, Shin-Ichiroh; Jong-Young, Lee; Mahmud, Jamaluddin

    2018-04-01

    This paper assesses the reliability of HD VideoCam–Kinovea as an alternative tool in conducting motion analysis and measuring knee relative angle of drop jump movement. The motion capture and analysis procedure were conducted in the Biomechanics Lab, Shibaura Institute of Technology, Omiya Campus, Japan. A healthy subject without any gait disorder (BMI of 28.60 ± 1.40) was recruited. The volunteered subject was asked to per the drop jump movement on preset platform and the motion was simultaneously recorded using an established infrared motion capture system (Hawk–Cortex) and a HD VideoCam in the sagittal plane only. The capture was repeated for 5 times. The outputs (video recordings) from the HD VideoCam were input into Kinovea (an open-source software) and the drop jump pattern was tracked and analysed. These data are compared with the drop jump pattern tracked and analysed earlier using the Hawk–Cortex system. In general, the results obtained (drop jump pattern) using the HD VideoCam–Kinovea are close to the results obtained using the established motion capture system. Basic statistical analyses show that most average variances are less than 10%, thus proving the repeatability of the protocol and the reliability of the results. It can be concluded that the integration of HD VideoCam–Kinovea has the potential to become a reliable motion capture–analysis system. Moreover, it is low cost, portable and easy to use. As a conclusion, the current study and its findings are found useful and has contributed to enhance significant knowledge pertaining to motion capture-analysis, drop jump movement and HD VideoCam–Kinovea integration.

  7. ANALYSIS OF BIOMECHANICAL PARAMETERS IN COLONIC ANASTOMOSIS.

    Science.gov (United States)

    Iwanaga, Tiago Cavalcanti; Aguiar, José Lamartine de Andrade; Martins-Filho, Euclides Dias; Kreimer, Flávio; Silva-Filho, Fernando Luiz; Albuquerque, Amanda Vasconcelos de

    2016-01-01

    The use of measures in colonic anastomoses to prevent dehiscences is of great medical interest. Sugarcane molasses, which has adequate tolerability and compatibility in vivo, has not yet been tested for this purpose. To analyze the biomechanical parameters of colonic suture in rats undergoing colectomy, using sugarcane molasses polysaccharide as tape or gel. 45 Wistar rats (Rattus norvegicus albinus) were randomized into three groups of 15 animals: irrigation of enteric sutures with 0.9% saline solution; application of sugarcane molasses polysaccharide as tape; and sugarcane molasses polysaccharide as gel. The rats underwent colon ressection, with subsequent reanastomosis using polypropylene suture; they were treated according to their respective groups. Five rats from each group were evaluated at different times after the procedure: 30, 90 and 180 days postoperatively. The following variables were evaluated: maximum rupture force, modulus of elasticity and specific deformation of maximum force. The biomechanical variables among the scheduled times and treatment groups were statistically calculated. The characteristics of maximum rupture force and modulus of elasticity of the specimens remained identical, regardless of treatment with saline, polysaccharide gel or tape, and treatment time. However, it was found that the specific deformation of maximum force of the intestinal wall was higher after 180 days in the group treated with sugarcane polysaccharide gel (p=0.09). Compared to control, it was detected greater elasticity of the intestinal wall in mice treated with sugarcane polysaccharide gel, without changing other biomechanical characteristics, regardless of type or time of treatment. A aplicação de produtos em anastomoses colônicas que possam prevenir o surgimento de deiscências são de grande interesse médico. O emprego do polissacarídeo de melaço de cana-de-açúcar (Saccharum officinarum), que possui adequada tolerabilidade e compatibilidade in vivo

  8. Neglected Distal Humeral Epiphyseal Injury - Two Case Reports

    Directory of Open Access Journals (Sweden)

    Dr. Pankaj Kumar

    2008-07-01

    Full Text Available Distal humeral epiphyseal separation is an uncommon injury in children, which can be missed or misdiagnosed at initial presentation. Awareness of this injury and appropriate radiological assessment helps in proper management. Neglected cases because of inappropriate diagnosis can result in cubitus varus deformity. Full range of movements of elbow can be achieved if properly diagnosed and managed. We present two cases of neglected distal humeral epiphyseal injury in children that resulted in cubitus varus deformity in one case. Full range of movements was achieved in both cases after proper management.

  9. Distal vertebral artery reconstruction when managing vertebrobasilar insufficiency

    Directory of Open Access Journals (Sweden)

    D. M. Galaktionov

    2017-11-01

    Full Text Available This article presents a literature review devoted to the reconstruction of the distal vertebral artery and a clinical case of successful surgical treatment of a patient suffering from vertebrobasilar insufficiency caused by occlusion of the vertebral artery in a proximal segment. The external carotid artery-distal vertebral artery bypass was performed by using the radial artery.Received 27 February 2017. Revised 25 July 2017. Accepted 3 August 2017.Funding: The study did not have sponsorship.Conflict of interest: The authors declare no conflict of interest. 

  10. Robotic spleen-preserving distal pancreatectomy. A case report.

    Science.gov (United States)

    Vasilescu, C; Sgarbura, O; Tudor, S; Herlea, V; Popescu, I

    2009-01-01

    Distal pancreatectomy (DP) is the removal of the pancreatic tissue at the left side of the superior mesenteric vein and it is traditionally approached by an open or laparoscopic exposure. Preservation of the spleen is optional but appears to have a better immunological outcome. We present the case of a 53-year old patient with a 2.4/2.2 tumor located in the tail of the pancreas, with high tumour marker values for whom we decided to perform a robotic spleen-preserving distal pancreatectomy (RSPDP). The postoperative outcome was satisfactory. In conclusion, we recommend this type of approach for small pancreatic tail lesions.

  11. Locking plates in distal humerus fractures: study of 43 patients

    Directory of Open Access Journals (Sweden)

    Gupta Rakesh Kumar

    2013-08-01

    Full Text Available 【Abstract】Objective: The treatment of multi-fragmentary, intraarticular fractures of the distal humerus is difficult, even in young patients with bone of good quality. Small distal fragment, diminished bone mineral quality and increased trauma-associated joint destruction make stable joint reconstruction more problematic. The anatomically preshaped locking plates allow angular stable fixation for these complex fractures. We evaluated functional results of patients treated with open reduction and internal fixation with distal humerus locking plates for complex distal hu-merus fractures. Methods: Forty-three consecutive patients with ar-ticular fractures of the distal humerus were treated by open reduction and internal fixation with AO distal humerus plate system and locking reconstruction plates. Forty patients were available for the final outcome analysis. According to AO/ASIF classification, there were 2 cases of type A2, 4 cases of type A3, 1 case of type B1, 1 case of type B2, 14 cases of type C1, 7 cases of type C2 and 11 cases of type C3. Open reduction with triceps splitting technique was used in all patients. The clinical and radiographic follow-up was performed and outcome measures included pain assessment, range of motion, and Mayo elbow performance score. Results: Forty patients were available for the final outcome analysis. There were 29 males and 11 females with an average age of 38.4 years (18-73 years. Clinical and ra-diological consolidation of the fracture was observed in all cases at an average of 11.6 weeks (9-14 weeks. The average follow-up was 12 months (10-18 months. Using the Mayo elbow performance score the results obtained were graded as excellent or good results in 33 patients (82.5%. One pa-tient had superficial infection, and 4 had myositis ossificans. There were no cases of primary malposition or secondary displacement, implant failure or ulnar neuropathy. Conclusion: Anatomically preshaped distal humerus locking

  12. Traumatisk distal humerus-epifysiolyse hos nyfødt

    DEFF Research Database (Denmark)

    Al-Aubaidi, Zaid; Nielsen, Keld Daubjerg

    2010-01-01

    Traumatic distal humerus epiphysiolysis (TDHE) is a rare injury in infants with an incidence of about 1:35,000 births. It is primarily a birth injury, but it is also seen in cases of battered child syndrome. Because of its rare occurrence and the diagnostic difficulties, the lesion may be overloo......Traumatic distal humerus epiphysiolysis (TDHE) is a rare injury in infants with an incidence of about 1:35,000 births. It is primarily a birth injury, but it is also seen in cases of battered child syndrome. Because of its rare occurrence and the diagnostic difficulties, the lesion may...

  13. Primary bone lymphoma of the distal tibia mimicking brodie's abscess

    International Nuclear Information System (INIS)

    Park, Jina; Lee, Seung Hun; Joo, Kyung Bin; Park, Chan Kum

    2014-01-01

    The 'penumbra sign' on an unenhanced T1-weighted image is a well-known characteristic of Brodie's abscess, and this sign is extremely helpful for discriminating subacute osteomyelitis from other bone lesions. We present a case of primary bone lymphoma of the distal tibia mimicking subacute osteomyelitis with Brodie's abscess in a 50-year-old woman. Initial radiographs and MRI showed a lesion in the distal tibia consistent with Brodie's abscess with the penumbra sign. Histopathological examination of the surgical biopsy specimen confirmed the presence of a diffuse large B-cell lymphoma involving the bone.

  14. Nontraumatic osteonecrosis of the distal pole of the scaphoid

    Directory of Open Access Journals (Sweden)

    Bhavuk Garg

    2011-01-01

    Full Text Available Post traumatic osteonecrosis of distal pole of scaphoid is very rare. We present a case of 34 years old male, drill operator by occupation with nontraumatic osteonecrosis of distal pole of the scaphoid. The patient was managed conservatively and was kept under regular follow-up every three months. The patient was also asked to change his profession. Two years later, the patient had no pain and had mild restriction of wrist movements (less than 15 degrees in either direction. The radiographs revealed normal density of the scaphoid suggesting revascularization.

  15. Osteoblastoma-like osteosarcoma of the distal tibia

    Energy Technology Data Exchange (ETDEWEB)

    Abramovici, Luigia; Steiner, German C. [Department of Pathology and Laboratory Medicine, Hospital for Joint Diseases, New York, NY (United States); Kenan, Samuel [Department of Orthopaedic Oncology Surgery, Hospital for Joint Diseases, New York, NY (United States); Hytiroglou, Prodromos [Aristotle University, Thessaloniki (Greece); Rafii, Mahvash [Department of Radiology, Hospital for Joint Diseases, New York, NY (United States)

    2002-03-01

    We report a case of a 14-year-old boy with an intracompartmental lytic lesion with poorly defined margins in the right distal tibia that was originally treated with curettage and bone grafting. Histologic examination showed an osteoblastic tumor with unusual features, which was found on consultation to be an osteoblastoma-like osteosarcoma, a rare, low-grade variant of osteosarcoma. Subsequently, the patient underwent en bloc resection of the distal tibia, which was replaced with vascularized bone graft and followed by chemotherapy. Two years later, he is alive with lung metastases. (orig.)

  16. Osteoblastoma-like osteosarcoma of the distal tibia

    International Nuclear Information System (INIS)

    Abramovici, Luigia; Steiner, German C.; Kenan, Samuel; Hytiroglou, Prodromos; Rafii, Mahvash

    2002-01-01

    We report a case of a 14-year-old boy with an intracompartmental lytic lesion with poorly defined margins in the right distal tibia that was originally treated with curettage and bone grafting. Histologic examination showed an osteoblastic tumor with unusual features, which was found on consultation to be an osteoblastoma-like osteosarcoma, a rare, low-grade variant of osteosarcoma. Subsequently, the patient underwent en bloc resection of the distal tibia, which was replaced with vascularized bone graft and followed by chemotherapy. Two years later, he is alive with lung metastases. (orig.)

  17. Distal renal tubular acidosis and amelogenesis imperfecta: A rare association

    Directory of Open Access Journals (Sweden)

    P Ravi

    2013-01-01

    Full Text Available Renal tubular acidosis (RTA is characterized by a normal anion gap with hyperchloremic metabolic acidosis. Primary distal RTA (type I is the most common RTA in children. Childhood presentation of distal RTA includes vomiting, failure to thrive, metabolic acidosis, and hypokalemia. Amelogenesis imperfecta (AI represents a condition where the dental enamel and oral tissues are affected in an equal manner resulting in the hypoplastic or hypopigmented teeth. We report a 10-year-old girl, previously asymptomatic presented with the hypokalemic paralysis and on work-up found out to have type I RTA. The discoloration of teeth and enamel was diagnosed as AI.

  18. Modified distal shoe appliance--fabrication and clinical performance.

    Science.gov (United States)

    Gujjar, Kumar Raghav; Indushekar, K R; Amith, H V; Sharma, Shefali Li

    2012-01-01

    When the primary second molar is prematurely lost, mesial movement and migration of the permanent first molar often occurs. This is one of the most difficult problems of the developing dentition confronted by pediatric dentists. Use of a space maintainer that will guide the permanent first molar into its normal position is indicated. In cases with bilateral premature loss of primary molars, the conventional design of distal shoe poses a variety of problems and, therefore, necessitates a customized design for the eruption guidance of permanent first molars. The purpose of this case report is to discuss an innovative design of a distal shoe appliance, which was used with good clinical results.

  19. Screening renal stone formers for distal renal tubular acidosis

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    A group of 110 consecutive renal stone formers were screened for distal renal tubular acidosis (RTA) using morning fasting urinary pH (mfUpH) levels followed by a short ammonium chloride loading test in patients with levels above 6.0. In 14 patients (12.7%) a renal acidification defect was noted...... RTA in renal stone formers. Regardless of whether the acidification defect is primary or secondary to stone formation, however, all renal stone formers with distal RTA can expect to benefit from prophylactic alkaline therapy and it is recommended that the screening procedure, which is easy to use...

  20. Computational biomechanics for medicine new approaches and new applications

    CERN Document Server

    Miller, Karol; Wittek, Adam; Nielsen, Poul

    2015-01-01

    The Computational Biomechanics for Medicine titles provide an opportunity for specialists in computational biomechanics to present their latest methodologiesand advancements. Thisvolumecomprises twelve of the newest approaches and applications of computational biomechanics, from researchers in Australia, New Zealand, USA, France, Spain and Switzerland. Some of the interesting topics discussed are:real-time simulations; growth and remodelling of soft tissues; inverse and meshless solutions; medical image analysis; and patient-specific solid mechanics simulations. One of the greatest challenges facing the computational engineering community is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, the biomedical sciences, and medicine. We hope the research presented within this book series will contribute to overcoming this grand challenge.

  1. Intestinal morphometric and biomechanical changes during aging in rats

    DEFF Research Database (Denmark)

    Zhao, Jingbo; Gregersen, Hans

    2015-01-01

    Background and aim: Previously we demonstrated pronounced morphometric and biomechanical remodeling in the rat intestine during physiological growth up to 32 weeks of age. The aim of the present study is to study intestinal geometric and biomechanical changes in aging rats. Materials and methods...... in the circumferential direction. In conclusion pronounced morphometric and biomechanical remodeling occurred in the rat intestine during aging. The observed changes likely reflect the changes of the physiological function of the intestine during ageing, similar to other tissues where function, mechanical loading......: Twenty-four male Wistar rats, aged from 6 to 22 months, were used in the study. The body weight and the wet weight per length of duodenal and ileal segments were measured at the termination of experiment. Morphometric data were obtained by measuring the wall thickness and wall cross-sectional area...

  2. Computational biomechanics for medicine imaging, modeling and computing

    CERN Document Server

    Doyle, Barry; Wittek, Adam; Nielsen, Poul; Miller, Karol

    2016-01-01

    The Computational Biomechanics for Medicine titles provide an opportunity for specialists in computational biomechanics to present their latest methodologies and advancements. This volume comprises eighteen of the newest approaches and applications of computational biomechanics, from researchers in Australia, New Zealand, USA, UK, Switzerland, Scotland, France and Russia. Some of the interesting topics discussed are: tailored computational models; traumatic brain injury; soft-tissue mechanics; medical image analysis; and clinically-relevant simulations. One of the greatest challenges facing the computational engineering community is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, the biomedical sciences, and medicine. We hope the research presented within this book series will contribute to overcoming this grand challenge.

  3. Biomechanical analysis technique choreographic movements (for example, "grand battman jete"

    Directory of Open Access Journals (Sweden)

    Batieieva N.P.

    2015-04-01

    Full Text Available Purpose : biomechanical analysis of the execution of choreographic movement "grand battman jete". Material : the study involved students (n = 7 of the department of classical choreography faculty of choreography. Results : biomechanical analysis of choreographic movement "grand battman jete" (classic exercise, obtained kinematic characteristics (path, velocity, acceleration, force of the center of mass (CM bio parts of the body artist (foot, shin, thigh. Built bio kinematic model (phase. The energy characteristics - mechanical work and kinetic energy units legs when performing choreographic movement "grand battman jete". Conclusions : It was found that the ability of an athlete and coach-choreographer analyze the biomechanics of movement has a positive effect on the improvement of choreographic training of qualified athletes in gymnastics (sport, art, figure skating and dance sports.

  4. Biomechanics of Wheat/Barley Straw and Corn Stover

    Energy Technology Data Exchange (ETDEWEB)

    Christopher T. Wright; Peter A. Pryfogle; Nathan A. Stevens; Eric D. Steffler; J. Richard Hess; Thomas H. Ulrich

    2005-03-01

    The lack of understanding of the mechanical characteristics of cellulosic feedstocks is a limiting factor in economically collecting and processing crop residues, primarily wheat and barley stems and corn stover. Several testing methods, including compression, tension, and bend have been investigated to increase our understanding of the biomechanical behavior of cellulosic feedstocks. Biomechanical data from these tests can provide required input to numerical models and help advance harvesting, handling, and processing techniques. In addition, integrating the models with the complete data set from this study can identify potential tools for manipulating the biomechanical properties of plant varieties in such a manner as to optimize their physical characteristics to produce higher value biomass and more energy efficient harvesting practices.

  5. Is gender influencing the biomechanical results after autologous chondrocyte implantation?

    Science.gov (United States)

    Kreuz, Peter C; Müller, Sebastian; Erggelet, Christoph; von Keudell, Arvind; Tischer, Thomas; Kaps, Christian; Niemeyer, Philipp; Hirschmüller, Anja

    2014-01-01

    The influence of gender on the biomechanical outcome after autologous chondrocyte implantation (ACI) including isokinetic muscle strength measurements has not been investigated. The present prospective study was performed to evaluate gender-specific differences in the biomechanical function 48 months after ACI. Fifty-two patients (mean age 35.6 ± 8.5 years) that met our inclusion criteria, underwent ACI with Bioseed C(®) and were evaluated with the KOOS score preoperatively, 6, 12 and 48 months after surgery. At final follow-up, 44 out of the 52 patients underwent biomechanical evaluation with isokinetic strength measurements of both knees. All data were evaluated separately for men and women and compared for each time interval using the Mann-Whitney U test. Clinical scores improved significantly over the whole study period (p genders. Isokinetic muscle strength measures are significantly worse in women (p role for the explanation of gender-specific results after ACI.

  6. Distally based superficial sural artery flap for soft tissue coverage in the distal 2/3 of leg and foot

    Directory of Open Access Journals (Sweden)

    Kamath B

    2005-01-01

    Full Text Available Background: Skin coverage for defects in the lower 2/3 of leg, ankle region and posterior heel has always been a difficult challenge for reconstructive surgeon. Methods: We describe our experience with the distally based superficial sural artery flap coverage in 48 patients with moderate sized defects in these difficult areas. Results: One out of 48 flaps (in 48 patients was lost totally and 3 suffered marginal necrosis which did not require any secondary procedure. These complications could have been avoided by proper selection of cases and refining technical skills. Conclusion: This simple procedure could be an important and versatile tool for any reconstructive surgeon in providing skin coverage in the distal leg and proximal foot. Preservation of major arteries of the lower limb, minimal donor defect, relatively uninjured donor area in compound fracture or poly trauma involving distal leg are some of the advantages of the flap.

  7. Vesicle biomechanics in a time-varying magnetic field.

    Science.gov (United States)

    Ye, Hui; Curcuru, Austen

    2015-01-01

    Cells exhibit distortion when exposed to a strong electric field, suggesting that the field imposes control over cellular biomechanics. Closed pure lipid bilayer membranes (vesicles) have been widely used for the experimental and theoretical studies of cellular biomechanics under this electrodeformation. An alternative method used to generate an electric field is by electromagnetic induction with a time-varying magnetic field. References reporting the magnetic control of cellular mechanics have recently emerged. However, theoretical analysis of the cellular mechanics under a time-varying magnetic field is inadequate. We developed an analytical theory to investigate the biomechanics of a modeled vesicle under a time-varying magnetic field. Following previous publications and to simplify the calculation, this model treated the inner and suspending media as lossy dielectrics, the membrane thickness set at zero, and the electric resistance of the membrane assumed to be negligible. This work provided the first analytical solutions for the surface charges, electric field, radial pressure, overall translational forces, and rotational torques introduced on a vesicle by the time-varying magnetic field. Frequency responses of these measures were analyzed, particularly the frequency used clinically by transcranial magnetic stimulation (TMS). The induced surface charges interacted with the electric field to produce a biomechanical impact upon the vesicle. The distribution of the induced surface charges depended on the orientation of the coil and field frequency. The densities of these charges were trivial at low frequency ranges, but significant at high frequency ranges. The direction of the radial force on the vesicle was dependent on the conductivity ratio between the vesicle and the medium. At relatively low frequencies (biomechanics under a time-varying magnetic field. Biological effects of clinical TMS are not likely to occur via alteration of the biomechanics of brain

  8. The healing process of intracorporeally and in situ devitalized distal femur by microwave in a dog model and its mechanical properties in vitro.

    Directory of Open Access Journals (Sweden)

    Zhenwei Ji

    Full Text Available BACKGROUND: Limb-salvage surgery has been well recognized as a standard treatment and alternative to amputation for patients with malignant bone tumors. Various limb-sparing techniques have been developed including tumor prosthesis, allograft, autograft and graft-prosthesis composite. However, each of these methods has short- and long-term disadvantages such as nonunion, mechanical failures and poor limb function. The technique of intracorporeal devitalization of tumor-bearing bone segment in situ by microwave-induced hyperthermia after separating it from surrounding normal tissues with a safe margin is a promising limb-salvage method, which may avoid some shortcomings encountered by the above-mentioned conventional techniques. The purpose of this study is to assess the healing process and revitalization potential of the devitalized bone segment by this method in a dog model. In addition, the immediate effect of microwave on the biomechanical properties of bone tissue was also explored in an in vitro experiment. METHODS: We applied the microwave-induced hyperthermia to devitalize the distal femurs of dogs in situ. Using a monopole microwave antenna, we could produce a necrotic bone of nearly 20 mm in length in distal femur. Radiography, bone scintigraphy, microangiography, histology and functional evaluation were performed at 2 weeks and 1, 2, 3, 6, 9 and 12 months postoperatively to assess the healing process. In a biomechanical study, two kinds of bone specimens, 3 and 6 cm in length, were used for compression and three-point bending test respectively immediately after extracorporeally devitalized by microwave. FINDINGS: An in vivo study showed that intracorporeally and in situ devitalized bone segment by microwave had great revitalization potential. An in vitro study revealed that the initial mechanical strength of the extracorporeally devitalized bone specimen may not be affected by microwave. CONCLUSION: Our results suggest that the

  9. Forward lunge knee biomechanics before and after partial meniscectomy

    DEFF Research Database (Denmark)

    Hall, Michelle; Nielsen, Jonas Høberg; Holsgaard-Larsen, Anders

    2015-01-01

    partial meniscectomy (APM) on knee joint mechanics. The purpose of this study was to evaluate changes in knee joint biomechanics during a forward lunge in patients with a suspected degenerative meniscal tear from before to three months after APM. METHODS: Twenty-two patients (35-55years old......) with a suspected degenerative medial meniscal tear participated in this study. Three dimensional knee biomechanics were assessed on the injured and contralateral leg before and three months after APM. The visual analogue scale was used to assess knee pain and the Knee Injury Osteoarthritis Outcome Score was used...

  10. Biomechanical Response and Behavior of Users under Emergency Buffer Crash

    Directory of Open Access Journals (Sweden)

    R. Miralbes

    2013-01-01

    Full Text Available This paper aims to study the biomechanical effects on elevator users and the injuries sustained should an elevator crash happen. The analysis will focus on buffer impact, signaling that the earlier mentioned buffer is usually located at the bottom of the pit. In order to carry out this analysis, a numerical technique based on finite element method will be used, while elevator users will be simulated by means of automotive dummies. Two crash factors will be studied, namely, location of dummy and fall velocity. The analysis criteria will be damages sustained by the dummy, based on biomechanical index such as HIC, CSI, forces, and accelerations.

  11. Development of esMOCA Biomechanic, Motion Capture Instrumentation for Biomechanics Analysis

    Science.gov (United States)

    Arendra, A.; Akhmad, S.

    2018-01-01

    This study aims to build motion capture instruments using inertial measurement unit sensors to assist in the analysis of biomechanics. Sensors used are accelerometer and gyroscope. Estimation of orientation sensors is done by digital motion processing in each sensor nodes. There are nine sensor nodes attached to the upper limbs. This sensor is connected to the pc via a wireless sensor network. The development of kinematics and inverse dynamamic models of the upper limb is done in simulink simmechanic. The kinematic model receives streaming data of sensor nodes mounted on the limbs. The output of the kinematic model is the pose of each limbs and visualized on display. The dynamic inverse model outputs the reaction force and reaction moment of each joint based on the limb motion input. Model validation in simulink with mathematical model of mechanical analysis showed results that did not differ significantly

  12. A trans-ethnic genome-wide association study identifies gender-specific loci influencing pediatric aBMD and BMC at the distal radius.

    Science.gov (United States)

    Chesi, Alessandra; Mitchell, Jonathan A; Kalkwarf, Heidi J; Bradfield, Jonathan P; Lappe, Joan M; McCormack, Shana E; Gilsanz, Vicente; Oberfield, Sharon E; Hakonarson, Hakon; Shepherd, John A; Kelly, Andrea; Zemel, Babette S; Grant, Struan F A

    2015-09-01

    Childhood fractures are common, with the forearm being the most common site. Genome-wide association studies (GWAS) have identified more than 60 loci associated with bone mineral density (BMD) in adults but less is known about genetic influences specific to bone in childhood. To identify novel genetic factors that influence pediatric bone strength at a common site for childhood fractures, we performed a sex-stratified trans-ethnic genome-wide association study of areal BMD (aBMD) and bone mineral content (BMC) Z-scores measured by dual energy X-ray absorptiometry at the one-third distal radius, in a cohort of 1399 children without clinical abnormalities in bone health. We tested signals with P BMC-Z). Signals at the CPED1-WNT16-FAM3C locus have been previously associated with BMD at other skeletal sites in adults and children. Our result at the distal radius underscores the importance of this locus at multiple skeletal sites. The 9p21.3 locus is within a gene desert, with the nearest gene flanking each side being MIR31HG and MTAP, neither of which has been implicated in BMD or BMC previously. These findings suggest that genetic determinants of childhood bone accretion at the radius, a skeletal site that is primarily cortical bone, exist and also differ by sex. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Genetics Home Reference: CAV3-related distal myopathy

    Science.gov (United States)

    ... gene causes a peculiar form of distal myopathy. Neurology. 2002 Jan 22;58(2):323-5. Erratum in: Neurology 2002 Mar 12;58(5):839. Itoyoma Y [ ... 3 cause four distinct autosomal dominant muscle diseases. Neurology. 2004 Feb 24;62(4):538-43. Review. ...

  14. Urethral advancement procedure in the treatment of primary distal ...

    African Journals Online (AJOL)

    advancement in the repair of primary distal penile hypospadias with regard to feasibility, complication rates .... stones and growth, and any associated congenital anomaly. Meticulous local examination was performed ... with a tourniquet placed on the root of the penis. A submeatal crescent-like incision was performed a few.

  15. Neglected distal humeral epiphyseal injury - Two Case Reports ...

    African Journals Online (AJOL)

    We present two cases of neglected distal humeral epiphyseal injury in children that resulted in cubitus varus deformity in one case. Full range of movements was achieved in both cases after proper management. Keywords: Neglected epiphyseal injury; Cubitus varus; Diagnosis; Treatment Internet Journal of Medical Update ...

  16. Evaluation of Various Filling Techniques in Distal Canals of ...

    African Journals Online (AJOL)

    2017-03-06

    Mar 6, 2017 ... How to cite this article: Dumani A, Yilmaz S, Yoldas O, Kuden C. Evaluation ... Niger J. Clin Pract 2017;20:307-12. This is an open access article distributed ... in oval-shaped distal canals of mandibular molars was inadequate.

  17. Social Support Contributes to Outcomes following Distal Radius Fractures

    Directory of Open Access Journals (Sweden)

    Caitlin J. Symonette

    2013-01-01

    Full Text Available Background. Distal radius fractures are the most common fracture of the upper extremity and cause variable disability. This study examined the role of social support in patient-reported pain and disability at one year following distal radius fracture. Methods. The Medical Outcomes Study Social Support Survey was administered to a prospective cohort of 291 subjects with distal radius fractures at their baseline visit. Pearson correlations and stepwise linear regression models (F-to-remove 0.10 were used to identify whether social support contributes to wrist fracture outcomes. The primary outcome of pain and disability at one year was measured using the Patient Rated Wrist Evaluation. Results. Most injuries were low energy (67.5% and were treated nonoperatively (71.9%. Pearson correlation analysis revealed that higher reported social support correlated with improved Patient Rated Wrist Evaluation scores at 1 year, r(n=181=-0.22, P<0.05. Of the subscales within the Social Support Survey, emotional/informational support explained a significant proportion of the variance in 1-year Patient Rated Wrist Evaluation scores, R2=4.7%, F (1, 181 = 9.98, P<0.05. Conclusion. Lower emotional/informational social support at the time of distal radius fracture contributes a small but significant percentage to patient-reported pain and disability outcomes.

  18. Simultaneous bilateral distal biceps tendon repair: case report

    Directory of Open Access Journals (Sweden)

    Thiago Medeiros Storti

    Full Text Available ABSTRACT Simultaneous bilateral rupture of the distal biceps tendon is a rare clinical entity, seldom reported in the literature and with unclear therapeutic setting. The authors report the case of a 39-year-old white man who suffered a simultaneous bilateral rupture while working out. When weightlifting with elbows at 90° of flexion, he suddenly felt pain on the anterior aspect of the arms, coming for evaluation after two days. He presented bulging contour of the biceps muscle belly and ecchymosis in the antecubital fossa, extending distally to the medial aspect of the forearm, as well as a marked decrease of supination strength and pain in active elbow flexion. MRI confirmed the rupture with retraction of the distal biceps bilaterally. The authors opted for performing the tendon repairs simultaneously through the double incision technique and fixation to the bicipital tuberosity with anchors. The patient progressed quite well, with full return to labor and sports activities, being satisfied with the result after two years of surgery. In the literature search, few reports of simultaneous bilateral rupture of the distal biceps were retrieved, with only one treated in the acute phase of injury. Therefore, the authors consider this procedure to be a good option to solve this complex condition.

  19. Simultaneous bilateral distal biceps tendon repair: case report.

    Science.gov (United States)

    Storti, Thiago Medeiros; Paniago, Alexandre Firmino; Faria, Rafael Salomon Silva

    2017-01-01

    Simultaneous bilateral rupture of the distal biceps tendon is a rare clinical entity, seldom reported in the literature and with unclear therapeutic setting. The authors report the case of a 39-year-old white man who suffered a simultaneous bilateral rupture while working out. When weightlifting with elbows at 90° of flexion, he suddenly felt pain on the anterior aspect of the arms, coming for evaluation after two days. He presented bulging contour of the biceps muscle belly and ecchymosis in the antecubital fossa, extending distally to the medial aspect of the forearm, as well as a marked decrease of supination strength and pain in active elbow flexion. MRI confirmed the rupture with retraction of the distal biceps bilaterally. The authors opted for performing the tendon repairs simultaneously through the double incision technique and fixation to the bicipital tuberosity with anchors. The patient progressed quite well, with full return to labor and sports activities, being satisfied with the result after two years of surgery. In the literature search, few reports of simultaneous bilateral rupture of the distal biceps were retrieved, with only one treated in the acute phase of injury. Therefore, the authors consider this procedure to be a good option to solve this complex condition.

  20. Evaluation of various filling techniques in distal canals of mandibular ...

    African Journals Online (AJOL)

    Evaluation of various filling techniques in distal canals of mandibular molars instrumented with different single-file nickel-titanium systems. ... Comparisons between groups were applied using Student's t-test or one-way ANOVA for normally distributed data. The Mann-Whitney U-test or Kruskal-Wallis test was used when ...

  1. A unique physeal injury of the distal phalanx.

    Science.gov (United States)

    Berber, Onur; Singh, Bijayendra

    2015-01-01

    An unusual Salter-Harris Type 1 fracture variant of the distal phalanx of the index finger is described. The epiphysis was dislocated, sitting dorsally over the middle phalanx head with the articular surface facing dorsal. Reduction could only be achieved through an open procedure. The reduction was stable without supplemental fixation.

  2. Unusual migration of ventriculo peritoneal distal catheter into vagina

    Directory of Open Access Journals (Sweden)

    Sghavamedin Tavallaee

    2015-04-01

    Full Text Available VP shunt is one of the most popular methods for ICP reduction and treatment of hydrocephalus. Various complications of this method are not uncommon such as shunt malfunction, infection and unusual migration of distal catheter. I present a case of migration of the peritoneal catheter out of the vagina.

  3. Laparoscopic versus open distal pancreatectomy for pancreatic cancer

    NARCIS (Netherlands)

    Riviere, D.M.; Gurusamy, K.S.; Kooby, D.A.; Vollmer, C.M.; Besselink, M.G.; Davidson, B.R.; Laarhoven, C.J.H.M. van

    2016-01-01

    BACKGROUND: Surgical resection is currently the only treatment with the potential for long-term survival and cure of pancreatic cancer. Surgical resection is provided as distal pancreatectomy for cancers of the body and tail of the pancreas. It can be performed by laparoscopic or open surgery. In

  4. Laparoscopic versus open distal pancreatectomy for pancreatic cancer

    NARCIS (Netherlands)

    Riviere, Deniece; Gurusamy, Kurinchi Selvan; Kooby, David A.; Vollmer, Charles M.; Besselink, Marc G. H.; Davidson, Brian R.; van Laarhoven, Cornelis J. H. M.

    2016-01-01

    Surgical resection is currently the only treatment with the potential for long-term survival and cure of pancreatic cancer. Surgical resection is provided as distal pancreatectomy for cancers of the body and tail of the pancreas. It can be performed by laparoscopic or open surgery. In operations on

  5. Autosomal dominant distal myopathy: Linkage to chromosome 14

    Energy Technology Data Exchange (ETDEWEB)

    Laing, N.G.; Laing, B.A.; Wilton, S.D.; Dorosz, S.; Mastaglia, F.L.; Kakulas, B.A. [Australian Neuromuscular Research Institute, Perth (Australia); Robbins, P.; Meredith, C.; Honeyman, K.; Kozman, H.

    1995-02-01

    We have studied a family segregating a form of autosomal dominant distal myopathy (MIM 160500) and containing nine living affected individuals. The myopathy in this family is closest in clinical phenotype to that first described by Gowers in 1902. A search for linkage was conducted using microsatellite, VNTR, and RFLP markers. In total, 92 markers on all 22 autosomes were run. Positive linkage was obtained with 14 of 15 markers tested on chromosome 14, with little indication of linkage elsewhere in the genome. Maximum two-point LOD scores of 2.60 at recombination fraction .00 were obtained for the markers MYH7 and D14S64 - the family structure precludes a two-point LOD score {ge} 3. Recombinations with D14S72 and D14S49 indicate that this distal myopathy locus, MPD1, should lie between these markers. A multipoint analysis assuming 100% penetrance and using the markers D14S72, D14S50, MYH7, D14S64, D14S54, and D14S49 gave a LOD score of exactly 3 at MYH7. Analysis at a penetrance of 80% gave a LOD score of 2.8 at this marker. This probable localization of a gene for distal myopathy, MPD1, on chromosome 14 should allow other investigators studying distal myopathy families to test this region for linkage in other types of the disease, to confirm linkage or to demonstrate the likely genetic heterogeneity. 24 refs., 3 figs., 1 tab.

  6. Detection of Lateglacial distal tephra layers in the Netherlands

    NARCIS (Netherlands)

    Davies, S.M.; Hoek, W.Z.; Bohncke, S.J.P.; Lowe, J.; Pyne O'Donnle, S.; Turney, C.S.M.

    2005-01-01

    Three distal tephra layers or cryptotephras have been detected within a sedimentary sequence from the Netherlands that spans the last glacial-interglacial transition. Geochemical analyses identify one as the Vedde Ash, which represents the southernmost discovery of this mid-Younger Dryas tephra so

  7. Outcome of management of distal radius fractures in ...

    African Journals Online (AJOL)

    Background and Purpose: Distal radial fractures are common fractures of postmenopausal age group patients. They are often called fractures of osteoporosis. These fractures are considered to be one of the commonest minor injuries to cause major morbidity in the community. A lot of patient who need surgery, fail to afford ...

  8. Snodgrass repair for distal hypospadias: a review of 75 cases

    African Journals Online (AJOL)

    urologists for distal hypospadias correction. We review our cases to find out whether there was any difference in the rate of urethrocutaneous fistula after the use of single- versus double-layer tubularization, the use of thick versus thin dorsal prepuce subcutaneous flap (DPF), the use of. DPF versus the ventral dartos flap for ...

  9. Spontaneous resolution of splenic infarcts after distal splenorenal ...

    African Journals Online (AJOL)

    Background: In cases of portal hypertension with splenic infarcts, splenectomy with proximal splenorenal shunt has been recommended. We are sharing our experience with distal splenorenal shunt in these cases contrary to the popular belief. Materials and Methods: Splenic infarcts were graded as mild, moderate and ...

  10. Class II correction prior to orthodontics with the carriere distalizer.

    Science.gov (United States)

    McFarlane, Bruce

    2013-01-01

    Class II correction is a challenge in orthodontics with many existing devices being complex, too compliance-driven, or too prone to breakage. The Carriere Distalizer allows for straightforward Class II correction prior to orthodontics (fixed or clear aligners) at a time when no other mechanics interfere, and compliance is at its best.

  11. The distal shoe space maintainer chairside fabrication and clinical performance.

    Science.gov (United States)

    Brill, Warren A

    2002-01-01

    The chairside-fabricated distal shoe appliance, with a stainless steel crown as the retainer, is an efficacious and cost-effective appliance for guiding the unerupted permanent first molar into position after premature loss or extraction of the second primary molar. The fabrication technique is illustrated in this case report and data is presented on the success rate of the appliance.

  12. Laparoscopic radical nephroureterectomy: dilemma of the distal ureter.

    Science.gov (United States)

    Steinberg, Jordan R; Matin, Surena F

    2004-03-01

    Laparoscopic nephroureterectomy has recently emerged as a safe, minimally invasive approach to upper tract urothelial cancers. The most controversial and challenging feature of laparoscopic nephroureterectomy is the management of the distal ureter. We review the most common methods of managing the distal ureter, with emphasis on contemporary oncologic outcomes, indications, advantages, and disadvantages. There are currently in excess of five different approaches to the lower ureter. These techniques often combine features of endoscopic, laparoscopic, or open management. They include open excision, a transvesical laparoscopic detachment and ligation technique, laparoscopic stapling of the distal ureter and bladder cuff, the "pluck" technique, and ureteral intussusception. Each technique has distinct advantages and disadvantages, differing not only in technical approach, but oncological principles as well. While the existing published data do not overwhelmingly support one approach over the others, the open approach remains one of the most reliable and oncologically sound procedures. The principles of surgical oncology dictate that a complete, en-bloc resection, with avoidance of tumor seeding, remains the preferred treatment of all urothelial cancers. The classical open technique of securing the distal ureter and bladder cuff achieves this principle and has withstood the test of time. Transvesical laparoscopic detachment and ligation is an oncologically valid approach in patients without bladder tumors, but is limited by technical considerations. The laparoscopic stapling technique maintains a closed system but risks leaving behind ureteral and bladder cuff segments. Both transurethral resection of the ureteral orifice (pluck) and intussusception techniques should be approached with caution, as the potential for tumor seeding exists. Additional long-term comparative outcomes are needed to solve the dilemma of the distal ureter.

  13. Distal pancreatectomy and splenectomy: a robotic or LESS approach.

    Science.gov (United States)

    Ryan, Carrie E; Ross, Sharona B; Sukharamwala, Prashant B; Sadowitz, Benjamin D; Wood, Thomas W; Rosemurgy, Alexander S

    2015-01-01

    The role and application of robotic surgery are debated, particularly given the expansion of laparoscopy, especially laparoendoscopic single-site (LESS) surgery. This cohort study was undertaken to delineate differences in outcomes between LESS and robotic distal pancreatectomy and splenectomy. With Institutional Review Board approval, patients undergoing LESS or robotic distal pancreatectomy and splenectomy from September 1, 2012, through December 31, 2014, were prospectively observed, and data were collected. The results are expressed as the median, with the mean ± SD. Thirty-four patients underwent a minimally invasive distal pancreatectomy and splenectomy: 18 with robotic and 16 with LESS surgery. The patients were similar in sex, age, and body mass index. Conversions to open surgery and estimated blood loss were similar. There were two intraoperative complications in the group that underwent the robotic approach. Time spent in the operating room was significantly longer with the robot (297 vs 254 minutes, P = .03), although operative duration (i.e., incision to closure) was not longer (225 vs 190 minutes; P = .15). Of the operations studied, 79% were undertaken for neoplastic processes. Tumor size was 3.5 cm for both approaches; R0 resections were achieved in all patients. Length of stay was similar in the two study groups (5 vs 4 days). There was one 30-day readmission after robotic surgery. Patient outcomes are similar with LESS or robotic distal pancreatectomy and splenectomy. Robotic operations require more time in the operating room. Both are safe and efficacious minimally invasive operations that follow similar oncologic principles for similar tumors, and both should be in the surgeon's armamentarium for distal pancreatectomy and splenectomy.

  14. Distal Oblique Bundle Reinforcement for Treatment of DRUJ Instability.

    Science.gov (United States)

    Brink, Peter R G; Hannemann, Pascal F W

    2015-08-01

    Background Chronic, dynamic bidirectional instability in the distal radioulnar joint (DRUJ) is diagnosed clinically, based on the patient's complaints and the finding of abnormal laxity in the vicinity of the distal ulna. In cases where malunion is ruled out or treated and there are no signs of osteoarthritis, stabilization of the DRUJ may offer relief. To this end, several different techniques have been investigated over the past 90 years. Materials and Methods In this article we outline the procedure for a new technique using a tendon graft to reinforce the distal edge of the interosseous membrane. Description of Technique A percutaneous technique is used to harvest the palmaris longus tendon and to create a tunnel, just proximal to the sigmoid notch, through the ulna and radius in an oblique direction. By overdrilling the radial cortex, the knotted tendon can be pulled through the radius and ulna and the knot blocked at the second radial cortex, creating a strong connection between the radius and ulna at the site of the distal oblique bundle (DOB). The tendon is fixed in the ulna with a small interference screw in full supination, preventing subluxation of the ulna out of the sigmoid notch during rotation. Results Fourteen patients were treated with this novel technique between 2011 and October 2013. The QuickDASH score at 25 months postoperatively (range 16-38 months) showed an improvement of 32 points. Similarly, an improvement of 33 points (67-34 months) was found on the PRWHE. Only one recurrence of chronic, dynamic bidirectional instability in the DRUJ was observed. Conclusion This simple percutaneous tenodesis technique between radius and ulna at the position of the distal edge of the interosseous membrane shows promise in terms of both restoring stability and relieving complaints related to chronic subluxation in the DRUJ.

  15. Anatomical and biomechanical study on the interosseous membrane of the cadaveric forearm

    Directory of Open Access Journals (Sweden)

    YI Xian-hong

    2011-06-01

    Full Text Available 【Abstract】 Objective: To study the anatomical and biomechanical features of the interosseous membrane (IOM of the cadaveric forearm. Methods: Ten radius-IOM-ulna structures were har- vested from fresh-frozen cadavers to measure the length, width and thickness of the tendinous portion of IOM. Then, the tendinous portion was isolated along with the ulnar and radial ends to which the tendon attached after measurement. The proximal portion of the radius and the distal portion of the ulna were embedded and fixed in the dental base acrylic resin powder. The embedded specimen was clamped and fixed by the MTS 858 test machine using a 10 000 N load cell for the entire tensile test. IOM was stretched at a speed of 50 mm/min until it was ruptured. The load-displacement curve was depicted with a computer and the maximum load and stiffness were recorded at the same time. Results: The IOM of the forearm was composed of three portions: central tendinous tissue, membranous tis- sue and dorsal affiliated oblique cord. IOM was stretched at a neutral position, and flexed at pronation and supination positions. The tendinous portion of IOM was lacerated in 6 specimens when the point of the maximum load reached to 1 021.50 N± 250.13 N, the stiffness to 138.24 N/m±24.29 N/m, and the length of stretch to 9.77 mm±1.77 mm. Fracture occurred at the fixed end of the ulna before laceration of the tendinous portion in 4 specimens when the maximum load was 744.40 N±109.85 N, the stiffness was 151.17 N/m±30.68 N/m, and the length of the stretch was 6.51 mm±0.51 mm. Conclusions: The IOM of the forearm is a structure having ligamentous characteristics between the radius and the ulna. It is very important for maintenance of the longitu- dinal stability of the forearm. The anatomical and biome- chanical data can be used as an objective criterion for evalu- ating the reconstructive method of IOM of the forearm. Key words: Forearm; Anatomy; Biomechanics

  16. Biomechanics research in ski jumping, 1991-2006.

    Science.gov (United States)

    Schwameder, Hermann

    2008-01-01

    In this paper, I review biomechanics research in ski jumping with a specific focus on publications presented between 1991 and 2006 on performance enhancement, limiting factors of the take-off, specific training and conditioning, aerodynamics, and safety. The first section presents a brief description of ski jumping phases (in-run, take-off, early flight, stable flight, and landing) regarding the biomechanical and functional fundamentals. The most important and frequently used biomechanical methods in ski jumping (kinematics, ground reaction force analyses, muscle activation patterns, aerodynamics) are summarized in the second section. The third section focuses on ski jumping articles and research findings published after the establishment of the V-technique in 1991, as the introduction of this technique has had a major influence on performance enhancement, ski jumping regulations, and the construction of hill profiles. The final section proposes topics for future research in the biomechanics of ski jumping, including: take-off and early flight and the relative roles of vertical velocity and forward somersaulting angular momentum; optimal jumping patterns utilizing the capabilities of individual athletes; development of kinematic and kinetic feedback systems for hill jumps; comparisons of simulated and hill jumps; effect of equipment modifications on performance and safety enhancement.

  17. Biomechanical, anthropometric, and psychological determinants of barbell back squat strength.

    Science.gov (United States)

    Vigotsky, Andrew D; Bryanton, Megan A; Nuckols, Greg; Beardsley, Chris; Contreras, Bret; Evans, Jessica; Schoenfeld, Brad J

    2018-02-27

    Previous investigations of strength have only focused on biomechanical or psychological determinants, while ignoring the potential interplay and relative contributions of these variables. The purpose of this study was to investigate the relative contributions of biomechanical, anthropometric, and psychological variables to the prediction of maximum parallel barbell back squat strength. Twenty-one college-aged participants (male = 14; female = 7; age = 23 ± 3 years) reported to the laboratory for two visits. The first visit consisted of anthropometric, psychometric, and parallel barbell back squat one-repetition maximum (1RM) testing. On the second visit, participants performed isometric dynamometry testing for the knee, hip, and spinal extensors in a sticking point position-specific manner. Multiple linear regression and correlations were used to investigate the combined and individual relationships between biomechanical, anthropometric, and psychological variables and squat 1RM. Multiple regression revealed only one statistically predictive determinant: fat free mass normalized to height (standardized estimate ± SE = 0.6 ± 0.3; t(16) = 2.28; p = 0.037). Correlation coefficients for individual variables and squat 1RM ranged from r = -0.79-0.83, with biomechanical, anthropometric, experiential, and sex predictors showing the strongest relationships, and psychological variables displaying the weakest relationships. These data suggest that back squat strength in a heterogeneous population is multifactorial and more related to physical rather than psychological variables.

  18. Biomechanics of the elbow joint in tennis players.

    NARCIS (Netherlands)

    Eygendaal, D.; Rahussen, F.T.; Diercks, R.L.

    2007-01-01

    Elbow injuries constitute a sizeable percentage of tennis injuries. A basic understanding of biomechanics of tennis and analysis of forces, loads and motions of the elbow during tennis can will improve the understanding of the pathophysiology of these injuries. All different strokes in tennis have a

  19. Future of crash dummies and biomechanical mathematical models

    NARCIS (Netherlands)

    Wismans, J.S.H.M.

    2000-01-01

    Thorough knowledge of the characteristics of the human body and its behaviour under extreme loading conditions is essential in order to prevent the serious consequences of road and other accidents. This field of research is called injury or impact biomechanics. In order to study the human body

  20. The Effect of Pterygium and Pterygium Surgery on Corneal Biomechanics.

    Science.gov (United States)

    Koç, Mustafa; Yavrum, Fuat; Uzel, Mehmet Murat; Aydemir, Emre; Özülken, Kemal; Yılmazbaş, Pelin

    2018-01-01

    To evaluate the effect of pterygium and pterygium surgery on corneal biomechanics by ocular response analyzer (ORA, Reichert, USA). This study considered 68 eyes (from 34 patients with a mean age of 21.2±7.1 years) with unilateral nasal, primary pterygium (horizontal length biomechanics. The correlation of the ORA measurements with the pterygium area was evaluated. Mean pterygium horizontal length and area were 3.31±1.43 mm and 6.82±2.17 mm 2 , respectively. There was no statistically significant difference between the eyes with and without pterygium in corneal hysteresis (CH, p=0.442), corneal resistance factor (CRF, p=0.554), corneal-compensated intraocular pressure (IOP cc , p=0.906), and Goldmann-correlated IOP (IOP g , p=0.836). All preoperative parameters decreased after surgery; however, none of them were statistically significant (CH, p=0.688; CRF, p=0.197; IOP cc , p=0.503; IOP g , p=0.231). There were no correlations between pterygium area and ORA measurements (p>0.05). Pterygium biomechanics. These results may be taken into account when cornea biomechanics, mainly intraocular pressure measurements, are important.

  1. Corneal Biomechanics in Ectatic Diseases: Refractive Surgery Implications

    Science.gov (United States)

    Ambrósio, Jr, Renato; Correia, Fernando Faria; Lopes, Bernardo; Salomão, Marcella Q.; Luz, Allan; Dawson, Daniel G.; Elsheikh, Ahmed; Vinciguerra, Riccardo; Vinciguerra, Paolo; Roberts, Cynthia J.

    2017-01-01

    Background: Ectasia development occurs due to a chronic corneal biomechanical decompensation or weakness, resulting in stromal thinning and corneal protrusion. This leads to corneal steepening, increase in astigmatism, and irregularity. In corneal refractive surgery, the detection of mild forms of ectasia pre-operatively is essential to avoid post-operative progressive ectasia, which also depends on the impact of the procedure on the cornea. Method: The advent of 3D tomography is proven as a significant advancement to further characterize corneal shape beyond front surface topography, which is still relevant. While screening tests for ectasia had been limited to corneal shape (geometry) assessment, clinical biomechanical assessment has been possible since the introduction of the Ocular Response Analyzer (Reichert Ophthalmic Instruments, Buffalo, USA) in 2005 and the Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) in 2010. Direct clinical biomechanical evaluation is recognized as paramount, especially in detection of mild ectatic cases and characterization of the susceptibility for ectasia progression for any cornea. Conclusions: The purpose of this review is to describe the current state of clinical evaluation of corneal biomechanics, focusing on the most recent advances of commercially available instruments and also on future developments, such as Brillouin microscopy. PMID:28932334

  2. Comparing handrim biomechanics for treadmill and overground wheelchair propulsion

    Science.gov (United States)

    Kwarciak, Andrew M.; Turner, Jeffrey T.; Guo, Liyun; Richter, W. Mark

    2010-01-01

    Study design Cross-sectional study. Objectives To compare handrim biomechanics recorded during overground propulsion to those recorded during propulsion on a motor-driven treadmill. Setting Biomechanics laboratory. Methods Twenty-eight manual wheelchair users propelled their own wheelchairs, at a self-selected speed, on a low-pile carpet and on a wheelchair accessible treadmill. Handrim biomechanics were recorded with an OptiPush instrumented wheelchair wheel. Results Across the two conditions, all handrim biomechanics were found to be similar and highly correlated (r > 0.85). Contact angle, peak force, average force, and peak axle moment differed by 1.6% or less across the two conditions. While not significant, power output and cadence tended to be slightly higher for the treadmill condition (3.5% and 3.6%, respectively), due to limitations in adjusting the treadmill grade. Conclusion Based on the results of this study, a motor-driven treadmill can serve as a valid surrogate for overground studies of wheelchair propulsion. PMID:21042332

  3. Biomechanical models of damage and healing processes for voice health

    DEFF Research Database (Denmark)

    Granados Corsellas, Alba; Brunskog, Jonas; Jacobsen, Finn

    2013-01-01

    the vocal-fold plane are available. This data is used to improve existing continuum biomechanical models of the vocal-folds by analyzing the injury processes. The project is expected to result in methods that objectively demonstrate the impact of high voice-load on voice. A detailed description...

  4. Focusing on the Hard parts: A Biomechanics Laboratory Exercise

    Science.gov (United States)

    Fingerut, Jonathan; Orbe, Kristina; Flynn, Daniel; Habdas, Piotr

    2013-01-01

    As part of a biomechanics course aimed at both upper-division Biology and Physics majors, this laboratory exercise introduces students to the ingenious ways in which organisms vary the composition and form of support and defensive structures such as bone and shell to maximize their strength while minimizing the energetic cost needed to produce…

  5. Using Clinical Gait Case Studies to Enhance Learning in Biomechanics

    Science.gov (United States)

    Chester, Victoria

    2011-01-01

    Clinical case studies facilitate the development of clinical reasoning strategies through knowledge and integration of the basic sciences. Case studies have been shown to be more effective in developing problem-solving abilities than the traditional lecture format. To enhance the learning experiences of students in biomechanics, clinical case…

  6. Quantitative modelling of the biomechanics of the avian syrinx

    DEFF Research Database (Denmark)

    Elemans, Coen P. H.; Larsen, Ole Næsbye; Hoffmann, Marc R.

    2003-01-01

    We review current quantitative models of the biomechanics of bird sound production. A quantitative model of the vocal apparatus was proposed by Fletcher (1988). He represented the syrinx (i.e. the portions of the trachea and bronchi with labia and membranes) as a single membrane. This membrane acts...

  7. Sequential and Biomechanical Factors Constrain Timing and Motion in Tapping

    NARCIS (Netherlands)

    Loehr, J.D.; Palmer, C.

    2009-01-01

    The authors examined how timing accuracy in tapping sequences is influenced by sequential effects of preceding finger movements and biomechanical interdependencies among fingers. Skilled pianists tapped Sequences at 3 rates; in each sequence, a finger whose motion was more or less independent of

  8. Biomechanics of the Gastrointestinal Tract in Health and Disease

    DEFF Research Database (Denmark)

    Zhao, Jingbo; Liao, Donghua; Gregersen, Hans

    2010-01-01

    . The biomechanical properties are crucial for GI motor function because peristaltic motion that propels the food through the GI tract is a result of interaction of the passive and active tissue forces and the hydrodynamic forces in the food bolus and remodeling of the mechanical properties reflects the changes...... of the efficacy and safety of new drugs on GI function....

  9. The biomechanical and physiological effect of two dynamic workstations

    NARCIS (Netherlands)

    Botter, J.; Burford, E.M.; Commissaris, D.; Könemann, R.; Mastrigt, S.H.V.; Ellegast, R.P.

    2013-01-01

    The aim of this research paper was to investigate the effect, both biomechanically and physiologically, of two dynamic workstations currently available on the commercial market. The dynamic workstations tested, namely the Treadmill Desk by LifeSpan and the LifeBalance Station by RightAngle, were

  10. Surface-based prostate registration with biomechanical regularization

    Science.gov (United States)

    van de Ven, Wendy J. M.; Hu, Yipeng; Barentsz, Jelle O.; Karssemeijer, Nico; Barratt, Dean; Huisman, Henkjan J.

    2013-03-01

    Adding MR-derived information to standard transrectal ultrasound (TRUS) images for guiding prostate biopsy is of substantial clinical interest. A tumor visible on MR images can be projected on ultrasound by using MRUS registration. A common approach is to use surface-based registration. We hypothesize that biomechanical modeling will better control deformation inside the prostate than a regular surface-based registration method. We developed a novel method by extending a surface-based registration with finite element (FE) simulation to better predict internal deformation of the prostate. For each of six patients, a tetrahedral mesh was constructed from the manual prostate segmentation. Next, the internal prostate deformation was simulated using the derived radial surface displacement as boundary condition. The deformation field within the gland was calculated using the predicted FE node displacements and thin-plate spline interpolation. We tested our method on MR guided MR biopsy imaging data, as landmarks can easily be identified on MR images. For evaluation of the registration accuracy we used 45 anatomical landmarks located in all regions of the prostate. Our results show that the median target registration error of a surface-based registration with biomechanical regularization is 1.88 mm, which is significantly different from 2.61 mm without biomechanical regularization. We can conclude that biomechanical FE modeling has the potential to improve the accuracy of multimodal prostate registration when comparing it to regular surface-based registration.

  11. Early Specialization in Youth Sport: A Biomechanical Perspective

    Science.gov (United States)

    Mattson, Jeffrey M.; Richards, Jim

    2010-01-01

    This article examines, from a biomechanical perspective, three issues related to early specialization: overuse injuries, the developmental aspects, and the performance aspects. It concludes that "there is no evidence that early specialization causes overuse injuries or hinders growth and maturation." At the same time, early specialization has…

  12. Biomechanical, microvascular, and cellular factors promote muscle and bone regeneration.

    Science.gov (United States)

    Duda, Georg N; Taylor, William R; Winkler, Tobias; Matziolis, Georg; Heller, Markus O; Haas, Norbert P; Perka, Carsten; Schaser, Klaus-D

    2008-04-01

    It is becoming clear that the long-term outcome of complex bone injuries benefits from approaches that selectively target biomechanical, vascular, and cellular pathways. The typically held view of either biological or mechanical aspects of healing is oversimplified and does not correspond to clinical reality. The fundamental mechanisms of soft tissue regeneration most likely hold the key to understanding healing response.

  13. Assessment and characterization of in situ rotator cuff biomechanics

    Science.gov (United States)

    Trent, Erika A.; Bailey, Lane; Mefleh, Fuad N.; Raikar, Vipul P.; Shanley, Ellen; Thigpen, Charles A.; Dean, Delphine; Kwartowitz, David M.

    2013-03-01

    Rotator cuff disease is a degenerative disorder that is a common, costly, and often debilitating, ranging in severity from partial thickness tear, which may cause pain, to total rupture, leading to loss in function. Currently, clinical diagnosis and determination of disease extent relies primarily on subjective assessment of pain, range of motion, and possibly X-ray or ultrasound images. The final treatment plan however is at the discretion of the clinician, who often bases their decision on personal experiences, and not quantitative standards. The use of ultrasound for the assessment of tissue biomechanics is established, such as in ultrasound elastography, where soft tissue biomechanics are measured. Few studies have investigated the use of ultrasound elastography in the characterization of musculoskeletal biomechanics. To assess tissue biomechanics we have developed a device, which measures the force applied to the underlying musculotendentious tissue while simultaneously obtaining the related ultrasound images. In this work, the musculotendinous region of the infraspinatus of twenty asymptomatic male organized baseball players was examined to access the variability in tissue properties within a single patient and across a normal population. Elastic moduli at percent strains less than 15 were significantly different than those above 15 percent strain within the normal population. No significant difference in tissue properties was demonstrated within a single patient. This analysis demonstrated elastic moduli are variable across individuals and incidence. Therefore threshold elastic moduli will likely be a function of variation in local-tissue moduli as opposed to a specific global value.

  14. The history of biomechanics in total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Jan Van Houcke

    2017-01-01

    Full Text Available Biomechanics of the hip joint describes how the complex combination of osseous, ligamentous, and muscular structures transfers the weight of the body from the axial skeleton into the appendicular skeleton of the lower limbs. Throughout history, several biomechanical studies based on theoretical mathematics, in vitro, in vivo as well as in silico models have been successfully performed. The insights gained from these studies have improved our understanding of the development of mechanical hip pathologies such as osteoarthritis, hip fractures, and developmental dysplasia of the hip. The main treatment of end-stage degeneration of the hip is total hip arthroplasty (THA. The increasing number of patients undergoing this surgical procedure, as well as their demand for more than just pain relief and leading an active lifestyle, has challenged surgeons and implant manufacturers to deliver higher function as well as longevity with the prosthesis. The science of biomechanics has played and will continue to play a crucial and integral role in achieving these goals. The aim of this article, therefore, is to present to the readers the key concepts in biomechanics of the hip and their application to THA.

  15. Biomechanical comparison of osteosynthesis with poly‑L‑lactic acid ...

    African Journals Online (AJOL)

    Background and Aims: The aim of this study was to compare the biomechanical stability of poly‑L‑lactic acid and titanium screws in the fixation of intracapsular condylar fractures, in 10 polyurethane hemimandibles. Materials and Methods: Artificial intracapsular fractures were created with a steel disk and electronic ...

  16. The medical simulation markup language - simplifying the biomechanical modeling workflow.

    Science.gov (United States)

    Suwelack, Stefan; Stoll, Markus; Schalck, Sebastian; Schoch, Nicolai; Dillmann, Rüdiger; Bendl, Rolf; Heuveline, Vincent; Speidel, Stefanie

    2014-01-01

    Modeling and simulation of the human body by means of continuum mechanics has become an important tool in diagnostics, computer-assisted interventions and training. This modeling approach seeks to construct patient-specific biomechanical models from tomographic data. Usually many different tools such as segmentation and meshing algorithms are involved in this workflow. In this paper we present a generalized and flexible description for biomechanical models. The unique feature of the new modeling language is that it not only describes the final biomechanical simulation, but also the workflow how the biomechanical model is constructed from tomographic data. In this way, the MSML can act as a middleware between all tools used in the modeling pipeline. The MSML thus greatly facilitates the prototyping of medical simulation workflows for clinical and research purposes. In this paper, we not only detail the XML-based modeling scheme, but also present a concrete implementation. Different examples highlight the flexibility, robustness and ease-of-use of the approach.

  17. A highly versatile autonomous underwater vehicle with biomechanical propulsion

    NARCIS (Netherlands)

    Simons, D.G.; Bergers, M.M.C.; Henrion, S.; Hulzenga, J.I.J.; Jutte, R.W.; Pas, W.M.G.; Van Schravendijk, M.; Vercruyssen, T.G.A.; Wilken, A.P.

    2009-01-01

    An autonomous underwater vehicle with a biomechanical propulsion system is a possible answer to the demand for small, silent sensor platforms in many fields. The design of Galatea, a bio-mimetic AUV, involves four aspects: hydrodynamic shape, the propulsion, the motion control systems and payload.

  18. Biomechanical Indices for Rupture Risk Estimation in Abdominal Aortic Aneurysms

    NARCIS (Netherlands)

    Leemans, Eva L.; Willems, Tineke P.; van der Laan, Maarten J.; Slump, Cornelis H.; Zeebregts, Clark J.

    2017-01-01

    Purpose: To review the use of biomechanical indices for the estimation of abdominal aortic aneurysm (AAA) rupture risk, emphasizing their potential use in a clinical setting. Methods: A search of the PubMed, Embase, Scopus, and Compendex databases was made up to June 2015 to identify articles

  19. Initial stress in biomechanical models of atherosclerotic plaques

    NARCIS (Netherlands)

    Speelman, L.; Akyildiz, A.C.; Adel, den B.; Wentzel, J.J.; Steen, van der A.F.W.; Virmani, R.; Weerd, van der L.; Jukema, J.W.; Poelmann, R.E.; Brummelen, van E.H.; Gijsen, F.J.H.

    2011-01-01

    Rupture of atherosclerotic plaques is the underlying cause for the majority of acute strokes and myocardial infarctions. Rupture of the plaque occurs when the stress in the plaque exceeds the strength of the material locally. Biomechanical stress analyses are commonly based on pressurized

  20. Unified Approach to the Biomechanics of Dental Implantology

    Science.gov (United States)

    Grenoble, D. E.; Knoell, A. C.

    1973-01-01

    The human need for safe and effective dental implants is well-recognized. Although many implant designs have been tested and are in use today, a large number have resulted in clinical failure. These failures appear to be due to biomechanical effects, as well as biocompatibility and surgical factors. A unified approach is proposed using multidisciplinary systems technology, for the study of the biomechanical interactions between dental implants and host tissues. The approach progresses from biomechanical modeling and analysis, supported by experimental investigations, through implant design development, clinical verification, and education of the dental practitioner. The result of the biomechanical modeling, analysis, and experimental phases would be the development of scientific design criteria for implants. Implant designs meeting these criteria would be generated, fabricated, and tested in animals. After design acceptance, these implants would be tested in humans, using efficient and safe surgical and restorative procedures. Finally, educational media and instructional courses would be developed for training dental practitioners in the use of the resulting implants.

  1. On seed physiology, biomechanics and plant phenology in Eragrostis tef

    NARCIS (Netherlands)

    Delden, van S.H.

    2011-01-01

    • Key words: Teff (Eragrostis tef (Zuccagni) Trotter), germination, temperature, model, leaf appearance, phyllochron, development rate, lodging, biomechanics, safety factor, flowering, heading, day length, photoperiod.

    • Background Teff (Eragrostis tef (Zuccagni) Trotter) is a C4 annual

  2. Important learning factors in high- and low-achieving students in undergraduate biomechanics.

    Science.gov (United States)

    Hsieh, ChengTu; Knudson, Duane

    2017-07-21

    The purpose of the present study was to document crucial factors associated with students' learning of biomechanical concepts, particularly between high- and-low achieving students. Students (N = 113) from three introductory biomechanics classes at two public universities volunteered for the study. Two measures of students' learning were obtained, final course grade and improvement on the Biomechanics Concept Inventory version 3 administered before and after the course. Participants also completed a 15-item questionnaire documenting student learning characteristics, effort, and confidence. Partial correlations controlling for all other variables in the study, confirmed previous studies that students' grade point average (p biomechanics, (p biomechanics concepts. Students' confidence when encountering difficult biomechanics concepts was also significantly (p biomechanics and confidence in solving relevant professional problems in order to improve learning for both low- and high-ability students.

  3. An Anatomic and Biomechanical Comparison of Bankart Repair Configurations.

    Science.gov (United States)

    Judson, Christopher H; Voss, Andreas; Obopilwe, Elifho; Dyrna, Felix; Arciero, Robert A; Shea, Kevin P

    2017-11-01

    Suture anchor repair for anterior shoulder instability can be performed using a number of different repair techniques, but none has been proven superior in terms of anatomic and biomechanical properties. Purpose/Hypothesis: The purpose was to compare the anatomic footprint coverage and biomechanical characteristics of 4 different Bankart repair techniques: (1) single row with simple sutures, (2) single row with horizontal mattress sutures, (3) double row with sutures, and (4) double row with labral tape. The hypotheses were as follows: (1) double-row techniques would improve the footprint coverage and biomechanical properties compared with single-row techniques, (2) horizontal mattress sutures would increase the footprint coverage compared with simple sutures, and (3) repair techniques with labral tape and sutures would not show different biomechanical properties. Controlled laboratory study. Twenty-four fresh-frozen cadaveric specimens were dissected. The native labrum was removed and the footprint marked and measured. Repair for each of the 4 groups was performed, and the uncovered footprint was measured using a 3-dimensional digitizer. The strength of the repair sites was assessed using a servohydraulic testing machine and a digital video system to record load to failure, cyclic displacement, and stiffness. The double-row repair techniques with sutures and labral tape covered 73.4% and 77.0% of the footprint, respectively. These percentages were significantly higher than the footprint coverage achieved by single-row repair techniques using simple sutures (38.1%) and horizontal mattress sutures (32.8%) ( P row and double-row groups or between the simple suture and horizontal mattress suture techniques. Likewise, there was no difference in the biomechanical properties of the double-row repair techniques with sutures versus labral tape. Double-row repair techniques provided better coverage of the native footprint of the labrum but did not provide superior

  4. Energetics, Biomechanics, and Performance in Masters' Swimmers: A Systematic Review.

    Science.gov (United States)

    Ferreira, Maria I; Barbosa, Tiago M; Costa, Mário J; Neiva, Henrique P; Marinho, Daniel A

    2016-07-01

    Ferreira, MI, Barbosa, TM, Costa, MJ, Neiva, HP, and Marinho, DA. Energetics, biomechanics, and performance in masters' swimmers: a systematic review. J Strength Cond Res 30(7): 2069-2081, 2016-This study aimed to summarize evidence on masters' swimmers energetics, biomechanics, and performance gathered in selected studies. An expanded search was conducted on 6 databases, conference proceedings, and department files. Fifteen studies were selected for further analysis. A qualitative evaluation of the studies based on the Quality Index (QI) was performed by 2 independent reviewers. The studies were thereafter classified into 3 domains according to the reported data: performance (10 studies), energetics (4 studies), and biomechanics (6 studies). The selected 15 articles included in this review presented low QI scores (mean score, 10.47 points). The biomechanics domain obtained higher QI (11.5 points), followed by energetics and performance (10.6 and 9.9 points, respectively). Stroke frequency (SF) and stroke length (SL) were both influenced by aging, although SF is more affected than SL. Propelling efficiency (ηp) decreased with age. Swimming performance declined with age. The performance declines with age having male swimmers deliver better performances than female counterparts, although this difference tends to be narrow in long-distance events. One single longitudinal study is found in the literature reporting the changes in performance over time. The remaining studies are cross-sectional designs focusing on the energetics and biomechanics. Overall, biomechanics parameters, such as SF, SL, and ηp, tend to decrease with age. This review shows the lack of a solid body of knowledge (reflected in the amount and quality of the articles published) on the changes in biomechanics, energetics, and performance of master swimmers over time. The training programs for this age-group should aim to preserve the energetics as much as possible and, concurrently, improve the

  5. Biomechanics Associated with Patellofemoral Pain and ACL Injuries in Sports.

    Science.gov (United States)

    Weiss, Kaitlyn; Whatman, Chris

    2015-09-01

    Knee injuries are prevalent among a variety of competitive sports and can impact an athlete's ability to continue to participate in their sport or, in the worst case, end an athlete's career. The aim was to evaluate biomechanics associated with both patellofemoral pain syndrome (PFPS) and anterior cruciate ligament (ACL) injuries (in sports involving landing, change in direction, or rapid deceleration) across the three time points frequently reported in the literature: pre-injury, at the time of injury, and following injury. A search of the literature was conducted for research evaluating biomechanics associated with ACL injury and PFPS. The Web of Science, SPORTDiscus, EBSCO, PubMed, and CINAHL databases, to March 2015, were searched, and journal articles focused on ACL injuries and PFPS in sports that met the inclusion criteria were reviewed. The search methodology was created with the intent of extracting case-control, case, and cohort studies of knee injury in athletic populations. The search strategy was restricted to only full-text articles published in English. These articles were included in the review if they met all of the required selection criteria. The following inclusion criteria were used: (1) The study must report lower extremity biomechanics in one of the following settings: (a) a comparison of currently injured and uninjured participants, (b) a prospective study evaluating risk factors for injury, or (c) a study reporting on the injury event itself. (2) The study must include only currently active participants who were similar at baseline (i.e. healthy, high school level basketball players currently in-season) and include biomechanical analysis of either landing, change in direction, or rapid deceleration. (3) The study must include currently injured participants. The studies were graded on the basis of quality, which served as an indication of risk of bias. An adapted version of the 'Strengthening the Reporting of Observational Studies in

  6. Radiographic evaluation of acute distal radius fracture stability: A comparative cadaveric study between a thermo-formable bracing system and traditional fiberglass casting.

    Science.gov (United States)

    Santoni, Brandon G; Aira, Jazmine R; Diaz, Miguel A; Kyle Stoops, T; Simon, Peter

    2017-08-01

    Distal radius fractures are common musculoskeletal injuries and many can be treated non-operatively with cast immobilization. A thermo-formable brace has been developed for management of such fractures, but no data exist regarding its comparative stabilizing efficacy to fiberglass casting. A worst-case distal radius fracture was created in 6 cadaveric forearms. A radiolucent loading fixture was created to apply cantilever bending/compression loads ranging from 4.5N to 66.7N across the simulated fracture in the: (1) non-stabilized, (2) braced; and (3) casted forearms, each forearm serving as its own control. Fracture fragment translations and rotations were measured radiographically using orthogonal radiographs and a 2D-3D, CT-based transformation methodology. Under 4.5N of load in the non-stabilized condition, average sagittal plane rotation and 3D center of mass translation of the fracture fragment were 12.3° and 5.3mm, respectively. At the 4.5N load step, fragment rotation with the brace (avg. 0.0°) and cast (0.1°) reduced sagittal plane rotation compared to the non-stabilized forearm (Pthermo-formable brace stabilized the fracture in a manner that was not radiographically or biomechanically different from traditional fiberglass casting. Study results support the use of the thermo-formable brace clinically. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Multicentre prospective evaluation of implant-assisted mandibular bilateral distal extension removable partial dentures: patient satisfaction

    NARCIS (Netherlands)

    Wismeijer, D.; Tawse-Smith, A.; Payne, A.G.T.

    2013-01-01

    Objective To compare the levels of patient satisfaction with either conventional mandibular bilateral distal extension partial dentures or those assisted by bilateral distal implants. Materials and methods Forty-eight participants who were dissatisfied with their existing conventional mandibular

  8. Minimally invasive versus open distal pancreatectomy (LEOPARD) : Study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    de Rooij, Thijs; van Hilst, Jony; Vogel, Jantien A.; van Santvoort, Hjalmar C.; de Boer, Marieke T.; Boerma, Djamila; van den Boezem, Peter B.; Bonsing, Bert A.; Bosscha, Koop; Coene, Peter-Paul; Daams, Freek; van Dam, Ronald M.; Dijkgraaf, Marcel G.; van Eijck, Casper H.; Festen, Sebastiaan; Gerhards, Michael F.; Koerkamp, Bas Groot; Hagendoorn, Jeroen; van der Harst, Erwin; de Hingh, Ignace H.; Dejong, Cees H.; Kazemier, Geert; Klaase, Joost; de Kleine, Ruben H.; van Laarhoven, Cornelis J.; Lips, Daan J.; Luyer, Misha D.; Molenaar, I. Quintus; Nieuwenhuijs, Vincent B.; Patijn, Gijs A.; Roos, Daphne; Scheepers, Joris J.; van der Schelling, George P.; Steenvoorde, Pascal; Swijnenburg, Rutger-Jan; Wijsman, Jan H.; Abu Hilal, Moh'd; Busch, Olivier R.; Besselink, Marc G.

    2017-01-01

    Background: Observational cohort studies have suggested that minimally invasive distal pancreatectomy (MIDP) is associated with better short-term outcomes compared with open distal pancreatectomy (ODP), such as less intraoperative blood loss, lower morbidity, shorter length of hospital stay, and

  9. Multicenter comparative study of laparoscopic and open distal pancreatectomy using propensity score-matching.

    Science.gov (United States)

    Nakamura, Masafumi; Wakabayashi, Go; Miyasaka, Yoshihiro; Tanaka, Masao; Morikawa, Takanori; Unno, Michiaki; Tajima, Hiroshi; Kumamoto, Yusuke; Satoi, Sohei; Kwon, Masanori; Toyama, Hirochika; Ku, Yonson; Yoshitomi, Hideyuki; Nara, Satoshi; Shimada, Kazuaki; Yokoyama, Takahide; Miyagawa, Shinichi; Toyama, Yoichi; Yanaga, Katsuhiko; Fujii, Tsutomu; Kodera, Yasuhiro; Tomiyama, Yasuyuki; Miyata, Hiroaki; Takahara, Takeshi; Beppu, Toru; Yamaue, Hiroki; Miyazaki, Masaru; Takada, Tadahiro

    2015-10-01

    Laparoscopic distal pancreatectomy has been shown to be associated with favorable postoperative outcomes using meta-analysis. However, there have been no randomized controlled studies yet. This study aimed to compare laparoscopic and open distal pancreatectomy using propensity score-matching. We retrospectively collected perioperative data of 2,266 patients who underwent distal pancreatectomy in 69 institutes from 2006-2013 in Japan. Among them, 2,010 patients were enrolled in this study and divided into two groups, laparoscopic distal pancreatectomy and open distal pancreatectomy. Perioperative outcomes were compared between the groups using unmatched and propensity matched analysis. After propensity score-matching, laparoscopic distal pancreatectomy was associated with favorable perioperative outcomes compared with open distal pancreatectomy, including higher rate of preservation of spleen and splenic vessels (P pancreatectomy was associated with more favorable perioperative outcomes than open distal pancreatectomy. © 2015 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  10. Design considerations for studies of the biomechanical environment of the femoropopliteal arteries.

    Science.gov (United States)

    Ansari, Farzana; Pack, Lindsay K; Brooks, Steven S; Morrison, Tina M

    2013-09-01

    The purpose of this study was to review the available literature regarding the biomechanics of the superficial femoral artery (SFA) and popliteal artery (PA) in patients with peripheral arterial disease (PAD). Stents are one of many available therapies used to treat patients with PAD. Because stents are permanent implants, they undergo a variety of deformations as patients go about their daily activities such as walking, sitting in a chair, or climbing stairs. As a part of the marketing application for United States Food and Drug Administration approval, stents need to be evaluated for long-term durability under a variety of loading modes. The information available in the literature provides direction for such evaluation. We performed a literature search of the PubMed database looking for "key vessel" and "mechanics" (all fields) or "deformation" (all fields) or "flexion" (all fields) or "mechanical environment" (all fields) or "tortuosity" (all fields) or "dynamics" (all fields) or "forces" (all fields), where the "key vessel" was "Femoral Artery," "Superficial Femoral Artery," "Popliteal Artery," and "Femoropopliteal." Using a decision tree, we found 12 relevant articles that focused solely on the nonradial cyclic deformations associated with musculoskeletal motion. Despite the many limitations associated with combining these studies, we learned that under walking conditions, the proximal and mid-SFA deforms, on average, by shortening in the axial direction 4.0%, by twisting 2.1°/cm, and by bending 72.1 mm; the distal SFA and proximal PA deform by shortening in the axial direction 13.9%, by twisting 3.5°/cm, and by being pinched such that the aspect ratio of the lumen changes 4.6%. The distal PA deforms by shortening in the axial direction 12.3%, by twisting 3.5°/cm, by bending 22.1 mm, and by being pinched such that the aspect ratio of the lumen changes 12.5%. A review of the current literature reveals heterogeneous study designs that confound interpretation

  11. Single absorbable polydioxanone pin fixation for distal chevron bunion osteotomies.

    Science.gov (United States)

    Deorio, J K; Ware, A W

    2001-10-01

    The distal chevron osteotomy is a well-established technique for correction of symptomatic mild to moderate metatarsus primus varus with hallux valgus deformity. Fixation of the osteotomy ranges from none to bone pegs, Kirschner wires, screws, or absorbable pins. We evaluated one surgeon's (J.K.D.) results of distal chevron osteotomy fixation with a single, nonpredrilled, 1.3-mm poly-p-dioxanone pin and analyzed any differences in patients with unilateral or bilateral symptomatic metatarsus primus varus with hallux valgus deformities. All osteotomies healed without evidence of infection, osteolysis, nonunion, or necrosis. Equal correction was achieved in unilateral and bilateral procedures. The technique is quick and easy, and adequate fixation is achieved.

  12. Osteomyelitis Caused by Candida glabrata in the Distal Phalanx

    Directory of Open Access Journals (Sweden)

    Shunichi Toki

    2014-01-01

    Full Text Available Osteomyelitis caused by Candida glabrata is rare and its optimal treatment is unknown. Here we report a case of osteomyelitis caused by C. glabrata in the distal phalanx in a 54-year-old woman. Despite partial resection of the nail and administering a 1-month course of antibiotics for paronychia, the local swelling remained and an osteolytic lesion was found. C. glabrata osteomyelitis of the distal phalanx was later diagnosed after curettage. Thereafter, the patient was treated with antifungal agents for 3 months. The infection eventually resolved, and radiological healing of the osteolytic lesion was achieved. Antifungal susceptibility testing should be performed in the case of osteomyelitis caused by nonalbicans Candida species, due to their resistance to fluconazole.

  13. Retrograde nailing for distal femur fractures in the elderly

    Directory of Open Access Journals (Sweden)

    Giddie Jasdeep

    2015-01-01

    Full Text Available Introduction: We report the results of treating a series of 56 fractures in 54 elderly patients with a distal femur fracture with a retrograde femoral nail. Methods: Fifty-four of the nails were inserted percutaneously with a closed reduction. After surgery all patients were allowed to weight bear as tolerated. Four fractures were supported in a temporary external splint. Results: The mean age of patients was 80.6 years (range 51–103 years, 52/54 (96% were females. There were no cases of nail related complications and no re-operations were required. One patient was lost to follow up. The 30-day mortality was 5/54 (9.3% and the one year mortality was 17/54 (31.5%. Conclusions: Distal femoral nail fixation provides a good method of fixation allowing immediate mobilisation for this group of patients.

  14. Pendulum Therapy of Molar Distalization in Mixed Dentition.

    Science.gov (United States)

    Patil, Raju Umaji; Prakash, Amit; Agarwal, Anshu

    2016-01-01

    Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient's compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73.

  15. Unravelling intention: distal intentions increase the subjective sense of agency.

    Science.gov (United States)

    Vinding, Mikkel C; Pedersen, Michael N; Overgaard, Morten

    2013-09-01

    Experimental studies investigating the contribution of conscious intention to the generation of a sense of agency for one's own actions tend to rely upon a narrow definition of intention. Often it is operationalized as the conscious sensation of wanting to move right before movement. Existing results and discussion are therefore missing crucial aspects of intentions, namely intention as the conscious sensation of wanting to move in advance of the movement. In the present experiment we used an intentional binding paradigm, in which we distinguished between immediate (proximal) intention, as usually investigated, and longer standing (distal) intention. The results showed that the binding effect was significantly enhanced for distal intentions compared to proximal intentions, indicating that the former leads to stronger sense of agency. Our finding provides empirical support for a crucial distinction between at least two types of intention when addressing the efficacy of conscious intentions. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Optimal fit of chairside-fabricated distal shoe space maintainer.

    Science.gov (United States)

    Nouri, M R; Kennedy, D B

    2013-10-01

    Premature loss of a primary second molar may lead to space loss in the dental arch. This space loss tends to be more severe in unfavourable malocclusions. The distal shoe space maintainer (DSSM) may be beneficial in controlling the path of eruption of an unerupted permanent first molar from the primary into the early mixed dentition. This article describes the technique for achieving optimal fit of a chairside-fabricated band and DSSM in a single visit by contouring the distal shoe blade, and by extending it to the mesial surface of the permanent first molar. Upon the eruption of the permanent first molar DSSM may be modified to a reverse band-and-loop, or replaced by a lingual holding arch.

  17. The effect of distal utility value intervention for students’ learning

    OpenAIRE

    KERA, Masaki; NAKAYA, Motoyuki

    2017-01-01

    The purpose of this study was to determine whether a utility value intervention influenced students’motivation and performance. Specifically, we examined the effect of distal utility value (i.e., the recognition of content usefulness for skill development that can improve daily and future endeavors) instruction in this study.Fifty-one Japanese undergraduate students completed an experimental session in the laboratory, in which they performed a series of logical reasoning problem-solving tasks...

  18. Epidemiology of distal forearm fractures in Oslo, Norway.

    Science.gov (United States)

    Lofthus, C M; Frihagen, F; Meyer, H E; Nordsletten, L; Melhuus, K; Falch, J A

    2008-06-01

    The population of Oslo has the highest incidence of hip fracture reported. The present study shows that the overall incidence of distal forearm fractures in Oslo is higher than in other countries and has not changed significantly when comparing the incidence of 1998/99 with 1979. The population of Oslo has the highest incidence of hip fracture reported. The present study reports the incidence of distal forearm fracture in Oslo and the fracture rates of immigrants. Patients aged > or = 20 years resident in Oslo sustaining a distal forearm fracture in a one-year period in 1998/99 were identified using electronic diagnosis registers, patient protocols, and/or X-ray registers of the clinics in Oslo. Medical records were obtained and the diagnosis verified. The age- and sex-specific incidence rates were calculated and compared with those for 1979. Data on immigrant category and country of origin of the patients were obtained. The age-adjusted fracture rates per 10,000 for the age group > or = 50 years were 109.8 and 25.4 in 1998/99 compared with 108.3 and 23.5 in 1979 for women and men, respectively (n.s.). The relative risk of fracture in Asians was 0.72 (95% CI 0.53-1.00) compared with ethnic Norwegians. The overall incidence of distal forearm fractures in Oslo is higher than in other countries and has not changed significantly when comparing the incidence of 1998/99 with 1979. Furthermore, the present data suggest that Asian immigrants in Oslo have a slightly lower fracture risk than ethnic Norwegians.

  19. Dual-port distal gastrectomy for the early gastric cancer

    OpenAIRE

    Kashiwagi, Hiroyuki; Kumagai, Kenta; Monma, Eiji; Nozue, Mutsumi

    2014-01-01

    Background Although recent trends in laparoscopic procedures have been toward minimizing the number of incisions, four or five ports are normally required to complete laparoscopic gastrectomy because of the complexity of this procedure. Multi-channel ports, such as the SILS port (Covidien, JAPAN), are now available and are crucial for performing single-incision laparoscopic surgery (SILS) or reduced port surgery (RPS). We carried out reduced port distal gastrectomy (RPDG) using a dual-port me...

  20. Factors Associated with Infection Following Open Distal Radius Fractures

    OpenAIRE

    Glueck, Dane A.; Charoglu, Constantine P.; Lawton, Jeffrey N.

    2009-01-01

    Open fractures are often classified according to a system described by Gustilo and Anderson. However, this system was applied to open long bone factures, which may not predict the incidence of infection in open metaphyseal fractures of the upper extremity. Other studies have found that wound contamination and systemic illness were the best predictors of infections in open hand fractures. Our study assessed infection in open distal radius fractures and identifies factors that are associated wi...

  1. Is nonoperative management of partial distal biceps tears really successful?

    Science.gov (United States)

    Bauer, Tyler M; Wong, Justin C; Lazarus, Mark D

    2018-04-01

    The current treatment of partial distal biceps tears is a period of nonoperative management, followed by surgery, if symptoms persist. Little is known about the success rate and outcomes of nonoperative management of this illness. We identified 132 patients with partial distal biceps tears through an International Classification of Diseases, Ninth Revision code query of our institution's database. Patient records were reviewed to abstract demographic information and confirm partial tears of the distal biceps tendon based on clinical examination findings and confirmatory magnetic resonance imaging (MRI). Seventy-four patients completed an outcome survey. In our study, 55.7% of the contacted patients who tried a nonoperative course (34 of 61 patients) ultimately underwent surgery, and 13 patients underwent immediate surgery. High-need patients, as defined by occupation, were more likely to report that they recovered ideally if they underwent surgery, as compared with those who did not undergo surgery (odds ratio, 11.58; P = .0138). For low-need patients, the same analysis was not statistically significant (P = .139). There was no difference in satisfaction scores between patients who tried a nonoperative course before surgery and those who underwent immediate surgery (P = .854). An MRI-diagnosed tear of greater than 50% was a predictor of needing surgery (odds ratio, 3.0; P = .006). This study has identified clinically relevant information for the treatment of partial distal biceps tears, including the following: the failure rate of nonoperative treatment, the establishment of MRI percent tear as a predictor of failing nonoperative management, the benefit of surgery for the high-need occupational group, and the finding that nonoperative management does not negatively affect outcome if subsequent surgery is necessary. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  2. Characterisation of osseous bodies of the distal phalanx of foals

    International Nuclear Information System (INIS)

    Kaneps, A.J.; O'Brien, T.R.; Redden, R.F.; Stover, S.M.; Pool, R.R.

    1993-01-01

    The distal phalanx and metacarpal physis of both forelimbs of 32 Thoroughbred foals 3-32 weeks of age were radiographed to identify those limbs with osseous bodies at a palmar process (PP) of the distal phalanx. Osseous bodies (ossicles) were identified radiographically in 19% of the foals. Sixteen of the 32 foals were selected for microradiographic and histological evaluation: 6 foals with radiographic evidence of ossicles and 10 foals without. Fourteen ossicles of the PP were observed radiographically. Ossicles were either a triangular bone fragment at the palmar aspect of the distal angle of the PP, or an oblong bone fragment separated from P3 by a radiolucent line extending 1-3 cm from the incisure of the PP to the solar margin. One foal had radiographic evidence of bilateral distal metacarpal physitis. Seventeen of 35 PPs examined microradiographically were considered normal, in that the dorsal and solar cortices were thin with trabecular bone orientated parallel to the cortical surfaces, and there was a depression in the dorsal cortical surface (i.e. parietal sulcus). Abnormal microradiographic findings in the other 18 PPs included a fracture line extending from the dorsal cortical surfaces and trabecular bridging of the fracture gap. The fracture line was often continuous with the parietal sulcus. Microradiographic evidence of a fracture was found in 75% of foals evaluated. Normal histological findings in 16 PPs included thin dorsal and solar cortices with trabeculae orientated parallel to the cortical surfaces, parallel-fibred dense connective tissue attachments of the deep digital flexor tendon to the solar cortical surfaces, and a neurovascular bundle associated with the parietal sulcus

  3. External jig in the placement of distal interlocking screws | Ikem ...

    African Journals Online (AJOL)

    Retrograde (52.2%) was the commonest surgical approach used for femur. The main indication for SIGN interlocking surgery was recent fracture 77.8%. Open reduction 97.8% was the commonest method of reduction used. The mean±SD bone union time was 3.58±0.56 months and range 3-5 months. Distal screw insertion ...

  4. A PROSPECTIVE STUDY OF DISTAL TIBIAL FRACTURES BY MIPO (LCP)

    OpenAIRE

    Chandra Sekharam Naidu; Ch.Murali Krishna; Sankara Rao; Dharma Rao; Ashok Kumar

    2015-01-01

    INTRODUCTION: D istal tibial fractures represent a significant challenge to most of the surgeons even today. They constitute 1 - 10% of all lower extremity fractures . 1 The difficulty in treating the fractures of distal tibial end is exemplif ied by orthopedists, who in the first half of twentieth century, believed these injuries were so severe and fraught with so many complications, that these fractures wer...

  5. Distal renal tubular acidosis in recurrent renal stone formers

    DEFF Research Database (Denmark)

    Osther, P J; Hansen, A B; Røhl, H F

    1989-01-01

    Renal acidification ability was examined in 90 recurrent renal stone formers, using fasting morning urinary pH levels followed by a short ammonium chloride loading test in subjects with pH levels above 6.0. Fifteen patients (16.6%) revealed a distal renal tubular acidification defect: one patient......, this has important therapeutic implications. The pathological sequence in renal stone formers with dRTA is discussed....

  6. Impact of a Nationwide Training Program in Minimally Invasive Distal Pancreatectomy (LAELAPS)

    NARCIS (Netherlands)

    de Rooij, Thijs; van Hilst, Jony; Boerma, Djamila; Bonsing, Bert A.; Daams, Freek; van Dam, Ronald M.; Dijkgraaf, Marcel G.; van Eijck, Casper H.; Festen, Sebastiaan; Gerhards, Michael F.; Koerkamp, Bas Groot; van der Harst, Erwin; de Hingh, Ignace H.; Kazemier, Geert; Klaase, Joost; de Kleine, Ruben H.; van Laarhoven, Cornelis J.; Lips, Daan J.; Luyer, Misha D.; Molenaar, I. Quintus; Patijn, Gijs A.; Roos, Daphne; Scheepers, Joris J.; van der Schelling, George P.; Steenvoorde, Pascal; Vriens, Menno R.; Wijsman, Jan H.; Gouma, Dirk J.; Busch, Olivier R.; Hilal, Mohammed Abu; Besselink, Marc G.; de Boer, Marieke T.

    2016-01-01

    Objective:To study the feasibility and impact of a nationwide training program in minimally invasive distal pancreatectomy (MIDP).Summary of Background Data:Superior outcomes of MIDP compared with open distal pancreatectomy have been reported. In the Netherlands (2005 to 2013) only 10% of distal

  7. Cost-effectiveness of laparoscopic versus open distal pancreatectomy for pancreatic cancer

    NARCIS (Netherlands)

    Gurusamy, Kurinchi Selvan; Riviere, Deniece; van Laarhoven, C. J. H.; Besselink, Marc; Abu-Hilal, Mohammed; Davidson, Brian R.; Morris, Steve

    2017-01-01

    A recent Cochrane review compared laparoscopic versus open distal pancreatectomy for people with for cancers of the body and tail of the pancreas and found that laparoscopic distal pancreatectomy may reduce the length of hospital stay. We compared the cost-effectiveness of laparoscopic distal

  8. Computer tomographic assessment of postoperative peripancreatic collections after distal pancreatectomy.

    Science.gov (United States)

    Uchida, Yuichiro; Masui, Toshihiko; Sato, Asahi; Nagai, Kazuyuki; Anazawa, Takayuki; Takaori, Kyoichi; Uemoto, Shinji

    2018-03-27

    Peripancreatic collections occur frequently after distal pancreatectomy. However, the sequelae of peripancreatic collections vary from case to case, and their clinical impact is uncertain. In this study, the correlations between CT findings of peripancreatic collections and complications after distal pancreatectomy were investigated. Ninety-six consecutive patients who had undergone distal pancreatectomy between 2010 and 2015 were retrospectively investigated. The extent and heterogeneity of peripancreatic collections and background clinicopathological characteristics were analyzed. The extent of peripancreatic collections was calculated based on three-dimensional computed tomography images, and the degree of heterogeneity of peripancreatic collections was assessed based on the standard deviation of their density on computed tomography. Of 85 patients who underwent postoperative computed tomography imaging, a peripancreatic collection was detected in 77 (91%). Patients with either a large extent or a high degree of heterogeneity of peripancreatic collection had a significantly higher rate of clinically relevant pancreatic fistula than those without (odds ratio 5.95, 95% confidence interval 2.12-19.72, p = 0.001; odds ratio 8.0, 95% confidence interval 2.87-24.19, p = 0.0001, respectively). A large and heterogeneous peripancreatic collection was significantly associated with postoperative complications, especially clinically relevant postoperative pancreatic fistula. A small and homogenous peripancreatic collection could be safely observed.

  9. Total elbow arthroplasty for the treatment of distal humeral fractures.

    Science.gov (United States)

    Gallucci, G L; Larrondo Calderón, W; Boretto, J G; Castellaro Lantermo, J A; Terán, J; de Carli, P

    2016-01-01

    To report the clinical-functional outcomes of the treatment of humeral distal fractures with a total elbow prosthesis. This retrospective study was performed in two surgical centres. A total of 23patients were included, with a mean age of 79years, and of which 21 were women. The inclusion criteria were: patients with humeral distal fractures, operated on using a Coonrad-Morrey prosthesis, and with a follow-up of more than one year. According to AO classification, 15fractures were type C3, 7 C2 and 1 A2. All patients were operated on without de-insertion of the extensor mechanism. The mean follow-up was 40 months. Flexor-extension was 123-17°, with a total mobility arc of 106° (80% of the contralateral side). Pain, according to a visual analogue scale was 1. The Mayo Elbow Performance Index (MEPI) was 83 points. Excellent results were obtained in 8 patients, good in 13, medium in 1, and poor in 1. The mean DASH (disability) score was 24 points. Treatment of humeral distal fractures with total elbow arthroplasty could be a good treatment option, but indications must be limited to patients with complex fractures, poor bone quality, with osteoporosis and low functional demands. In younger patients, the use is limited to serious cases where there is no other treatment option. Level of Evidence IV. Copyright © 2016 SECOT. Published by Elsevier Espana. All rights reserved.

  10. Distal antebrachial fractures in toy-breed dogs

    International Nuclear Information System (INIS)

    Muir, P.

    1997-01-01

    Antebrachial fractures account for approximately 17% of all canine fractures, with motor vehicle trauma cited as one of the primary causes. However, antebrachial fractures in toy-breed dogs are often sustained after apparently minimal trauma, such as jumping or falling, and are usually distal. The cause of antebrachial fractures in toy breeds is not well understood. Complications after treatment of distal antebrachial fractures in toy-breed dogs, including delayed union, nonunion, and malunion, are common and are potentially serious because they may necessitate limb amputation. This article reports on distal antebrachial fractures in 26 toy-breed dogs that wee presented to the University of California, Davis, Veterinary Medical Teaching Hospital from April 1987 to March 1996. The author found that (1) these fractures typically occur in growing or adolescent dogs; (2) the presence of complications of union is typically associated with prior treatment using intramedullary pinning or external coaptation; and (3) successful healing of this type of fracture is obtained via rigid stabilization with bone plating in combination with cancellous bone autograft

  11. Suture anchor tenodesis in repair of distal Achilles tendon injuries.

    Science.gov (United States)

    Kiliçoğlu, Onder; Türker, Mehmet; Yildız, Fatih; Akalan, Ekin; Temelli, Yener

    2014-01-01

    Distal Achilles tendon avulsions are in the form of either bony and nonbony avulsion of Achilles tendon from its calcaneal insertion. Four patients with distal Achilles tendon avulsions or ruptures which were treated with tendon to bone repair using suture anchors are presented here. Operated leg was immobilized in above-knee cast for 4 weeks while the patient walked non-weight-bearing. Then, cast was changed to below knee, and full weight-bearing was allowed. Patients underwent gait analysis minimum at first postoperative year. Mean American Orthopedics Foot Ankle Society ankle/hindfoot score of patients at last visit was 88.75 (range 85-100), and Achilles tendon total rupture score was 77.75 (range 58-87). Mean passive dorsiflexion of injured ankles (14° ± 5°) was lower than uninjured ankles (23° ± 9°). All the kinematic parameters of gait analysis were comparable to the uninjured side. Maximum plantar flexion power of injured ankle was 1.40 W/kg, and this was significantly lower than the contralateral side value 2.38 W/kg; (P = 0.0143). There were no visually altered gait or problems in daily life. Suture anchor tenodesis technique of distal Achilles tendon avulsions was successful in achieving durable osteotendinous repairs.

  12. Laparoscopic distal pancreatectomy for adenocarcinoma of the pancreas

    Science.gov (United States)

    Björnsson, Bergthor; Sandström, Per

    2014-01-01

    Since the first report on laparoscopic distal pancreatectomy (LDP) appeared in the 1990s, the procedure has been performed increasingly frequently to treat both benign and malignant lesions of the pancreas. Many earlier publications have shown LDP to be a good alternative to open distal pancreatectomy for benign lesions, although this has never been studied in a prospective, randomized manner. The evidence for the use of LDP to treat adenocarcinoma of the pancreas is not as well established. The purpose of this review is to evaluate the current evidence for LDP in cases of pancreatic adenocarcinoma. We conducted a review of English language publications reporting LDP results between 1990 and 2013. All studies reporting results in patients with histologically proven pancreatic adenocarcinoma were included. Thirty-nine publications were found and included in the results for a total of 309 cases of pancreatic adenocarcinoma (potential double publications were not eliminated). Most LDP procedures are performed in selected cases and generally involve smaller tumors than open distal pancreatectomy (ODP) procedures. Some of the papers report unselected cases and include procedures on larger tumors. The number of lymph nodes harvested using LDP is comparable to the number obtained with ODP, as is the frequency of R0 resections. Current data suggest that similar short term oncological results can be obtained using LDP as those obtained using ODP. PMID:25309072

  13. Importance of early audiologic assessment in distal renal tubular acidosis

    Directory of Open Access Journals (Sweden)

    Elizabeth Norgett

    2010-12-01

    Full Text Available Anand P Swayamprakasam1, Elizabeth Stover1, Elizabeth Norgett1, Katherine G Blake-Palmer1, Michael J Cunningham2, Fiona E Karet11Department of Medical Genetics, Cambridge Institute for Medical Research, Cambridge, UK; 2Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USAAbstract: Autosomal recessive distal renal tubular acidosis is usually a severe disease of childhood, often presenting as failure to thrive in infancy. It is often, but not always, accompanied by sensorineural hearing loss, the clinical severity and age of onset of which may be different from the other clinical features. Mutations in either ATP6V1B1 or ATP6V0A4 are the chief causes of primary distal renal tubular acidosis with or without hearing loss, although the loss is often milder in the latter. We describe a kindred with compound heterozygous alterations in ATP6V0A4, where hearing loss was formally diagnosed late in both siblings such that they missed early opportunities for hearing support. This kindred highlights the importance of routine audiologic assessments of all children with distal renal tubular acidosis, irrespective either of age at diagnosis or of which gene is mutated. In addition, when diagnostic genetic testing is undertaken, both genes should be screened irrespective of current hearing status. A strategy for this is outlined.Keywords: sensorineural hearing loss, renal tubular acidosis, recessive, genetics, mutation

  14. Ionotropic GABA Receptors and Distal Retinal ON and OFF Responses

    Directory of Open Access Journals (Sweden)

    E. Popova

    2014-01-01

    Full Text Available In the vertebrate retina, visual signals are segregated into parallel ON and OFF pathways, which provide information for light increments and decrements. The segregation is first evident at the level of the ON and OFF bipolar cells in distal retina. The activity of large populations of ON and OFF bipolar cells is reflected in the b- and d-waves of the diffuse electroretinogram (ERG. The role of gamma-aminobutyric acid (GABA, acting through ionotropic GABA receptors in shaping the ON and OFF responses in distal retina, is a matter of debate. This review summarized current knowledge about the types of the GABAergic neurons and ionotropic GABA receptors in the retina as well as the effects of GABA and specific GABAA and GABAC receptor antagonists on the activity of the ON and OFF bipolar cells in both nonmammalian and mammalian retina. Special emphasis is put on the effects on b- and d-waves of the ERG as a useful tool for assessment of the overall function of distal retinal ON and OFF channels. The role of GABAergic system in establishing the ON-OFF asymmetry concerning the time course and absolute and relative sensitivity of the ERG responses under different conditions of light adaptation in amphibian retina is also discussed.

  15. Three-stage treatment protocol for recalcitrant distal femoral nonunion.

    Science.gov (United States)

    Ma, Ching-Hou; Chiu, Yen-Chun; Tu, Yuan-Kun; Yen, Cheng-Yo; Wu, Chin-Hsien

    2017-04-01

    In this study, we proposed a three-stage treatment protocol for recalcitrant distal femoral nonunion and aimed to analyze the clinical results. We retrospective reviewed 12 consecutive patients with recalcitrant distal femoral nonunion undergoing our three-stage treatment protocol from January 2010 to December 2014 in our institute. The three-stage treatment protocol comprised debridement of the nonunion site, lengthening to eliminate leg length discrepancy, deformity correction, stabilization with a locked plate, filling of the defect with cement spacer for inducing membrane formation, and bone reconstruction using a cancellous bone autograft (Masquelet technique) or free vascularized fibular bone graft. The bone union time, wound complication, lower limbs alignment, amount of lengthening, knee range of motion, and functional outcomes were evaluated. Osseous union with angular deformity lengthening was 5.88 cm (range 3.5-12 cm). Excellent or good outcomes were obtained in 9 patients. Although the current study involved only a small number of patients and the intervention comprised three stages, we believe that such a protocol may be a valuable alternative for the treatment of recalcitrant distal femoral nonunion.

  16. Biomechanical optimization of different fixation modes for a proximal femoral L-osteotomy

    Directory of Open Access Journals (Sweden)

    Chen Hsih-Hao

    2009-09-01

    Full Text Available Abstract Background Numerous proposed surgical techniques have had minimal success in managing greater trochanter overgrowth secondary to retarded growth of the femoral capital epiphysis. For reconstruction of residual hip deformities, a novel type of proximal femur L-osteotomy was performed with satisfactory results. Although the clinical outcome was good, the biomechanical characteristics of the femur after such an osteotomy have not been clearly elucidated. Therefore, this study presents a three dimensional finite element analysis designed to understand the mechanical characteristics of the femur after the L-osteotomy. Methods A patient with left hip dysplasia was recruited as the study model for L-osteotomy. The normal right hip was used as a reference for performing the corrective surgery. Four FEA models were constructed using different numbers of fixation screws but the same osteotomy lengths together with four FEA models with the same number of fixation screws but different osteotomy lengths. The von Mises stress distributions and femoral head displacements were analyzed and compared. Results The results revealed the following: 1. The fixation devices (plate and screws sustained most of the external loading, and the peak value of von Mises stress on the fixation screws decreased with an increasing number of screws. 2. Additional screws are more beneficial on the proximal segment than on the distal segment for improving the stability of the postoperative femur. 3. The extent of osteotomy should be limited because local stress might be concentrated in the femoral neck region with increasing length of the L-osteotomy. Conclusion Additional screw placement on the proximal segment improves stability in the postoperative femur. The cobra-type plate with additional screw holes in the proximal area might improve the effectiveness of L-osteotomies.

  17. Effects of Bone Young’s Modulus on Finite Element Analysis in the Lateral Ankle Biomechanics

    Directory of Open Access Journals (Sweden)

    W. X. Niu

    2013-01-01

    Full Text Available Finite element analysis (FEA is a powerful tool in biomechanics. The mechanical properties of biological tissue used in FEA modeling are mainly from experimental data, which vary greatly and are sometimes uncertain. The purpose of this study was to research how Young’s modulus affects the computations of a foot-ankle FEA model. A computer simulation and an in-vitro experiment were carried out to investigate the effects of incremental Young’s modulus of bone on the stress and strain outcomes in the computational simulation. A precise 3-dimensional finite element model was constructed based on an in-vitro specimen of human foot and ankle. Young’s moduli were assigned as four levels of 7.3, 14.6, 21.9 and 29.2 GPa respectively. The proximal tibia and fibula were completely limited to six degrees of freedom, and the ankle was loaded to inversion 10° and 20° through the calcaneus. Six cadaveric foot-ankle specimens were loaded as same as the finite element model, and strain was measured at two positions of the distal fibula. The bone stress was less affected by assignment of Young’s modulus. With increasing of Young’s modulus, the bone strain decreased linearly. Young’s modulus of 29.2 GPa was advisable to get the satisfactory surface strain results. In the future study, more ideal model should be constructed to represent the nonlinearity, anisotropy and inhomogeneity, as the same time to provide reasonable outputs of the interested parameters.

  18. Decellularization of Human Internal Mammary Artery: Biomechanical Properties and Histopathological Evaluation.

    Science.gov (United States)

    Kajbafzadeh, Abdol-Mohammad; Khorramirouz, Reza; Kameli, Seyede Maryam; Hashemi, Javad; Bagheri, Amin

    2017-01-01

    This study undertook to create small-diameter vascular grafts and assess their structure and mechanical properties to withstand arterial implantation. Twenty samples of intact human internal mammary arteries (IMAs) were collected and decellularized using detergent-based methods. To evaluate residual cellular and extracellular matrix (ECM) components, histological analysis was performed. Moreover, collagen typing and ECM structure were analyzed by Picrosirius red and Movat's pentachrome staining. Scanning electron microscopy was also applied to assess microarchitecture of both endothelial and adventitial surfaces of native and decellularized arterial samples. Furthermore, mechanical tests were performed to evaluate the rigidity and suture strength of the arteries. Human IMAs were completely decellularized in all three segments (proximal, middle, and distal). ECM proteins such as collagen and elastic fibers were efficiently preserved and no structural distortion in intima, media, and adventitial surfaces was observed. The parameters of the mechanical tests revealed no significant differences in the mechanical properties of decellularized arteries in comparison to native arteries with considerable strength, suture retention, and stress relaxation (Young's modulus [MPa] = 0.22 ± 0.023 [native] and 0.22 ± 0.015 [acellular]; and suture strength 0.56 ± 0.19 [native] vs. 0.56 ± 0.12 [acellular], respectively). Decellularized IMA represents a potential arterial scaffold as an alternative to autologous grafts for future arterial bypass surgeries. By this technique, microarchitecture and mechanical integrity of decellularized arteries were considerably similar to native arteries. The goal of this study was to introduce an efficient method for complete decellularization of human IMA and evaluate the ECM and biomechanical properties.

  19. Computer simulation of human motion in sports biomechanics.

    Science.gov (United States)

    Vaughan, C L

    1984-01-01

    This chapter has covered some important aspects of the computer simulation of human motion in sports biomechanics. First the definition and the advantages and limitations of computer simulation were discussed; second, research on various sporting activities were reviewed. These activities included basic movements, aquatic sports, track and field athletics, winter sports, gymnastics, and striking sports. This list was not exhaustive and certain material has, of necessity, been omitted. However, it was felt that a sufficiently broad and interesting range of activities was chosen to illustrate both the advantages and the pitfalls of simulation. It is almost a decade since Miller [53] wrote a review chapter similar to this one. One might be tempted to say that things have changed radically since then--that computer simulation is now a widely accepted and readily applied research tool in sports biomechanics. This is simply not true, however. Biomechanics researchers still tend to emphasize the descriptive type of study, often unfortunately, when a little theoretical explanation would have been more helpful [29]. What will the next decade bring? Of one thing we can be certain: The power of computers, particularly the readily accessible and portable microcomputer, will expand beyond all recognition. The memory and storage capacities will increase dramatically on the hardware side, and on the software side the trend will be toward "user-friendliness." It is likely that a number of software simulation packages designed specifically for studying human motion [31, 96] will be extensively tested and could gain wide acceptance in the biomechanics research community. Nevertheless, a familiarity with Newtonian and Lagrangian mechanics, optimization theory, and computers in general, as well as practical biomechanical insight, will still be a prerequisite for successful simulation models of human motion. Above all, the biomechanics researcher will still have to bear in mind that

  20. [Results After Distal Digital Replantation - Is It Worth The Effort?

    Science.gov (United States)

    Braig, David; Thiele, Jan R; Penna, Vincenzo; Stark, G Björn; Eisenhardt, Steffen U

    2017-02-01

    There are only relative indications for distal digital replantation in zones 1 and 2 according to Tamai. In contrast to primary closure for fingertip amputations, replantation is a complex procedure that requires skills in supermicrosurgical techniques, as vessels with diameters between 0.3-0.8 mm are connected. In addition the time spent in hospital and the time off from work are longer. Distal digital replantation is thus only indicated, if the expected functional and aesthetic benefits surmount those of primary closure. We retrospectively analysed all fingertip amputations in zone 1 and 2 according to Tamai between 9/2009 and 7/2014 where we attempted distal digital replantation. The success of replantation, wound healing and functional results were evaluated according to Yamano. We performed 11 distal digital replantations in the study period. There were 6 total amputations, 4 subtotal amputations and 1 avulsion of the digital pulp. Revascularisation with long-term reattachment of the amputated tissues was possible in 8 cases (73%). In 3 cases (27%) secondary amputation closure was necessary. The mean operating time was 3 h 56 min. 6 patients, which had a successful replantation, were available for follow-up examinations after a mean period of 19 months. 5 patients were satisfied with the result and would again prefer replantation over primary amputation closure. 4 patients reported a good function of the replanted digits and did not complain about any limitations in their use. 2 patients complained about restricted function. All patients could return to their previous places of employment and were free of pain. Of the 12 affected digital nerves 11 nerves had a 2-point discrimination (2-PD) of ≤15 mm, 3 of them had a 2-PD between 7 and 10 mm and 4 of them of replanted digits and nail deformities in 2 patients. Distal digital replantation is complex and technically challenging. It leads to high patient satisfaction with only minimal functional

  1. [Advances on biomechanics and kinematics of sprain of ankle joint].

    Science.gov (United States)

    Zhao, Yong; Wang, Gang

    2015-04-01

    Ankle sprains are orthopedic clinical common disease, accounting for joint ligament sprain of the first place. If treatment is not timely or appropriate, the joint pain and instability maybe develop, and even bone arthritis maybe develop. The mechanism of injury of ankle joint, anatomical basis has been fully study at present, and the diagnostic problem is very clear. Along with the development of science and technology, biological modeling and three-dimensional finite element, three-dimensional motion capture system,digital technology study, electromyographic signal study were used for the basic research of sprain of ankle. Biomechanical and kinematic study of ankle sprain has received adequate attention, combined with the mechanism research of ankle sprain,and to explore the the biomechanics and kinematics research progress of the sprain of ankle joint.

  2. Meshless methods in biomechanics bone tissue remodelling analysis

    CERN Document Server

    Belinha, Jorge

    2014-01-01

    This book presents the complete formulation of a new advanced discretization meshless technique: the Natural Neighbour Radial Point Interpolation Method (NNRPIM). In addition, two of the most popular meshless methods, the EFGM and the RPIM, are fully presented. Being a truly meshless method, the major advantages of the NNRPIM over the FEM, and other meshless methods, are the remeshing flexibility and the higher accuracy of the obtained variable field. Using the natural neighbour concept, the NNRPIM permits to determine organically the influence-domain, resembling the cellulae natural behaviour. This innovation permits the analysis of convex boundaries and extremely irregular meshes, which is an advantage in the biomechanical analysis, with no extra computational effort associated.   This volume shows how to extend the NNRPIM to the bone tissue remodelling analysis, expecting to contribute with new numerical tools and strategies in order to permit a more efficient numerical biomechanical analysis.

  3. Hand Posture Prediction Using Neural Networks within a Biomechanical Model

    Directory of Open Access Journals (Sweden)

    Marta C. Mora

    2012-10-01

    Full Text Available This paper proposes the use of artificial neural networks (ANNs in the framework of a biomechanical hand model for grasping. ANNs enhance the model capabilities as they substitute estimated data for the experimental inputs required by the grasping algorithm used. These inputs are the tentative grasping posture and the most open posture during grasping. As a consequence, more realistic grasping postures are predicted by the grasping algorithm, along with the contact information required by the dynamic biomechanical model (contact points and normals. Several neural network architectures are tested and compared in terms of prediction errors, leading to encouraging results. The performance of the overall proposal is also shown through simulation, where a grasping experiment is replicated and compared to the real grasping data collected by a data glove device.

  4. Biomechanical bases of rehabilitation of children with cerebral palsy

    Science.gov (United States)

    Davlet'yarova, K. V.; Korshunov, S. D.; Kapilevich, L. V.

    2015-11-01

    Biomechanical analysis and the study results of children's with cerebral palsy (CP) muscles bioelectrical activity while walking on a flat surface are represented. Increased flexion in the hip and shoulder joints and extension in the elbow joint in children with cerebral palsy were observed, with the movement of the lower limbs had less smooth character in comparison with the control group. Herewith, the oscillation amplitude was significantly increased, and the frequency in the m. gastrocnemius and m. lateralis was decreased. It was shown, that the dynamic stereotype of walking in children with cerebral palsy was characterized by excessive involvement of m. gastrocnemius and m.latissimus dorsi in locomotion. Thus, resulting biomechanical and bioelectrical parameters of walking should be considered in the rehabilitation programs development.

  5. Biomechanical tactics of chiral growth in emergent aquatic macrophytes

    Science.gov (United States)

    Zhao, Zi-Long; Zhao, Hong-Ping; Li, Bing-Wei; Nie, Ben-Dian; Feng, Xi-Qiao; Gao, Huajian

    2015-01-01

    Through natural selection, many plant organs have evolved optimal morphologies at different length scales. However, the biomechanical strategies for different plant species to optimize their organ structures remain unclear. Here, we investigate several species of aquatic macrophytes living in the same natural environment but adopting distinctly different twisting chiral morphologies. To reveal the principle of chiral growth in these plants, we performed systematic observations and measurements of morphologies, multiscale structures, and mechanical properties of their slender emergent stalks or leaves. Theoretical modeling of pre-twisted beams in bending and buckling indicates that the different growth tactics of the plants can be strongly correlated with their biomechanical functions. It is shown that the twisting chirality of aquatic macrophytes can significantly improve their survivability against failure under both internal and external loads. The theoretical predictions for different chiral configurations are in excellent agreement with experimental measurements. PMID:26219724

  6. The Biomechanics of Cranial Forces During Figure Skating Spinning Elements.

    Science.gov (United States)

    Wang, David H; Kostyun, Regina O; Solomito, Matthew J

    2015-03-01

    Several facets of figure skating, such as the forces associated with jumping and landing, have been evaluated, but a comprehensive biomechanical understanding of the cranial forces associated with spinning has yet to be explored. The purpose of this case study was to quantify the cranial rotational acceleration forces generated during spinning elements. This case report was an observational, biomechanical analysis of a healthy, senior-level, female figure skating athlete who is part of an on-going study. A triaxial accelerometer recorded the gravitational forces (G) during seven different spinning elements. Our results found that the layback spin generated significant cranial force and these forces were greater than any of the other spin elements recorded. These forces led to physical findings of ruptured capillaries, dizziness, and headaches in our participant.

  7. Smart Materials in Structural Health Monitoring, Control and Biomechanics

    CERN Document Server

    Soh, Chee-Kiong; Bhalla, Suresh

    2012-01-01

    "Smart Materials in Structural Health Monitoring, Control and Biomechanics" presents the latest developments in structural health monitoring, vibration control and biomechanics using smart materials. The book mainly focuses on piezoelectric, fibre optic and ionic polymer metal composite materials. It introduces concepts from the very basics and leads to advanced modelling (analytical/ numerical), practical aspects (including software/ hardware issues) and case studies spanning civil, mechanical and aerospace structures, including bridges, rocks and underground structures. This book is intended for practicing engineers, researchers from academic and R&D institutions and postgraduate students in the fields of smart materials and structures, structural health monitoring, vibration control and biomedical engineering. Professor Chee-Kiong Soh and Associate Professor Yaowen Yang both work at the School of Civil and Environmental Engineering, Nanyang Technological University, Singapore. Dr. Suresh Bhalla is an A...

  8. Esophageal morphometric and biomechanical changes during aging in rats

    DEFF Research Database (Denmark)

    Zhao, Jingbo; Gregersen, Hans

    of the present study is to investigate the esophageal geometry and biomechanical changes during aging in rats. Materials and methods Twenty-four male Wistar rats, aged from 6 to 22 months, were used in the study. The body weight and the wet weight per length of esophageal segment were measured at the termination...... was found among 12, 18 and 22 months groups (p>0.05). The longitudinal stress-strain curves shifted from right to the left during aging (pstiffness has no obvious...... change after 12 months in the circumferential direction. Furthermore, we confirm that the esophagus was stiffer in the longitudinal direction than in the circumferential direction. Conclusions A pronounced morphometric and biomechanical remodeling was occurred in the rat esophagus during aging...

  9. Evidence of Big Five and Aggressive Personalities in Gait Biomechanics

    OpenAIRE

    Satchell, Liam; Morris, Paul; Mills, Chris; O?Reilly, Liam; Marshman, Paul; Akehurst, Lucy

    2016-01-01

    Behavioral observation techniques which relate action to personality have long been neglected (Furr and Funder in Handbook of research methods in personality psychology, The Guilford Press, New York, 2007) and, when employed, often use human judges to code behavior. In the current study we used an alternative to human coding (biomechanical research techniques) to investigate how personality traits are manifest in gait. We used motion capture technology to record 29 participants walking on a t...

  10. Biomechanics important to interpret radiographs of the hip

    International Nuclear Information System (INIS)

    Rosenthal, D.I.; Scott, J.A.

    1983-01-01

    Biomechanic principles have important implications to film interpretation. Angulation of the femoral neck results in four different types of forces: compression on the medial side, tension on the lateral side, shear stress in the center, and torque forces at the neck-shaft angle. The body's response to these forces results in recognicable trabecular patterns which respond in a predictable manner to disease states. Surgical intervention in the form of hip replacement or fracture fixation must reflect these engineering consideration. (orig.)

  11. Global models for the biomechanics of green plants: 1

    International Nuclear Information System (INIS)

    Bestman, A.R.

    1990-12-01

    The paper considers the biomechanics of green plants for Reynolds number flow in the stem. In particular, it is assumed that the stem is cylindrical and the flow fully-developed. So that if the aspect ratio is defined as the ratio of the stem radius to its length, then when the aspect ratio is small analytical solutions have been developed for the concentration, temperature and the axial velocity. The process of translocation and transpiration are discussed quantitatively. (author). 4 refs, 2 figs

  12. Cerebrospinal Fluid Pressure: Revisiting Factors Influencing Optic Nerve Head Biomechanics

    Science.gov (United States)

    Hua, Yi; Voorhees, Andrew P.; Sigal, Ian A.

    2018-01-01

    Purpose To model the sensitivity of the optic nerve head (ONH) biomechanical environment to acute variations in IOP, cerebrospinal fluid pressure (CSFP), and central retinal artery blood pressure (BP). Methods We extended a previously published numerical model of the ONH to include 24 factors representing tissue anatomy and mechanical properties, all three pressures, and constraints on the optic nerve (CON). A total of 8340 models were studied to predict factor influences on 98 responses in a two-step process: a fractional factorial screening analysis to identify the 16 most influential factors, followed by a response surface methodology to predict factor effects in detail. Results The six most influential factors were, in order: IOP, CON, moduli of the sclera, lamina cribrosa (LC) and dura, and CSFP. IOP and CSFP affected different aspects of ONH biomechanics. The strongest influence of CSFP, more than twice that of IOP, was on the rotation of the peripapillary sclera. CSFP had similar influence on LC stretch and compression to moduli of sclera and LC. On some ONHs, CSFP caused large retrolamina deformations and subarachnoid expansion. CON had a strong influence on LC displacement. BP overall influence was 633 times smaller than that of IOP. Conclusions Models predict that IOP and CSFP are the top and sixth most influential factors on ONH biomechanics. Different IOP and CSFP effects suggest that translaminar pressure difference may not be a good parameter to predict biomechanics-related glaucomatous neuropathy. CON may drastically affect the responses relating to gross ONH geometry and should be determined experimentally. PMID:29332130

  13. Probabilistic Modeling of Intracranial Pressure Effects on Optic Nerve Biomechanics

    Science.gov (United States)

    Ethier, C. R.; Feola, Andrew J.; Raykin, Julia; Myers, Jerry G.; Nelson, Emily S.; Samuels, Brian C.

    2016-01-01

    Altered intracranial pressure (ICP) is involved/implicated in several ocular conditions: papilledema, glaucoma and Visual Impairment and Intracranial Pressure (VIIP) syndrome. The biomechanical effects of altered ICP on optic nerve head (ONH) tissues in these conditions are uncertain but likely important. We have quantified ICP-induced deformations of ONH tissues, using finite element (FE) and probabilistic modeling (Latin Hypercube Simulations (LHS)) to consider a range of tissue properties and relevant pressures.

  14. Biomechanical Strength of Retrograde Fixation in Proximal Third Scaphoid Fractures.

    Science.gov (United States)

    Daly, Charles A; Boden, Allison L; Hutton, William C; Gottschalk, Michael B

    2018-04-01

    Current techniques for fixation of proximal pole scaphoid fractures utilize antegrade fixation via a dorsal approach endangering the delicate vascular supply of the dorsal scaphoid. Volar and dorsal approaches demonstrate equivalent clinical outcomes in scaphoid wrist fractures, but no study has evaluated the biomechanical strength for fractures of the proximal pole. This study compares biomechanical strength of antegrade and retrograde fixation for fractures of the proximal pole of the scaphoid. A simulated proximal pole scaphoid fracture was produced in 22 matched cadaveric scaphoids, which were then assigned randomly to either antegrade or retrograde fixation with a cannulated headless compression screw. Cyclic loading and load to failure testing were performed and screw length, number of cycles, and maximum load sustained were recorded. There were no significant differences in average screw length (25.5 mm vs 25.6 mm, P = .934), average number of cyclic loading cycles (3738 vs 3847, P = .552), average load to failure (348 N vs 371 N, P = .357), and number of catastrophic failures observed between the antegrade and retrograde fixation groups (3 in each). Practical equivalence between the 2 groups was calculated and the 2 groups were demonstrated to be practically equivalent (upper threshold P = .010). For this model of proximal pole scaphoid wrist fractures, antegrade and retrograde screw configuration have been proven to be equivalent in terms of biomechanical strength. With further clinical study, we hope surgeons will be able to make their decision for fixation technique based on approaches to bone grafting, concern for tenuous blood supply, and surgeon preference without fear of poor biomechanical properties.

  15. correlation with µCT and biomechanical testing

    OpenAIRE

    Kentenich, Marie

    2013-01-01

    Purpose: Assessment of trabecular bone structure may enhance estimation of biomechanical strength and therefore improve diagnostic standards for osteoporosis. Still visualization of the trabecular microstructure in vivo is challenging. We tested the feasibility of assessing trabecular bone structure for evaluation of bone quality on intact human cadavers using multidetector CT (MDCT) in an experimental in situ and therefore simulated in vivo setup. Methods: Bone structure (BV/TV: ...

  16. Tree Branching: Leonardo da Vinci's Rule versus Biomechanical Models

    Science.gov (United States)

    Minamino, Ryoko; Tateno, Masaki

    2014-01-01

    This study examined Leonardo da Vinci's rule (i.e., the sum of the cross-sectional area of all tree branches above a branching point at any height is equal to the cross-sectional area of the trunk or the branch immediately below the branching point) using simulations based on two biomechanical models: the uniform stress and elastic similarity models. Model calculations of the daughter/mother ratio (i.e., the ratio of the total cross-sectional area of the daughter branches to the cross-sectional area of the mother branch at the branching point) showed that both biomechanical models agreed with da Vinci's rule when the branching angles of daughter branches and the weights of lateral daughter branches were small; however, the models deviated from da Vinci's rule as the weights and/or the branching angles of lateral daughter branches increased. The calculated values of the two models were largely similar but differed in some ways. Field measurements of Fagus crenata and Abies homolepis also fit this trend, wherein models deviated from da Vinci's rule with increasing relative weights of lateral daughter branches. However, this deviation was small for a branching pattern in nature, where empirical measurements were taken under realistic measurement conditions; thus, da Vinci's rule did not critically contradict the biomechanical models in the case of real branching patterns, though the model calculations described the contradiction between da Vinci's rule and the biomechanical models. The field data for Fagus crenata fit the uniform stress model best, indicating that stress uniformity is the key constraint of branch morphology in Fagus crenata rather than elastic similarity or da Vinci's rule. On the other hand, mechanical constraints are not necessarily significant in the morphology of Abies homolepis branches, depending on the number of daughter branches. Rather, these branches were often in agreement with da Vinci's rule. PMID:24714065

  17. Comparing dynamical systems concepts and techniques for biomechanical analysis

    OpenAIRE

    van Emmerik, Richard E.A.; Ducharme, Scott W.; Amado, Avelino C.; Hamill, Joseph

    2016-01-01

    Traditional biomechanical analyses of human movement are generally derived from linear mathematics. While these methods can be useful in many situations, they do not describe behaviors in human systems that are predominately nonlinear. For this reason, nonlinear analysis methods based on a dynamical systems approach have become more prevalent in recent literature. These analysis techniques have provided new insights into how systems (1) maintain pattern stability, (2) transition into new stat...

  18. Tree branching: Leonardo da Vinci's rule versus biomechanical models.

    Science.gov (United States)

    Minamino, Ryoko; Tateno, Masaki

    2014-01-01

    This study examined Leonardo da Vinci's rule (i.e., the sum of the cross-sectional area of all tree branches above a branching point at any height is equal to the cross-sectional area of the trunk or the branch immediately below the branching point) using simulations based on two biomechanical models: the uniform stress and elastic similarity models. Model calculations of the daughter/mother ratio (i.e., the ratio of the total cross-sectional area of the daughter branches to the cross-sectional area of the mother branch at the branching point) showed that both biomechanical models agreed with da Vinci's rule when the branching angles of daughter branches and the weights of lateral daughter branches were small; however, the models deviated from da Vinci's rule as the weights and/or the branching angles of lateral daughter branches increased. The calculated values of the two models were largely similar but differed in some ways. Field measurements of Fagus crenata and Abies homolepis also fit this trend, wherein models deviated from da Vinci's rule with increasing relative weights of lateral daughter branches. However, this deviation was small for a branching pattern in nature, where empirical measurements were taken under realistic measurement conditions; thus, da Vinci's rule did not critically contradict the biomechanical models in the case of real branching patterns, though the model calculations described the contradiction between da Vinci's rule and the biomechanical models. The field data for Fagus crenata fit the uniform stress model best, indicating that stress uniformity is the key constraint of branch morphology in Fagus crenata rather than elastic similarity or da Vinci's rule. On the other hand, mechanical constraints are not necessarily significant in the morphology of Abies homolepis branches, depending on the number of daughter branches. Rather, these branches were often in agreement with da Vinci's rule.

  19. Biomechanical analysis of the camelid cervical intervertebral disc

    Directory of Open Access Journals (Sweden)

    Dean K. Stolworthy

    2015-01-01

    Full Text Available Chronic low back pain (LBP is a prevalent global problem, which is often correlated with degenerative disc disease. The development and use of good, relevant animal models of the spine may improve treatment options for this condition. While no animal model is capable of reproducing the exact biology, anatomy, and biomechanics of the human spine, the quality of a particular animal model increases with the number of shared characteristics that are relevant to the human condition. The purpose of this study was to investigate the camelid (specifically, alpaca and llama cervical spine as a model of the human lumbar spine. Cervical spines were obtained from four alpacas and four llamas and individual segments were used for segmental flexibility/biomechanics and/or morphology/anatomy studies. Qualitative and quantitative data were compared for the alpaca and llama cervical spines, and human lumbar specimens in addition to other published large animal data. Results indicate that a camelid cervical intervertebral disc (IVD closely approximates the human lumbar disc with regard to size, spinal posture, and biomechanical flexibility. Specifically, compared with the human lumbar disc, the alpaca and llama cervical disc size are approximately 62%, 83%, and 75% with regard to area, depth, and width, respectively, and the disc flexibility is approximately 133%, 173%, and 254%, with regard to range of motion (ROM in axial-rotation, flexion-extension, and lateral-bending, respectively. These results, combined with the clinical report of disc degeneration in the llama lower cervical spine, suggest that the camelid cervical spine is potentially well suited for use as an animal model in biomechanical studies of the human lumbar spine.

  20. Biochemical and biomechanical characterisation of equine cervical facet joint cartilage.

    Science.gov (United States)

    O'Leary, S A; White, J L; Hu, J C; Athanasiou, K A

    2018-04-15

    The equine cervical facet joint is a site of significant pathology. Located bilaterally on the dorsal spine, these diarthrodial joints work in conjunction with the intervertebral disc to facilitate appropriate spinal motion. Despite the high prevalence of pathology in this joint, the facet joint is understudied and thus lacking in viable treatment options. The goal of this study was to characterise equine facet joint cartilage and provide a comprehensive database describing the morphological, histological, biochemical and biomechanical properties of this tissue. Descriptive cadaver studies. A total of 132 facet joint surfaces were harvested from the cervical spines of six skeletally mature horses (11 surfaces per animal) for compiling biomechanical and biochemical properties of hyaline cartilage of the equine cervical facet joints. Gross morphometric measurements and histological staining were performed on facet joint cartilage. Creep indentation and uniaxial strain-to-failure testing were used to determine the biomechanical compressive and tensile properties. Biochemical assays included quantification of total collagen, sulfated glycosaminoglycan and DNA content. The facet joint surfaces were ovoid in shape with a flat articular surface. Histological analyses highlighted structures akin to articular cartilage of other synovial joints. In general, biomechanical and biochemical properties did not differ significantly between the inferior and superior joint surfaces as well as among spinal levels. Interestingly, compressive and tensile properties of cervical facet articular cartilage were lower than those of articular cartilage from other previously characterised equine joints. Removal of the superficial zone reduced the tissue's tensile strength, suggesting that this zone is important for the tensile integrity of the tissue. Facet surfaces were sampled at a single, central location and do not capture the potential topographic variation in cartilage properties. This

  1. Biomechanics of Head, Neck, and Chest Injury Prevention for Soldiers

    Science.gov (United States)

    2011-03-01

    30 am – 5:00 pm Overview of Blast Physics and Applications Doubletree Hotel Crystal City Arlington VA, Between the Pentagon and National Airport at...provided) 8:30 Introduction and Overview Dr. Stefan Duma, Virginia Tech Head Injury Biomechanics 8:45 “Instrumented Helmet Data Collection and Analysis...of NASA Suit Interface and Landing Conditions” Ms. Kerry Danelson, Wake Forest University 4:05 “Modeling Human Variation: Orbit Anthropometry and

  2. Multiscale computer modeling in biomechanics and biomedical engineering

    CERN Document Server

    2013-01-01

    This book reviews the state-of-the-art in multiscale computer modeling, in terms of both accomplishments and challenges. The information in the book is particularly useful for biomedical engineers, medical physicists and researchers in systems biology, mathematical biology, micro-biomechanics and biomaterials who are interested in how to bridge between traditional biomedical engineering work at the organ and tissue scales, and the newer arenas of cellular and molecular bioengineering.

  3. Concave distal end of ulna metaphysis alone is not a sign of rickets

    Energy Technology Data Exchange (ETDEWEB)

    Oestreich, Alan E. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, 5031, Cincinnati, OH (United States)

    2015-07-15

    Statements have been made in the literature and in legal testimony that misrepresent the radiographic finding of concave distal end of the ulnar metaphysis. To demonstrate that a concave distal end of the ossified ulna in infancy can be normal. Eighty distal wrists of randomly selected infants in the first year of life with radiographic evidence that ruled out rickets were reviewed. In 16 of the cases (20%), mild or moderate concavity of the distal end of the ulna was seen. An intact metaphyseal collar of distal radius or ulna confirmed the absence of radiographic rickets. The finding of 20% of concave distal ulnas in the first year of life confirms the widely acknowledged statements that concave distal end of the ulna alone is not indicative of rickets. Statements to the contrary are not justified. (orig.)

  4. Concave distal end of ulna metaphysis alone is not a sign of rickets

    International Nuclear Information System (INIS)

    Oestreich, Alan E.

    2015-01-01

    Statements have been made in the literature and in legal testimony that misrepresent the radiographic finding of concave distal end of the ulnar metaphysis. To demonstrate that a concave distal end of the ossified ulna in infancy can be normal. Eighty distal wrists of randomly selected infants in the first year of life with radiographic evidence that ruled out rickets were reviewed. In 16 of the cases (20%), mild or moderate concavity of the distal end of the ulna was seen. An intact metaphyseal collar of distal radius or ulna confirmed the absence of radiographic rickets. The finding of 20% of concave distal ulnas in the first year of life confirms the widely acknowledged statements that concave distal end of the ulna alone is not indicative of rickets. Statements to the contrary are not justified. (orig.)

  5. Graphic-based musculoskeletal model for biomechanical analyses and animation.

    Science.gov (United States)

    Chao, Edmund Y S

    2003-04-01

    The ability to combine physiology and engineering analyses with computer sciences has opened the door to the possibility of creating the 'Virtual Human' reality. This paper presents a broad foundation for a full-featured biomechanical simulator for the human musculoskeletal system physiology. This simulation technology unites the expertise in biomechanical analysis and graphic modeling to investigate joint and connective tissue mechanics at the structural level and to visualize the results in both static and animated forms together with the model. Adaptable anatomical models including prosthetic implants and fracture fixation devices and a robust computational infrastructure for static, kinematic, kinetic, and stress analyses under varying boundary and loading conditions are incorporated on a common platform, the VIMS (Virtual Interactive Musculoskeletal System). Within this software system, a manageable database containing long bone dimensions, connective tissue material properties and a library of skeletal joint system functional activities and loading conditions are also available and they can easily be modified, updated and expanded. Application software is also available to allow end-users to perform biomechanical analyses interactively. This paper details the design, capabilities, and features of the VIMS development at Johns Hopkins University, an effort possible only through academic and commercial collaborations. Examples using these models and the computational algorithms in a virtual laboratory environment are used to demonstrate the utility of this unique database and simulation technology. This integrated system will impact on medical education, basic research, device development and application, and clinical patient care related to musculoskeletal diseases, trauma, and rehabilitation.

  6. A scalable platform for biomechanical studies of tissue cutting forces

    International Nuclear Information System (INIS)

    Valdastri, P; Tognarelli, S; Menciassi, A; Dario, P

    2009-01-01

    This paper presents a novel and scalable experimental platform for biomechanical analysis of tissue cutting that exploits a triaxial force-sensitive scalpel and a high resolution vision system. Real-time measurements of cutting forces can be used simultaneously with accurate visual information in order to extract important biomechanical clues in real time that would aid the surgeon during minimally invasive intervention in preserving healthy tissues. Furthermore, the in vivo data gathered can be used for modeling the viscoelastic behavior of soft tissues, which is an important issue in surgical simulator development. Thanks to a modular approach, this platform can be scaled down, thus enabling in vivo real-time robotic applications. Several cutting experiments were conducted with soft porcine tissues (lung, liver and kidney) chosen as ideal candidates for biopsy procedures. The cutting force curves show repeated self-similar units of localized loading followed by unloading. With regards to tissue properties, the depth of cut plays a significant role in the magnitude of the cutting force acting on the blade. Image processing techniques and dedicated algorithms were used to outline the surface of the tissues and estimate the time variation of the depth of cut. The depth of cut was finally used to obtain the normalized cutting force, thus allowing comparative biomechanical analysis

  7. Citation metrics of excellence in sports biomechanics research.

    Science.gov (United States)

    Knudson, Duane

    2017-11-13

    This study extended research on key citation metrics of winners of two career scholar awards in sports biomechanics. Google Scholar (GS) was searched using Harzing's Publish or Perish software for the 13 most recent winners of the ISBS Geoffrey Dyson Award and the ASB Jim Hay Memorial Award. Returned records were corrected for author, and publications excluded for all but peer-reviewed journal articles, proceedings articles, chapters and books in English. These recent award winners had published about 150 publications that had been cited typically 4,082 and 6,648 times over a 26- and 28-year period before receiving these career awards for sports biomechanics research. Estimated median citations at time of their awards were 2,927 and 4,907 for the Dyson and Hay awards, respectively. Award winners had mean Hirsh indexes of 32-45 and mean h i of 19-28. Their mean g indexes (59-84) and their numerous citation classics (C > 100) indicated that they had many influential publications. The citation metrics of these scholars were outstanding and consistent with recent studies of top scholars in biomechanics and kinesiology/exercise science. Careful searching, cleaning and interpretation of several scholar-level citation metrics may provide useful confirmatory evidence for evaluations of awards committees.

  8. Morphogenesis and Biomechanics of Engineered Skin Cultured Under Uniaxial Strain.

    Science.gov (United States)

    Blackstone, Britani N; Powell, Heather M

    2012-04-01

    Split-thickness autograft is the standard wound treatment for full-thickness burns. In large burns, sparse availability of uninjured skin prevents rapid closure of the wound, resulting in increased scar tissue formation or mortality. Tissue-engineered skin (ES) offers promise when autografts are not available. ES, constructed from a polymeric scaffold and skin cells, has been shown to reduce donor site area required to permanently close wounds, mortality, and morbidity from scarring but cannot restore all skin functions. Current generations of ES are orders of magnitude weaker than normal human skin, leading to difficulty in surgical application, greater susceptibility to mechanical damage during fabrication and application, and less elasticity and strength once engrafted. Previous studies to improve ES biomechanics focus on altering the scaffolding material, which resulted in modest improvements but often inhibited proper skin development. As the skin is naturally under static strain, adding these mechanical cues to the culture environment is hypothesized to improve ES biomechanics. ES was cultured under applied static strains ranging from 0% to 40% strain for a total of 10 days. Strain magnitudes of 10% and 20% strain resulted in significantly stronger ES than unstrained controls, showed upregulation of many genes encoding structural extracellular matrix proteins, and exhibited increased epidermal cell proliferation and differentiation. Enhanced biomechanical properties of ES can allow for facile surgical application and less damage during dressing changes. These findings suggest that mechanical cues play a significant role in skin development and should be further explored.

  9. Optical spectroscopic characterization of human meniscus biomechanical properties

    Science.gov (United States)

    Ala-Myllymäki, Juho; Danso, Elvis K.; Honkanen, Juuso T. J.; Korhonen, Rami K.; Töyräs, Juha; Afara, Isaac O.

    2017-12-01

    This study investigates the capacity of optical spectroscopy in the visible (VIS) and near-infrared (NIR) spectral ranges for estimating the biomechanical properties of human meniscus. Seventy-two samples obtained from the anterior, central, and posterior locations of the medial and lateral menisci of 12 human cadaver joints were used. The samples were subjected to mechanical indentation, then traditional biomechanical parameters (equilibrium and dynamic moduli) were calculated. In addition, strain-dependent fibril network modulus and permeability strain-dependency coefficient were determined via finite-element modeling. Subsequently, absorption spectra were acquired from each location in the VIS (400 to 750 nm) and NIR (750 to 1100 nm) spectral ranges. Partial least squares regression, combined with spectral preprocessing and transformation, was then used to investigate the relationship between the biomechanical properties and spectral response. The NIR spectral region was observed to be optimal for model development (83.0%≤R2≤90.8%). The percentage error of the models are: Eeq (7.1%), Edyn (9.6%), Eɛ (8.4%), and Mk (8.9%). Thus, we conclude that optical spectroscopy in the NIR range is a potential method for rapid and nondestructive evaluation of human meniscus functional integrity and health in real time during arthroscopic surgery.

  10. A novel biomechanical model assessing continuous orthodontic archwire activation

    Science.gov (United States)

    Canales, Christopher; Larson, Matthew; Grauer, Dan; Sheats, Rose; Stevens, Clarke; Ko, Ching-Chang

    2013-01-01

    Objective The biomechanics of a continuous archwire inserted into multiple orthodontic brackets is poorly understood. The purpose of this research was to apply the birth-death technique to simulate insertion of an orthodontic wire and consequent transfer of forces to the dentition in an anatomically accurate model. Methods A digital model containing the maxillary dentition, periodontal ligament (PDL), and surrounding bone was constructed from human computerized tomography data. Virtual brackets were placed on four teeth (central and lateral incisors, canine and first premolar), and a steel archwire (0.019″ × 0.025″) with a 0.5 mm step bend to intrude the lateral incisor was virtually inserted into the bracket slots. Forces applied to the dentition and surrounding structures were simulated utilizing the birth-death technique. Results The goal of simulating a complete bracket-wire system on accurate anatomy including multiple teeth was achieved. Orthodontic force delivered by the wire-bracket interaction was: central incisor 19.1 N, lateral incisor 21.9 N, and canine 19.9 N. Loading the model with equivalent point forces showed a different stress distribution in the PDL. Conclusions The birth-death technique proved to be a useful biomechanical simulation method for placement of a continuous archwire in orthodontic brackets. The ability to view the stress distribution throughout proper anatomy and appliances advances understanding of orthodontic biomechanics. PMID:23374936

  11. BIOMECHANIC EVALUATION OF CARPENTRY WORKERS IN THE DISTRITO FEDERAL, BRAZIL

    Directory of Open Access Journals (Sweden)

    Nilton Cesar Fiedler

    2010-08-01

    Full Text Available The aim of this study was the biomechanical assessment of carpentry woodworkers, located in Brasília, DF. It was filmed the profile of each worker during the performance of his activities in the carpentry and the forces involved in the work were assessed. The image of each woodworker was congealed to accomplish the measurement of articulation angles. The data were submitted to the software of posture analysis “Winowas” (OWAS Method and to the biomechanic model of posture prognosis and static forces, developed by Michigan University. The OWAS method showed that, for all machines and carpentries assessed, the worst posture occurred when the worker lifted and placed the pieces of wood on the floor and during the feeding in the smoother. The tridimensional biomechanic model registered the worst posture in different phases of the work cycle. In the first one, there were problems in all articulations, except the hips, when placing the pieces on the floor from the smoother. In the second one, there were problems in all articulations, except the elbows and the L5-S1 column disc, by feeding the surface planer. The third one, the ankles were the most injured when feeding the smoother, the surface planer, the circular saw and the band saw. According to the results, the woodworkers should try to eliminate the constant work standing upright, use auxiliary machinery to handle pieces of wood, reduce the load during feeding the machines and improve postures.

  12. Biomechanical analysis on stent materials used as cardiovascular implants

    Science.gov (United States)

    Kumar, Vasantha; Ramesha, C. M.; Sajjan, Sudheer S.

    2018-04-01

    Atherosclerosis is the most common cause of death in the world, accounting for 48% of all deaths in the world. Atherosclerosis, also known as coronary artery disease occurs when excess cholesterol attaches itself to the walls of blood vessels. Coronary stent implantation is one of the most important procedures to treating coronary artery disease such atherosclerosis. Due to its efficiency, flexibility and simplicity, the use of coronary stents procedures has increased rapidly. In order to have better output of stent implantation, it is needed to study and analyze the biomechanical behavior of this device before manufacturing and put into use. Biomaterials are commonly used for medical application in cardiovascular stent implantation. A biomaterial is a non-viable material used as medical implant, so it is intended to interact with biological system. In this paper, an explicit dynamic analysis is used for analyzing the biomechanical behavior of cardiovascular stent by using finite element analysis tool, ABAQUS 6.10. Results showed that a best suitable biomaterial for cardiovascular stent implants, which exhibits an outstanding biocompatibility and biomechanical characteristics will be aimed at which will be quite useful to the human beings worldwide.

  13. Sensitivity of Tumor Motion Simulation Accuracy to Lung Biomechanical Modeling Approaches and Parameters

    OpenAIRE

    Tehrani, Joubin Nasehi; Yang, Yin; Werner, Rene; Lu, Wei; Low, Daniel; Guo, Xiaohu; Wang, Jing

    2015-01-01

    Finite element analysis (FEA)-based biomechanical modeling can be used to predict lung respiratory motion. In this technique, elastic models and biomechanical parameters are two important factors that determine modeling accuracy. We systematically evaluated the effects of lung and lung tumor biomechanical modeling approaches and related parameters to improve the accuracy of motion simulation of lung tumor center of mass (TCM) displacements. Experiments were conducted with four-dimensional com...

  14. Factors associated with infection following open distal radius fractures.

    Science.gov (United States)

    Glueck, Dane A; Charoglu, Constantine P; Lawton, Jeffrey N

    2009-09-01

    Open fractures are often classified according to a system described by Gustilo and Anderson. However, this system was applied to open long bone fractures, which may not predict the incidence of infection in open metaphyseal fractures of the upper extremity. Other studies have found that wound contamination and systemic illness were the best predictors of infections in open hand fractures. Our study assessed infection in open distal radius fractures and identifies factors that are associated with these infections. We hypothesize that contamination, rather than absolute wound size, is the best predictor of infection associated with open distal radius fractures. A review by CPT code yielded 42 patients with open distal radius fractures between 1997 and 2002 treated at a level one trauma center. Medical records and radiographic follow-up were reviewed to assess the time to irrigation and debridement, the number of debridements in initial treatment period, the method of operative stabilization, the Gustilo and Anderson type of fracture, the Swanson type of fracture, and description of wound contamination. Forty-two patients were followed up for an average of 15 months (range 4 to 68 months). Twenty-four fractures were classified as Gustilo and Anderson type I, ten were type II, and eight were type III, 30 were Swanson type I, and 12 were Swanson type II. Five of the 42 fractures were considered contaminated. Two were exposed to fecal contamination. The others were contaminated with tar, dirt/grass, and gravel, respectively. Three of 42 (7%) fractures developed infections. All three infected cases received a single irrigation and debridement. Two of five contaminated fractures (40%) developed a polymicrobial infection. Both were exposed to fecal contamination and, therefore, considered Swanson type II fractures. They were classified as Gustilo and Anderson type II and IIIB based solely upon the size of the wound. Both required multiple debridements and eventually wrist

  15. Left ventricular contractile function after distal protection in primary percutaneous coronary intervention Results from the Drug Elution and Distal Protection in ST-Elevation Myocardial Infarction trial

    DEFF Research Database (Denmark)

    Kofoed, K F; Kelbæk, H; Thuesen, L

    2011-01-01

    Coronary intervention (PCI) may result in an increased infarct size. We evaluated the effect of distal protection during PCI for ST-segment elevation myocardial infarction (STEMI) on myocardial function.......Coronary intervention (PCI) may result in an increased infarct size. We evaluated the effect of distal protection during PCI for ST-segment elevation myocardial infarction (STEMI) on myocardial function....

  16. Outcomes of Distal Femur Fracture Treated with Dynamic Condylar Screw

    International Nuclear Information System (INIS)

    Razaq, M. N. U.; Muhammad, T.; Ahmed, A.; Adeel, M.; Ahmad, S.; Ahmad, S.; Sultan, S.

    2016-01-01

    Background: Implants for open reduction and internal fixation of distal femoral fracture includes angle blade plate, rush nails, enders nail and interlocking nails. But all these devices are technically demanding and less effective in providing inter-fragmentary compression in osteoporotic bones. These problems can be solved with dynamic condylar screw (DCS).The objective of the study was to determine the frequency of different outcomes of distal femoral fracture treated with dynamic condylar screw Methods: This case series study was carried out in the Department of Trauma and Orthopaedics, Ayub Teaching Hospital Abbottabad from 1st October 2014 to August 2015, after approval of the ethical committee of the institution. Data of all patients with distal femoral fractures aged 20-70 years, recruited through emergency, OPD or consultant clinic collected on a proforma. Standard treatment of trauma was given to the patients. Detailed history was taken including the past medical and surgical history. Detailed examination including air-way, breathing and circulation, general physical examination and abdomino-pelvic examination was done in each patient. Investigations including urinalysis, haemoglobin percent, full blood count, X-ray (both AP and lateral view) of the involved femur (including hip and knee) was done. Results: Mean age of the patients was 43.18±14.647 ranging from 20 to 70 years. Mean duration of hospital stay in days was 2.21±1.111 ranging from 1 to 6 days. Patients follow-up assessment after 4 months of surgery for union of femoral fracture treated with dynamic condylar screw was found in 96 (94.1 percent), wound infection was found in 7 (6.9 percent), knee stiffness was found in 21 (20.6 percent) and limb shortening was found in 7 (6.9 percent). Conclusion: Dynamic condylar screw is an easy, scientifically less difficult and satisfying method of treatment for fractures of femur. (author)

  17. [Lithiasis of the distal ureter: ESWL or URS].

    Science.gov (United States)

    González Enguita, C; Sánchez Gómez, J; Rodríguez-Miñon Cifuentes, J L; Cabrera Pérez, J; Calahorra Fernández, F J; García Cardoso, J; García de la Peña, E; Vela Navarrete, R

    1998-10-01

    A nephritic colic is the clinical picture that evidences the presence of ureteral stones, the natural evolution being their spontaneous passing. Stones in the distal ureter are self-eliminated in about 71-80% cases. The adoption of a "watchful wait" involves an uncertain occupational and medical evolution since, although in some cases the stones will pass with no problems, in other instances they can result in severe, life threatening situations for the patient's health (intractable pain, anuria or sepsis). When a decision is made to treat the condition, there are two choices available: "in situ" SWEL (extracorporeal lithotrity), or URS (ureterorenoscopy), long-standing conflicting techniques each with its own advantages and disadvantages, which should now be considered complementary. SWEL's major disadvantage is the number of repetitions required and the long wait, sometimes even months, until the last fragment is passed. The greater strength of URS is that it can be resolutive in just one episode (95% cases), thus avoiding the obstruction problems that can arise after SWEL. In the Lithiasis-Lithotrity Unit of FJD, SWEL is the first therapeutical option for the treatment of stones in the distal ureter. SWEL and URS are equally likely to be performed although SWEL is the initial choice for efficiency reasons that are explained. We achieve 93.6% positive results with a 1.82% re-SWEL rate (retreatment), 0.60 coefficient of efficiency (EQ) and 0.69 modified coefficient of efficiency (EQM) (Chart). No serious complications were recorded. Morbidity is variable with little clinical significance. Distal ureter lithiasis can be treated with either URS and SWEL, both considered "different and complementary". The choice in each particular case and within each hospital will depend on availability of means to perform one or the other, equipment's efficiency, skill of the urologist, patient's preference and cost of each treatment.

  18. Clinicopathologic characteristics and prognosis of proximal and distal gastric cancer

    Directory of Open Access Journals (Sweden)

    Yu X

    2018-02-01

    Full Text Available Xuefeng Yu,1,* Fulan Hu,2,* Chunfeng Li,1 Qiang Yao,1 Hongfeng Zhang,1 Yingwei Xue1 1Department of Gastrointestinal Surgery, Harbin Medical University Cancer Hospital, Harbin Medical University, Harbin, China; 2Department of Epidemiology, Public Health College, Harbin Medical University, Harbin, China *These authors contributed equally to this work Background and objectives: The dismal prognosis of gastric cancer patients is a global problem. We aim to evaluate the clinicopathologic features and prognostic factors of proximal and distal gastric cancer.Materials and methods: Gastric cancer cases diagnosed and treated at the same surgical unit between 2007 and 2010 were reviewed. Follow-up data from all patients were collected for at least 5 years until 2015. A total of 964 patients were studied (distal gastric cancer [DG], n=777 and proximal gastric cancer [PG], n=187.Results: DG patients had a relatively higher percentage of females, more thorough therapy (R0 [D0/D1/D2], fewer combined organ resections, younger age, smaller tumors (<5 cm, shorter surgery durations, less blood loss during surgery, and a relatively lower percentage of nodal metastases and a TNM stage of 4 (p<0.05. A significantly higher 5-year survival rate was observed in DG patients compared to PG patients (DG: 51%, PG: 28%; p<0.001. A multivariate analysis demonstrated that tumor size, blood loss during surgery, surgery approach of lymph node dissection, treatment with palliative surgery, histopathologic type, TNM stage, and tumor location were independent predictors of poor outcome.Conclusion: The different characteristics and prognosis of DG and PG cases have implications for the development of guiding strategies for a surgical program and assessment of prognosis of gastric cancer patients based on tumor location. Keywords: gastric cancer, tumor location, clinicopathologic features, prognosis, distal gastric cancer, proximal gastric cancer 

  19. Outcome Assessment after Aptis Distal Radioulnar Joint (DRUJ Implant Arthroplasty

    Directory of Open Access Journals (Sweden)

    Amir Reza Kachooei

    2014-09-01

    Full Text Available Background:  Conventional treatments after complicated injuries of the distal radioulnar joint (DRUJ such as Darrach and Kapandji-Sauvé procedures have many drawbacks, which may eventually lead to a painful unstable distal ulna.  The development of DRUJ prosthesis has significantly evolved over the past years. In this study, we assessed the outcome results of patients after DRUJ implant arthroplasty using the Aptis (Scheker prosthesis. Methods: We identified 13 patients with 14 prosthesis during the past 10 years. Patients underwent DRUJ arthroplasty due to persistent symptoms of instability, chronic pain, and stiffness. Records and follow-up visits were reviewed to find the final post-operative symptoms, pain, range of motion, and grip strength with a mean follow-up of 12 months (range: 2-25 months. Also, patients were contacted prospectively by phone in order to  minister the disabilities of the armshoulder and hand (DASH, patient rated wrist evaluation (PRWE, and visual analogue scale (VAS, and to interview regarding satisfaction and progress in daily activities. Eleven patients out of 13 could be reached with a median followup time of 60 months (range: 2 to 102 months.  Results: No patient required removal of the prosthesis. Only two patients underwent secondary surgeries in which both required debridement of the screw tip over the radius. The median DASH score, PRWE score, VAS, and satisfaction were 1.3, 2.5, 0, and 10, respectively. The mean range of flexion, extension, supination, and pronation was 62, 54, 51, and 64, respectively. Conclusions: Distal radioulnar joint injuries are disabling and patients usually undergo one or more salvage surgeries prior to receiving an arthroplasty. The Scheker prosthesis has shown satisfactory results with 100% survival rate in all reports. The constrained design of this prosthesis gives enough stability to prevent painful subluxation.

  20. Medical expulsive treatment of distal ureteral stone using tamsulosin

    International Nuclear Information System (INIS)

    Ahmad, H.; Azim, W.; Akmal, M.; Murtaza, B.

    2015-01-01

    Many minimally invasive interventional techniques as well as expectant treatments exist for the management of lower ureteric calculi. This study was conducted to evaluate the efficacy of tamsulosin as an expulsive pharmacologic therapy for the treatment of distal ureteral stone. Methods: This randomized control trial included 100 patients over 18 years of age with stone Size = 8mm in distal 1/3 of ureter. Patients were randomly assigned into two groups (A and B). Group A Patients were given Capsule Tamsulosin 0.4 mg, 1 daily up to 4 weeks while group B patients were given placebo, 1 Capsule daily up to 4 weeks. The primary endpoint was expulsion rate. A written informed consent was taken from all the patients. Expulsion time, need for analgesics, need for hospitalization and drug side effects were secondary endpoints. Results: A total of 49 patients in group A and 48 patients in group B reported back, therefore 97 out of 100 patients were evaluated. Mean age of the patients was 36.34 years (range 18-57 years). Mean stone size was 5.78 mm (range 4-8 mm) in greatest dimension. A stone expulsion rate of 85.71% (42 patients) was noted in group A and 54.20% (26 patients) in group B. Group A revealed a statistically significant advantage in term of stone expulsion rate (p=0.032). Considering expulsion time in days group A showed statistically significant advantage (p=0.015). Regarding age, sex, stone size and stone lateralization (right/left), there was no significant difference between the group A and B. No drug side effects were noted in both the groups. Conclusion: By using tamsulosin a higher stone expulsion rates can be achieved in a shorter time. More randomized control trials are required to establish tamsulosin as a standard medical expulsive treatment for small distal ureteric calculus. (author)

  1. Analysis of emboli during carotid stenting with distal protection device.

    Science.gov (United States)

    Chen, Chin-I; Iguchi, Yasuyuki; Garami, Zsolt; Malkoff, Marc D; Smalling, Richard W; Campbell, Morgan S; Alexandrov, Andrei V

    2006-01-01

    The newly developed multi-frequency transcranial Doppler (TCD) is able to differentiate gaseous from solid emboli. Our goal was to apply this technology to initially characterize emboli detected during carotid stenting with distal protection. Patients undergoing carotid angiography and stenting were monitored with 2-2.5 MHz TCD (Embo-Dop, DWL) over the middle cerebral artery unilateral to stent deployment. Sonographers insured optimal signal recordings during the procedures. Automated emboli detection and classification software (MultiXLab version 2.0) was applied for offline count and analysis. Monitoring using the Filter Wire EX (Boston Scientific) and ACCUNET system (Guidant Corporation) was performed. A total of 9,649 embolic signals were detected during 11 angiographic and 10 stenting procedures. An observer confirmed the signals using the International Consensus definition. Automated software classified these events into 5,900 gaseous and 3,749 solid emboli. During contrast injections without the protection device, 1,013 emboli were detected with 28% of these being solid. With deployment of the distal protection device, 8,636 emboli were found with 40% being solid (p protection device, 7,395 emboli with 42% solids were detected (p protection device still deployed, yielded 1,241 emboli with 31% solids (NS). Only 1 patient developed transient hemiparesthesia during ballooning that reduced the flow velocity to zero for 14 s. Neither gaseous nor solid emboli resulted in a mean flow velocity decrease or clinical symptoms. Microembolization frequently occurs during stenting even with deployment of the distal protection device. More solid emboli are seen during manipulations associated with lesion crossing. Although novel TCD methods yield a high frequency of embolic signals, further validation of this technique to determine the true nature, size, and number of emboli is needed.

  2. Prevention of distal extension cantilever fracture in mandibular overdentures.

    Science.gov (United States)

    Quirynen, Thomas; Quirynen, Marc; Duyck, Joke

    2015-09-01

    Fractures of distal bar extensions, supporting a mandibular overdenture, do occur with significant functional and economic consequences for the patient. This study therefore aims to evaluate the effect of different bar cross-sectional shapes and surfaces, bar extension lengths and the placement of a support rib under the distal bar extension on fracture resistance. The 2nd moment area and static strength were calculated for 11 frequently used bar designs using finite element analysis (FEA). For two specific designs (Ackermann round Ø 1.8mm and Dolder-Y macro, the former with and without a support rib) additional physical static and fatigue strength tests were included. The FEA static strength data corresponded well to the 2nd moment area (a similar ranking when maximum allowed force was considered). The application of a rib support (Ackermann Ø 1.8mm) and limitations of the bar extension length (6mm for the Ackermann Ø 1.8mm, 8mm for the Dolder-Y macro) allowed the bars to exceed 5 × 10(6) cycles of 120 and 250N, respectively, before fracture. The region of highest stresses in FEA corresponded well with the locations of the fractures observed in static- and fatigue-testing. With some simple guidelines/modifications, the number of bar extension fractures can be reduced significantly. This study focusses on distal bar extensions which improve the positioning of an implant supported overdenture. By combining laboratory testing and finite element simulations we aim to: (1) explain why fractures occur (dependent on physical characteristics of the bar), and (2) give clinical guidelines on how to prevent such fractures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Fractal analysis of bone architecture at distal radius

    International Nuclear Information System (INIS)

    Tomomitsu, Tatsushi; Mimura, Hiroaki; Murase, Kenya; Sone, Teruki; Fukunaga, Masao

    2005-01-01

    Bone strength depends on bone quality (architecture, turnover, damage accumulation, and mineralization) as well as bone mass. In this study, human bone architecture was analyzed using fractal image analysis, and the clinical relevance of this method was evaluated. The subjects were 12 healthy female controls and 16 female patients suspected of having osteoporosis (age range, 22-70 years; mean age, 49.1 years). High-resolution CT images of the distal radius were acquired and analyzed using a peripheral quantitative computed tomography (pQCT) system. On the same day, bone mineral densities of the lumbar spine (L-BMD), proximal femur (F-BMD), and distal radius (R-BMD) were measured by dual-energy X-ray absorptiometry (DXA). We examined the correlation between the fractal dimension and six bone mass indices. Subjects diagnosed with osteopenia or osteoporosis were divided into two groups (with and without vertebral fracture), and we compared measured values between these two groups. The fractal dimension correlated most closely with L-BMD (r=0.744). The coefficient of correlation between the fractal dimension and L-BMD was very similar to the coefficient of correlation between L-BMD and F-BMD (r=0.783) and the coefficient of correlation between L-BMD and R-BMD (r=0.742). The fractal dimension was the only measured value that differed significantly between both the osteopenic and the osteoporotic subjects with and without vertebral fracture. The present results suggest that the fractal dimension of the distal radius can be reliably used as a bone strength index that reflects bone architecture as well as bone mass. (author)

  4. Combined Effects of Scaffold Stiffening and Mechanical Preconditioning Cycles on Construct Biomechanics, Gene Expression, and Tendon Repair Biomechanics

    OpenAIRE

    Nirmalanandhan, Victor Sanjit; Juncosa-Melvin, Natalia; Shearn, Jason T.; Boivin, Gregory P.; Galloway, Marc T.; Gooch, Cynthia; Bradica, Gino; Butler, David L.

    2009-01-01

    Our group has previously reported that in vitro mechanical stimulation of tissue-engineered tendon constructs significantly increases both construct stiffness and the biomechanical properties of the repair tissue after surgery. When optimized using response surface methodology, our results indicate that a mechanical stimulus with three components (2.4% strain, 3000 cycles/day, and one cycle repetition) produced the highest in vitro linear stiffness. Such positive correlations between construc...

  5. Biomechanics of the elbow joint in tennis players and relation to pathology.

    Science.gov (United States)

    Eygendaal, Denise; Rahussen, F Th G; Diercks, R L

    2007-11-01

    Elbow injuries constitute a sizeable percentage of tennis injuries. A basic understanding of biomechanics of tennis and analysis of the forces, loads and motions of the elbow during tennis will improve the understanding of the pathophysiology of these injuries. All different strokes in tennis have a different repetitive biomechanical nature that can result in tennis-related injuries. In this article, a biomechanically-based evaluation of tennis strokes is presented. This overview includes all tennis-related pathologies of the elbow joint, whereby the possible relation of biomechanics to pathology is analysed, followed by treatment recommendations.

  6. Platelet biomechanics, platelet bioenergetics, and applications to clinical practice and translational research.

    Science.gov (United States)

    George, Mitchell J; Bynum, James; Nair, Prajeeda; Cap, Andrew P; Wade, Charles E; Cox, Charles S; Gill, Brijesh S

    2018-07-01

    The purpose of this review is to explore the relationship between platelet bioenergetics and biomechanics and how this relationship affects the clinical interpretation of platelet function devices. Recent experimental and technological advances highlight platelet bioenergetics and biomechanics as alternative avenues for collecting clinically relevant data. Platelet bioenergetics drive energy production for key biomechanical processes like adhesion, spreading, aggregation, and contraction. Platelet function devices like thromboelastography, thromboelastometry, and aggregometry measure these biomechanical processes. Platelet storage, stroke, sepsis, trauma, or the activity of antiplatelet drugs alters measures of platelet function. However, the specific mechanisms governing these alterations in platelet function and how they relate to platelet bioenergetics are still under investigation.

  7. Biomechanics of Head, Neck, and Chest Injury Prevention for Soldiers: Phase 2 and 3

    Science.gov (United States)

    2016-08-01

    AWARD NUMBER: W81XWH-10-2-0165 TITLE: “ Biomechanics of Head, Neck, and Chest Injury Prevention for Soldiers: Phase 2 & 3”.” PRINCIPAL INVESTIGATOR...27Sep2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-10-2-0165 “ Biomechanics of Head, Neck, and Chest Injury Prevention for Soldiers: Phase 2...Virginia Tech – Wake Forest University, Center for Injury Biomechanics and the U.S. Army entitled “ Biomechanics of Head, Neck, and Chest Injury

  8. Lesiones de la sindesmosis tibioperonea distal: Review article

    OpenAIRE

    Álvarez López, Alejandro; Rodríguez Rodríguez, Eugenio; García Lorenzo, Yenima; Muñoz Infante, Arnaldo

    2008-01-01

    Se realizó una revisión bibliográfica sobre las lesiones traumáticas de la articulación tibioperonea distal. Se recuerda y actualiza sobre aspectos como: anatomía, mecanismo de producción y cuadro clínico. Reciben especial énfasis los estudios imagenológicos y se subraya el uso e interpretación de la radiografía simple. Para terminar esta revisión se exponen las variantes de tratamiento tanto para las lesiones ligamentosas aisladas o asociadas a fractura del tobillo y su manejo posoperatorio....

  9. Paediatric post-traumatic cortical defects of the distal radius

    International Nuclear Information System (INIS)

    Roach, Richard T.; Summers, Bruce N.; Cassar-Pullicino, Victor

    2002-01-01

    Paediatric post-traumatic cortical defects, although rare, are predominately seen affecting the distal radius following a greenstick or torus fracture. We review the literature and present a further two cases supported by CT and MRI. Images from an acute greenstick fracture are also presented to help understand the pathogenesis. Defects are typically solitary on plain radiographs and are usually noticed late, proximal to the site of compression. They are non-expansile in an otherwise healthy child. CT and MRI may reveal smaller multiple subperiosteal defects. Typical defects require no further management other than reassurance and advice that they may occasionally cause discomfort but resolve with time. (orig.)

  10. Proximal and distal adjustments of reaching behavior in preterm infants.

    Science.gov (United States)

    de Toledo, Aline Martins; Soares, Daniele de Almeida; Tudella, Eloisa

    2011-01-01

    The authors aimed to investigate proximal and distal adjustments of reaching behavior and grasping in 5-, 6-, and 7-month-old preterm infants. Nine low-risk preterm and 10 full-term infants participated. Both groups showed the predominance of unimanual reaching, an age-related increase in the frequency of vertical-oriented and open hand movement, and also an increase in successful grasping from 6 to 7 months. The frequency of open hand was higher in the preterm group at 6 months. Intrinsic restrictions imposed by prematurity did not seem to have impaired reaching performance of preterm infants throughout the months of age.

  11. Perimenopausal risk of falling and incidence of distal forearm fracture.

    OpenAIRE

    Winner, S. J.; Morgan, C. A.; Evans, J. G.

    1989-01-01

    A postal survey of 2000 women and 2000 men sampled from the electoral roll in Oxford was undertaken to ascertain whether changes with age in the risk of falling might explain the stepwise increases in age specific incidence rates of distal forearm fracture which occur in women at around the age of 50. Corrected response rates were 83% for women and 72% for men. In women, but not in men, there was a rise in the risk of falling from 45 years, peaking in the 55-59 year age group, and sinking to ...

  12. Giant cells tumor of radius distal end and bone reconstruction

    International Nuclear Information System (INIS)

    La O Duran, Eldis; Monzon Fernandez, Abel Nicolas; Sanz Delgado, Licett

    2009-01-01

    This is the case of a black women aged 40 presenting with a tumor of distal end of right radium with histological diagnosis of low-grade malignancy giant cells tumor and proposal of limb amputation. A conservative surgery was performed with a two-steps total exeresis of lesion sparing the oncologic margin. A fibular free-graft was used and wrist arthrodesis and internal fixation of graft using AO system. There was a good graft consolidation and an active incorporation of patient to social activities. The diagnosis, treatment, follow-up, rehabilitation and case prognosis are exposed

  13. Cost-effectiveness of laparoscopic versus open distal pancreatectomy for pancreatic cancer.

    Science.gov (United States)

    Gurusamy, Kurinchi Selvan; Riviere, Deniece; van Laarhoven, C J H; Besselink, Marc; Abu-Hilal, Mohammed; Davidson, Brian R; Morris, Steve

    2017-01-01

    A recent Cochrane review compared laparoscopic versus open distal pancreatectomy for people with for cancers of the body and tail of the pancreas and found that laparoscopic distal pancreatectomy may reduce the length of hospital stay. We compared the cost-effectiveness of laparoscopic distal pancreatectomy versus open distal pancreatectomy for pancreatic cancer. Model based cost-utility analysis estimating mean costs and quality-adjusted life years (QALYs) per patient from the perspective of the UK National Health Service. A decision tree model was constructed using probabilities, outcomes and cost data from published sources. A time horizon of 5 years was used. One-way and probabilistic sensitivity analyses were undertaken. The probabilistic sensitivity analysis showed that the incremental net monetary benefit was positive (£3,708.58 (95% confidence intervals (CI) -£9,473.62 to £16,115.69) but the 95% CI includes zero, indicating that there is significant uncertainty about the cost-effectiveness of laparoscopic distal pancreatectomy versus open distal pancreatectomy. The probability laparoscopic distal pancreatectomy was cost-effective compared to open distal pancreatectomy for pancreatic cancer was between 70% and 80% at the willingness-to-pay thresholds generally used in England (£20,000 to £30,000 per QALY gained). Results were sensitive to the survival proportions and the operating time. There is considerable uncertainty about whether laparoscopic distal pancreatectomy is cost-effective compared to open distal pancreatectomy for pancreatic cancer in the NHS setting.

  14. Correction of Hallux Valgus Interphalangeus With an Osteotomy of the Distal End of the Proximal Phalanx (Distal Akin Osteotomy).

    Science.gov (United States)

    Vander Griend, Robert

    2017-02-01

    Operative correction of a symptomatic hallux valgus interphalangeus (HVI) deformity is often achieved with an osteotomy at the proximal end of the proximal phalanx (Akin osteotomy). However, the apex of the typical HVI deformity (center of rotation angle) is at the interphalangeal joint of the hallux. This study was done to evaluate the results of performing a medial closing wedge osteotomy at the distal end of the proximal phalanx. Thirty-three patients (33 feet) underwent an osteotomy at the distal end of the proximal phalanx for correction of HVI. All of the patients had other forefoot deformities which were corrected at the same time. Eight of these were revision procedures of prior forefoot operations. The length of follow-up was determined by the associated procedures with a minimum follow-up of 4 months. The preoperative hallux valgus interphalangeus angle averaged 16 degrees of valgus (range 7-32 degrees) and was corrected to an average of 2 degrees of valgus (range 5 degrees valgus to 5 degrees varus). All of the patients were satisfied with the postoperative appearance and function of the first toe. Because of simultaneous correction of numerous other forefoot problems, it was not possible to specifically isolate or evaluate the effects and benefits of this osteotomy using outcomes measures. There was one intraoperative complication resulting in a fracture extending into the adjacent IP joint. Correction of an HVI deformity can be achieved with an osteotomy at the distal end of the proximal phalanx. This was a safe technique with few complications and with good results in terms of both correction and patient satisfaction. Level IV, retrospective case series.

  15. Comparison of 3 Minimally Invasive Methods for Distal Tibia Fractures.

    Science.gov (United States)

    Fang, Jun-Hao; Wu, Yao-Sen; Guo, Xiao-Shan; Sun, Liao-Jun

    2016-07-01

    This study compared the results of external fixation combined with limited open reduction and internal fixation (EF + LORIF), minimally invasive percutaneous plate osteosynthesis (MIPPO), and intramedullary nailing (IMN) for distal tibia fractures. A total of 84 patients with distal tibia shaft fractures were randomized to operative stabilization using EF + LORIF (28 cases), MIPPO (28 cases), or IMN (28 cases). The 3 groups were comparable with respect to patient demographics. Data were collected on operative time and radiation time, union time, complications, time of recovery to work, secondary operations, and measured joint function using the American Orthopaedic Foot and Ankle Society (AOFAS) score. There was no significant difference in time to union, incidence of union status, time of recovery to work, and AOFAS scores among the 3 groups (P>.05). Mean operative time and radiation time in the MIPPO group were longer than those in the IMN or EF + LORIF groups (Pknee pain occurred frequently after IMN (32.1%), and irritation symptoms were encountered more frequently after MIPPO (46.4%). Although EF + LORIF was associated with fewer secondary procedures vs MIPPO or IMN, it was related with more pin-tract infections (14.3%). Findings indicated that EF + LORIF, MIPPO, and IMN all achieved similar good functional results. However, EF + LORIF had some advantages over MIPPO and IMN in reducing operative and radiation times, postoperative complications, and reoperation rate. [Orthopedics. 2016; 39(4):e627-e633.]. Copyright 2016, SLACK Incorporated.

  16. DIAGNOSTICS AND TREATMENT OF DISTAL RADIOULNAR JOINT INJURIES

    Directory of Open Access Journals (Sweden)

    A. V. Skoroglyadov

    2010-01-01

    Full Text Available We present the experience of treatment of 169 patients with distal radioulnar joint injuries, operated in specialized hand surgery department of the Clinic of traumatology and orthopedics of Russian State Medical University on the base of Moscow city clinical hospital № 4. We have carried out the following operations: closed osteoclasia of the distal epimetaphys fractures, osteotomy of the radius with the external fixator application in 97 (57,4% patients, percutaneous 2 Kirschner wires fixation of the ulna head to the radius after reposition of dislocation - 38 (22,5% patients, lavsanoplasty of DRUJ ligaments - 12 (7,1%, fixation of the ulna head to the radius by pin - 7 (4,1%, open reposition of dislocation of the ulna head and K-wire fixation - 8 (4,8%, osteotomy of synostosis of forearm bones, W. Darrach and Sauve-Kapandji operations - 7 (4,1%. Complications were observed in 13 (7,7% cases. Postponed results (1 year after operation were studied in 110 patients. We got good results in 95 (86,4% cases, satisfactory - in 12 (10,9% cases, unsatisfactory - in 3 (2,7% cases.

  17. Complicated distal femoral epiphyseolysis treated by Ilizarov method: Case report

    Directory of Open Access Journals (Sweden)

    Jovanović Vesna

    2010-01-01

    Full Text Available Introduction Injuries of the distal femur are rare in children; however, they are frequently associated with complications. They are almost always physeal, most frequently Salter-Harris type II epiphyseolysis. The treatment of such injuries is similar in all physeal injuries. It is intended to provide growth plate recovery by gentle reduction and stable fixation thus preventing secondary complications, and also to provide decompression of the segment to solve the compartment syndrome and recover the neurovascular structures. Case Outline A seven-year old boy presented with a right knee injury while sleigh riding. He was admitted three weeks following the injury with distal femoral epiphysiolysis associated with peroneal palsy. A day after admission to our Institute the reduction was performed using the Ilizarov device. Physical therapy was started immediately after surgery, as well as walking with weight bearing on the operated leg. Five months after surgery the patient was anatomically and functionally recovered. Conclusion The presented method is recommended in the treatment of such injuries because of several reasons; reposition is simple and complete, there is no need to open the fracture site, fixation is stable, the growth plate is preserved, there is no need for additional external immobilisation, and physical therapy involving walking with weight bearing on the operated leg may be started immediately after surgery. .

  18. Distraction lengthening of the proximal phalanx in distal thumb amputations.

    Science.gov (United States)

    Cansü, Eren; Ünal, Mehmet Bekir; Parmaksızoğlu, Fatih; Gürcan, Serkan

    2015-01-01

    Thumb amputation is a major cause of hand dysfunction, and the treatment for distal thumb amputations remains controversial. Although finger reconstruction methods using distraction lengthening are known to restore finger length and function, we found no reports in the literature regarding phalangeal lengthening in thumb amputations. We aimed to evaluate proximal phalangeal lengthening in thumb amputations at or near the interphalangeal (IP) joint. We retrospectively evaluated patients who had undergone distraction lengthening of the proximal phalanx of the thumb. All patients underwent osteotomy, either during the initial procedure or as a second-stage procedure. Distraction began 10 days after osteotomy with the use of an external fixator that remained in place until ossification of the gap occurred without bone grafting. Patients were evaluated using the QuickDASH score. Fourteen patients with a mean age of 27 years and a mean follow-up period of 7 years were enrolled. The mean phalangeal lengthening achieved was 20 mm. Ossification occurred at all distraction sites, and the fixators were maintained for a mean of 85 days. The mean healing index was 42.5 days/cm. All 14 patients achieved the desired amount of phalangeal lengthening without major complications such as nonunion, premature union, or gross infection. For reconstruction in cases of distal thumb amputations, distraction lengthening of the proximal phalanx can be used to improve absolute length, web space, and grip distance. The technique is safe and effective, improves functionality/cosmesis, and offers a low complication risk.

  19. Intramedullary Venous Drainage System for Distal Fingertip Replantations.

    Science.gov (United States)

    Purisa, Husrev; Ozturk, Muhammed Besir; Kabakas, Fatih; Mersa, Berkan; Ozcelik, Ismail Bulent; Sezer, Ilker

    2017-08-01

    The number of venous anastomoses performed during fingertip replantation is one of the most important factors affecting the success of replantation. However, because vessel diameters decrease in the zone 1 level, vessel anastomoses, especially vein anastomoses, are technically difficult and, thus, cannot be performed in most cases. Alternative venous drainage methods are crucial when any reliable vein repair is not possible. In the literature, so many artery-only replantation techniques have been defined, such as arteriovenous anastomoses, forming an arteriovenous or venocutaneous fistula, manual milking and massage, puncturing, and external bleeding via a fishmouth incision and using a medical leech. It has been shown that, in distal fingertip replantations, the medullary cavity may also be a good way for venous return. In this study, we introduce an alternative intramedullary venous drainage system we developed to facilitate venous drainage in artery-only fingertip replantations. The results of 24 fingertip replantations distal to the nail fold by using this system are presented with a literature review.

  20. Radiographic evaluation for AVN following distal metatarsal Stoffella bunion osteotomy.

    Science.gov (United States)

    Klein, Christian; Zembsch, Alexander; Dorn, Ulrich

    2009-01-01

    Avascular necrosis of the metatarsal head, delayed bone healing and nonunion are complications that may occur after distal first metatarsal osteotomies. Intraoperative damage to the extraosseous blood supply, the location of the osteotomy and postoperative vasospasm have been cited as possible causes of such changes. We evaluated Stoffella's subcapital osteotomies which were performed at our department for the correction of moderate to severe hallux valgus deformities. Standardized radiographs of 300 feet, taken 6weeks, 3 months, and 6 months postoperatively and at the final followup were examined with regard to postoperative AVN or signs of delayed bone healing. Of 228 patients, 202 were women and 26 were men. The patients' mean age was 49 years, and the mean followup was 12 months. In 278 cases the radiographs revealed an unremarkable first metatarsal head. Seventeen cases showed diffuse or localized osteopenia or small cysts in the subchondral bone. These changes fully resolved on subsequent radiographs. The X-rays of two patients revealed progressive narrowing of the joint space, irregular contours on the surface of the joint and an abnormal bone structure. The patients subsequently developed a characteristic picture of avascular necrosis, in one case combined with nonunion. Three patients had delayed bone healing, but ultimately healed successfully. Ischemic changes in bone are known to occur after distal first metatarsal osteotomies. There is a very low incidence of postoperative perfusion problems after Stoffella;s technique, even with lateral soft tissue release.

  1. DO PROXIMAL AND DISTAL GASTRIC TUMOURS BEHAVE DIFFERENTLY?

    Science.gov (United States)

    Costa, Laurence Bedin da; Toneto, Marcelo Garcia; Moreira, Luis Fernando

    2016-01-01

    Although the incidence of gastric (adenocarcinoma) cancer has been decreasing over time, it is still one of the most common malignancies worldwide, and proximal tumours tend to have a worse prognosis. To compare surgical outcomes and prognosis between proximal - excluding tumours of the cardia - and distal gastric cancer. Out of 293 cases reviewed - 209 with distal and 69 with proximal gastric cancer - were compared for clinical and pathological features, stage, surgical outcome, mortality and survival. Statistically, there was no significant difference between patients in both groups regarding mortality (p=0.661), adjuvant chemotherapy (p 0.661), and radiation (p=1.000). However, there was significant difference in the degree of lymph node dissection employed (p=0.002) and the number of positive lymph nodes resected (p=0.038) between the two groups. The odds of death at five years for patients who had a D0 dissection was three times greater (odds ratio 2.78; (95%CI 1.33-5.82) than that for patients who had a D2 dissection, while for patients who had a D1 dissection the odds ratio was only 1.41 (95%CI 0.71-2.83) compared to D2-dissected patients. Although no significant differences were found between proximal and distal gastric cancer, the increased risk of death in D0- and D1-dissected patients clearly suggests an important role of radical D2 lymph node dissection in survival. Embora a incidência do câncer gástrico esteja diminuindo nas últimas décadas, ele ainda aparece como uma das neoplasias malignas mais comuns, e tumores proximais tendem a ter pior prognóstico. Comparar os resultados cirúrgicos e o prognóstico entre o câncer gástrico proximal, excluindo os tumores da cárdia e junção esofagogástrica, e o distal. De 293 casos revistos - 209 distais e 69 proximais - foram comparados quanto aos achados clínicos e patológicos, estágio, resultados cirúrgicos, mortalidade e sobrevida. Estatisticamente não houve diferença entre pacientes em ambos

  2. Renal denervation beyond the bifurcation: The effect of distal ablation placement on safety and blood pressure.

    Science.gov (United States)

    Beeftink, Martine M A; Spiering, Wilko; De Jong, Mark R; Doevendans, Pieter A; Blankestijn, Peter J; Elvan, Arif; Heeg, Jan-Evert; Bots, Michiel L; Voskuil, Michiel

    2017-04-01

    Renal denervation may be more effective if performed distal in the renal artery because of smaller distances between the lumen and perivascular nerves. The authors reviewed the angiographic results of 97 patients and compared blood pressure reduction in relation to the location of the denervation. No significant differences in blood pressure reduction or complications were found between patient groups divided according to their spatial distribution of the ablations (proximal to the bifurcation in both arteries, distal to the bifurcation in one artery and distal in the other artery, or distal to the bifurcation in both arteries), but systolic ambulatory blood pressure reduction was significantly related to the number of distal ablations. No differences in adverse events were observed. In conclusion, we found no reason to believe that renal denervation distal to the bifurcation poses additional risks over the currently advised approach of proximal denervation, but improved efficacy remains to be conclusively established. ©2017 Wiley Periodicals, Inc.

  3. Weightbath hydrotraction treatment: application, biomechanics, and clinical effects

    Directory of Open Access Journals (Sweden)

    Márta Kurutz

    2010-04-01

    Full Text Available Márta Kurutz1, Tamás Bender21Department of Structural Mechanics, Budapest University of Technology and Economics, Hungary; 2Department of Physical Medicine, Polyclinic and Hospital of the Hospitaller Brothers of St. John of God, Budapest, Medical University of Szeged, HungaryBackground and purpose: Weightbath hydrotraction treatment (WHT is a simple noninvasive effective method of hydro- or balneotherapy to stretch the spine or lower limbs, applied successfully in hospitals and health resort sanitaria in Hungary for more than fifty years. This study aims to introduce WHT with its biomechanical and clinical effects. History, development, equipment, modes of application, biomechanics, spinal traction forces and elongations, indications and contraindications of WHT are precented.Subjects and methods: The calculation of traction forces acting along the spinal column during the treatment is described together with the mode of suspension and the position of extra weight loads applied. The biomechanics of the treatment are completed by in vivo measured elongations of lumbar segments using a special underwater ultrasound measuring method. The clinical effects, indications, and contraindications of the treatment are also presented.Results: In the underwater cervical suspension of a human body, approximately 25 N stretching load occurs in the cervical spine, and about 11 N occurs in the lumbar spine. By applying extra weights, the above tensile forces along the spinal column can be increased. Thus, the traction effect can be controlled by applying such loads during the treatment. Elongations of segments L3–L4, L4–L5, and L5–S1 were measured during the usual WHT of patients suspended cervically in water for 20 minutes, loaded by 20–20 N lead weights on the ankles. The mean initial elastic elongations of spinal segments were about 0.8 mm for patients aged under 40 years, 0.5 mm between 40–60 years, and 0.2 mm for patients over 60 years. The mean

  4. Physiological and Biomechanical Mechanisms of Distance Specific Human Running Performance.

    Science.gov (United States)

    Thompson, M A

    2017-08-01

    Running events range from 60-m sprints to ultra-marathons covering 100 miles or more, which presents an interesting diversity in terms of the parameters for successful performance. Here, we review the physiological and biomechanical variations underlying elite human running performance in sprint to ultramarathon distances. Maximal running speeds observed in sprint disciplines are achieved by high vertical ground reaction forces applied over short contact times. To create this high force output, sprint events rely heavily on anaerobic metabolism, as well as a high number and large cross-sectional area of type II fibers in the leg muscles. Middle distance running performance is characterized by intermediates of biomechanical and physiological parameters, with the possibility of unique combinations of each leading to high-level performance. The relatively fast velocities in mid-distance events require a high mechanical power output, though ground reaction forces are less than in sprinting. Elite mid-distance runners exhibit local muscle adaptations that, along with a large anaerobic capacity, provide the ability to generate a high power output. Aerobic capacity starts to become an important aspect of performance in middle distance events, especially as distance increases. In distance running events, V˙O2max is an important determinant of performance, but is relatively homogeneous in elite runners. V˙O2 and velocity at lactate threshold have been shown to be superior predictors of elite distance running performance. Ultramarathons are relatively new running events, as such, less is known about physiological and biomechanical parameters that underlie ultra-marathon performance. However, it is clear that performance in these events is related to aerobic capacity, fuel utilization, and fatigue resistance. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology 2017. This work is written by US Government employees and is in

  5. Correlation of breast image alignment using biomechanical modelling

    Science.gov (United States)

    Lee, Angela; Rajagopal, Vijay; Bier, Peter; Nielsen, Poul M. F.; Nash, Martyn P.

    2009-02-01

    Breast cancer is one of the most common causes of cancer death among women around the world. Researchers have found that a combination of imaging modalities (such as x-ray mammography, magnetic resonance, and ultrasound) leads to more effective diagnosis and management of breast cancers because each imaging modality displays different information about the breast tissues. In order to aid clinicians in interpreting the breast images from different modalities, we have developed a computational framework for generating individual-specific, 3D, finite element (FE) models of the breast. Medical images are embedded into this model, which is subsequently used to simulate the large deformations that the breasts undergo during different imaging procedures, thus warping the medical images to the deformed views of the breast in the different modalities. In this way, medical images of the breast taken in different geometric configurations (compression, gravity, etc.) can be aligned according to physically feasible transformations. In order to analyse the accuracy of the biomechanical model predictions, squared normalised cross correlation (NCC2) was used to provide both local and global comparisons of the model-warped images with clinical images of the breast subject to different gravity loaded states. The local comparison results were helpful in indicating the areas for improvement in the biomechanical model. To improve the modelling accuracy, we will need to investigate the incorporation of breast tissue heterogeneity into the model and altering the boundary conditions for the breast model. A biomechanical image registration tool of this kind will help radiologists to provide more reliable diagnosis and localisation of breast cancer.

  6. Biomechanics of the spine. Part I: Spinal stability

    International Nuclear Information System (INIS)

    Izzo, Roberto; Guarnieri, Gianluigi; Guglielmi, Giuseppe; Muto, Mario

    2013-01-01

    Biomechanics, the application of mechanical principles to living organisms, helps us to understand how all the bony and soft spinal components contribute individually and together to ensure spinal stability, and how traumas, tumours and degenerative disorders exert destabilizing effects. Spine stability is the basic requirement to protect nervous structures and prevent the early mechanical deterioration of spinal components. The literature reports a number of biomechanical and clinical definitions of spinal stability, but a consensus definition is lacking. Any vertebra in each spinal motion segment, the smallest functional unit of the spine, can perform various combinations of the main and coupled movements during which a number of bony and soft restraints maintain spine stability. Bones, disks and ligaments contribute by playing a structural role and by acting as transducers through their mechanoreceptors. Mechanoreceptors send proprioceptive impulses to the central nervous system which coordinates muscle tone, movement and reflexes. Damage to any spinal structure gives rise to some degree of instability. Instability is classically considered as a global increase in the movements associated with the occurrence of back and/or nerve root pain. The assessment of spinal instability remains a major challenge for diagnostic imaging experts. Knowledge of biomechanics is essential in view of the increasing involvement of radiologists and neuroradiologists in spinal interventional procedures and the ongoing development of new techniques and devices. Bioengineers and surgeons are currently focusing on mobile stabilization systems. These systems represent a new frontier in the treatment of painful degenerative spine and aim to neutralize noxious forces, restore the normal function of spinal segments and protect the adjacent segments. This review discusses the current concepts of spine stability

  7. Transesophageal echocardiographic strain imaging predicts aortic biomechanics: Beyond diameter.

    Science.gov (United States)

    Emmott, Alexander; Alzahrani, Haitham; Alreishidan, Mohammed; Therrien, Judith; Leask, Richard L; Lachapelle, Kevin

    2018-03-11

    Clinical guidelines recommend resection of ascending aortic aneurysms at diameters 5.5 cm or greater to prevent rupture or dissection. However, approximately 40% of all ascending aortic dissections occur below this threshold. We propose new transesophageal echocardiography strain-imaging moduli coupled with blood pressure measurements to predict aortic dysfunction below the surgical threshold. A total of 21 patients undergoing aortic resection were recruited to participate in this study. Transesophageal echocardiography imaging of the aortic short-axis and invasive radial blood pressure traces were taken for 3 cardiac cycles. By using EchoPAC (GE Healthcare, Madison, Wis) and postprocessing in MATLAB (MathWorks, Natick, Mass), circumferential stretch profiles were generated and combined with the blood pressure traces. From these data, 2 in vivo stiffness moduli were calculated: the Cardiac Cycle Pressure Modulus and Cardiac Cycle Stress Modulus. From the resected aortic ring, testing squares were isolated for ex vivo mechanical analysis and histopathology. Each square underwent equibiaxial tensile testing to generate stress-stretch profiles for each patient. Two ex vivo indices were calculated from these profiles (energy loss and incremental stiffness) for comparison with the Cardiac Cycle Pressure Modulus and Cardiac Cycle Stress Modulus. The echo-derived stiffness moduli demonstrate positive significant covariance with ex vivo tensile biomechanical indices: energy loss (vs Cardiac Cycle Pressure Modulus: R 2  = 0.5873, P biomechanics and histopathology, which demonstrates the added benefit of using simple echocardiography-derived biomechanics to stratify patient populations. Copyright © 2018. Published by Elsevier Inc.

  8. A review of biomechanically informed breast image registration

    International Nuclear Information System (INIS)

    Hipwell, John H; Vavourakis, Vasileios; Mertzanidou, Thomy; Eiben, Björn; Hawkes, David J; Han, Lianghao

    2016-01-01

    Breast radiology encompasses the full range of imaging modalities from routine imaging via x-ray mammography, magnetic resonance imaging and ultrasound (both two- and three-dimensional), to more recent technologies such as digital breast tomosynthesis, and dedicated breast imaging systems for positron emission mammography and ultrasound tomography. In addition new and experimental modalities, such as Photoacoustics, Near Infrared Spectroscopy and Electrical Impedance Tomography etc, are emerging. The breast is a highly deformable structure however, and this greatly complicates visual comparison of imaging modalities for the purposes of breast screening, cancer diagnosis (including image guided biopsy), tumour staging, treatment monitoring, surgical planning and simulation of the effects of surgery and wound healing etc. Due primarily to the challenges posed by these gross, non-rigid deformations, development of automated methods which enable registration, and hence fusion, of information within and across breast imaging modalities, and between the images and the physical space of the breast during interventions, remains an active research field which has yet to translate suitable methods into clinical practice. This review describes current research in the field of breast biomechanical modelling and identifies relevant publications where the resulting models have been incorporated into breast image registration and simulation algorithms. Despite these developments there remain a number of issues that limit clinical application of biomechanical modelling. These include the accuracy of constitutive modelling, implementation of representative boundary conditions, failure to meet clinically acceptable levels of computational cost, challenges associated with automating patient-specific model generation (i.e. robust image segmentation and mesh generation) and the complexity of applying biomechanical modelling methods in routine clinical practice. (topical review)

  9. Preliminary evidence of altered biomechanics in adolescents with juvenile fibromyalgia.

    Science.gov (United States)

    Sil, Soumitri; Thomas, Staci; DiCesare, Christopher; Strotman, Daniel; Ting, Tracy V; Myer, Gregory; Kashikar-Zuck, Susmita

    2015-01-01

    Juvenile fibromyalgia (FM) is characterized by chronic musculoskeletal pain and marked reduction in physical activity. Despite recommendations for exercise to manage juvenile FM pain, exercise adherence is poor. Because of pain and activity avoidance, adolescents with juvenile FM are at risk for altered joint mechanics that may make them susceptible to increased pain and reduced tolerance for exercise. The primary aim of this study was to assess functional deficits in patients with juvenile FM compared to healthy controls using objective biomechanical assessment. Female adolescent patients with juvenile FM (n = 17) and healthy controls (n = 14) completed biomechanical assessments, including gait analysis and tests of lower extremity strength (isokinetic knee extension/flexion and hip abduction) and functional performance (drop vertical jump test) along with self-reported measures of disability (Functional Disability Inventory), pain intensity, depressive symptoms (Children's Depression Inventory), and fear of movement (Tampa Scale of Kinesiophobia). Patients with juvenile FM demonstrated mild deficiencies in walking gait and functional performance (P < 0.05 for both) and significantly lower left knee extension and flexion strength (18-22% deficit) and bilateral hip abduction strength (34-38%) compared with healthy controls (P < 0.008 for all). Patients with juvenile FM reported significantly higher functional disability, pain intensity, depressive symptoms, and fear of movement relative to controls (P < 0.01 for all). This study showed that adolescents with juvenile FM exhibited objective alterations in biomechanics and self-reported fear of movement that may have reinforced their activity avoidance. Interventions for juvenile FM should include a focus on correcting functional deficits and instilling greater confidence in adolescents with juvenile FM to engage in exercise to improve functional outcomes. Copyright © 2015 by the American College of Rheumatology.

  10. Corneal biomechanical properties from air-puff corneal deformation imaging

    Science.gov (United States)

    Marcos, Susana; Kling, Sabine; Bekesi, Nandor; Dorronsoro, Carlos

    2014-02-01

    The combination of air-puff systems with real-time corneal imaging (i.e. Optical Coherence Tomography (OCT), or Scheimpflug) is a promising approach to assess the dynamic biomechanical properties of the corneal tissue in vivo. In this study we present an experimental system which, together with finite element modeling, allows measurements of corneal biomechanical properties from corneal deformation imaging, both ex vivo and in vivo. A spectral OCT instrument combined with an air puff from a non-contact tonometer in a non-collinear configuration was used to image the corneal deformation over full corneal cross-sections, as well as to obtain high speed measurements of the temporal deformation of the corneal apex. Quantitative analysis allows direct extraction of several deformation parameters, such as apex indentation across time, maximal indentation depth, temporal symmetry and peak distance at maximal deformation. The potential of the technique is demonstrated and compared to air-puff imaging with Scheimpflug. Measurements ex vivo were performed on 14 freshly enucleated porcine eyes and five human donor eyes. Measurements in vivo were performed on nine human eyes. Corneal deformation was studied as a function of Intraocular Pressure (IOP, 15-45 mmHg), dehydration, changes in corneal rigidity (produced by UV corneal cross-linking, CXL), and different boundary conditions (sclera, ocular muscles). Geometrical deformation parameters were used as input for inverse finite element simulation to retrieve the corneal dynamic elastic and viscoelastic parameters. Temporal and spatial deformation profiles were very sensitive to the IOP. CXL produced a significant reduction of the cornea indentation (1.41x), and a change in the temporal symmetry of the corneal deformation profile (1.65x), indicating a change in the viscoelastic properties with treatment. Combining air-puff with dynamic imaging and finite element modeling allows characterizing the corneal biomechanics in-vivo.

  11. Biomechanics of the spine. Part I: Spinal stability

    Energy Technology Data Exchange (ETDEWEB)

    Izzo, Roberto, E-mail: roberto1766@interfree.it [Neuroradiology Department, “A. Cardarelli” Hospital, Napoli (Italy); Guarnieri, Gianluigi, E-mail: gianluigiguarnieri@hotmail.it [Neuroradiology Department, “A. Cardarelli” Hospital, Napoli (Italy); Guglielmi, Giuseppe, E-mail: g.gugliemi@unifg.it [Department of Radiology, University of Foggia, Foggia (Italy); Muto, Mario, E-mail: mutomar@tiscali.it [Neuroradiology Department, “A. Cardarelli” Hospital, Napoli (Italy)

    2013-01-15

    Biomechanics, the application of mechanical principles to living organisms, helps us to understand how all the bony and soft spinal components contribute individually and together to ensure spinal stability, and how traumas, tumours and degenerative disorders exert destabilizing effects. Spine stability is the basic requirement to protect nervous structures and prevent the early mechanical deterioration of spinal components. The literature reports a number of biomechanical and clinical definitions of spinal stability, but a consensus definition is lacking. Any vertebra in each spinal motion segment, the smallest functional unit of the spine, can perform various combinations of the main and coupled movements during which a number of bony and soft restraints maintain spine stability. Bones, disks and ligaments contribute by playing a structural role and by acting as transducers through their mechanoreceptors. Mechanoreceptors send proprioceptive impulses to the central nervous system which coordinates muscle tone, movement and reflexes. Damage to any spinal structure gives rise to some degree of instability. Instability is classically considered as a global increase in the movements associated with the occurrence of back and/or nerve root pain. The assessment of spinal instability remains a major challenge for diagnostic imaging experts. Knowledge of biomechanics is essential in view of the increasing involvement of radiologists and neuroradiologists in spinal interventional procedures and the ongoing development of new techniques and devices. Bioengineers and surgeons are currently focusing on mobile stabilization systems. These systems represent a new frontier in the treatment of painful degenerative spine and aim to neutralize noxious forces, restore the normal function of spinal segments and protect the adjacent segments. This review discusses the current concepts of spine stability.

  12. Trunk biomechanics during hemiplegic gait after stroke: A systematic review.

    Science.gov (United States)

    Van Criekinge, Tamaya; Saeys, Wim; Hallemans, Ann; Velghe, Silke; Viskens, Pieter-Jan; Vereeck, Luc; De Hertogh, Willem; Truijen, Steven

    2017-05-01

    Stroke commonly results in trunk impairments that are associated with decreased trunk coordination and limited trunk muscle strength. These impairments often result in biomechanical changes during walking. Additionally, the so-called pelvic step might be influenced by these impairments. Therefore, the aim of this review was twofold. First, to gain more insight into trunk biomechanics during walking in stroke patients compared to healthy individuals. Second, to investigate the influence of walking speed on trunk biomechanics. The search strategy was performed by the PRISMA guidelines and registered in the PROSPERO database (no. CRD42016035797). Databases MEDLINE, Web of Science, Cochrane Library, ScienceDirect, and Rehabdata were systematically searched until December 2016. Sixteen of the 1099 studies met the eligibility criteria and were included in this review. Risk of bias was assessed by the Newcastle-Ottawa Scale. The majority of studies reported on trunk kinematics during walking, data on trunk kinetics and muscle activity is lacking. Following stroke, patients walk with increased mediolateral trunk sway and larger sagittal motion of the lower trunk. Although rotation of the upper trunk is increased, the trunk shows a more in-phase coordination. Acceleration of the trunk diminishes while instability and asymmetry increase as there are less movement towards the paretic side. However, it is of great importance to differentiate between compensatory trunk movements and intrinsic trunk control deficits. Specific exercise programs, assistive devices and orthoses might be of help in controlling these deficits. Importantly, studies suggested that more natural trunk movements were observed when walking speed was increased. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Dietary water affects human skin hydration and biomechanics

    Directory of Open Access Journals (Sweden)

    Palma L

    2015-08-01

    Full Text Available Lídia Palma,1 Liliana Tavares Marques,1 Julia Bujan,2,3 Luís Monteiro Rodrigues1,4 1CBIOS – Research Center for Health Science and Technologies, Universidade Lusófona, Campo Grande, Lisboa, Portugal; 2Department of Medicine and Medical Specialities, Universidad de Alcalá de Henares, Madrid, Spain; 3CIBER-BBN, Madrid, España, Spain; 4Department of Pharmacological Sciences, School of Pharmacy, Universidade de Lisboa, Lisboa, Portugal Abstract: It is generally assumed that dietary water might be beneficial for the health, especially in dermatological (age preventing terms. The present study was designed to quantify the impact of dietary water on major indicators of skin physiology. A total of 49 healthy females (mean 24.5±4.3 years were selected and characterized in terms of their dietary daily habits, especially focused in water consumption, by a Food Frequency Questionnaire. This allowed two groups to be set – Group 1 consuming less than 3,200 mL/day (n=38, and Group 2 consuming more than 3,200 mL/day (n=11. Approximately 2 L of water were added to the daily diet of Group 2 individuals for 1 month to quantify the impact of this surplus in their skin physiology. Measurements involving epidermal superficial and deep hydration, transepidermal water loss, and several biomechanical descriptors were taken at day 0 (T0, 15 (T1, and 30 (T2 in several anatomical sites (face, upper limb, and leg. This stress test (2 L/day for 30 days significantly modified superficial and deep skin hydration, especially in Group 1. The same impact was registered with the most relevant biomechanical descriptors. Thus, in this study, it is clear that higher water inputs in regular diet might positively impact normal skin physiology, in particular in those individuals with lower daily water consumptions. Keywords: dietary water, water consume, skin hydration, TEWL, skin biomechanics

  14. Locking plate fixation in distal metaphyseal tibial fractures: series of 79 patients

    OpenAIRE

    Gupta, Rakesh K.; Rohilla, Rajesh Kumar; Sangwan, Kapil; Singh, Vijendra; Walia, Saurav

    2009-01-01

    Open reduction and internal fixation in distal tibial fractures jeopardises fracture fragment vascularity and often results in soft tissue complications. Minimally invasive osteosynthesis, if possible, offers the best possible option as it permits adequate fixation in a biological manner. Seventy-nine consecutive adult patients with distal tibial fractures, including one patient with a bilateral fracture of the distal tibia, treated with locking plates, were retrospectively reviewed. The 4.5-...

  15. Intersphincteric Resection and Coloanal Anastomosis in Treatment of Distal Rectal Cancer

    OpenAIRE

    Cipe, Gokhan; Muslumanoglu, Mahmut; Yardimci, Erkan; Memmi, Naim; Aysan, Erhan

    2012-01-01

    In the treatment of distal rectal cancer, abdominoperineal resection is traditionally performed. However, the recognition of shorter safe distal resection line, intersphincteric resection technique has given a chance of sphincter-saving surgery for patients with distal rectal cancer during last two decades and still is being performed as an alternative choice of abdominoperineal resection. The first aim of this study is to assess the morbidity, mortality, oncological, and functional outcomes ...

  16. Classification of Distal Fingertip Amputation Based on the Arterial System for Replantation

    OpenAIRE

    Park, Hyun Chul; Bahar-Moni, Ahmed Suparno; Cho, Sang Hyun; Kim, Sang Soo; Park, Hyun Sik; Ahn, Sang Cheon

    2012-01-01

    During replantation of distal fingertip amputation, identification of the artery is the most important but time consuming procedure. Depending on the damaged arterial structure, we classified distal fingertip amputations into 4 zones, on the basis of three dimensional concept. Zone 1 injury was defined as damage to the proximal central pulp artery; zone 2 injury, damage to the branch of the central pulp artery; zone 3 injury, damage to the distal central pulp artery; and zone 4 injury, no inj...

  17. Reliability of radiographic measurements for acute distal radius fractures

    International Nuclear Information System (INIS)

    Watson, Narelle J.; Asadollahi, Saeed; Parrish, Frank; Ridgway, Jacqueline; Tran, Phong; Keating, Jennifer L.

    2016-01-01

    The management of distal radial fractures is guided by the interpretation of radiographic findings. The aim of this investigation was to determine the intra- and inter-observer reliability of eight traditionally reported anatomic radiographic parameters in adults with an acute distal radius fracture. Five observers participated. All were routinely involved in making treatment decisions based on distal radius fracture radiographs. Observers performed independent repeated measurements on 30 radiographs for eight anatomical parameters: dorsal shift (mm), intra-articular gap (mm), intra-articular step (mm), palmar tilt (degrees), radial angle (degrees), radial height (mm), radial shift (mm), ulnar variance (mm). Intraclass correlation coefficients (ICCs) and the magnitude of retest errors were calculated. Measurement reliability was summarised as high (ICC > 0.80), moderate (0.60–0.80) or low (<0.60). Intra-observer reliability was high for dorsal shift and palmar tilt; moderate for radial angle, radial height, ulnar variance and radial shift; and low for intra-articular gap and step. Inter-observer reliability was high for palmar tilt; moderate for dorsal shift, ulnar variance, radial angle and radial height; and low for radial shift, intra-articular gap and step. Error magnitude (95 % confidence interval) was within 1–2 mm for intra-articular gap and step, 2–4 mm for ulnar variance, 4–6 mm for radial shift, dorsal shift and radial height, and 6–8° for radial angle and palmar tilt. Based on previous reports of critical values for palmar tilt, ulnar variance and radial angle, error margins appear small enough for measurements to be useful in guiding treatment decisions. Our findings indicate that clinicians cannot reliably measure values ≤1 mm for intra-articular gap and step when interpreting radiographic parameters using the standardised methods investigated in this study. As a guide for treatment selection, palmar tilt, ulnar variance and radial angle

  18. How Can Sport Biomechanics Contribute to the Advance of World Record and Best Athletic Performance?

    Science.gov (United States)

    Li, Li

    2012-01-01

    Modern history has evidence that sport biomechanics provide valuable contribution in the pursuit of "faster, higher, and stronger." In this article, the contribution of sport biomechanics to the Olympic Games has been divided into three different categories: improve the physical capacity of the athletes, develop innovative techniques in…

  19. Relapse and stability of surgically assisted rapid maxillary expansion, an anatomical biomechanical study

    NARCIS (Netherlands)

    Koudstaal, M.J.; Smeets, J.B.J.; Kleinrensink, G.J.; Schulten, A.J.M.; van der Wal, K.G.H.

    2009-01-01

    Purpose: This anatomic biomechanical study was undertaken to gain insight into the underlining mechanism of tipping of the maxillary segments during transverse expansion using tooth-borne and bone-borne distraction devices. Materials and Methods: An anatomic biomechanical study was performed on 10

  20. Training for Women's Basketball: A Biomechanical Emphasis for Preventing Anterior Cruciate Ligament Injury.

    Science.gov (United States)

    Pettitt, Robert W.; Bryson, Erin R.

    2002-01-01

    Summarizes proposed variables linked with higher incidences of anterior cruciate ligament tears in females and the biomechanical aspects of the lower extremity during the performance of common basketball skills, focusing on gender differences in knee joint stability and neuromuscular control, biomechanical aspects of lower extremity skills in…