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Sample records for distal radius-a biomechanical

  1. A novel non-bridging external fixator construct versus volar angular stable plating for the fixation of intra-articular fractures of the distal radius--a biomechanical study.

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    Windolf, Markus; Schwieger, Karsten; Ockert, Ben; Jupiter, Jesse B; Gradl, Georg

    2010-02-01

    Non-bridging external fixation has recently been introduced as an alternative to volar angular stable plating for the fixation of unstable intra-articular distal radial fractures. The purpose of this study was to biomechanically compare a new non-bridging external fixator construct to volar angular stable plate fixation in a dorsally comminuted intra-articular fracture model of the distal radius. Five pairs of fresh frozen human cadaveric radii were randomly supplied with either a non-bridging external fixator or a stainless steel volar locking plate. A three-fragmental AO 23-C2.1 fracture was created by removing a 15 degrees dorsal wedge with remaining volar cortical contact and by an intra-articular osteotomy lateral to the lister-tubercle. Physiological load transfer via the wrist was simulated by means of a custom-made seesaw. For biomechanical testing, the bones were loaded in cyclic axial compression. Starting at 100N, the load was monotonically increased at 0.025 degrees N per cycle until failure of the construct. Motion of the lunate and scaphoid fragments with respect to the radial diaphysis was acquired by optical three-dimensional (3D) motion tracking. Plastic wedge deformation was determined after 2000, 4000 and 6000 cycles. The amplitude of wedge motion at the beginning of the test as a measure for construct stiffness was significantly lower for the fixator group (P=0.003, power=0.99). Plastic wedge deformation after 2000, 4000 and 6000 cycles was found significantly lower for the external fixator (repeated measures analysis of variance (ANOVA), P=0.009, power=0.86). Displacement of the intra-articular gap was found below 0.6mm (mean) for both groups (P>0.05). The study revealed superior biomechanical properties of the proposed non-bridging external fixation compared to volar locked plating in an unstable intra-articular fracture model with volar cortical support. However, both fixation techniques seem to apply sufficient stabilisation to restore and

  2. Biomechanical analysis of distal biceps tendon repair methods.

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    Henry, Jon; Feinblatt, Jeff; Kaeding, Christopher C; Latshaw, James; Litsky, Alan; Sibel, Roman; Stephens, Julie A; Jones, Grant L

    2007-11-01

    The 1-incision and 2-incision techniques are commonly used methods to repair a distal biceps rupture, and they differ in the location of reinsertion of tendon into bone. The native distal biceps brachii tendon inserts on the posterior-ulnar aspect of the bicipital tuberosity, which functions as a cam, increasing the tendon's moment arm during its principal action of forearm supination. Repair of the distal biceps tendon to the anterior aspect of the tuberosity compromises forearm supination due to absence of the bicipital tuberosity's cam effect. Controlled laboratory study. Eleven matched pairs of fresh-frozen cadaveric upper extremities were prepared for repair of the distal biceps tendon using either anterior or posterior reattachment with transosseous suture fixation. Specimens were tested on a materials testing machine with intact distal biceps insertion and after repair. A load cell at the distal radial-ulnar joint measured resultant elbow flexion and forearm supination torque produced by 100-N force applied to the proximal aspect of the tendon. Although there was a trend (P= .104) toward loss of supination torque with the anterior reconstruction method, no significant differences in torque (0.80 vs 0.89 N.m) or flexion force (11.87 vs 12.07 N) were found between the anterior and posterior reconstruction techniques. There is no statistically significant difference in flexion force or supination torque between the anterior and posterior reconstruction techniques. This study supports existing limited clinical data suggesting no functional differences exist between 2 common repair methods. Further biomechanical and clinical investigations directly comparing the results of distal biceps tendon repairs made to the anterior aspect versus the posterior aspect of the tuberosity are necessary to definitely determine if differences exist in resultant elbow flexion and forearm supination functions.

  3. Biomechanical comparison of orthogonal versus parallel double plating systems in intraarticular distal humerus fractures

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    Ata C. Atalar

    2017-01-01

    Conclusion: Our study showed that both plating systems had similar biomechanical stabilities when anatomic plates with distal locking screws were used in intraarticular distal humerus fractures in artificial humerus models.

  4. Setscrew distal locking for intramedullary nails: a biomechanical study.

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    Köse, N; Günal, I; Wang, X; Athanasiou, K A; Agrawal, C M; Mabrey, J D

    2000-08-01

    This biomechanical study was undertaken to examine the effectiveness of setscrew distal locking in a static intramedullary (IM) femoral nail on the stability of fixation of femoral shaft fractures. Fifteen fresh-frozen cadeveric femora were randomly separated into three groups of five bones and transversely sectioned immediately distal to the isthmus. After the insertion of the large-diameter nails, distal locking was obtained by conventional method in the first group. In the second group, set-screw design was used in which two transverse screws penetrated only the lateral cortex of the femur and compressed the nail in the intramedullary canal. No distal locking was used in the third group. All instrumented femurs were mounted on a servohydraulic testing machine and tested in both rotations (20 degrees) and axial compression (amplitude: 1,000 Newton). Loading-versus-displacement data, acquired at a ten-Hertz sampling rate, were calibrated and used to calculate maximum torque, stiffness, and energy capacity to failure. Maximum displacement and axial stiffness also were determined. Mean maximum torque at 10 degrees for each group were 15.3+/-4.8 newton-meters for the interlocking group, 8.5 +/-1.2 newton-meters for the setscrew group, and 3.6+/-2.7 newton-meters for the nonlocked femora. At 20 degrees of rotational displacement, the torque measured 37.4+/-2.6 newton-meters; 15.0+/-4.0 newton-meters; and 5.3+/-3.1 newton-meters, respectively (p 0.05). The setscrew design provided 87 percent of the torsional rigidity of the interlocking group. In the axial compression test, mean maximum shortening was 1.1+/-0.3 millimeters in the interlocking group and 1.4+/-0.6 millimeters in the setscrew group (p > 0.05). The mean stiffness on longitudinal compression provided by the interlocking screws and the setscrews was 918 and 860 newton-meters per millimeter, respectively. The distal setscrew design provides adequate distal fixation of intramedullary nail for patients in the

  5. Biomechanical characterization of an osteoporotic artificial bone model for the distal femur.

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    Wähnert, Dirk; Hoffmeier, Konrad L; Klos, Kajetan; Stolarczyk, Yves; Fröber, Rosemarie; Hofmann, Gunther O; Mückley, Thomas

    2012-01-01

    The treatment of osteoporotic distal femur fractures is still an unsolved problem of trauma surgery. The poor bone stock often leads to secondary loss of reduction and implant failure. Therefore, the development of new implants and their biomechanical testing is essential. In a previous study, we developed and initially characterized an artificial osteoporotic bone model of the distal femur. This follow-up study was performed to characterize this model in a biomechanical comparison. We investigated two different artificial bones: five foam cortical shell (Sawbones) and 10 custom-made artificial femoral condyles. Additionally, eight human femora were used for comparison. For biomechanical testing, two intramedullary nails (distal femur nail (DFN) and supracondylar nail (SCN)) were cyclically axial loaded in an AO 33 C2 unstable distal femoral fracture model. In our testing, the artificial bone showed a decrease in the axial stiffness of 27% for the SCN and 28% for the DFN compared to the human results. Also the number of cycles for a deformation of 2.5 mm was reduced by 55% (SCN) and 62% (DFN). This decrease was homogenous and caused by the relative high bone mineral density of the human specimen used. The modes of failure showed no difference between the artificial and human bones. Our customized artificial bone provides suitable results. In relation to the human bones classified as mildly osteoporotic, we assume that the biomechanical properties match to serve as an osteoporotic bone. Yet, we suggest to check transferability of the results with human material.

  6. Reinforced fixation of distal fibula fractures in elderly patients; A meta-analysis of biomechanical studies.

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    Dingemans, Siem A; Lodeizen, Olivia A P; Goslings, J Carel; Schepers, Tim

    2016-07-01

    There is an increasing incidence of fragility fractures of the ankle in the elderly population. The open reduction and internal fixation of these fractures is challenging, due to reduced bone stock quality as a result of osteoporosis. Biomechanical studies have shown contradicting results using reinforced constructions in the fixation of fibular fractures. We therefore performed a meta-analysis of biomechanical studies on reinforced fixation of distal fibular fractures. A literature search was conducted utilizing three online databases considering biomechanical testing of different fixation techniques of distal fibular fractures. A meta-analysis was performed on two biomechanical outcome measures; torsional stiffness and torque to failure. In a total number of 13 studies 8 different reinforcement techniques were identified. Of these studies, six compared locked lateral plating with conventional lateral plating. There were no statistically significant differences between the locking and non-locking lateral plate for torque to failure or torsional stiffness. Locked plating strength was independent from bone mineral density in four studies. An antiglide plate proved to be biomechanically superior compared to a lateral plate in one study and to a locked plate in another. Locked lateral plates are not biomechanically superior to conventional lateral plates. However the strength of locked plating may be independent of bone mineral density and could make this technique more suitable in the fixation of severe osteoporotic fractures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Biomechanical evaluation of mini-fragment hardware for supination external rotation fractures of the distal fibula.

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    Bariteau, Jason T; Blankenhorn, Brad D; Lareau, Craig R; Paller, David J; DiGiovanni, Christopher W

    2013-04-01

    Supination external rotation distal fibula fractures are common, requiring fixation when associated with talar displacement. Subcutaneous distal fibula hardware may become painful, necessitating operative removal. We hypothesize that mini-fragment and small-fragment constructs will demonstrate similar biomechanical stability. A biomechanical comparison was performed in synthetic osteoporotic sawbones. The first arm compared two 2.4-mm lag screws with one 3.5-mm lag screw for fixation of a simulated supination external rotation distal fibula fracture. The second arm compared a 2.4-mm plate-screw construct with a 3.5-mm lag screw and one-third tubular neutralization plate. During torsional testing, torque and displacement were recorded, and stiffness and peak torque were determined. Differences in mean stiffness and mean load at failure were not statistically significant with lag screw-only fixation. The 3.5-mm plate-screw construct outperformed the 2.4-mm plate-screw construct, but neither mean stiffness nor mean load at failure were statistically significantly different. Dynamic testing also demonstrated similar results. Our data suggest that isolated 2.4-mm screws function similarly to one 3.5-mm screw. Although the 3.5-mm plate-screw construct was stiffer, mean load at failure was equivalent for the 2 constructs. These data provide biomechanical evidence to support further investigation in the use of mini-fragment hardware for distal fibula fracture fixation. Therapeutic, Level V.

  8. Biomechanical comparison of orthogonal versus parallel double plating systems in intraarticular distal humerus fractures.

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    Atalar, Ata C; Tunalı, Onur; Erşen, Ali; Kapıcıoğlu, Mehmet; Sağlam, Yavuz; Demirhan, Mehmet S

    2017-01-01

    In intraarticular distal humerus fractures, internal fixation with double plates is the gold standard treatment. However the optimal plate configuration is not clear in the literature. The aim of this study was to compare the biomechanical stability of the parallel and the orthogonal anatomical locking plating systems in intraarticular distal humerus fractures in artificial humerus models. Intraarticular distal humerus fracture (AO13-C2) with 5 mm metaphyseal defect was created in sixteen artificial humeral models. Models were fixed with either orthogonal or parallel plating systems with locking screws (Acumed elbow plating systems). Both systems were tested for their stiffness with loads in axial compression, varus, valgus, anterior and posterior bending. Then plastic deformation after cyclic loading in posterior bending and load to failure in posterior bending were tested. The failure mechanisms of all the samples were observed. Stiffness values in every direction were not significantly different among the orthogonal and the parallel plating groups. There was no statistical difference between the two groups in plastic deformation values (0.31 mm-0.29 mm) and load to failure tests in posterior bending (372.4 N-379.7 N). In the orthogonal plating system most of the failures occurred due to the proximal shaft fracture, whereas in the parallel plating system failure occurred due to the shift of the most distal screw in proximal fragment. Our study showed that both plating systems had similar biomechanical stabilities when anatomic plates with distal locking screws were used in intraarticular distal humerus fractures in artificial humerus models. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  9. The biomechanical analysis of three-dimensional distal radius fracture model with different fixed splints.

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    Hua, Zhen; Wang, Jian-Wei; Lu, Zhen-Fei; Ma, Jian-Wei; Yin, Heng

    2018-01-30

    The distal radius fracture is one of the common clinical fractures. At present, there are no reports regarding application of the finite element method in studying the mechanism of Colles fracture and the biomechanical behavior when using splint fixation. To explore the mechanism of Colles fracture and the biomechanical behavior when using different fixed splints. Based on the CT scanning images of forearm for a young female volunteer, by using model construction technology combined with RPOE and ANSYS software, a 3-D distal radius fracture forearm finite element model with a real shape and bioactive materials is built. The material tests are performed to obtain the mechanical properties of the paper-based splint, the willow splint and the anatomical splint. The numerical results are compared with the experimental results to verify the correctness of the presented model. Based on the verified model, the stress distribution of different tissues are analyzed. Finally, the clinical tests are performed to observe and verify that the anatomical splint is the best fit for human body. Using the three kinds of splints, the transferred bone stress focus on the distal radius and ulna, which is helpful to maintain the stability of fracture. Also the stress is accumulated in the distal radius which may be attributed to flexion position. Such stress distribution may be helpful to maintain the ulnar declination. By comparing the simulation results with the experimental observations, the anatomical splint has the best fitting to the limb, which can effectively avoid the local compression. The anatomical splint is the most effective for fixing and curing the fracture. The presented model can provide theoretical basis and technical guide for further investigating mechanism of distal radius fracture and clinical application of anatomical splint.

  10. Is there a benefit of proximal locking screws in osteoporotic distal radius fractures? - A biomechanical study.

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    Bockmann, Benjamin; Budak, Can; Figiel, Jens; Lechler, Philipp; Bliemel, Christopher; Debus, Florian; Schwarting, Tim; Oberkircher, Ludwig; Frink, Michael

    2016-08-01

    The distal radial fracture is a common fracture and frequently seen in geriatric patients. During the last years, volar plating has become a popular treatment option. While the application of locking screws at the distal fragment is widely accepted, there is no evidence for their use at the radial shaft. In six osteoporotic pairs of matched human cadaver radii an extra-articular model creating an AO 23-A2.1 fracture was employed. Osteosynthesis were performed using the APTUS 2.5 Adaptive TriLock Distal Radius System (Medartis AG) with locking (LS) or non-locking screws (NLS) for proximal fixation. Biomechanical testing was performed in a staircase fashion: starting with 50 cycles at 200N, the load was continuously increased by 50N every 80 cycles up to a maximum force of 400N. Finally, load to failure was analyzed with failure defined as sudden loss of force measured (20%) or major deformation of the radii (10mm). At 200N, 250N, 300N, 400N and load to failure, the NLS group showed a higher degree of elastic modulus. In contrast, the LS group showed higher elastic modulus at 350N. Maximum force was higher in the LS group without reaching statistical significance. Reasons for loss of fixation were longitudinal shaft fractures, horizontal peri-implant fractures and distal cutting out. No difference was seen between the two groups concerning the development of the above mentioned complications. Our study did not show biomechanical superiority for distal radius fracture fixation by using locking screws in the proximal holes in an osteoporotic cadaver study. At load to failure, longitudinal shaft fractures and peri-implant fractures seemed to be a more relevant problem rather than failure of the proximal fixation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Treatment of distal humeral fractures using conventional implants. Biomechanical evaluation of a new implant configuration

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    Braunstein Volker

    2010-08-01

    Full Text Available Abstract Background In the face of costly fixation hardware with varying performance for treatment of distal humeral fractures, a novel technique (U-Frame is proposed using conventional implants in a 180° plate arrangement. In this in-vitro study the biomechanical stability of this method was compared with the established technique which utilizes angular stable locking compression plates (LCP in a 90° configuration. Methods An unstable distal 3-part fracture (AO 13-C2.3 was created in eight pairs of human cadaveric humeri. All bone pairs were operated with either the "Frame" technique, where two parallel plates are distally interconnected, or with the LCP technique. The specimens were cyclically loaded in simulated flexion and extension of the arm until failure of the construct occurred. Motion of all fragments was tracked by means of optical motion capturing. Construct stiffness and cycles to failure were identified for all specimens. Results Compared to the LCP constructs, the "Frame" technique revealed significant higher construct stiffness in extension of the arm (P = 0.01. The stiffness in flexion was not significantly different (P = 0.16. Number of cycles to failure was found significantly larger for the "Frame" technique (P = 0.01. Conclusions In an in-vitro context the proposed method offers enhanced biomechanical stability and at the same time significantly reduces implant costs.

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

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    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.)

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

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    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.)

  14. Assessment of a novel biomechanical fracture model for distal radius fractures

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    Baumbach Sebastian Felix

    2012-12-01

    Full Text Available Abstract Background Distal radius fractures (DRF are one of the most common fractures and often need surgical treatment, which has been validated through biomechanical tests. Currently a number of different fracture models are used, none of which resemble the in vivo fracture location. The aim of the study was to develop a new standardized fracture model for DRF (AO-23.A3 and compare its biomechanical behavior to the current gold standard. Methods Variable angle locking volar plates (ADAPTIVE, Medartis were mounted on 10 pairs of fresh-frozen radii. The osteotomy location was alternated within each pair (New: 10 mm wedge 8 mm / 12 mm proximal to the dorsal / volar apex of the articular surface; Gold standard: 10 mm wedge 20 mm proximal to the articular surface. Each specimen was tested in cyclic axial compression (increasing load by 100 N per cycle until failure or −3 mm displacement. Parameters assessed were stiffness, displacement and dissipated work calculated for each cycle and ultimate load. Significance was tested using a linear mixed model and Wald test as well as t-tests. Results 7 female and 3 male pairs of radii aged 74 ± 9 years were tested. In most cases (7/10, the two groups showed similar mechanical behavior at low loads with increasing differences at increasing loads. Overall the novel fracture model showed a significant different biomechanical behavior than the gold standard model (p Conclusion The novel biomechanical fracture model for DRF more closely mimics the in vivo fracture site and shows a significantly different biomechanical behavior with increasing loads when compared to the current gold standard.

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

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

    2015-01-01

    Traditional fixation of unstable Orthopaedic Trauma Association type B/C ankle fractures consists of a lag screw and a lateral or posterolateral neutralization plate. Several studies have demonstrated the clinical success of lag screw only fixation; however, to date no biomechanical comparison of the different constructs has been performed. The purpose of the present study was to evaluate the biomechanical strength of these different constructs. Osteotomies were created in 40 Sawbones(®) distal fibulas and reduced using 1 bicortical 3.5-mm stainless steel lag screw, 2 bicortical 3.5-mm lag screws, 3 bicortical 3.5-mm lag screws, or a single 3.5-mm lag screw coupled with a stainless steel neutralization plate with 3 proximal cortical and 3 distal cancellous screws. The constructs were tested to determine the stiffness in lateral bending and rotation and failure torque. No significant differences in lateral bending or rotational stiffness were detected between the osteotomies fixed with 3 lag screws and a plate. Constructs fixed with 1 lag screw were weaker for both lateral bending and rotational stiffness. Osteotomies fixed with 2 lag screws were weaker in lateral bending only. No significant differences were found in the failure torque. Compared with lag screw only fixation, plate fixation requires larger incisions and increased costs and is more likely to require follow-up surgery. Despite the published clinical success of treating simple Orthopaedic Trauma Association B/C fractures with lag screw only fixation, many surgeons still have concerns about stability. For noncomminuted, long oblique distal fibula fractures, lag screw only fixation techniques offer construct stiffness similar to that of traditional plate and lag screw fixation. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  16. En bloc excision and autogenous fibular reconstruction for aggressive giant cell tumor of distal radius: a report of 12 cases and review of literature

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    Dhillon Mandeep S

    2011-03-01

    Full Text Available Abstract Introduction Giant cell tumor (GCT of distal radius follows a comparatively aggressive behaviour. Wide excision is the management of choice, but this creates a defect at the distal end of radius. The preffered modalities for reconstruction of such a defect include vascularized/non-vascularized bone graft, osteoarticular allografts and custom-made prosthesis. We here present our experience with wide resection and non-vascularised autogenous fibula grafting for GCT of distal radius. Materials and methods Twelve patients with a mean age of 34.7 years (21-43 years with Campanacci Grade II/III GCT of distal radius were managed with wide excision of tumor and reconstruction with ipsilateral nonvascularised fibula, fixed with small fragment plate to the remnant of the radius. Primary autogenous iliac crest grafting was done at the fibuloradial junction in all the patients. Results Mean follow up period was 5.8 years (8.2-3.7 years. Average time for union at fibuloradial junction was 33 weeks (14-69 weeks. Mean grip strength of involved side was 71% (42-86%. The average range of movements were 52° forearm supination, 37° forearm pronation, 42° of wrist palmerflexion and 31° of wrist dorsiflexion with combined movements of 162°. Overall revised musculoskeletal tumor society (MSTS score averaged 91.38% (76.67-93.33% with five excellent, four good and three satisfactory results. There were no cases with graft related complications or deep infections, 3 cases with wrist subluxation, 2 cases with non union (which subsequently united with bone grafting and 1 case of tumor recurrence. Conclusion Although complication rate is high, autogenous non-vascularised fibular autograft reconstruction of distal radius can be considered as a reasonable option after en bloc excision of Grade II/III GCT.

  17. 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

  18. 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 <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. En bloc resection and reconstruction with a personalized uncemented 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.

  19. 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

  20. Distal soft tissue procedure in hallux valgus surgery: biomechanical background and technique.

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    Schneider, Wolfgang

    2013-09-01

    The distal soft tissue procedure has evolved into an indispensable additional surgical procedure to increase the corrective effect in hallux valgus surgery. Considering the biomechanical development of hallux valgus deformity, degenerative changes of the soft tissues around the first metatarsophalangeal joint contribute much more to the deformity than changes in the bony structures which can rather be seen as degenerative changes secondary to the deformity. Thus the principles in hallux valgus correction should aim to reverse all pathogenetic steps leading to deformity: release of the contracted lateral soft tissue structures, tightening of the torn-out medial structures and reduction and rebalancing the first metatarsal head onto the sesamoid complex. The scientific discussion over the last decades has clarified the impact of different surgical steps and methods on the efficacy of the lateral release, the risk of creating overcorrection or instability of the joint and the risk of avascular necrosis of the first metatarsal head. According to anatomical and clinical data, a lateral soft tissue release can be combined with a distal metatarsal osteotomy, provided that the osteotomy is performed in a defined safe zone without increasing the risk for avascular necrosis of the first metatarsal head. Transecting the lateral metatarsosesamoid suspensory ligament is the key to a successful lateral release in hallux valgus surgery. Release of the deep transverse metatarsal ligament and the adductor hallucis muscle does not contribute to hallux valgus correction. The lateral short sesamophalangeal ligament and the plantar attachment of the articular capsule should be preserved to avoid possible joint instability. Thus today, the distal soft tissue procedure cannot be seen only as a supplementary surgical procedure in cases where the bony procedure needs additional correction, but rather is an indispensable procedure to restore the physiological situation and function of the

  1. Fixation of distal fibular fractures: A biomechanical study of plate fixation techniques.

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    Marvan, Jiri; Horak, Zdenek; Vilimek, Miloslav; Horny, Lukas; Kachlik, David; Baca, Vaclav

    2017-01-01

    Ankle fractures are complex injuries with variable prognoses that depend upon many factors. The aim of the treatment is to restore the ankle joint biomechanical stability with maximum range of motion. Most ankle fractures are fibular fractures, which have a typical oblique fracture line in the distal fibula located in the area of the tibiofibular syndesmosis. The aim of this study was to simulate numerically several fixation techniques of the distal fibular fractures, evaluate their stability, determine their impact on surrounding tissue load, and correlate the results to clinical treatment experience. The following three models of fibular fracture fixation were used: (a) plate fixation with three screws attached above/below and lag screws, (b) plate fixation with two screws attached above/below and lag screws, and (c) three lag screws only. All three fracture fixation models were analyzed according to their use in both healthy physiological bone and osteoporotic bone tissue. Based on the results of Finite Element Analysis for these simulations, we found that the most appropriate fixation method for Weber-B1 fibular fractures was an unlocked plate fixation using six screws and lag screws, both in patients with physiological and osteoporotic bone tissue. Conversely, the least appropriate fixation method was an unlocked plate fixation with four screws and lag screws. Although this fixation method reduces the stress on patients during surgery, it greatly increased loading on the bone and, thus, the risk of fixation failure. The final fixation model with three lag screws only was found to be appropriate only for very limited indications.

  2. Distal fibula fracture fixation: Biomechanical evaluation of three different fixation implants.

    Science.gov (United States)

    Knutsen, Ashleen R; Sangiorgio, Sophia N; Liu, Chang; Zhou, Steve; Warganich, Tibor; Fleming, John; Harris, Thomas G; Ebramzadeh, Edward

    2016-12-01

    The goal of this study was to evaluate the biomechanical performance of three distal fibula fracture fixation implants in a matched pair cadaveric fibula model: (1) a 5-hole compression plate with lag screw, (2) a 5-hole locking plate with lag screw, and (3) the 6-hole tabbed-plate with locking screws. Three-dimensional motions between the proximal and distal fibular segments were measured under cyclic valgus bending, cyclic compressive axial loading, and cyclic torsional external-rotation loading. During loading, strains were measured on the surfaces of each fibula near the simulated fracture site, and on the plate, to assess load transfer. Bone quality was quantified globally for each donor using bone mineral density (BMD) measured using Dual X-ray absorptiometry (DEXA) and locally at the fracture site using bone mineral content (BMC) measured using peripheral quantitative computed tomography (pQCT). Mean failure loads were below 0.2Nm of valgus bending and below 4Nm of external-rotational torque. Mean failure angulation was below 1degree for valgus bending, and failure rotation was below 7degrees for external-rotation. In the compression plate group, significant correlations were observed between bone quality (global BMD and local BMC) and strain in every one of the five locations (Pearson correlation coefficients >0.95, p<0.05). In contrast, in the locking and tabbed-plate groups, BMD and BMC correlated with far fewer strain locations. Overall, the tabbed-plate had similar construct stability and strength to the compression and locking plates. However, the distribution of load with the locking and tabbed-plates was not as heavily dependent on bone quality. Copyright © 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  3. Retrograde Tibial Nailing: a minimally invasive and biomechanically superior alternative to angle-stable plate osteosynthesis in distal tibia fractures

    Science.gov (United States)

    2014-01-01

    Background Currently, antegrade intramedullary nailing and minimally invasive plate osteosynthesis (MIPO) represent the main surgical alternatives in distal tibial fractures. However, neither choice is optimal for all bony and soft tissue injuries. The Retrograde Tibial Nail (RTN) is a small-caliber prototype implant, which is introduced through a 2-cm-long incision at the tip of the medial malleolus with stab incisions sufficient for interlocking. During this project, we investigated the feasibility of retrograde tibial nailing in a cadaver model and conducted biomechanical testing. Methods Anatomical implantations of the RTN were carried out in AO/OTA 43 A1-3 fracture types in three cadaveric lower limbs. Biomechanical testing was conducted in an AO/OTA 43 A3 fracture model for extra-axial compression, torsion, and destructive extra-axial compression. Sixteen composite tibiae were used to compare the RTN against an angle-stable plate osteosynthesis (Medial Distal Tibial Plate, Synthes®). Statistical analysis was performed by Student's t test. Results Retrograde intramedullary nailing is feasible in simple fracture types by closed manual reduction and percutaneous reduction forceps, while in highly comminuted fractures, the use of a large distractor can aid the reduction. Biomechanical testing shows a statistically superior stability (p nail meets the requirements of maximum soft tissue protection by a minimally invasive surgical approach with the ability of secure fracture fixation by multiple locking options. Retrograde tibial nailing with the RTN is a promising concept in the treatment of distal tibia fractures. PMID:24886667

  4. Percutaneous pins versus volar plates for unstable distal radius fractures: a biomechanic study using a cadaver model.

    Science.gov (United States)

    Knox, Jeffrey; Ambrose, Heidi; McCallister, Wren; Trumble, Thomas

    2007-01-01

    A biomechanic study using a cadaver model of a dorsally unstable distal radius fracture was used to compare the stability of percutaneous pinning and volar fixed-angle plating. Among the many surgical options for treating distal radius fractures are percutaneous pinning and internal plate fixation. Although percutaneous pin fixation requires less soft-tissue trauma and has low complication rates, plate fixation allows for early active movement with good clinical results. The biomechanic stability of these 2 methods was studied by using a cadaver model of a dorsally unstable intra-articular distal radius fracture. This study was performed on 7 fresh-frozen cadaver arms, in each of which an unstable intra-articular fracture with dorsal comminution was created. The fracture was first fixed with 0.062-mm K-wires inserted in standard crossed fashion and was tested in a pneumatic loading device that indirectly loaded the wrists through the 5 motor tendons 3 times at each level of force in flexion and extension. Testing was then repeated after removal of the pins and fixation with a fixed-angle DVR distal volar radius plate system (Hand Innovations, Inc., Miami, FL). Testing was performed in flexion up to 68 N and in extension up to 100 N, and the distance across the fracture site was measured. Volar plating was significantly more stable than pinning, with an average movement across the fracture site of 2.51 mm for pin fixation and 1.07 mm for plate fixation. The pins also showed a substantial degree of slipping after repeated stressing, but the plates remained stable. These results show the superior biomechanic stability of internal fixation using plates for dorsally comminuted intra-articular distal radius fractures in this cadaver model. Further clinical correlations are needed.

  5. Distal femoral fixation: a biomechanical comparison of retrograde nail, retrograde intramedullary nail, and prototype locking retrograde nail.

    Science.gov (United States)

    Heiney, Jake P; Battula, Suneel; O'Connor, Jill A; Ebraheim, Nabil; Schoenfeld, Andrew J; Vrabec, Gregory

    2012-08-01

    Distal femur fractures continue to be a complex surgical problem for which the incidence is increasing. Presently, there is a need for different constructs to address these complex fractures. This study attempts to define the biomechanical properties of several implants. A novel, prototype locking retrograde intramedullary nail and the Russell-Taylor femoral retrograde nail were tested at non-destructive, physiological, axial mode load strength using a young, synthetic bone model for a medial segmental shaft defect in the supracondylar region of the distal femur (medial gap of 10mm, 65mm proximal to the distal joint and parallel to the knee axis). Each specimen was compressively loaded and unloaded to the peak load for 80,000cycles at a 0.5Hz frequency. These were compared to the results from the same lab of the retrograde Trigen intramedullary nail. Motion and peak displacement were measured across the fracture site as a reflection of construct stability. Previous testing demonstrated that Trigen intramedullary nail had significantly less motion across the gap and increased overall stiffness of the construct (Pnails. Locking technology used in a nail biomechanically appears to lead to more micro-motion across the fracture gap and to less stiffness in this construct. Further research needs to be invested into intramedullary, locking technology before introducing it into clinical practice. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2017-03-01

    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.

  7. A Biomechanical Comparison of Locking Versus Conventional Plate Fixation for Distal Fibula Fractures in Trimalleolar Ankle Injuries.

    Science.gov (United States)

    Nguyentat, Annie; Camisa, William; Patel, Sandeep; Lagaay, Pieter

    2016-01-01

    Previous biomechanical studies have advocated the use of locking plates for isolated distal fibula fractures in osteoporotic bone. Complex rotational ankle injuries involve an increased number of fractures, which can result in instability, potentially requiring the same fixed angle properties afforded by locking plates. However, the mechanical indication for locking plate technology has not been tested in this fracture model. The purpose of the present study was to compare the biomechanical properties of locking and conventional plate fixation for distal fibula fractures in trimalleolar ankle injuries. Fourteen (7 matched pairs) fresh-frozen cadaver leg specimens were used. The bone mineral density of each was obtained using dual x-ray absorptiometry scans. The fracture model simulated an OTA 44-B3.3 fracture. The syndesmosis was not disrupted. Each fracture was fixated in the same fashion, except for the distal fibula plate construct: locking (n = 7) and one-third tubular (n = 7). The specimens underwent axial and torsional cyclic loading, followed by torsional loading to failure. No statistically significant differences were found between the locking and conventional plate constructs during both fatigue and torque to failure testing (p > .05). Our specimen bone mineral density averages did not represent poor bone quality. The clinical implication of the present study is that distal fibular locking plates do not provide a mechanical advantage for trimalleolar ankle injuries in individuals with normal bone density and in the absence of fracture comminution. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  8. A biomechanical comparison of one-third tubular plates versus periarticular plates for fixation of osteoporotic distal fibula fractures.

    Science.gov (United States)

    Davis, Adrian T; Israel, Heidi; Cannada, Lisa K; Bledsoe, J Gary

    2013-09-01

    The purpose of this study was to test the biomechanical properties of locking and nonlocking plates using one-third tubular and periarticular plate designs in an osteoporotic distal fibula fracture model. Twenty-four cadaveric specimens, whose bone mineral densities were obtained using dual x-ray absorptiometry scans, were tested. The fracture model simulated an OTA 44-B2.1 fracture. The constructs included (1) nonlocking one-third tubular plate, (2) locking one-third tubular plate, (3) nonlocking periarticular plate, and (4) locking periarticular plate. The specimens underwent axial loading followed by torsional loading to failure. Statistical analysis was performed using Kruskal-Wallis testing and further analysis with Mann-Whitney testing. The periarticular plates had greater rotational stiffness compared with the one-third tubular plates (P = 0.04). The nonlocking plates had greater torque to failure than the locking plates (P = 0.01). The nonlocking one-third tubular plate had greater torque to failure than the locking one-third tubular plate (P = 0.03). No significant differences were found in any of the comparisons regarding axial stiffness. In biomechanical testing using an osteoporotic model of OTA 44-B2.1 fractures, periarticular plates were superior to one-third tubular plates in rotational stiffness only. Locking plates did not outperform their nonlocking counterparts. Periarticular plates should be considered when treating osteoporotic distal fibula fractures, but one-third tubular plates and nonlocking plates provide adequate fixation for these injuries.

  9. Biomechanical Assessment of the Dorsal Spanning Bridge Plate in Distal Radius Fracture Fixation: Implications for Immediate Weight-Bearing.

    Science.gov (United States)

    Huang, Jerry I; Peterson, Bret; Bellevue, Kate; Lee, Nicolas; Smith, Sean; Herfat, Safa

    2017-04-01

    The goal of this study was to compare the biomechanical stability of a 2.4-mm dorsal spanning bridge plate with a volar locking plate (VLP) in a distal radius fracture model, during simulated crutch weight-bearing. Five paired cadaveric forearms were tested. A 1-cm dorsal wedge osteotomy was created to simulate an unstable distal radius fracture with dorsal comminution. Fractures were fixed with a VLP or a dorsal bridge plate (DBP). Specimens were mounted to a crutch handle, and optical motion-tracking sensors were attached to the proximal and distal segments. Specimens were loaded in compression at 1 mm/s on a servohydraulic test frame until failure, defined as 2 mm of gap site displacement. The VLP construct was significantly more stable to axial load in a crutch weight-bearing model compared with the DBP plate (VLP: 493 N vs DBP: 332 N). Stiffness was higher in the VLP constructs, but this was not statistically significant (VLP: 51.4 N/mm vs DBP: 32.4 N/mm). With the crutch weight-bearing model, DBP failed consistently with wrist flexion and plate bending, whereas VLP failed with axial compression at the fracture site and dorsal collapse. Dorsal spanning bridge plating is effective as an internal spanning fixator in treating highly comminuted intra-articular distal radius fracture and prevents axial collapse at the radiocarpal joint. However, bridge plating may not offer advantages in early weight-bearing or transfer in polytrauma patients, with less axial stability in our crutch weight-bearing model compared with volar plating. A stiffer 3.5-mm DBP or use of a DBP construct without the central holes may be considered for distal radius fractures if the goal is early crutch weight-bearing through the injured extremity.

  10. A biomechanical evaluation of locked plating for distal fibula fractures in an osteoporotic sawbone model.

    Science.gov (United States)

    Bariteau, Jason T; Fantry, Amanda; Blankenhorn, Brad; Lareau, Craig; Paller, David; Digiovanni, Christopher W

    2014-03-01

    Supination external rotation (SER) injuries are commonly fixed with a one third tubular neutralization plate. This study investigated if a combination locked plate with additional fixation options was biomechanically superior in osteoporotic bone and comminuted fracture models. Using an osteoporotic and a comminuted Sawbones model, SER injuries were fixed with a lag screw for simple oblique fibula fractures, and either a one third tubular neutralization plate or a locking plate. Samples were tested in stiffness, peak torque, displacement at failure, and torsion fatigue. There was no statistically significant difference in biomechanical testing for fractures treated with a lag screw and plate. For comminuted fractures, locked plating demonstrated statistically significant stiffer fixation. A combination locked plate is biomechanically superior to a standard one third tubular plate in comminuted SER ankle fractures. There was no biomechanical superiority between locked and one third tubular plates when the fracture was amenable to a lag screw. Copyright © 2013 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  11. Volar versus dorsal fixed-angle fixation of dorsally unstable extra-articular distal radius fractures: a biomechanic study.

    Science.gov (United States)

    McCall, Todd A; Conrad, Bryan; Badman, Brian; Wright, Thomas

    2007-01-01

    To evaluate and compare the biomechanic rigidity and strength of 3 fixed-angle plates used to treat extra-articular distal radius fractures that are dorsally unstable. Volar fixed-angle plates were compared with a dorsal fixed-angle nail plate. Three plate constructs were tested: the dorsal nail plate (DNP), distal volar radius (DVR) plate, and locking compression plate (LCP) volar distal radius plate. With anatomic, third-generation, artificial composite radii, dorsally unstable extra-articular distal radius fracture models were made by cutting a wedge osteotomy with an 8-mm dorsal gap 1 cm from the articular surface. These models were then fixed with the 3 implants by the method recommended by the manufacturer. The proximal radii of each specimen were attached to the base of a materials testing machine with a probe centered at the radial side of the lunate fossa. The specimens were loaded at a constant rate to failure under axial compression. Load and displacement were plotted graphically, and the resulting rigidities and strengths of each plate were assessed statistically. The DVR group had significantly greater stiffness than the LCP group. The DVR group had significantly higher maximum loads than both the DNP and LCP groups. There were no significant differences in yield loads. Both the DNP and DVR groups had significantly less displacement at yield than the LCP group. These 3 groups had similar yield loads. However, the LCP was less stiff than the DVR and had more displacement at yield than both the DVR and DNP. The yield load of all 3 implants was much higher than previously described loads for active wrist and finger motion.

  12. Biomechanical analysis of arch-guided molar distalization when employing superelastic NiTi coil springs.

    Science.gov (United States)

    Schneevoigt, R; Bourauel, C; Harzer, W; Eckardt, L

    1999-01-01

    Two typical treatment situations (distalization of a last molar, distalization of a molar with the guiding arch fixed on the most distal abutment tooth) were simulated experimentally using the Orthodontic Measurement and Simulation System (OMSS). For this purpose an upper first molar was guided along steel arches with differing cross sections (0.016" x 0.022"/0.41 mm x 0.56 mm; 0.017" x 0.025"/0.43 mm x 0.64 mm) using a nickel-titanium (NiTi) compression spring. The 6 NiTi springs investigated differed in their design and in the type of force delivery. The force application that was eccentric with respect to the center of resistance caused a conflict situation between the tube and the guiding arch through rotations of the molar. Although the force level of the springs was almost constant, the orthodontically effective forces measured fluctuated due to frictional losses. With progressing distalization the mean frictional forces increased, reaching values between 50 and 80% of the applied force of the compression springs. Simultaneously fluctuations in the frictional losses increased. Lower frictional losses were determined with a 0.016" x 0.022", than with a 0.017" x 0.025" guiding arch. Fixing the arch on the 3rd molar resulted in higher frictional losses compared to the distalization of a last molar. There were intensive interactions of the compression springs with the guiding arch and the tube. This resulted in extreme frictional losses even in the initial phase of the movement and in a complete stop to the distalizing movement in extreme cases. After removal of the convertible, the freedom of the molar movement could be regulated by the tension of the ligature wire. The friction varied accordingly. The distalization rate was not influenced by the force delivered by the compression spring. Small forces are biologically more favorable and thus should be preferred.

  13. Biomechanical comparison of a lateral polyaxial locking plate with a posterolateral polyaxial locking plate applied to the distal fibula.

    Science.gov (United States)

    Hallbauer, Jakob; Klos, Kajetan; Rausch, Sascha; Gräfenstein, Andreas; Wipf, Felix; Beimel, Claudia; Hofmann, Gunther; Mückley, Thomas

    2014-09-01

    Polyaxial locking plates are becoming popular for the fixation of distal fibula fractures. This study establishes how construct stiffness and plate loosening, measured as range of motion, differs between lateral and posterolateral plate location. Seven matched pairs of cadaver fibulae were osteotomized in standardized fashion to produce a Weber type B distal fibula fracture. The fragments were fixated with an interfragmentary lag screw and polyaxial locking plates, with one fibula in each pair receiving a posterolateral anti-glide-plate, and the other a lateral neutralization-plate. In a biomechanical test, the bending and torsional stiffnesses of the constructs and the ranges of motion (ROM) were measured and subjected to a paired comparison. The laterally plated group had a higher median (interquartile range) bending stiffness (29.2 (19.7) N/mm) and a smaller range of motion (2.06 (1.99) mm) than the posterolaterally plated group (14.6 (20.6) N/mm, and 4.11 (3.28) mm, respectively); however, the results were not statistically significant (pbending=0.314; pROM=0.325). Similarly, the torsional stiffness did not differ significantly between the two groups (laterally plated: 426 (259) Nmm/°; posterolaterally plated: 248 (399) Nmm/°; ptorsion=0.900). The range of motion measurements between the two groups under torsional loading were also statistically insignificant (laterally plated: 8.88 (6.30) mm; posterolaterally plated: 15.34 (12.64) mm; pROM=0.900). In biomechanical cadaver-model tests of Weber type B fracture fixation with polyaxial locking plates, laterally plated constructs and posterolaterally plated constructs performed without significantly difference. Therefore, other considerations, such as access morbidity, associated injuries, patient anatomy, or surgeon's preference, may guide the choice of plating pattern. Further clinical studies will be needed for the establishment of definitive recommendations. Information on the behavior of polyaxial locking

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

    Directory of Open Access Journals (Sweden)

    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

  15. Biomechanical comparison of 4 different lateral plate constructs for distal fibula fractures.

    Science.gov (United States)

    Eckel, Tobin T; Glisson, Richard R; Anand, Prashanth; Parekh, Selene G

    2013-11-01

    Displaced lateral malleolar fractures are often treated with reduction and surgical stabilization. However, there has not been a comprehensive laboratory comparison to determine the most appropriate device for treating these patients. This study subjected a range of contemporary lateral fibular plates to a series of mechanical tests designed to reveal performance differences. Forty fresh frozen lower extremities were divided into 4 groups. A Weber B distal fibula fracture was simulated with an osteotomy and stabilized using 1 of 4 plate systems: a standard Synthes one-third tubular plate with interfragmentary lag screw, a Synthes LCP locking plate with lag screw, an Orthohelix MaxLock Extreme low-profile locking plate with lag screw, or a TriMed Sidewinder nonlocking plate. Controlled monotonic bending and cyclic torsional loading were applied and bending stiffness, torsional stiffness, and fracture site motion were quantified. Resistance to cyclic torsional loading was determined by quantifying the number of loads withstood before excessive rotation occurred. Correlation between bone mineral density and each of the mechanical measures was determined. There was no difference in angulation or bending stiffness between plates. All plates except the LCP showed greater lateral deflection than in the other bending directions. Bending stiffness was lowest in lateral distal fragment deflection for all 4 plates. There was a positive correlation between bone mineral density and bending stiffness for all plate types. There was no difference in fracture site rotation between plate types in internal or external torsion, but internal rotation of the distal fragment consistently exceeded external rotation. Torsional stiffness in external rotation exceeded stiffness in internal rotation in nearly all specimens. LCP plates performed relatively poorly under cyclic torsion. Significant differences in plate performance were not demonstrated. The effects of bone quality variability

  16. [Biomechanical analysis of arch-guided molar distalization with super-elastic nickel-titanium springs].

    Science.gov (United States)

    Schneevoigt, R; Bourauel, C; Harzer, W; Eckardt, L

    1998-05-01

    The typical characteristics of orthodontic devices and their effectiveness during tooth movement are of major importance for the success of orthodontic treatment and the stability of the result. To investigate this situation, two typical tooth movements were simulated experimentally using an Orthodontic Measurement and Simulation System (OMSS). These were Distalisation of an upper last molar and Distalisation of a molar including fixation of the guiding arch to a distal supporting last molar. The movements were simulated by employing various different NiTi coil compression springs and two standard steel guiding arches with the dimensions 0.016" x 0.022" and 0.017" x 0.025". The six NiTi springs differed significantly in shape and force characteristics. The eccentric application of the orthodontic force system relative to the centre of resistance brings about a tilting of the tube and arch via molar rotation. Although the forces developed by the springs are relatively constant, frictional losses result in variations in the effective orthodontic forces. With progressive distalisation, the average frictional losses varied between 50% and 80% of the spring-generated force, and frictional variations increased. Lower frictional losses were seen with a 0.016" x 0.022" guiding arch as compared with one measuring 0.017" x 0.025". In comparison with distalisation of a last molar, fixation of the arch to a third molar was associated with higher frictional losses. The interaction of the springs with the tube-guiding arch system could be so powerful that frictional losses were detected already during the initial phase of movement, and in extreme cases led to cessation of distalisation. The rate of distalisation was not affected by the forces generated by the springs. For physiological reasons, therefore, springs developing smaller forces should be used preferentially.

  17. A biomechanic comparison of an internal radiocarpal-spanning 2.4-mm locking plate and external fixation in a model of distal radius fractures.

    Science.gov (United States)

    Wolf, Jonathon C; Weil, Wayne M; Hanel, Douglas P; Trumble, Thomas E

    2006-12-01

    To compare the biomechanic stability of distal radius fracture fixation with a new internal radiocarpal-spanning 2.4-mm locking plate, which acts as an internal distal radius fixator, versus a standard distal radius external fixator. The number of locking screws necessary for adequate fracture fixation was also assessed. Ten cadaveric specimens were mounted in a loading fixture with cables attached to the 2 flexor and 3 extensor wrist tendons. A 1-cm osteotomy was created to simulate an unstable distal radius fracture. The radiocarpal-spanning locking plate was fixed to the radius and index metacarpal with 4 screws proximally and 4 distally. The specimen was incrementally loaded through the tendons. Motion at the fracture site was determined. Screws were sequentially removed from the construct, the specimen was again incrementally loaded, and fracture motion was measured. The fixation was then changed to an external fixator, and the loading tests were repeated. Fracture fixation with the radiocarpal-spanning 2.4-mm locking plate was significantly more stable with 4 screws proximally and 4 screws distally (4 x 4) and with the 3 x 3 configuration than with the external fixator in both flexion and extension. The 4 x 4 screw configuration was not significantly different from the 3 x 3 screw configuration. The 4 x 4 screw configuration was significantly more stable than the 2 x 2 and 1 x 1 screw configurations in both flexion and extension. All internal fixator configurations and the external fixator showed more fracture displacement at increasingly higher loads. Fracture fixation with the new internal radiocarpal-spanning 2.4-mm locking plate is more stable than with a standard distal radius external fixator. Only three 2.4-mm locking screws proximally and three 2.4-mm locking screws distally are required for adequate fixation of the locking spanning plate.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. A Biomechanical Comparison of 3.5 Locking Compression Plate Fixation to 3.5 Limited Contact Dynamic Compression Plate Fixation in a Canine Cadaveric Distal Humeral Metaphyseal Gap Model

    OpenAIRE

    Filipowicz, Dean

    2008-01-01

    Objective- To compare the biomechanical properties of 3.5 locking compression plate (LCP) fixation to 3.5 limited contact dynamic compression plate (LC-DCP) fixation in a canine cadaveric, distal humeral metaphyseal gap model in static axial compression and cyclic axial compression and torsion. Study Design- Biomechanical in vitro study. Sample Population- 30 paired humeri from adult, medium to large breed dogs. Methods- Testing was performed monotonically to failure in axial compres...

  1. Effect on dynamic mechanical stability and interfragmentary movement of angle-stable locking of intramedullary nails in unstable distal tibia fractures: a biomechanical study.

    Science.gov (United States)

    Gueorguiev, Boyko; Wähnert, Dirk; Albrecht, Daniel; Ockert, Ben; Windolf, Markus; Schwieger, Karsten

    2011-02-01

    Unstable distal tibia fractures are challenging injuries that require surgery. Increasingly, intramedullary nails are being used. However, fracture site anatomy may cause distal-fragment stabilization and fixation problems and lead to malunion/nonunion. We studied the influence of angle-stable nail locking on fracture gap movement and other biomechanical parameters. Eight pairs of fresh human cadaver tibiae were used. The bone mineral density (BMD) was determined. All tibiae were nailed with a Synthes Expert tibial nail. Within each pair, one tibia was randomized to receive conventional locking screws; the other, angle-stable screws with sleeves. A 7-mm osteotomy was created 10 mm above the upper distal locking screw, to simulate an AO 42-A3 fracture. Biomechanical testing involved nondestructive mediolateral and anteroposterior pure bending, followed by cyclic combined axial and torsional loading to catastrophic failure. The neutral zone was determined. Fracture gap movement was monitored with 3-D motion tracking. The angle-stable locked constructs had a significantly smaller mediolateral neutral zone (mean: 0.04 degree; p=0.039) and significantly smaller fracture gap angulation (p=0.043). The number of cycles to failure did not differ significantly between the locking configurations. BMD was a significant covariate affecting the number of cycles to failure (p=0.008). However, over the first 20,000 cycles, there was no significant correlation in the angle-stable construct. Angle-stable locking of the Expert tibial nail was associated with a significant reduction in the mediolateral neutral zone and in fracture gap movement. Angle-stable fixation also reduced the influence of BMD over the first 20,000 cycles.

  2. A biomechanical comparison study of a modern fibular nail and distal fibular locking plate in AO/OTA 44C2 ankle fractures.

    Science.gov (United States)

    Switaj, Paul J; Fuchs, Daniel; Alshouli, Mohammed; Patwardhan, Avinash G; Voronov, Leonard I; Muriuki, Muturi; Havey, Robert M; Kadakia, Anish R

    2016-09-15

    A lateral approach with open reduction and internal fixation with a plate is a very effective technique for the majority of distal fibular fractures. However, this open approach for ankle fixation may be complicated by wound dehiscence and infection, especially in high-risk patients. An alternative to plating is an intramedullary implant, which allows maintenance of length, alignment, and rotation and which allows for decreased soft tissue dissection. While there has been clinical data suggesting favorable short-term outcomes with these implants, there is no current biomechanical literature investigating this technology in this particular fracture pattern. This study sought to biomechanically compare an emerging technology with an established method of fixation for distal fibular fractures that traditionally require an extensive exposure. Ten matched cadaveric pairs from the proximal tibia to the foot were prepared to simulate an Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) 44C2 ankle fracture and randomized to fixation with a distal fibular locking plate or intramedullary fibular rod. A constant 700-N axial load was applied, and all specimens underwent testing for external rotation stiffness, external rotation cyclic loading, and torque to failure. The syndesmotic diastasis, stiffness, torque to failure, angle at failure, and mode of failure were obtained from each specimen. There was no significant difference in syndesmotic diastasis during cyclic loading or at maximal external rotation between the rod and plate groups. Post-cycle external rotation stiffness across the syndesmosis was significantly higher for the locking plate than the fibular rod. There was no significant difference between the rod and plate in torque at failure or external rotation angle. The majority of specimens had failure at the syndesmotic screw. In the present cadaveric study of an AO/OTA 44C2 ankle fracture, a modern fibular rod demonstrated less

  3. Biomechanical evaluation of the dynamic radioulnar convergence after ulnar head resection, two soft tissue stabilization methods of the distal ulna and ulnar head prosthesis implantation.

    Science.gov (United States)

    Sauerbier, Michael; Hahn, Michael E; Berglund, Lawrence J; An, Kai-Nan; Berger, Richard A

    2011-01-01

    The biomechanical performance of the Darrach procedure, its stabilizing methods and the effectiveness of an ulnar head prosthesis was evaluated in this experiment. The purpose of this study was to: (1) analyze the dynamic effects of the resection of the distal ulna on radioulnar convergence; and (2) evaluate the mechanical performance of two soft tissue stabilizing procedures (pronator quadratus advancement flap and ECU/FCU tenodesis) for the unstable distal ulnar stump and the implantation of an ulnar head prosthesis (uHead) following a distal ulnar resection (Darrach procedure) on radioulnar convergence. With a dynamic PC-controlled forearm simulator, cadaveric forearm rotation was actively and passively performed while simultaneously loading the relevant muscles. The resultant total forearm torque and the three-dimensional kinematics of the ulna, radius and third metacarpal were simultaneously recorded in seven fresh-frozen cadaver upper extremities. The resection of the distal ulna created an extreme instability of the forearm with movement of the radius toward the ulna (0.92-0.38 cm compared to the intact state) in each particular loading condition. The implantation of the ulnar head prosthesis effectively restored the stability of the DRUJ by simulating the geometry of the ulnar head. There were significantly better results after the implantation of the prosthesis compared with the Darrach and the soft tissue stabilization procedures. This study provides laboratory validity to the option of implanting an ulnar head endoprosthesis as an attempt to stabilize the distal forearm with instability after Darrach resection in lieu of performing soft tissue stabilization techniques.

  4. 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.

    Science.gov (United States)

    Malone, Paul S C; Shaw, Oliver G; Lees, Vivien C

    2016-01-01

    Previous work from this laboratory has evidenced the biomechanical role of forearm osseoligamentous structures in load transfer of applied forces. It has shown that forces transmitted 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. The 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). The 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 radius to ulna bone volume ratio of 0.81. When the olecranon was disregarded, radius volume was on average of 4% greater than ulna volume. This study demonstrates and defines the anatomical relationships between the two forearm bones and their articulating joints when matched for specimen. The data obtained are consistent with the theory of integrated forearm function generated from published biomechanical studies.

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

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    Yamashita Toshihiko

    2010-12-01

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

  6. Biomechanical performance of flexible intramedullary nails with end caps tested in distal segmental defects of pediatric femur models.

    Science.gov (United States)

    Volpon, José Batista; Perina, Maurício Martins; Okubo, Rodrigo; Maranho, Daniel Augusto Carvalho

    2012-01-01

    Unstable distal femoral fractures in children are challenging lesions with restricted surgical options for adequate stabilization. Elastic nails have become popular for treating femoral shaft fractures, yet they are still challenging for using in distal fractures. The aim of this study was to test whether end caps (CAP) inserted into the nail extremity improved the mechanical stabilization of a segmental defect at the distal femoral metaphyseal-diaphyseal junction created in an artificial pediatric bone model. Two 3.5-mm titanium elastic nails (TEN) were introduced intramedullary into pediatric femur models, and a 7.0-mm-thick segmental defect was created at the distal diaphyseal-metaphyseal junction. Nondestructive 4-point bending, axial-bending, and torsion tests were conducted. After this, the end caps were inserted into the external tips of the nails and then screwed into the bone cortex. The mechanical tests were repeated. Stiffness, displacement, and torque were analyzed using the Wilcoxon nonparametric test for paired samples. In the combined axial-bending tests, the TEN+CAP combination was 8.75% stiffer than nails alone (Ptorsion tests, the TEN+CAP was 14% stiffer than nails alone (Pbending test did not show differences between the methods (P=0.91, stiffness; P=0.51, displacement). Thus, the end caps contributed to an increase in the construct stability for torsion and axial-bending forces but not for 4-point bending forces. These findings indicate that end caps fitted to elastic nails may contribute to the stabilization of fractures that our model mimics (small distal fragment, bone comminution, and distal bone fragment loss). Type II [therapeutic study: lesser-quality randomized controlled trial (eg, <80% follow-up, no blinding, or improper randomization)].

  7. Angle stable interlocking screws improve construct stability of intramedullary nailing of distal tibia fractures: a biomechanical study.

    Science.gov (United States)

    Horn, J; J, Horn; Linke, B; B, Linke; Höntzsch, D; D, Höntzsch; Gueorguiev, B; B, Gueorguiev; Schwieger, K; K, Schwieger

    2009-07-01

    Intramedullary nailing is the treatment of choice for most displaced tibial shaft fractures. The ability to maintain a mechanically stable fixation becomes more difficult the further the fracture extends distally or proximally or when unreamed tibial nails are used. We assumed that a new angular stable locking option would provide improved stability and reduced interfragmentary movements in a distal tibia in vitro fracture model. Left and right bones of 8 pairs of human cadaveric tibiae were randomly assigned to either a group with conventional locked or a group with angular stable locked intramedullary nails. Nails of 10-mm-diameter were used after reaming up to 11 mm. A transverse distal osteotomy was performed and the specimens were tested mechanically under eccentric axial load. A video optical measurement system was used to determine the angular displacement of the osteotomy gap during loading. Construct stiffness, maximum load of the bone-nail construct and gap angle at 0.5 kN load were measured. The group with the angular stable locking option showed significantly higher stiffness values and reduced fracture gap motion compared to the group with conventional locked nails. A new angular stable locking option of intramedullary nails provides higher stability in terms of construct stiffness and reduced interfragmentary movements in a distal tibia in vitro fracture model.

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

    Science.gov (United States)

    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

  9. 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

    Directory of Open Access Journals (Sweden)

    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

  10. Effect of the number of abutments on biomechanics of Branemark prosthesis with straight and tilted distal implants

    Directory of Open Access Journals (Sweden)

    Marcos Michelon Naconecy

    2010-04-01

    Full Text Available OBJECTIVE: This study aimed to evaluate the bending moments, and compressive and tensile forces in implant-supported prostheses with three, four or five abutments. MATERIAL AND METHODS: Ten Pd-Ag frameworks were tested over two master models with: 1 parallel vertical implants, and 2 tilted distal implants. Strain gauges were fixed on the abutments of each master model to measure the deformation when a static load of 50 N was applied on the cantilever (15 mm. The deformation values were measured when the metallic frameworks were tested over three, four or five abutments, and transformed into force and bending moment values. Data were analyzed by ANOVA and Tukey's test for multiple comparisons at 5% level of significance. RESULTS: Abutment #1 (adjacent to the cantilever had the highest values of force and sagittal bending moment for all tests with three, four or five abutments. Independently from the number of abutments, axial force in abutment #1 was higher in the vertical model than in the tilted model. Total moment was higher with three abutments than with four or five abutments. Independently from the inclination of implants, the mean force with four or five abutments was lower than that with three abutments. CONCLUSION: The results suggest that in the set-ups with four or five abutments tilted distal implants reduced axial force and did not increase bending moments.

  11. Effect of the number of abutments on biomechanics of Branemark prosthesis with straight and tilted distal implants.

    Science.gov (United States)

    Naconecy, Marcos Michelon; Geremia, Tomás; Cervieri, André; Teixeira, Eduardo Rolim; Shinkai, Rosemary Sadami

    2010-01-01

    This study aimed to evaluate the bending moments, and compressive and tensile forces in implant-supported prostheses with three, four or five abutments. Ten Pd-Ag frameworks were tested over two master models with: 1) parallel vertical implants, and 2) tilted distal implants. Strain gauges were fixed on the abutments of each master model to measure the deformation when a static load of 50 N was applied on the cantilever (15 mm). The deformation values were measured when the metallic frameworks were tested over three, four or five abutments, and transformed into force and bending moment values. Data were analyzed by ANOVA and Tukey's test for multiple comparisons at 5% level of significance. Abutment #1 (adjacent to the cantilever) had the highest values of force and sagittal bending moment for all tests with three, four or five abutments. Independently from the number of abutments, axial force in abutment #1 was higher in the vertical model than in the tilted model. Total moment was higher with three abutments than with four or five abutments. Independently from the inclination of implants, the mean force with four or five abutments was lower than that with three abutments. The results suggest that in the set-ups with four or five abutments tilted distal implants reduced axial force and did not increase bending moments.

  12. Biomechanical Comparison of Volar Fixed-Angle Locking Plates for AO C3 Distal Radius Fractures: Titanium Versus Stainless Steel With Compression.

    Science.gov (United States)

    Marshall, Tyler; Momaya, Amit; Eberhardt, Alan; Chaudhari, Nilesh; Hunt, Thomas R

    2015-10-01

    To determine biomechanical differences between a fixed-angle locking volar titanium plate (VariAx; Stryker, Kalamazoo, MI) and a fixed-angle compression locking volar stainless steel plate (CoverLoc Volar Plate; Tornier, Amsterdam, Netherlands) in the fixation of simulated AO C3 distal radius fractures. Eighteen cadaveric upper extremities (9 matched pairs) with an average age of 54 years were tested. A 4-part AO C3 fracture pattern was created in each specimen. The fractures were reduced under direct vision and fixed with either the fixed-angle locking volar titanium plate or the fixed-angle compression locking volar stainless steel plate. Motion tracking analysis was then performed while the specimens underwent cyclic loading. Changes in displacement, rotation, load to failure, and mode of failure were recorded. The fragments, when secured with the fixed-angle compression locking stainless steel construct, demonstrated less displacement and rotation than the fragments secured with the fixed-angle locking titanium plate under physiological loading conditions. In the fixed-angle compression locking stainless steel group, aggregate displacement and rotation of fracture fragments were 5 mm and 3° less, respectively, than those for the fixed-angle locking titanium group. The differences between axial loads at mechanical failure and stiffness were not statistically significant. The compression locking stainless steel group showed no trend in mode of failure, and the locking titanium plate group failed most often by articular fixation failure (5 of 9 specimens). The fixed-angle compression locking stainless steel volar plate may result in less displacement and rotation of fracture fragments in the fixation of AO C3 distal radius fractures than fixation by the fixed-angle locking volar titanium plate. However, there were no differences between the plates in mechanical load to failure and stiffness. Fixation of distal radius AO C3 fracture patterns with the fixed

  13. Volar fixed-angle plating of distal radius extension fractures: influence of plate position on secondary loss of reduction--a biomechanic study in a cadaveric model.

    Science.gov (United States)

    Drobetz, Herwig; Bryant, Adam L; Pokorny, Tom; Spitaler, Ralf; Leixnering, Martin; Jupiter, Jesse B

    2006-04-01

    Treatment of extension fractures of the distal radius with volar fixed-angle plates has become increasingly popular in the past 2 years. It has been observed clinically that placement of the distal screws as close as possible to the subchondral zone is crucial to maintain radial length after surgery. The purposes of this study were (1) to evaluate radial shortening after plating with regard to plate position and (2) to evaluate whether plate position has an influence on the strength and rigidity of the plate-screw construct. An extra-articular fracture (AO classification, A3) was created in 7 pairs of fresh-frozen human cadaver radiuses. The radiuses then were plated with a volar distal radius locking compression plate. Seven plates were applied subchondrally; 7 plates were applied 4.5 mm to 7.5 mm proximal to the subchondral zone. The specimens were loaded with 800-N loads for 2,000 cycles to evaluate radial shortening in the 2 groups. Each specimen then was loaded to failure. Radial shortening was significantly greater when the distal screws were placed proximal to the subchondral zone. The amount of shortening after cyclic loading correlated significantly with the distance the distal screws were placed from the subchondral zone. Rigidity of the plate systems was significantly higher in radiuses in which the distal screws were placed close to the subchondral zone. To maintain radial length after volar fixed-angle plating, placement of the distal screws as subchondral as possible is essential. The subchondral plate-screw-bone constructs showed significantly greater rigidity, indicating higher resistance to postoperative loads and displacement forces.

  14. 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

  15. 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.

  16. An in vitro biomechanical comparison of dynamic condylar screw plate combined with a dorsal plate and double plate fixation of distal diaphyseal radial osteotomies in adult horses.

    Science.gov (United States)

    Janicek, John C; Wilson, David A; Carson, William L; Kramer, Joanne

    2009-08-01

    To compare stiffness and strength of a dynamic condylar screw plate combined with dorsal broad dynamic compression plate (DCS-bDCP) fixation with double broad dynamic compression plate (dbDCP) fixation used to repair oblique distal fractures of adult equine radii. Experimental. Adult equine radii (n=10 pair). An unconstrained three-dimensional loading-measurement system was used to determine stiffness of a 50 mm long intact, and then DCS-bDCP or dbDCP-plated osteotomized/ostectomized segment of radii when subjected to a nondestructive sequence of compression, torsion, and lateral-to-medial (LM), medial-to-lateral (ML), cranial-to-caudal (CrCa), and caudal-to-cranial (CaCr) bending. Uniform load over the entire length of construct identified its weakest characteristics during torsion and LM and CrCa bending to failure. No difference was observed between osteotomized/ostectomized DCS-bDCP and dbDCP construct stiffness for all 6 loading modes, and strength for all 3 failure loads. Ostectomized DCS-bDCP and dbDCP construct stiffness was significantly lower than osteotomized radii, the latter approaching intact for axial, LM, and CrCa bending. Most frequent failure was bone fracture through exit site of a screw located adjacent to osteotomy/ostectomy. DCS-DCP and dbDCP constructs had comparable strength and stiffness when repairing osteotomies/ostectomies in equine adult radius bone. Fracture reduction increased stiffness that approached intact bone for loads that placed the unplated side in compression. DCS-bDCP and dbDCP constructs are comparable in stiffness and strength when applied to oblique distal diaphyseal osteotomies/ostectomies in equine radius bone. However, the DCS's localized effect on distal epiphyseal structure because of additional bone removal remains to be investigated under in vivo articular loading conditions.

  17. 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

  18. 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.

  19. Distal movement of maxillary canines and premolars with sectional mechanics following Distal Jet application to molars.

    Science.gov (United States)

    Bolla, E; Doldo, T; Giorgetti, R

    2004-01-01

    to assess the effectiveness of Distal Jet without simultaneous fixed appliance treatment. twenty subjects with Class II malocclusion who received the Distal Jet appliance to move maxillary molars distally. Subsequently, the canine and premolar distal movements were achieved by the use of.017 x.025 Ni-Ti sectional wires and memory power chain. revealed that Distal Jet is more effective with less anchorage loss when this appliance is used independent of multibracket appliances. this study showed that Distal Jet is an effective and predictable appliance. The distal movements of upper premolars, canines and incisors with sectional wires fabricated from.017 x.025 Ni-Ti were biomechanically very effective, simple in clinical application, and did not require any patient compliance.

  20. Extensile surgical exposures of the radius: a comparative anatomic study.

    Science.gov (United States)

    Jockel, Christopher R; Zlotolow, Dan A; Butler, R Bryan; Becker, Edward H

    2013-04-01

    To evaluate and compare exposures of the radius using 3 surgical approaches. Our hypotheses were that the anterior flexor carpi radialis approach allows greater exposure of the distal radius than does the volar-ulnar approach, and the extensile flexor carpi radialis approach allows comparable proximal and midshaft exposure of the radius compared with the dorsal Thompson approach. We performed anterior and dorsal exposures of the radius on 10 matched pairs of cadavers (20 forearms) randomly assigned to 1 anterior and 1 dorsal approach. We measured and compared the anatomic features and limits of the anterior flexor carpi radialis approach, volar-ulnar approach to the distal radius, and the dorsal Thompson approach. The anterior flexor carpi radialis approach exposed 3.3 cm of distal radius width, was convertible to an extensile approach proximally, required sacrifice of 3 arterial branches, and was limited by the junction of the radial and ulnar arteries. This approach provided 79% of radius exposure and ended 4.7 cm distal to the radiocapitellar joint. The volar-ulnar approach to the distal radius exposed 3.1 cm of distal radius width. The dorsal Thompson approach sacrificed no arterial branches, provided 69% of radius exposure, was limited by the first compartment distally and the posterior interosseous nerve proximally, and ended within 2.6 cm of the radiocapitellar joint. The posterior interosseous nerve coursed 19, 14, and 6 mm dorsolateral to the distal, middle, and proximal margins, respectively, of the supinator insertion on the radius. The volar-ulnar approach provided less access to the radial styloid and was not as extensile as the flexor carpi radialis approach. The Thompson approach provided more proximal exposure than the flexor carpi radialis approach. Improved knowledge of the anatomy, limits of exposure, and comparison of features between approaches to the radius may facilitate surgical planning and exposure. Copyright © 2013 American Society for

  1. 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.)

  2. 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.

  3. 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.

  4. Dinosaur biomechanics

    OpenAIRE

    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 imp...

  5. 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; Osei, Daniel A.; Rikli, Daniel A.; Wascher, Daniel C.; Polatsch, Daniel; Silva, Dario Mejia; Nelson, David L.; Kalainov, David M.; Ruchelsman, David; Hoffmann, David Victoria; Weiss, David; Eygendaal, Denise; van Deurzen, Derek F. P.; McKee, Desirae M.; Verbeek, Diederik O. F.; Hanel, Doug; Hutchinson, Douglas T.; Brilej, Drago; Harvey, Edward; Stojkovska Pemovska, Emilija; Calvo, Emilio; Hammerberg, Eric Mark; Hofmeister, Eric P.; Kaplan, F. Thomas D.; Suarez, Fabio; Beeres, Frank J. P.; Walter, Frank L.; Frykman, Gary K.; Pess, Gary M.; Kuzma, Gary R.; Dyer, George S. M.; Thomas, George; Kohut, Georges; Kraan, Gerald A.; DeSilva, Gregory; Della Rocca, Gregory J.; Lob, Guenter; Gadbled, Guillaume; Bamberger, H. Brent; Mc Cutchan, Hal; Goost, Hans; Kreder, Hans J.; Grünwald, Heinz; Broekhuyse, Henry; Kimball, Hervey L.; Durchholz, Holger; van der Heide, Huub; McGraw, Iain; Choueka, Jack; Forigua, Jaime E.; Nappi, James F.; Reid, James G.; Kellam, James; Boler, James M.; Biert, Jan; Fanuele, Jason C.; Tavakolian, Jason D.; Jones, Jedediah; Johnson, Jeff W.; Wolf, Jennifer Moriatis; Murachovsky, Joel; Scheer, Johan H.; Rueger, Johannes M.; Erickson, John M.; McAuliffe, John; Boretto, Jorge G.; Rubio, Jorge; Ortiz, Jose A.; Ribeiro Filho, Jose Eduardo Grandi; Di Giovanni, José Fernando; Izzi, Joseph A.; Conflitti, Joseph M.; Abzug, Joshua M.; Cagnone, Juan Carlos; Adams, Julie; Chivers, Karel; Lee, Kendrick; Eng, Kevin; Malone, Kevin J.; Erol, Konul; Ponsen, Kornelis J.; Kabir, Koroush; Jeray, Kyle; Mica, Ladislav; Brunton, Lance M.; Adolfsson, Lars E.; Weiss, Lawrence; Katolik, Leonid; Paz, Lior; Poelhekke, Lodewijk M. S. J.; Escobar, Luis Felipe Naquira; Campinhos, Luiz Augusto B.; Abdel-Ghany, Mahmoud I.; Richard, Marc J. Richard; Swiontkowski, Marc; Rizzo, Marco; Pirpiris, Marinis; Boyer, Martin; Richardson, Martin; Kastelec, Matej; Turina, Matthias; Soong, Maximillian; Wood, Megan M.; Baskies, Michael; Behrman, Michael; Nancollas, Michael; Prayson, Michael; Quell, Michael; Verhofstad, Michael; Grafe, Michael W.; Kessler, Michael W.; van den Bekerom, Michel P. J.; van de Sande, Michiel A. J.; Mckee, Mike; Patel, Milan M.; Merchant, Milind; Tyllianakis, Minos; Wiegand, Mischa Ralph; Waseem, Mohammad; Parnes, Nata; Wilson, Neil; Elias, Nelson; Shortt, Nicholas L.; Schep, Niels; Semenkin, Oleg M.; Henry, Patrick D. G.; Martineau, Paul A.; Jebson, Peter; Kloen, Peter; Brink, Peter R. G.; Schandelmaier, Peter; Blazar, Philip; Streubel, Philipp N.; Vial, Philippe; Choudhari, Pradeep; Inna, Prashanth; Costanzo, Ralph M.; de Bedout, Ramon; Hauck, Randy; Smith, Raymond Malcolm; Fricker, Renato M.; Omid, Reza; Buckley, Richard; Jenkinson, Richard; Hutchison, Richard L.; GIlbert, Richard S.; Page, Richard S.; Nelissen, Rob; Haverlag, Robert; Wagenmakers, Robert; Pesantez, Rodrigo; Klinefelter, Ryan; Calfee, Ryan P.; Moghtaderi, Sam; Spruijt, Sander; Kakar, Sanjeev; Kaplan, Saul; Duncan, Scott F.; Mitchell, Scott; Rowinski, Sergio; Dodds, Seth; Kennedy, Stephen A.; Westly, Stephen K.; Kronlage, Steve; Beldner, Steven; McCabe, Steven J.; Rhemrev, Steven J.; Gosens, Taco; Baxamusa, Taizoon; Apard, Thomas; Dienstknecht, Thomas; Varecka, Thomas F.; Hughes, Thomas; Mittlmeier, Thomas; Pillukat, Thomas; Wright, Thomas; Havenhill, Timothy G.; Omara, Timothy; Siff, Todd; Giordano, Vincenzo; Hammert, Warren C.; Satora, Wojciech

    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

  6. A biomechanical comparison of 3.5 locking compression plate fixation to 3.5 limited contact dynamic compression plate fixation in a canine cadaveric distal humeral metaphyseal gap model.

    Science.gov (United States)

    Filipowicz, D; Lanz, O; McLaughlin, R; Elder, S; Werre, S

    2009-01-01

    3.5 locking compression plate (LCP) fixation was compared to 3.5 limited contact dynamic compression plate (LC-DCP) fixation in a canine cadaveric, distal humeral metaphyseal gap model. Thirty paired humeri from adult, large breed dogs were separated into equal groups based on testing: static compression, cyclic compression, and cyclic torsion. Humeral constructs stabilised with LCP were significantly stiffer than those plated with LC-DCP when loaded in static axial compression (P = 0.0004). When cyclically loaded in axial compression, the LCP constructs were significantly less stiff than the LC-DCP constructs (P = 0.0029). Constructs plated with LCP were significantly less resistant to torsion over 500 cycles than those plated with LC-DCP (Plocking plates may be attributed to the stability afforded by the plate-screw interface of locking plates. The LCP constructs demonstrated less stiffness in dynamic testing in this model, likely due to plate-bone offset secondary to non-anatomic contouring and occasional incomplete seating of the locking screws when using the torque-limiting screw driver. Resolution of these aspects of LCP application may help improve the stiffness of fixation in fractures modeled by the experimental set-up of this investigation.

  7. Dinosaur biomechanics.

    Science.gov (United States)

    Alexander, R McNeill

    2006-08-07

    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.

  8. 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)

  9. 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…

  10. Clinical relevance of distal biceps insertional and footprint anatomy.

    Science.gov (United States)

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

    2016-07-01

    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. A narrative review was performed using Pubmed/Medline using key words: Search terms were distal biceps, insertional, and anatomy. Last decade, the interest in both reconstruction techniques, as well as surgical anatomy of the distal biceps tendon, has increased. The insights into various aspects of distal biceps tendon anatomy (two tendons, bicipital tuberosity, lacertus fibrosis, bicipital-radial bursa, posterior interosseous nerve, and lateral antebrachial cutaneous nerve) have evolved significantly in the last years. Thorough knowledge of the anatomy is essential for the surgeon in order to understand the biomechanics of rupture and reconstruction of the distal biceps tendon and to avoid injuries of the nerves. Some tips and tricks are provided, and some pitfalls were described to avoid complications and optimize surgical outcome. IV.

  11. 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

  12. Surgical treatment of distal biceps rupture.

    Science.gov (United States)

    Sutton, Karen M; Dodds, Seth D; Ahmad, Christopher S; Sethi, Paul M

    2010-03-01

    Rupture of the distal biceps tendon accounts for 10% of all biceps brachii ruptures. Injuries typically occur in the dominant elbow of men aged 40 to 49 years during eccentric contraction of the biceps. Degenerative changes, decreased vascularity, and tendon impingement may precede rupture. Although nonsurgical management is an option, healthy, active persons with distal biceps tendon ruptures benefit from early surgical repair, gaining improved strength in forearm supination and, to a lesser degree, elbow flexion. Biomechanical studies have tested the strength and displacement of various repairs; the suspensory cortical button technique exhibits maximum peak load to failure in vitro, and suture anchor and interosseous screw techniques yield the least displacement. Surgical complications include sensory and motor neurapraxia, infection, and heterotopic ossification. Current trends in postoperative rehabilitation include an early return to motion and to activities of daily living.

  13. 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

  14. Pictorial essay: Distal colostography

    Directory of Open Access Journals (Sweden)

    Rahalkar Mukund

    2010-01-01

    Full Text Available Distal colostography (DC, also called distal colography or loopography, is an important step in the reparative management of anorectal malformations (ARMs with imperforate anus, Hirschsprung′s disease (occasionally and colonic atresia (rarely in children and obstructive disorders of the distal colon (colitis with stricture, carcinoma or complicated diverticulosis in adults. It serves to identify/confirm the type of ARM, presence/absence of fistulae, leakage from anastomoses, or patency of the distal colon. We present a pictorial essay of DC in a variety of cases.

  15. Biomechanics of corneal ectasia and biomechanical treatments.

    Science.gov (United States)

    Roberts, Cynthia J; Dupps, William J

    2014-06-01

    Many algorithms exist for the topographic/tomographic detection of corneas at risk for post-refractive surgery ectasia. It is proposed that the reason for the difficulty in finding a universal screening tool based on corneal morphologic features is that curvature, elevation, and pachymetric changes are all secondary signs of keratoconus and post-refractive surgery ectasia and that the primary abnormality is in the biomechanical properties. It is further proposed that the biomechanical modification is focal in nature, rather than a uniform generalized weakening, and that the focal reduction in elastic modulus precipitates a cycle of biomechanical decompensation that is driven by asymmetry in the biomechanical properties. This initiates a repeating cycle of increased strain, stress redistribution, and subsequent focal steepening and thinning. Various interventions are described in terms of how this cycle of biomechanical decompensation is interrupted, such as intrastromal corneal ring segments, which redistribute the corneal stress, and collagen crosslinking, which modifies the basic structural properties. Proprietary or commercial disclosures are listed after the references. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  16. 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.

  17. 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.

  18. Simultaneous ipsilateral fractures of distal and proximal ends of the radius

    OpenAIRE

    El Kadi, Khalid Ibn; Benabid, Mounir; Saliou, Sarr; El Assil, Oussama; Marzouki, Amine; Lahrach, Kamal; Boutayeb, Fawzi

    2017-01-01

    We treated a patient with a rare combination of ipsilateral fractures of the distal and proximal ends of the radius. A man aged 42 years had simultaneous fractures of the distal and proximal ends of the radius (radial neck) following a roadside accident. The distal end fracture of the radius was treated with surgical reduction and T-plate volar fixation, and the undisplaced radial neck fracture was treated by an above elbow splintage for 2 weeks. The elbow mobilization was started at 2 weeks....

  19. Giant distal humeral geode

    International Nuclear Information System (INIS)

    Maher, M.M.; Kennedy, J.; Hynes, D.; Murray, J.G.; O'Connell, D.

    2000-01-01

    We describe the imaging features of a giant geode of the distal humerus in a patient with rheumatoid arthritis, which presented initially as a pathological fracture. The value of magnetic resonance imaging in establishing this diagnosis is emphasized. (orig.)

  20. Distal driving of molar by smart distal-propeller appliance

    Directory of Open Access Journals (Sweden)

    U H Vijayashree

    2018-01-01

    Full Text Available In recent years, maxillary molar distalization with noncompliance mechanics has been an increasingly popular method for the resolution of Class II malocclusion. This communication describes one particular molar distalizing appliance, the Smart distal-propeller appliance which is simple, inexpensive, easily fabricated that can be used for unilateral or bilateral molar distalization.

  1. Biomechanically Engineered Athletes.

    Science.gov (United States)

    Perry, Tekla S.

    1991-01-01

    The real-world meeting of electronics, computer monitoring, control systems, and mathematics, introduced in the context of sports, is described. Recent advances in the field of biomechanics and its use in improving athletic performance are discussed. (KR)

  2. 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..

  3. 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.

  4. 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.

  5. Distal renal tubular acidosis

    Science.gov (United States)

    ... the body's immune system mistakenly attacks healthy tissue Wilson disease , an inherited disorder in which there is too much copper in the body's tissues Use of certain medicines, such as amphotericin B, lithium, and analgesics Symptoms Symptoms of distal renal tubular acidosis include any ...

  6. 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?.

  7. Gingival Recessions and Biomechanics

    DEFF Research Database (Denmark)

    Laursen, Morten Godtfredsen

    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....... The forces applied to bring the tooth back into the alveolar process generate opposite reactive forces, which can direct the adjacent teeth out towards the boundary of the bony envelope. A different force system can be achieved with a segmented appliance: The reaction forces from the root movement...

  8. [Retrograde locking nail osteosynthesis of distal femoral fractures with the distal femoral nail (DFN)].

    Science.gov (United States)

    Grass, R; Biewener, A; Rammelt, S; Zwipp, H

    2002-04-01

    Non-operative treatment with immobilization or isometric traction has been abandoned as treatment for fractures of the distal femur at the end of the 1960ies. The technique of open reduction and internal fixation with a condylar plate as suggested by the AO has been the golden standard since the 1970ies. However, anatomic reconstruction of the condylar region with interfragmentary screw fixation and axial realignment of the femur shaft with a plate are challenging procedures especially in the presence of severely compromised soft tissues and put periosteal blood supply at risk. Soft tissue complications, axial malalignment and delayed fracture healing times led to the consideration of alternative techniques, such as intramedullary nailing which has been practiced with success since the 1940ies by Gerhard Küntscher and colleagues for femoral shaft fractures with minimal complication rates and improved results after closed reduction. The era of retrograde femoral nailing began with the systematic approach through the intercondylar notch by Green. This paper reviews the biomechanical properties, indication, technique as well as potential hazards and pitfalls of fracture management with the AO "distal femoral nail" (DFN). With appropriate application this technique is suitable for all fractures of the distal third of the femoral shaft including highly instable bicondylar fractures without damage to the soft tissues and the knee joint.

  9. 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.

  10. 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...

  11. 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.

  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 biceps tendon rupture.

    Science.gov (United States)

    Savvidou, Olga D; Papagelopoulos, Panayiotis J; Mavrogenis, Andreas F; Partsinevelos, Antonios A; Karadimas, Evangelos J; Korres, Demetrios S

    2004-09-01

    The authors report a rupture of the distal tendon of biceps brachii in a 42-year-old athlete. Magnetic resonance imaging confirmed the injury. Early surgical repair was performed by reinsertion of the tendon on the radial tuberosity according to modified Boyd-Anderson technique. Indomethacin was administered prophylactically. No complications were noted. At the latest follow-up, the patient had full elbow range of motion and participated successfully in athletic activities and job.

  14. Optimal location of a single distal interlocking screw in intramedullary nailing of distal third femoral shaft fractures.

    Science.gov (United States)

    George, C J; Lindsey, R W; Noble, P C; Alexander, J W; Kamaric, E

    1998-05-01

    This biomechanical study was done to determine the effect of the level of a single distal screw in a static intramedullary (IM) femoral nail on the stability of fixation of a fracture in the distal third of the femur. Fifteen composite fiberglass femora were osteotomized transversely in the distal third of the femur. A Grosse-Kempf nail was implanted into the femurs, which were divided into three groups of five specimens. Single screw distal nail locking was varied distal to the osteotomy site for each group at 2.5, 5.0, and 7.5 centimeters, respectively. All instrumented femurs were mounted on a servohydraulic testing machine and fitted with transducers to measure axial, rotational, and bending displacements. Specimens were cyclically loaded (one hertz) in simultaneous torsion (moment: +/- 10 newton-meters) and axial compression (amplitude: 2,000 newtons) for 500 cycles with a 250-pound abductor force. Data from linear and rotational transducers were sampled at 100 hertz for five cycles before cycling, every 100 cycles of loading, and immediately after cycling. Custom computer software was developed to convert transducer signals into static and dynamic measurements of axial motion (in millimeters), rotation (in degrees), and angulation (in degrees). Osteotomy site dynamic rotation increased significantly in specimens locked at 7.5 centimeters when compared with the 2.5-centimeter group. There was minimal difference between the stability of the 5.0-centimeter and 7.5-centimeter groups. There was no significant change in position at the fracture site before or after cyclic loading with respect to axial shortening, rotation, or bending. Both dynamic axial and angular displacements were also unaffected by screw position. The location of a single distal interlocking screw in static IM nail fixation of distal third femur fractures can significantly affect rotational stability but not axial or angular fixation.

  15. Distal Radius Hemiarthroplasty.

    Science.gov (United States)

    Adams, Brian D; Lawler, Ericka A; Kuhl, Taften L

    2016-08-01

    Due to a higher risk for implant loosening, particularly of the distal component, patients with physically demanding lifestyles are infrequently considered for total wrist arthroplasty (TWA). A distal radius hemiarthroplasty may obviate the need for the strict restrictions recommended for patients treated by TWA, thus providing another surgical option for active patients with severe wrist arthritis, especially those with articular degeneration of the lunate facet of the radius, capitate head, or combination of both, who are not typically candidates for traditional motion-preserving procedures. Eight fresh-frozen cadaver limbs (age range, 43-82 years) with no history of rheumatoid arthritis or upper extremity trauma were used. Radiodense markers were inserted in the radius and hand. Posteroanterior (PA) fluoroscopic images with the wrist in neutral, radial deviation, and ulnar deviation, and lateral images with the wrist in neutral, flexion, and extension were obtained for each specimen before implantation, after distal radius hemiarthroplasty, and after combined hemiarthroplasty and PRC. On the PA images, the capitate remained within 1.42 and 2.21 mm of its native radial-ulnar position following hemiarthroplasty and hemiarthroplasty with PRC, respectively. Lateral images showed the capitate remained within 1.06 mm of its native dorsal-volar position following hemiarthroplasty and within 4.69 mm following hemiarthroplasty with PRC. Following hemiarthroplasty, capitate alignment changed 2.33 and 2.59 mm compared with its native longitudinal alignment on PA and lateral films, respectively. These changes did not reach statistical significance. As expected, significant shortening in longitudinal alignment was seen on both PA and lateral films for hemiarthroplasty with PRC. A distal radius implant hemiarthroplasty with or without a PRC provides good static alignment of the wrist in a cadaver model and thus supports the concept as potential treatment alternatives

  16. Subacute dislocation of the elbow following Galeazzi fracture-dislocation of the radius: A case report.

    Science.gov (United States)

    Rajeev, Aysha; Senevirathna, Shanaka; Harrison, John

    2011-12-20

    The Galeazzi fracture-dislocation was originally described by Sir Astley Cooper in 1822 but was named after Italian surgeon Ricardo Galeazzi in 1934. It is an injury classified as a radial shaft fracture with associated dislocation of the distal radioulnar joint and disruption of the forearm axis joint. The associated distal radioulnar joint injury may be purely ligamentous in nature, tearing the triangular fibrocartilaginous complex, or involve bony tissue (that is, ulnar styloid avulsions) or both. We report this case because of the rare association of posterior dislocation of the elbow along with Galeazzi fracture-dislocation. To the best of our knowledge, this has not been previously reported in the English literature. A 26-year-old Caucasian man presented to our department after a fall from a motorbike. He sustained a closed, isolated Galeazzi fracture-dislocation of the right forearm and no associated elbow injuries, and this necessitated open reduction and internal fixation of the radius. Post-operative radiographs films were satisfactory. However, clinical and radiological evidence of ipsilateral elbow dislocation was noted at a five-week follow-up, subsequently requiring open reduction of the joint and collateral ligament repair. Our patient was noted to have full elbow and forearm function at three months. Although the Galeazzi fracture-dislocation has been classically described as involving only the distal radioulnar joint, traumatic forces can be transmitted to the elbow via the interosseous membrane of the forearm. This can lead to instability of the elbow joint. Therefore, we recommend that, in every case of forearm fracture, both elbow and wrist joints be assessed clinically as well as radiologically for subluxation or dislocation.

  17. Biomechanics of the upper limb

    OpenAIRE

    Łukasz Jaworski; Robert Karpiński; Angelika Dobrowolska

    2016-01-01

    The article presents basics of the human upper limb’s anatomy, including skeletal system, joints and basic division of muscles in the limb. The biomechanics of the upper limb is introduced. The range of performed motions is depicted. The possible applications of anatomy and biomechanics of the upper limb are shown.

  18. Biomechanics in clinical practice.

    Science.gov (United States)

    Deusinger, R H

    1984-12-01

    Evidence from dynamic biomechanical analyses of physical activities has greatly expanded our knowledge about the mechanical bases for human movement function with potential implications for further understanding movement dysfunction. The purpose of this review is to relate these findings to present knowledge about the effect on human joints during movement, the role of muscle action on human skeletal levers during movement, and the application of this information to functional tasks by physical therapy clinicians. Also presented are some thoughts regarding what must be accomplished so that this material can be generalized to clinical practice.

  19. Management of distal femur fractures with modern plates and nails: state of the art.

    Science.gov (United States)

    Beltran, Michael J; Gary, Joshua L; Collinge, Cory A

    2015-04-01

    Fractures of the distal femur, even those with articular extension, are well suited to surgical fixation with modern precontoured anatomic plates and nails. Numerous adjuvant techniques are available to the treating surgeon to obtain and maintain reduction while preserving fracture biology. Yet despite their proven track record and benefits over older implants, technical errors are common and must be overcome with proper preoperative planning and intraoperative attention to detail. This review summarizes the current state of the art regarding distal femur fractures, with an emphasis on relevant modern plate and nail surgical techniques, tempered by our current understanding of implant biomechanics, fracture healing, and long-term outcomes.

  20. 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.

  1. Distal esophageal spasm.

    Science.gov (United States)

    Roman, Sabine; Kahrilas, Peter J

    2015-07-01

    Distal esophageal spasm (DES) is a rare esophageal motility disorder associated with dysphagia and chest pain. In 2011, the diagnosis of DES was refined based on the occurrence of premature (rather than rapid) contractions by high-resolution manometry. New therapeutic options have also been recently proposed. Thus, a review on DES incorporating publications since 2012 is timely because of these revisions in definition and management. DES remains a heterogeneous clinical disorder. Its pathophysiology is still debated and DES might be related to achalasia. Alternatively, it might be secondary to medications, especially opiates. Endoscopic ultrasound might be informative diagnostically by demonstrating muscularis propria hypertrophy and thickening. Botulinum toxin injection in the esophageal body has been shown superior to placebo to relieve symptoms associated with DES. Finally, per oral endoscopic myotomy is a promising therapeutic approach, but may be less effective in DES than in achalasia. The diagnosis of DES should lead to a systematic search for medication that might promote the occurrence of esophageal dysmotility. Endoscopic treatment of DES (botulinum toxin injection or per oral endoscopic myotomy) should be further evaluated in controlled studies using current diagnostic criteria by high-resolution manometry.

  2. Clinical and ultrasonographic evidence of a proximal positional fault of the radius. A case report.

    Science.gov (United States)

    Malo-Urriés, Miguel; Hidalgo-García, César; Bueno-Gracia, Elena; Estébanez-de-Miguel, Elena; Lucha-López, Orosia; Tricás-Moreno, José Miguel

    2014-06-01

    Positional faults are considered a possible underlying mechanism mimicking the symptoms of a joint sprain. Despite numerous clinical studies indicating the presence of positional faults, there is limited evidence of imaging studies confirming positional faults. This case report is a preliminary study that offers clinical and ultrasonographic evidence of a proximal positional fault of the radius, treated successfully with manual therapy techniques. Three weeks after a bike fall on the outstretched hand, the patient in this study presented with right wrist pain and a lack of progress with conventional conservative treatment (NSAIDs, rest and immobilization). Clinical findings indicating a proximal positional fault of the radius included pain during active pronation increased by associating a passive movement of the radius in a proximal direction and it was reduced by associating a passive movement of the radius in a distal direction. Ultrasonographic (US) images showed a reduction of radio-capitellar distance on the right side (11.4 mm) compared to the left side (13.3 mm). A positive response with a distal mobilization of the radius supported the proximal positional fault of the radius. After two manual therapy sessions, the patient had recovered normal asymptomatic function. The outcomes used to assess function and pain were active pronation range of motion, the Spanish version of the DASH questionnaire and a 0-10 numeric pain rating scale. Each measure was conducted prior and after each treatment session and one week post treatment. The patient was re-examined at 6 months follow-up, during which US images, demonstrated a normalization of the right radio-capitellar distance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Aeronautical Inspirations in Biomechanics

    Directory of Open Access Journals (Sweden)

    Maroński Ryszard

    2017-03-01

    Full Text Available Introduction. The goal of the paper is to show that some problems formulated in the dynamics of atmospheric flight are very similar to the problems formulated in the biomechanics of motion and medicine. Three problems were compared: minimumheat transfer from the boundary layer to the ballistic missile skin, minimum-time ski descent, and the minimisation of the negative cumulated effect of the drug in cancer chemotherapy. Material and methods. All these problems are solved using the same method originally developed for aerospace systems - the method of Miele (the extremisation method of linear integrals via Green’s theorem. Results. It is shown that the problems arising in different branches of knowledge are very similar in problem formulations, mathematical models, and solution methods used. Conclusions. There are no barriers between different disciplines.

  4. 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...

  5. 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...

  6. The effects of tibiofibularis anterior ligaments on ankle joint biomechanics.

    Science.gov (United States)

    Karakaşlı, Ahmet; Erduran, Mehmet; Baktıroğlu, Lütfü; Büdeyri, Aydın; Yıldız, Didem Venüs; Havıtçıoğlu, Hasan

    2015-03-01

    The aim of this study was to evaluate the biomechanical behavior of anterior inferior tibiofibularis ligament (AITFL) deficient human ankle under axial loading of ankle at stance phase of gait. In order to investigate the contribution of AITFL to ankle stability, an in vitro sequential experimental setup was simulated. The measurement of posterior displacement of distal tibia and anterior displacement of the foot, in neutral position, secondary to axial compression, was performed by two non-contact video extensometers. Eight freshly frozen, anatomically intact, cadaveric human ankle specimens were included and tested. An axial compression test machine was utilized from 0 to 800 Newtonswith a loading speed of 5 mm/min in order to simulate the axial weight-bearing sequence of the ankle at stance phase of human gait. There was a statistically significant difference between anteroposterior displacement values for AITFL-Intact and AITFL-Dissected specimens (p≤0.05). Mean AITFL-Intact and mean AITFL-Dissected ankle anteroposterior displacement was 1.28±0.47 mm and 2.06±0.7 mm, respectively. This study determined some numerical and quantitative data about the biomechanical properties of AITFL in neutral foot position. In the emergency department, diagnosis and treatment of AITFL injury, due to ankle distortion, is important. In AITFL injuries, ankle biomechanics is affected, and ankle instability occurs.

  7. 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

  8. Evaluation of a customized artificial osteoporotic bone model of the distal femur.

    Science.gov (United States)

    Wähnert, Dirk; Hoffmeier, Konrad L; Stolarczyk, Yves; Fröber, Rosemarie; Hofmann, Gunther O; Mückley, Thomas

    2011-11-01

    In the development of new implants biomechanical testing is essential. Since human bones vary markedly in density and geometry their suitability for biomechanical testing is limited. In contrast artificial bones are of great uniformity and therefore appropriate for biomechanical testing. However, the applied artificial bones have to be proved as comparable to human bone. An anatomical shaped artificial bone representing the distal human femur was created by foaming polyurethane. To get a bone model with properties of osteoporotic bone a foam density of 150 kg/m3 was used. The biomechanical properties of our artificial bones were evaluated against eight mildly osteoporotic fresh frozen human femora by mechanical testing. At the artificial bones all tested parameters showed a very small variation. In contrast significant correlation between bone mass density and tested parameters was found for the human bones. The artificial bones reached 39% of the compression strength and 41% of the screw pullout force of the human bone. In indentation testing the artificial bones reached 27% (cancellous) and 59% (cortical) respectively of the human bones strength. Regarding Shore hardness artificial bone and human bone showed comparable results for the cortical layer and at the cancellous layer the artificial bone reached 57% of human bones hardness. Our described method for customizing of artificial bones regarding their shape and bone stock quality provides suitable results. In relation to the as mildly osteoporotic classified human bones we assume that the biomechanical properties matching to serve osteoporotic bone.

  9. 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.

  10. 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.)

  11. 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

  12. FEBio: finite elements for biomechanics.

    Science.gov (United States)

    Maas, Steve A; Ellis, Benjamin J; Ateshian, Gerard A; Weiss, Jeffrey A

    2012-01-01

    In the field of computational biomechanics, investigators have primarily used commercial software that is neither geared toward biological applications nor sufficiently flexible to follow the latest developments in the field. This lack of a tailored software environment has hampered research progress, as well as dissemination of models and results. To address these issues, we developed the FEBio software suite (http://mrl.sci.utah.edu/software/febio), a nonlinear implicit finite element (FE) framework, designed specifically for analysis in computational solid biomechanics. This paper provides an overview of the theoretical basis of FEBio and its main features. FEBio offers modeling scenarios, constitutive models, and boundary conditions, which are relevant to numerous applications in biomechanics. The open-source FEBio software is written in C++, with particular attention to scalar and parallel performance on modern computer architectures. Software verification is a large part of the development and maintenance of FEBio, and to demonstrate the general approach, the description and results of several problems from the FEBio Verification Suite are presented and compared to analytical solutions or results from other established and verified FE codes. An additional simulation is described that illustrates the application of FEBio to a research problem in biomechanics. Together with the pre- and postprocessing software PREVIEW and POSTVIEW, FEBio provides a tailored solution for research and development in computational biomechanics.

  13. [Comparison of Short-Therm Results of Conservative versus Operative Treatment of Distal Ulna Fractures Associated with Distal Radius Fracture Treated by Plate Osteosynthesis].

    Science.gov (United States)

    Meluzinová, P; Kopp, L; Dráč, P; Edelmann, K; Obruba, P

    2017-01-01

    PURPOSE OF THE STUDY The study aims to evaluate and compare the results of conservative and operative treatment of individual types of distal ulna fractures associated with distal radius fracture treated by plate osteosynthesis and to verify the conclusions of the other authors regarding the recommended therapeutic procedures in these fractures. MATERIAL AND METHODS In the period from 08/2013 to 09/2015, a total of 81 patients participated in the prospective randomised study, with the mean follow-up period of 24 months (6-36). All the fractures of distal two thirds of ulnar styloid process were treated conservatively. The patients with the other types of ulnar fractures (fractures of the proximal third of ulnar styloid process, ulnar head fractures, subcapital fractures) were systematically divided into two cohorts, based on which the subsequent (conservative vs. operative) treatment of distal ulna fractures was indicated. The operative treatment of all the types of distal ulna fractures was performed by plate osteosynthesis using LCP Distal Ulna Plate implant so that a uniform method is applied. RESULTS In the post-operative follow-up not a single patient with tip fracture of ulnar styloid process in the cohort showed a posttraumatic instability or disorder of distal radioulnar joint (DRUJ) biomechanics (ROM 96.6% (91-100), MWS 61.3 points (75-100), QDASH 2.9 points (0-6.8)). The patients with a fracture of the proximal third of ulnar styloid process, a fracture of ulnar head and a subcapital fracture, treated operatively, achieved better early radiographic and functional outcome (ROM 95.7% (60-100), MWS 91.2 points (75-100), QDASH 3.5 points (0-11.4)) than patients treated conservatively (ROM 89.6% (64-100), MWS 70.4 points (35-85), QDASH 18.4 points (0-52.3)). DISCUSSION The study confirms the conclusions drawn by the other authors that tip fractures of ulna do not cause posttraumatic DRUJ instability and do not require operative treatment. Conservative

  14. [Effect of age and anti-osteoporotic drugs on bone strength and structure of the distal radius].

    Science.gov (United States)

    Uchiyama, Shigeharu

    2013-07-01

    The distal radius constitutes a proximal part of the wrist joint, which bears axial load from the carpal bones. Based on the biomechanical experiments, the load transmitted from the carpal bones to the distal articular surface of the radius is greater to the lunate fossa than the scaphoid fossa. The findings are consistent with the results obtained from HR-pQCT analysis of the distal radius. As ageing, bone mineral densities of the distal radius decrease, and structures of the cortical and trabecular bones also deteriorate. Such deterioration can be prevented by osteoporotic medicines such as PTH or bisphosphonate. Denosumab has been shown to increase mechanical indices of the bone structure of the distal radius. The distal radius of the individual is fractured when the load over approximately 5 times (2.5SD) of the weight is applied. It is possible to predict load of fracture in the distal radius from the results of DXA derived BMD or HR-pQCT derived bone parameters. We should not miss the opportunity of treatment for osteoporosis when the patients with fragility distal radius fracture are seen.

  15. Simultaneous ipsilateral fractures of distal and proximal ends of the radius.

    Science.gov (United States)

    El Kadi, Khalid Ibn; Benabid, Mounir; Saliou, Sarr; El Assil, Oussama; Marzouki, Amine; Lahrach, Kamal; Boutayeb, Fawzi

    2017-01-01

    We treated a patient with a rare combination of ipsilateral fractures of the distal and proximal ends of the radius. A man aged 42 years had simultaneous fractures of the distal and proximal ends of the radius (radial neck) following a roadside accident. The distal end fracture of the radius was treated with surgical reduction and T-plate volar fixation, and the undisplaced radial neck fracture was treated by an above elbow splintage for 2 weeks. The elbow mobilization was started at 2 weeks. The distal radius was protected for another 4 weeks in a below elbow functional brace. Ipsilateral proximal and distal radial fracture is an uncommon injury pattern. The series illustrates a number of problems associated with this combination. Firstly, one should be aware of this rare injury pattern and there should be greater emphasis on clinical examination of elbow in cases of wrist injuries and vice versa. Once diagnosed, one faces the dilemma of appropriate management in these cases. The appropriate management will depend on the injury characteristics including the age of the patient and the fracture pattern. One should try to preserve the radial head to prevent a possible proximal radial migration especially in younger patients.

  16. 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.

  17. Biomechanics of bird flight.

    Science.gov (United States)

    Tobalske, Bret W

    2007-09-01

    Power output is a unifying theme for bird flight and considerable progress has been accomplished recently in measuring muscular, metabolic and aerodynamic power in birds. The primary flight muscles of birds, the pectoralis and supracoracoideus, are designed for work and power output, with large stress (force per unit cross-sectional area) and strain (relative length change) per contraction. U-shaped curves describe how mechanical power output varies with flight speed, but the specific shapes and characteristic speeds of these curves differ according to morphology and flight style. New measures of induced, profile and parasite power should help to update existing mathematical models of flight. In turn, these improved models may serve to test behavioral and ecological processes. Unlike terrestrial locomotion that is generally characterized by discrete gaits, changes in wing kinematics and aerodynamics across flight speeds are gradual. Take-off flight performance scales with body size, but fully revealing the mechanisms responsible for this pattern awaits new study. Intermittent flight appears to reduce the power cost for flight, as some species flap-glide at slow speeds and flap-bound at fast speeds. It is vital to test the metabolic costs of intermittent flight to understand why some birds use intermittent bounds during slow flight. Maneuvering and stability are critical for flying birds, and design for maneuvering may impinge upon other aspects of flight performance. The tail contributes to lift and drag; it is also integral to maneuvering and stability. Recent studies have revealed that maneuvers are typically initiated during downstroke and involve bilateral asymmetry of force production in the pectoralis. Future study of maneuvering and stability should measure inertial and aerodynamic forces. It is critical for continued progress into the biomechanics of bird flight that experimental designs are developed in an ecological and evolutionary context.

  18. Biomechanics and the wheelchair.

    Science.gov (United States)

    McLaurin, C A; Brubaker, C E

    1991-04-01

    Wheelchair biomechanics involves the study of how a wheelchair user imparts power to the wheels to achieve mobility. Because a wheelchair can coast, power input need not be continuous, but each power strike can be followed by a period of recovery, with the stroking frequency depending on user preferences and the coasting characteristics of the wheelchair. The latter is described in terms of rolling resistance, wind resistance and the slope of the surface. From these three factors the power required to propel the wheelchair is determined, and must be matched by the power output of the user. The efficiency of propulsion is the ratio of this power output to the metabolic cost and is typically in the order of 5% in normal use. The features required in a wheelchair depend upon user characteristics and intended activities. The ideal wheelchair for an individual will have the features that closely match these characteristics and activities. Thus prescription is not just choosing a wheelchair, but choosing the components of the wheelchair that best serve the intended purpose. In this paper, each component is examined for available options and how these options effect the performance of the wheelchair for the individual. The components include wheels, tyres, castors, frames, bearings, materials, construction details, seats, backrests, armrests, foot and legrests, headrests, wheel locks, running brakes, handrims, levers, accessories, adjustments and detachable parts. Each component is considered in relation to performance characteristics including rolling resistance, versatility, weight, comfort, stability, maneouvrability, transfer, stowage, durability and maintenance. Where they exist, wheelchair standards are referred to as a source of information regarding these characteristics.

  19. Biomechanical Perspectives on Concussion in Sport

    Science.gov (United States)

    Rowson, Steven; Bland, Megan L.; Campolettano, Eamon T.; Press, Jaclyn N.; Rowson, Bethany; Smith, Jake A.; Sproule, David W.; Tyson, Abigail M.; Duma, Stefan M.

    2016-01-01

    Concussions can occur in any sport. Often, clinical and biomechanical research efforts are disconnected. This review paper analyzes current concussion issues in sports from a biomechanical perspective and is geared towards Sports Med professionals. Overarching themes of this review include: the biomechanics of the brain during head impact, role of protective equipment, potential population-based differences in concussion tolerance, potential intervention strategies to reduce the incidence of injury, and common biomechanical misconceptions. PMID:27482775

  20. Biomechanical and biochemical properties of the thoracic aorta in warmblood horses, Friesian horses, and Friesians with aortic rupture.

    Science.gov (United States)

    Saey, Veronique; Famaey, Nele; Smoljkic, Marija; Claeys, Erik; van Loon, Gunther; Ducatelle, Richard; Ploeg, Margreet; Delesalle, Catherine; Gröne, Andrea; Duchateau, Luc; Chiers, Koen

    2015-11-18

    Thoracic aortic rupture and aortopulmonary fistulation are rare conditions in horses. It mainly affects Friesian horses. Intrinsic differences in biomechanical properties of the aortic wall might predispose this breed. The biomechanical and biochemical properties of the thoracic aorta were characterized in warmblood horses, unaffected Friesian horses and Friesians with aortic rupture in an attempt to unravel the underlying pathogenesis of aortic rupture in Friesian horses. Samples of the thoracic aorta at the ligamentum arteriosum (LA), mid thoracic aorta (T1) and distal thoracic aorta (T2) were obtained from Friesian horses with aortic rupture (A), nonaffected Friesian (NA) and warmblood horses (WB). The biomechanical properties of these samples were determined using uniaxial tensile and rupture assays. The percentages of collagen and elastin (mg/mg dry weight) were quantified. Data revealed no significant biomechanical nor biochemical differences among the different groups of horses. The distal thoracic aorta displayed an increased stiffness associated with a higher collagen percentage in this area and a higher load-bearing capacity compared to the more proximal segments. Our findings match reported findings in other animal species. Study results did not provide evidence that the predisposition of the Friesian horse breed for aortic rupture can be attributed to altered biomechanical properties of the aortic wall.

  1. 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....

  2. Comparison of modern locked plating and antiglide plating for fixation of osteoporotic distal fibular fractures.

    Science.gov (United States)

    Switaj, Paul J; Wetzel, Robert J; Jain, Neel P; Weatherford, Brian M; Ren, Yupeng; Zhang, Li-Qun; Merk, Bradley R

    2016-09-01

    Fractures in osteoporotic patients can be difficult to treat because of poor bone quality and inability to gain screw purchase. The purpose of this study is to compare modern lateral periarticular distal fibula locked plating to antiglide plating in the setting of an osteoporotic, unstable distal fibula fracture. AO/OTA 44-B2 distal fibula fractures were created in sixteen paired fresh frozen cadaveric ankles and fixed with a lateral locking plate and an independent lag screw or an antiglide plate with a lag screw through the plate. The specimens underwent stiffness, cyclic loading, and load to failure testing. The energy absorbed until failure, torque to failure, construct stiffness, angle at failure, and energy at failure was recorded. The lateral locking construct had a higher torque to failure (p=0.02) and construct stiffness (p=0.04). The locking construct showed a trend toward increased angle at failure, but did not reach statistical significance (p=0.07). Seven of the eight lateral locking plate specimens failed through the distal locking screws, while the antiglide plating construct failed with pullout of the distal screws and displacement of the fracture in six of the eight specimens. In our study, the newly designed distal fibula periarticular locking plate with increased distal fixation is biomechanically stronger than a non-locking one third tubular plate applied in antiglide fashion for the treatment of AO/OTA 44-B2 osteoporotic distal fibula fractures. V: This is an ex-vivo study performed on cadavers and is not a study performed on live patients. Therefore, this is considered Level V evidence. Copyright © 2015. Published by Elsevier Ltd.

  3. 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

  4. Biomechanics of the chick embryonic heart outflow tract at HH18 using 4D optical coherence tomography imaging and computational modeling.

    Directory of Open Access Journals (Sweden)

    Aiping Liu

    Full Text Available During developmental stages, biomechanical stimuli on cardiac cells modulate genetic programs, and deviations from normal stimuli can lead to cardiac defects. Therefore, it is important to characterize normal cardiac biomechanical stimuli during early developmental stages. Using the chicken embryo model of cardiac development, we focused on characterizing biomechanical stimuli on the Hamburger-Hamilton (HH 18 chick cardiac outflow tract (OFT, the distal portion of the heart from which a large portion of defects observed in humans originate. To characterize biomechanical stimuli in the OFT, we used a combination of in vivo optical coherence tomography (OCT imaging, physiological measurements and computational fluid dynamics (CFD modeling. We found that, at HH18, the proximal portion of the OFT wall undergoes larger circumferential strains than its distal portion, while the distal portion of the OFT wall undergoes larger wall stresses. Maximal wall shear stresses were generally found on the surface of endocardial cushions, which are protrusions of extracellular matrix onto the OFT lumen that later during development give rise to cardiac septa and valves. The non-uniform spatial and temporal distributions of stresses and strains in the OFT walls provide biomechanical cues to cardiac cells that likely aid in the extensive differential growth and remodeling patterns observed during normal development.

  5. 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.

  6. 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 fascia release following modified distal osteotomy, under multiple Achilles loading conditions (p < 0.05). 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.

  7. 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.

  8. Osteopathology in the Equine Distal Phalanx Associated With the Development and Progression of Laminitis.

    Science.gov (United States)

    Engiles, J B; Galantino-Homer, H L; Boston, R; McDonald, D; Dishowitz, M; Hankenson, K D

    2015-09-01

    Although the equine distal phalanx and hoof lamellae are biomechanically and physiologically integrated, bony changes in the distal phalanx are poorly described in laminitis. The aims of this study were (1) to establish a laminitis grading scheme that can be applied to the wide spectrum of lesions seen in naturally occurring cases and (2) to measure and describe changes in the distal phalanx associated with laminitis using micro-computed tomography (micro-CT) and histology. Thirty-six laminitic and normal feet from 15 performance and nonperformance horses were evaluated. A laminitis grading scheme based on radiographic, gross, histopathologic, and temporal parameters was developed. Laminitis severity grades generated by this scheme correlated well with clinical severity and coincided with decreased distal phalanx bone volume and density as measured by micro-CT. Laminitic hoof wall changes included progressive ventral rotation and distal displacement of the distal phalanx with increased thickness of the stratum internum-corium tissues with lamellar wedge formation. Histologically, there was epidermal lamellar necrosis with basement membrane separation and dysplastic regeneration, including acanthosis and hyperkeratosis, corresponding to the lamellar wedge. The changes detected by micro-CT corresponded to microscopic findings in the bone, including osteoclastic osteolysis of trabecular and osteonal bone with medullary inflammation and fibrosis. Bone changes were identified in horses with mild/early stages of laminitis as well as severe/chronic stages. The authors conclude that distal phalangeal pathology is a quantifiable and significant component of laminitis pathology and may have important implications for early detection or therapeutic intervention of equine laminitis. © The Author(s) 2015.

  9. BIOMECHANICAL CHARACTERISTICS AND DETERMINANTS OF INSTEP SOCCER KICK

    Directory of Open Access Journals (Sweden)

    Eleftherios Kellis

    2007-06-01

    Full Text Available 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

  10. Root anatomical phenes predict root penetration ability and biomechanical properties in maize (Zea Mays).

    Science.gov (United States)

    Chimungu, Joseph G; Loades, Kenneth W; Lynch, Jonathan P

    2015-06-01

    The ability of roots to penetrate hard soil is important for crop productivity but specific root phenes contributing to this ability are poorly understood. Root penetrability and biomechanical properties are likely to vary in the root system dependent on anatomical structure. No information is available to date on the influence of root anatomical phenes on root penetrability and biomechanics. Root penetration ability was evaluated using a wax layer system. Root tensile and bending strength were evaluated in plant roots grown in the greenhouse and in the field. Root anatomical phenes were found to be better predictors of root penetrability than root diameter per se and associated with smaller distal cortical region cell size. Smaller outer cortical region cells play an important role in stabilizing the root against ovalization and reducing the risk of local buckling and collapse during penetration, thereby increasing root penetration of hard layers. The use of stele diameter was found to be a better predictor of root tensile strength than root diameter. Cortical thickness, cortical cell count, cortical cell wall area and distal cortical cell size were stronger predictors of root bend strength than root diameter. Our results indicate that root anatomical phenes are important predictors for root penetrability of high-strength layers and root biomechanical properties. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  11. RESULT OF PRE-CONTOURED DISTAL RADIUS INDIAN LOCKING PLATES IN DISTAL RADIUS FRACTURE

    OpenAIRE

    Shaleen; Baljit; Aditya; Parminder; Simarpreet S

    2014-01-01

    BACKGROUND: Fractures of the distal radius are common, open reduction and internal fixation using an interlocking plate system has gained popularity for the treatment of dorsally displaced distal radius fractures. The aim of the study was to assess how adequately distal radial fracture reduction was reproduced and maintained with the pre-contoured distal radius Indian locking plates and to evaluate the functional and radiological results of treating unstable distal radius ...

  12. 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.

  13. Genetics Home Reference: distal hereditary motor neuropathy, type V

    Science.gov (United States)

    ... Distal hereditary motor neuropathy, type V Distal hereditary motor neuropathy, type V Printable PDF Open All Close All Enable ... link) PubMed OMIM (2 links) NEURONOPATHY, DISTAL HEREDITARY MOTOR, TYPE VA NEURONOPATHY, DISTAL HEREDITARY MOTOR, TYPE VB Sources ...

  14. 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.

  15. Wearable Biomechanical Energy Harvesting Technologies

    Directory of Open Access Journals (Sweden)

    Young-Man Choi

    2017-09-01

    Full Text Available Energy harvesting has been attracting attention as a technology that is capable of replacing or supplementing a battery with the development of various mobile electronics. In environments where stable electrical supply is not possible, energy harvesting technology can guarantee an increased leisure and safety for human beings. Harvesting with several watts of power is essential for directly driving or efficiently charging mobile electronic devices such as laptops or cell phones. In this study, we reviewed energy harvesting technologies that harvest biomechanical energy from human motion such as foot strike, joint motion, and upper limb motion. They are classified based on the typical principle of kinetic energy harvesting: piezoelectric, triboelectric, and electromagnetic energy harvesting. We focused on the wearing position of high-power wearable biomechanical energy harvesters (WBEHs generating watt-level power. In addition, the features and future trends of the watt-level WBEHs are discussed.

  16. The Biomechanics of Cervical Spondylosis

    Science.gov (United States)

    Ferrara, Lisa A.

    2012-01-01

    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. PMID:22400120

  17. 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.

  18. 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.

  19. 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.

  20. Reconstruction of the distal biceps tendon using triceps graft: a technical note.

    Science.gov (United States)

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

    2017-01-01

    Rupture of the distal biceps brachii tendon typically occur in a contraction against resistance with the elbow in 90° of flexion. Chronic ruptures are uncommon and are complicated by tendon and muscle retraction and poor quality. Some reconstruction techniques have been described in the literature, with variations on the surgical exposures, type of graft (allo or autograft), graft donor site, and type of attachment to the radial tuberosity. The authors report the case of a patient presented a rupture of the distal biceps brachii tendon that took place five weeks earlier and, therefore, underwent reconstruction using autograft from the central strip of triceps tendon through double incision and fixation with anchors to the radial tuberosity. The use of the triceps brachii as autograft for reconstruction of chronic ruptures of the distal biceps had not yet been described in the literature. The authors have chosen to use it due to its biomechanical characteristics that qualify it as suitable for this procedure and because this is easier for collection, using the same operating field at the same joint, minimizing the negative effects of the donor area. After six months postoperatively, the patient has full movement arc and restoration of 96% of the flexion strength and 90% of the supination strength when compared with the contralateral limb. This procedure appears to be a good option for cases of chronic distal biceps rupture in older patients who have functional demand of supination.

  1. Reconstruction of the distal biceps tendon using triceps graft: a technical note

    Directory of Open Access Journals (Sweden)

    Thiago Medeiros Storti

    Full Text Available ABSTRACT Rupture of the distal biceps brachii tendon typically occur in a contraction against resistance with the elbow in 90° of flexion. Chronic ruptures are uncommon and are complicated by tendon and muscle retraction and poor quality. Some reconstruction techniques have been described in the literature, with variations on the surgical exposures, type of graft (allo or autograft, graft donor site, and type of attachment to the radial tuberosity. The authors report the case of a patient presented a rupture of the distal biceps brachii tendon that took place five weeks earlier and, therefore, underwent reconstruction using autograft from the central strip of triceps tendon through double incision and fixation with anchors to the radial tuberosity. The use of the triceps brachii as autograft for reconstruction of chronic ruptures of the distal biceps had not yet been described in the literature. The authors have chosen to use it due to its biomechanical characteristics that qualify it as suitable for this procedure and because this is easier for collection, using the same operating field at the same joint, minimizing the negative effects of the donor area. After six months postoperatively, the patient has full movement arc and restoration of 96% of the flexion strength and 90% of the supination strength when compared with the contralateral limb. This procedure appears to be a good option for cases of chronic distal biceps rupture in older patients who have functional demand of supination.

  2. The risk injury to the posterior interosseous nerve in standard approaches to the proximal radius: a cadaver study.

    Science.gov (United States)

    Heidari, Nima; Kraus, Tanja; Weinberg, Annelie M; Weiglein, Andreas H; Grechenig, Wolfgang

    2011-05-01

    The aim of this study was to provide guidance on the safe zones for the exposure of the proximal radius by measuring the distance from the PIN to various anatomical landmarks in the proximal forearm in pronation and supination. Twenty cadaveric arms were used for this study. On the anterior aspect of the forearm, the distance between insertion of the biceps tendon and the arcade of Frohse as well as the shortest distance between the PIN and the ulnar aspect of the radial neck were measured. On the posterior aspect of the forearm, the shortest distance between the PIN and the ulnar border of the interosseous membrane was measured at 30 and 50 mm distal to the articular surface of the radial head. The distance between the PIN and ulnar aspect of the radial neck had a mean of 21.6 mm in supination and 13.3 mm in pronation. The distance between the radial tuberosity and the arcade of Frohse was 18.6 mm. The mean distance between the PIN and the radial border of ulna at 30 mm distal to the articular surface of the proximal radius was 12.3 mm in supination and 22.3 mm in pronation. At 50 mm distal to the articular surface of the proximal radius the mean distance was 8 mm in supination and 16.2 mm in pronation. The course of this nerve is variable as it winds around the radial neck within the belly of the supinator muscle. Safe distances for dissection have been presented in our study.

  3. Biomechanics of the human uterus.

    Science.gov (United States)

    Myers, Kristin M; Elad, David

    2017-09-01

    The appropriate biomechanical function of the uterus is required for the execution of human reproduction. These functions range from aiding the transport of the embryo to the implantation site, to remodeling its tissue walls to host the placenta, to protecting the fetus during gestation, to contracting forcefully for a safe parturition and postpartum, to remodeling back to its nonpregnant condition to renew the cycle of menstruation. To serve these remarkably diverse functions, the uterus is optimally geared with evolving and contractile muscle and tissue layers that are cued by chemical, hormonal, electrical, and mechanical signals. The relationship between these highly active biological signaling mechanisms and uterine biomechanical function is not completely understood for normal reproductive processes and pathological conditions such as adenomyosis, endometriosis, infertility and preterm labor. Animal studies have illuminated the rich structural function of the uterus, particularly in pregnancy. In humans, medical imaging techniques in ultrasound and magnetic resonance have been combined with computational engineering techniques to characterize the uterus in vivo, and advanced experimental techniques have explored uterine function using ex vivo tissue samples. The collective evidence presented in this review gives an overall perspective on uterine biomechanics related to both its nonpregnant and pregnant function, highlighting open research topics in the field. Additionally, uterine disease and infertility are discussed in the context of tissue injury and repair processes and the role of computational modeling in uncovering etiologies of disease. WIREs Syst Biol Med 2017, 9:e1388. doi: 10.1002/wsbm.1388 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

  4. Relationships between physical and biomechanical parameters and ...

    African Journals Online (AJOL)

    A proficient golf swing is composed of a sequence of highly complex biomechanical movements and requires precisely timed and coordinated body movements to achieve great distance and accuracy. The aim of the current study was to identify the key physiological and biomechanical variables that relate to golf drive ...

  5. Biomechanical Factors in Tibial Stress Fractures

    Science.gov (United States)

    2004-08-01

    1996. Worthen, L., Hamill, J. Biomechanical issues in ballet : ankle alignment in pointe shoes. 15d, Annual Symposium on Medical Problems of Musicians... Mexico Race Walkers Association, Albuquerque, New Mexico , June, 1987. Biomechanics of fitness walking. American Diabetes Association, St. Louis, Missouri

  6. Biomechanical benefits of symmetrical strengthening of hip ...

    African Journals Online (AJOL)

    There is abundant literature encouraging athletes to engage in concurrent strength training. However, little emphasis is placed on the value of biomechanics with regard to symmetrical strengthening of force-couple relationships. A review of literature reveals 565 biomechanical papers versus 2085 physiological papers ...

  7. 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…

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. Pisiform malalignment associated with distal radius fractures.

    Science.gov (United States)

    Tajima, Takafumi; Zenke, Yukichi; Yamanaka, Yoshiaki; Menuki, Kunitaka; Sakai, Akinori

    2018-03-01

    The association of scaphoid or other carpal bone fractures with distal radius fractures is frequently reported, whereas few studies have described pisiform malalignment associated with distal radius fractures. The purpose of this study was to investigate the frequency and characteristics of pisiform malalignment associated with distal radius fractures. We performed a retrospective study by reviewing the data of 152 consecutive patients with a mean age of 63 years who were treated surgically for distal radius fractures during a five-year period. We evaluated the pisotriquetral joint via preoperative sagittal computed tomography (CT) and assessed pisiform malalignment. Pisiform malalignment was defined as follows: (1) wide type, joint space ≥4.0 mm; (2) non-parallel type, loss of parallelism of the joint surface of ≥20°; or (3) overriding type, proximal or distal overriding of the pisotriquetral joint ≥2.0 mm. We investigated the relationship between pisiform malalignment and the patterns of distal radius fractures. Pisiform malalignment was assessed using postoperative CT to determine whether it had been reduced. Pisiform malalignment was observed in 48 cases involving 44 patients with a mean age of 58 (17-81) years. The patients included 16, 17, and 15 cases of the wide type, non-parallel type, and overriding type, respectively. Distal radius fractures with dorsal displacement exhibited pisiform malalignment significantly more frequently than those with volar displacement. No significant difference was noted between intra- and extra-articular fractures or between patients with and without distal ulnar fractures. Among the 22 pisiform malalignment cases assessed via postoperative CT, 15 cases were reduced, and 7 cases remained malaligned. The non-parallel type exhibited the lowest reduction rate among the 3 types. Among distal radius fractures, 29% were complicated by pisiform malalignment. Distal radius fractures with dorsal displacement exhibited a

  13. Biomechanics in Paralympics: Implications for Performance.

    Science.gov (United States)

    Morriën, Floor; Taylor, Matthew J D; Hettinga, Florentina J

    2017-05-01

    To provide an overview of biomechanical studies in Paralympic research and their relevance for performance in Paralympic sports. The search terms paralympic biomechanics, paralympic sport performance, paralympic athlete performance, and paralympic athlete were entered into the electronic database PubMed. Thirty-four studies were found. Biomechanical studies in Paralympics mainly contributed to performance enhancement by technical optimization (n = 32) and/or injury prevention (n = 6). In addition, biomechanics was found to be important in understanding activity limitation caused by various impairments, which is relevant for evidence-based classification in Paralympic sports (n = 6). Distinctions were made between biomechanical studies in sitting (41%), standing (38%), and swimming athletes (21%). In sitting athletes, mostly kinematics and kinetics in wheelchair propulsion were studied, mainly in athletes with spinal-cord injuries. In addition, kinetics and/or kinematics in wheelchair basketball, seated discus throwing, stationary shot-putting, hand-cycling, sit-skiing, and ice sledge hockey received attention. In standing sports, primarily kinematics of athletes with amputations performing jump sports and running and the optimization of prosthetic devices were investigated. No studies were reported on other standing sports. In swimming, mainly kick rate and resistance training were studied. Biomechanical research is important for performance by gaining insight into technical optimization, injury prevention, and evidence-based classification in Paralympic sports. In future studies it is advised to also include physiological and biomechanical measures, allowing the assessment of the capability of the human body, as well as the resulting movement.

  14. Distal fibular malrotation and lateral ankle contact characteristics.

    Science.gov (United States)

    Stroh, D Alex; DeFontes, Kenneth; Paez, Adrian; Parks, Brent; Guyton, Gregory P

    2017-09-20

    Any amount of malreduction of the syndesmotic joint compared with the uninjured syndesmosis has been associated with an adverse effect on functional outcome. The amount of malrotation that may lead to clinically relevant pressure change in this joint has not been reported. Our purpose was to determine whether small degrees of external and internal malrotation would be associated with statistically significant changes in contact pressure in the tibiofibular and talofibular articulations. Twelve cadaveric ankles were osteotomized above the syndesmosis and instrumented with a rotatable distal fibula plate. Sensors at the distal tibiofibular and talofibular articulations recorded contact pressure and area at neutral position and at 5 and 10° of external and internal malrotation through a full range of ankle motion. Compared with neutral rotation, there was a significant decrease in contact pressure at the talofibular articulation with external rotation of 5° (103±113kPa versus 52±69kPa; P=0.01) and 10° (43±62kPa; P=0.01) in plantarflexion.Contact pressure at the tibiofibular articulation in plantarflexion increased with 10° of internal malrotation compared with neutral rotation (56±30kPa versus 74±38kPa; P=0.05) in plantarflexion. Contact area decreased significantly with plantarflexion and 10° of external rotation and increased significantly in plantarflexion and after cyclic loading with 10° of internal rotation (P≤0.05). Any degree of distal fibular external rotation significantly reduced contact pressure in the talofibular articulation with plantarflexion. A minimal increase in contact pressure was found in the tibiofibular and talofibular joints with plantarflexion and mild internal rotation of 5°, but pressure increased significantly in both articulations with 10° of internal rotation. The findings support clinical findings that subtle degrees of fibular malrotation may be associated with alteration of lateral ankle mechanics. Controlled

  15. Load transfer at the distal ulna following simulated distal radius fracture malalignment.

    Science.gov (United States)

    Ferreira, Louis M; Greeley, Gillian S; Johnson, James A; King, Graham J W

    2015-02-01

    To measure the effects of distal radius malalignment on loading at the distal ulna. Using an adjustable mechanism to simulate angulated and translated malalignments, clinically relevant distal radius deformities were simulated in a cadaveric model. A custom-built load cell was inserted just proximal to the native ulna head to measure the resultant force and torque in the distal ulna. Loads were measured before and after transecting the triangular fibrocartilage complex (TFCC). There was an increase in distal ulna load and torque with increasing dorsal translation and angulation. Combined conditions of angulation and translation increased force and torque in the distal ulna to a greater extent than with either condition in isolation. Transecting the TFCC resulted in a reduction in distal ulna load and torque. A progressive increase in load at the distal ulna was observed with increasing severity of malalignment, which may be an important contributor to residual ulnar wrist pain and dysfunction. However, no clear-cut threshold of malalignment of a dorsally angulated and translated distal radius fracture was identified. These observations suggest that radius deformities cause articular incongruity, which increases TFCC tension and distal radioulnar joint load. Cutting of the TFCC decreased distal ulna loading, likely by releasing the articular constraining effect of the TFCC on the distal radioulnar joint, allowing the radius to rotate more freely with respect to the ulna. Anatomical reduction of a distal radius fracture minimizes the forces in the distal ulna and may reduce residual ulnar wrist pain and dysfunction. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  16. Biomechanics-Hot Topics Part II.

    Science.gov (United States)

    Finkemeier, Christopher; Adams, John D; Bernstein, Mitchell; Lee, Mark A; Harvey, Ed; Crist, Brett D

    2018-03-01

    Orthopaedic surgery and biomechanics are intimately partnered topics in medicine. Biomechanical principles are used to design implants and fashion treatment protocols. Although it would seem that biomechanical principles in the design of fixation devices and fracture repair constructs have been already finalized, there are several points of controversy remaining. New technology has raised new questions, while at the same time, we still do not fully understand simple clinical principles such as time of fracture healing depending on the construct used. This review looks at several of these current controversies to better understand what work is needed in fracture care going forward.

  17. 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

  18. Biceps brachii tendon ruptures: a review of diagnosis and treatment of proximal and distal biceps tendon ruptures.

    Science.gov (United States)

    Geaney, Lauren E; Mazzocca, Augustus D

    2010-06-01

    The biceps brachii is a unique muscle with 2 proximal tendons and a single distal tendon. Although these tendons are part of the same muscle, they have significantly different functions. It is hypothesized that the long head of the biceps acts as a pain generator in the shoulder, though the biomechanical function is still under debate. Conversely, the distal biceps tendon is the major supinator of the forearm and serves a secondary flexor. As such, injuries to these tendons must be evaluated independently. Biceps brachii ruptures most often occur in middle-aged men following a traumatic event. Injuries to the long head of the biceps are primarily treated nonoperatively with adequate results. Injuries of distal tendon occur less often, but are receiving significant attention in the literature in regard to treatment options. Surgical repair of distal biceps ruptures is indicated in patients who want to restore supination strength and endurance. It is unclear which operative technique is superior, although the most recent data suggest increased strength of the cortical button repair. This article provides a comprehensive review of both proximal and distal biceps brachii ruptures in addition to our treatment algorithm.

  19. 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.

  20. Genetics Home Reference: distal 18q deletion syndrome

    Science.gov (United States)

    ... Health Conditions Distal 18q deletion syndrome Distal 18q deletion syndrome Printable PDF Open All Close All Enable ... view the expand/collapse boxes. Description Distal 18q deletion syndrome is a chromosomal condition that occurs when ...

  1. 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

  2. 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...

  3. FUNDAMENTA LS OF BIOMECHANIC BIOMEDICAL ENGINERING

    OpenAIRE

    Sriwijaya, Rachmat

    2017-01-01

    Studi tentang biomechanics telah berkembang pesat dari awalnya hanya aplikasi studi mekanika teknik yang sederhana kemudian meluas dengan pelibatan berbagai bidang studi. Dalam bidang biomechanics buku ini sangat membantu mahasiswa ataupun peneliti untuk memahami dasar-dasar mekanika dan dinamika tubuh manusia, yang menjadi bidang kajian penting dalam studi rekayasa biomedik. Buku ini memberikan pengetahuan yang memadai tentang konsep statika, gerak, dinamika, pemodelan, dan aplikasinya dikai...

  4. 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.

  5. Pathology of the distal phalanx in equine laminitis: more than just skin deep.

    Science.gov (United States)

    Engiles, Julie B

    2010-04-01

    The etiopathogenesis of laminitis is complex and involves multiple tissue types. It may be initiated by biomechanical, traumatic, inflammatory, vascular, toxic, and metabolic factors. Although histopathologic changes occurring within the lamellae of experimental models of laminitis are well described and reported, histopathologic changes occurring in the distal phalanx are not, even though gross and radiographic evidence of disease are often apparent and bony lesions could be considered a significant source of pain. Recent scientific evidence indicates that the microenvironment of bone is an important modulator of inflammatory processes that can both influence, and be influenced by components of other organ systems, including the immune, nervous, gastrointestinal, and integumentary systems. This article describes various laminitis-associated histopathological changes in the distal phalanx, introduces concepts of osteoimmunology with regards to equine laminitis, and provides a rationale for histopathological examination of the distal phalanx, as well as the soft tissue structures of the lamellae and corium in laminitis cases. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Tangential Bicortical Locked Fixation Improves Stability in Vancouver B1 Periprosthetic Femur Fractures: A Biomechanical Study.

    Science.gov (United States)

    Lewis, Gregory S; Caroom, Cyrus T; Wee, Hwabok; Jurgensmeier, Darin; Rothermel, Shane D; Bramer, Michelle A; Reid, John Spence

    2015-10-01

    The biomechanical difficulty in fixation of a Vancouver B1 periprosthetic fracture is purchase of the proximal femoral segment in the presence of the hip stem. Several newer technologies provide the ability to place bicortical locking screws tangential to the hip stem with much longer lengths of screw purchase compared with unicortical screws. This biomechanical study compares the stability of 2 of these newer constructs to previous methods. Thirty composite synthetic femurs were prepared with cemented hip stems. The distal femur segment was osteotomized, and plates were fixed proximally with either (1) cerclage cables, (2) locked unicortical screws, (3) a composite of locked screws and cables, or tangentially directed bicortical locking screws using either (4) a stainless steel locking compression plate system with a Locking Attachment Plate (Synthes) or (5) a titanium alloy Non-Contact Bridging system (Zimmer). Specimens were tested to failure in either axial or torsional quasistatic loading modes (n = 3) after 20 moderate load preconditioning cycles. Stiffness, maximum force, and failure mechanism were determined. Bicortical constructs resisted higher (by an average of at least 27%) maximum forces than the other 3 constructs in torsional loading (P steel construct in axial loading. Proximal fixation stability is likely improved with the use of bicortical locking screws as compared with traditional unicortical screws and cable techniques. In this study with a limited sample size, we found the addition of cerclage cables to unicortical screws may not offer much improvement in biomechanical stability of unstable B1 fractures.

  7. Villous adenoma of the distal appendix.

    Science.gov (United States)

    Taylor, J V; Thomas, M G; Kelly, S; Sutton, R

    1997-04-01

    Villous adenoma confined to the distal appendix has not been previously reported in conjunction with acute apendicitis. The presence of an adenoma indicates a need for further investigation due to an association with neoplasia elsewhere.

  8. 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 ...

  9. 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...

  10. 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.

  11. Biomechanics of single cortical neurons.

    Science.gov (United States)

    Bernick, Kristin B; Prevost, Thibault P; Suresh, Subra; Socrate, Simona

    2011-03-01

    This study presents experimental results and computational analysis of the large strain dynamic behavior of single neurons in vitro with the objective of formulating a novel quantitative framework for the biomechanics of cortical neurons. Relying on the atomic force microscopy (AFM) technique, novel testing protocols are developed to enable the characterization of neural soma deformability over a range of indentation rates spanning three orders of magnitude, 10, 1, and 0.1 μm s(-1). Modified spherical AFM probes were utilized to compress the cell bodies of neonatal rat cortical neurons in load, unload, reload and relaxation conditions. The cell response showed marked hysteretic features, strong non-linearities, and substantial time/rate dependencies. The rheological data were complemented with geometrical measurements of cell body morphology, i.e. cross-diameter and height estimates. A constitutive model, validated by the present experiments, is proposed to quantify the mechanical behavior of cortical neurons. The model aimed to correlate empirical findings with measurable degrees of (hyper)elastic resilience and viscosity at the cell level. The proposed formulation, predicated upon previous constitutive model developments undertaken at the cortical tissue level, was implemented in a three-dimensional finite element framework. The simulated cell response was calibrated to the experimental measurements under the selected test conditions, providing a novel single cell model that could form the basis for further refinements. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  12. 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

  13. Comparative stability of perpendicular versus parallel double-locking plating systems in osteoporotic comminuted distal humerus fractures.

    Science.gov (United States)

    Stoffel, Karl; Cunneen, Sam; Morgan, Robert; Nicholls, Rochelle; Stachowiak, Gwidon

    2008-06-01

    In distal humerus fractures, the restoration of stability is important to allow early mobilization and hence more favorable functional outcomes. In this article, we compare the biomechanical stability of perpendicular and parallel locking plating systems for the internal fixation of AO Type C2 distal humerus fractures in osteoporotic bone. Fractures were simulated in paired cadaveric bones and fixed using either the perpendicular 3.5 mm LCP distal humerus plating system (Synthes; Sydney, Australia) or the parallel Mayo Clinic Congruent elbow plate system (Acumed; Hillsboro, OR), using locking screws in both systems. Both systems were then tested for their stiffness (in compression and internal/external rotation), plastic deformation, and failure in torsion. Comparatively, the parallel locking plate system provided a significantly higher stability in compression (p = 0.005) and external rotation (p = 0.006), and a greater ability (p = 0.005) to resist axial plastic deformation. Stability for both constructs appeared to be dependent on bone quality, however the stability of the perpendicular system was generally more sensitive to bone mineral density, indicating a possible need for additional independent interfragmentary screws. A disadvantage of the parallel locking plate system was wear debris produced by its tapping system. In summary, the biomechanical findings of this study suggest that both locking plate systems allow early mobilization of the elbow in patients with osteoporotic bone following fixation of a comminuted distal humerus fracture. However, the parallel locking system showed improved stability compared with the perpendicular locking system, and therefore may be more indicated. (c) 2008 Orthopaedic Research Society.

  14. 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.

  15. Contralateral reversed distal femoral locking plate for fixation of subtrochanteric femoral fractures.

    Science.gov (United States)

    Gogna, Paritosh; Mukhopadhyay, Reetadyuti; Singh, Amanpreet; Devgan, Ashish; Arora, Sahil; Batra, Amit; Yadav, Sushil Kumar

    2015-01-01

    Subtrochanteric fractures of the femur are being managed successfully with various intramedullary and extramedulary implants with reasonable success. However, these implants require precise placement under image intensifier guidance, which exposes the surgeon to substantial amount of radiation. It also restricts the management of these fractures at peripheral centers where facility of image intensifiers is not available. Keeping this in mind we designed this study to identify if contralateral reversed distal femoral locking plate can be used successfully without the use of image intensifier. Twenty-four consecutive patients (18 men and 6 women) with a mean age of 28 years (range 19-47 years) suffering subtrochanteric fractures of the femur underwent open reduction and internal fixation with reversed contralateral distal femoral locking plate. The outcome was assessed at the mean follow-up period of 3.2 years (range 2-4.6 years) using the Harris hip score. Twenty-one fractures united with the primary procedure, with a mean time of consolidation being 11 weeks (range, 9-16 weeks). One patient developed superficial suture line infection, which resolved with oral antibiotics. Another patient had a fall 3 weeks after surgery and broke the plate. Repeat surgery with reversed distal femoral locking compression plate was performed along with bone grafting and the fracture united. Two cases had nonunion, which went in for union after bone grafting. The mean Harris hip score at the time of final follow-up was 90.63 (range 82-97). The reversed contralateral distal femoral plate is a biomechanically sound implant, which when used for fixation of the subtrochanteric fractures with minimal soft tissue stripping shows results comparable to those achieved by using other extramedullary implants as well as intramedullary devices. The added advantage of this implant is its usability in the absence of an image intensifier.

  16. Calcium phosphate cement augmentation after volar locking plating of distal radius fracture significantly increases stability.

    Science.gov (United States)

    Kainz, Hans; Dall'Ara, Enrico; Antoni, Anna; Redl, Heinz; Zysset, Philippe; Weninger, Patrick

    2014-08-01

    Distal radius fractures represent the most common fractures in adults. Volar locking plating to correct unstable fractures has become increasingly popular. Although reasonable primary reduction is possible in most cases, maintenance of reduction until the fracture is healed is often problematic in osteoporotic bone. To our knowledge, no biomechanical studies have compared the effect of enhancement with biomaterial on two different volar fixed-angle plates. Human fresh-frozen cadaver pairs of radii were used to simulate an AO/OTA 23-A3 fracture. In a total of four groups (n = 7 for each group), two volar fixed-angle plates (Aptus 2.5 mm locking fracture plate, Medartis, Switzerland and VA-LCP two-column distal radius plate 2.4, volar, Synthes, Switzerland) with or without an additional injection of a biomaterial (Hydroset Injectable HA Bone Substitute, Stryker, Switzerland) into the dorsal comminution zone were used to fix the distal metaphyseal fragment. Each specimen was tested load-controlled under cyclic loading with a servo-hydraulic material testing machine. Displacement, stiffness, dissipated work and failure mode were recorded. Improved mechanical properties (decreased displacement, increased stiffness, decreased dissipated work) were found in both plates if the biomaterial was additionally injected. Improvement of mechanical parameters after biomaterial injection was more evident in the Synthes plate compared to the Aptus plate. Pushing out of the screws was noticed as a failure mode only in samples lacking supplementary biomaterial. Injection of a biomaterial into the dorsal comminution zone increases stability after volar locking plating of distal radius fractures in vitro.

  17. Distal biceps rupture: the coil sign.

    Science.gov (United States)

    Austin, Luke; Pepe, Matt; VanBeek, Corinne; Tjoumakaris, Fotios

    2014-06-01

    Delayed repair of the distal biceps brachii tendon can lead to the formation of scar tissue and coiling of the tendon. Dissection of the scar tissue and unraveling of the tendon may allow for anatomic repair to the radial tuberosity. A 50-year-old man had a distal biceps brachii tendon tear with an intact lacertus fibrosis. Surgery was performed 22 days after injury. On inspection, the distal biceps tendon was coiled, encased in scar tissue, and unable to be reduced to the radial tuberosity. Dissection of the scar tissue and unraveling of the tendon provided additional length, allowing anatomic repair. Postoperatively, the patient regained full range of motion and strength and returned to work without restrictions. After a distal biceps brachii tear in which the lacertus fibrosis remains intact, the coiled tendon may become enveloped in a sheath of scar tissue. Dissection of the "pseudosheath" unveils the native tendon and allows reduction to the radial tuberosity. Cadaveric analysis shows that the pseudosheath may conceal 6 cm of coiled tendon. When the lacertus fibrosis remains intact after distal biceps tendon rupture, the tethered tendon stump may coil, become encased in scar tissue, and resemble the native tendon. Failure to identify the native tendon could result in the loss of 6 cm of tendon. Copyright 2014, SLACK Incorporated.

  18. 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

  19. SPORT AND EXERCISE BIOMECHANICS (BIOS INSTANT NOTES

    Directory of Open Access Journals (Sweden)

    Paul Grimshaw

    2007-06-01

    Full Text Available DESCRIPTION Instant Notes on Sport and Exercise Biomechanics provides a broad overview of the fundamental concepts in exercise and sport biomechanics. PURPOSE The book aims to provide instant notes on essential information about biomechanics, and is designed to help undergraduate students to grasp the corresponding subjects in physical effort rapidly and easily. AUDIENCE The book provides a useful resource for undergraduate and graduate students as a fundamental reference book. For the researcher and lecturer it would be a starting point to plan and prepare more detailed experimental designs or lecture and/or laboratory classes in the field of exercise and sport biomechanics. It would also be interest to anyone who wonders the concepts like momentum possessed, whole body angular momentum, opposite parallel forces, superman position, parabolic flight path, joint/normal reaction force, etc. FEATURES This textbook is divided into following sections from A to F: kinematics of motion, kinetics of linear motion, kinetics of angular motion, special topics, applications and measurement techniques, respectively. In sub-sections the kinematics of motion are reviewed in detail, outlining the physics of motion. Furthermore, the discussions of mechanical characteristics of motion, the mechanisms of injury, and the analysis of the sport technique provide a source of valuable information for both students and lecturers in appropriate fields. ASSESSMENT This book is an important reading for biomechanics students, teachers and even researchers as well as anyone interested in understanding motion.

  20. [Biomechanic of the asymmetrical headgear].

    Science.gov (United States)

    Sander, F G

    1990-11-01

    The asymmetrical headgear is a very useful treatment device for the unilateral distalisation of molars or for the correction of an unilateral anchorage loss. 1. The dimension of the asymmetrical effect depends on the configuration of the outer bows. 2. The function of an asymmetrical face-bow can be increased or decreased by eccentric bendings. 3. According to the geometry at the outer-bows the force at the outer-bow is divided at a different percentage onto the molars. 4. While the forces increase the asymmetrical effect will decrease when the outer-bow is too flexible. 5. Attention has to be payed at each control-appointment to the distance of the longer outer-bow to the cheek. 6. The asymmetrical swivel face-bow did not produce a greater asymmetrical function than other asymmetrical headgears. The reason of this fact is, that only the geometry of the outer-bows is responsible for the unilateral distalisation. 7. The asymmetrical swivel face-bow as described above is advisable to use because eccentric bendings and less forces at the outer-bows will decrease, stop or even reverse the asymmetrical effect. 8. The side-effect of any asymmetrical face-bow is a lateral force-component. This force-component can cause a cross-bite at the molar which has to be more distalized. The molar which is not be moved by the asymmetrical face-bow will be moved buccally by this force-component. 9. The swivel face-bow according to Sander prevents the buccal movement of the molar which should not be moved. But the tendency to create a cross-bite for the molar which should be more distalized, increases. 10. The swivel face-bow according to Sander can be combined with all well-known extraoral tractions. 11. Equal forces at the outer-bows can be reached while using a cervical-pull neckstrap according to Sander. 12. The asymmetrical face-bow and the bite-jumping-appliance can be used simultaneously if the face-bow inserts directly into the attachments of the molar bands.

  1. 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.

  2. 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.

  3. Potassium secretion in mammalian distal colon

    DEFF Research Database (Denmark)

    Sørensen, Mads Vaarby

    2009-01-01

    . 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......2 subunits in mice treated on an aldosterone increasing diet (high K+). Immunolabelling showed BK channel localisation in the luminal membrane which also was up-regulated in animals treated on a high K+ diet. Taken together these results firmly prove that aldosterone-stimulated K+ secretion......-/- mouse, we could functionally isolate the cAMP-activated K+ conductance as the BK channel. In addition we found the cAMP-activated K+ conductance to be further up-regulated by aldosterone. Taken together, these results show cAMP-activated K+ secretion occurs via a regulated specific splice variant...

  4. Osteochondritis of the Distal Tibial Epiphysis

    Directory of Open Access Journals (Sweden)

    Firass EL Hajj

    2012-01-01

    Full Text Available Osteochondritis of the distal tibial epiphysis is a very rare entity. 9 cases have been described in 7 articles and 8 other cases have been mentioned in textbooks. This paper describes the 10th case of osteochondritis of the distal tibial epiphysis and summarizes the clinical and radiological presentations of the 9 other cases. The etiology of this entity is well debated in the literature. We believe that it results from a vascular abnormality in the distal tibial epiphysis associated with a mechanical stress (trauma, excessive overload, etc.. Since it is a self-limited disease, the prognosis is good and the younger the patient is the better the prognosis will be. In general, this entity responds well to conservative treatment.

  5. Diagnostic modalities for distal radioulnar joint.

    Science.gov (United States)

    Jens, S; Luijkx, T; Smithuis, F F; Maas, M

    2017-05-01

    The first imaging modality in patients suspected of distal radioulnar joint pathology should be conventional radiography to exclude or diagnose wrist pathology including osteoarthritis, rheumatoid arthritis, calcium pyrophosphate deposition disease, (healed) fractures, or impaction syndromes. When conventional radiography is inconclusive, high resolution 3 Tesla magnetic resonance imaging is advised. We provide a broad overview of the literature regarding the use of intra-articular contrast both with computed tomography (CTA) or magnetic resonance imaging (MRA). Conventional arthrography and unenhanced computed tomography are not indicated. This article discusses the most useful imaging techniques in terms of clinical indications, patient positioning, technical imaging requirements, and diagnostic performance in patients with suspected distal radioulnar joint pathology. Furthermore, the most prevalent pathologies are discussed, with the focus on imaging characteristics in both stable and unstable distal radioulnar joints.

  6. 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.

  7. 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...

  8. 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

  9. Management of Malunions of the Distal Radius

    OpenAIRE

    Yaniel Truffin Rodriguez; Osmany Pérez Martínez; Rafael Esmandy Gómez Arregoitía; Indira L. Gómez Gil

    2015-01-01

    Fractures of the distal radius often present with a group of major complications. Of these, malunion is one of the most disabling. Its management through salvage procedures is essential for its correction. The case of a 60-year-old healthy woman of urban origin treated at the Dr. Gustavo Aldereguía Lima University General Hospital in Cienfuegos because of a malunion of the distal end of the left radius as a result of a previous Colles' fracture is presented. The patient complained of severe p...

  10. 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.

  11. Biomechanics of intramedullary fracture fixation.

    Science.gov (United States)

    Kyle, R F

    1985-11-01

    Intramedullary rodding allows excellent control of bending forces on long bone fractures when adequate sized rods are used. This is made possible by reaming when necessary. Torsional stability is poor if adequate bone nail contact is not obtained and there is little bone fragment interdigitation. This can be optimized with the interlocking system, especially with proximal and distal fractures. Intramedullary rods allow transmission of compressive load so there must be adequate bone to bone contact without comminution to prevent shortening. If a great deal of comminution is present, an interlocking system must be used to resist compressive loads. The interlocked devices have not been proven to be a detriment to union and indeed are a semi-rigid fixation system when used in comminuted shaft fractures. The strength of an osteosynthesis with an intramedullary rod depends on the geometry of the rod and the geometry of the fracture complex. Both locked and nonlocked intramedullary rods perform extremely well when one understands the mechanical principles involved in intramedullary rodding and pays close attention to detail.

  12. The vertebral biomechanic previous and after kyphoplasty.

    Science.gov (United States)

    Pesce, V; Piazzolla, Andrea; Moretti, L; Carlucci, S; Parato, C; Maxy, P; Moretti, B

    2013-10-01

    The biomechanical understanding of increasing anterior column load with progressing kyphosis leading to subsequent vertebral compression fracture (VCF) established the basic rationale for kyphoplasty. The lumbar spine can support an effort of 500 kg in the axis of the vertebral body, and a bending moment of 20 Nm in flexion. Consequently, if this effort is forward deviated of only 10 cm, the acceptable effort will be reduced to 20 kg so it is important to restore the vertebral anterior wall after a VCF: the authors describe the biomechanical modifications in the spine after kyphoplasty.

  13. Comparison of Maxillary Molar Distalization with an Implant-Supported Distal Jet and a Traditional Tooth-Supported Distal Jet Appliance

    Directory of Open Access Journals (Sweden)

    Mauro Cozzani

    2014-01-01

    Full Text Available Aim. To investigate and compare the efficiency of two appliances for molar distalization: the bone-anchored distal screw (DS and the traditional tooth-supported distal jet (DJ for molar distalization and anchorage loss. Methods. Tests (18 subjects were treated with a DS and controls (18 subjects were treated with a DJ. Lateral cephalograms were obtained before and at the end of molar distalization and were analysed. Shapiro Wilk test, unpaired t-test, and Wilcoxon rank-sum test were applied according to values distribution. The α level was fixed at 0.05. Results. Maxillary first molars were successfully distalized into a Class I relationship in all patients. The mean molar distalization and treatment time were similar in both groups. The DS group exhibited a spontaneous distalization (2.1±0.9 mm of the first premolar with control of anchorage loss, distal tipping, extrusion, and skeletal changes. Conclusions. The DS is an adequate compliance-free distalizing appliance that can be used safely for the correction of Class II malocclusions. In comparison to the traditional DJ, the DS enables not only a good rate of molar distalization, but also a spontaneous distalization of the first premolars.

  14. Fracture of the Distal Ulna Metaphysis in the Setting of Distal Radius Fractures.

    Science.gov (United States)

    Paksima, Nader; Khurana, Sonya; Soojian, Michael; Patel, Vipul; Egol, Kenneth

    2017-04-01

    Fracture of the metaphyseal region of the distal ulna is an uncommon injury that has been reported to occur concomitantly with distal radius fracture. We aimed to report the incidence and types of distal ulnar head and neck fractures associated with distal radius fractures and compare outcomes in operatively versus non-operatively treated patients. Over a 5-year period a distal radius fracture registry was maintained at our institution. Eleven of 512 consecutive patients had metaphyseal distal ulna fractures in association with distal radius fractures and at least 1-year follow-up. Baseline radiographs and functional data were obtained, and patients were followed at 1-week, 2-week, 3-week, 6-week, 3-month, 6-month, 1-year, and 2-year intervals. Patients were split into two treatment groups: Group 1 consisted of five non-operatively treated patients, and Group 2 consisted of six operatively treated patients. Four separate fracture patterns were observed: simple transverse or oblique fracture of the ulnar neck just proximal to the ulnar head, fracture of the neck region with concomitant fracture of the tip of the ulnar styloid, simple fracture of the ulnar head, and comminuted fracture of the ulnar head. There were no statistical differences between the two groups with regard to flexion, extension, supination, pronation, and functional outcomes. Ulnar fracture patterns observed did not easily fall into previously described categories, and we have proposed a new classification system. Simple fractures of the ulnar neck or head often do not require operative fixation.

  15. Outcome following distally locked volar plating for distal radius fractures with metadiaphyseal involvement.

    Science.gov (United States)

    Matullo, Kristofer S; Dennison, David G

    2015-06-01

    The surgical treatment of metadiaphyseal distal radius fractures may be difficult due to the associated articular or periarticular extension that limits standard fixation techniques. Longer distal radius volar locking plates allow stable fixation of the distal fragments while providing standard plate fixation in the proximal radius. We hypothesize that this plating technique allows adequate fixation to both the distal radius and metadiaphyseal fragments. The purpose of the study is to describe the outcomes, radiographic parameters, secondary surgeries, and complication rate with this device. A retrospective chart review was conducted on adult patients with a distal radius fracture and metadiaphyseal involvement treated with a volar, distally locked plate. All patients were followed up for radiographic union, with a mean time of 219 days (range 38-575). Fracture patterns, outcomes of range of motion, grip strength, and complications, as well as injury, post open reduction and internal fixation (ORIF), and finally, healed radiographic parameters were recorded. Twenty patients with 21 fractures were included. At union, mean radiographic parameters were the following: volar tilt of 8°, radial inclination of 27°, radial height of 14 mm, and ulnar variance of -1 mm. The mean final range of motion was 52° flexion, 50° extension, 68° pronation, and 66° supination. Complications included one infection and one plate removal. Four patients developed a nonunion requiring secondary procedures. There were no incidents of hardware failure or adhesions requiring tenolysis. Distally locked long volar plating for metadiaphyseal distal radius fractures is a safe and effective treatment option for these complex fracture patterns allowing anatomic restoration of the radial shaft and distal radius.

  16. Intramedullary nailing in distal tibial fracture

    Directory of Open Access Journals (Sweden)

    Damian Arroquy

    2015-11-01

    Methods The inclusion criteria of this study were skeletally mature patients with displaced fractures of the distal tibia treated with intramedullary nail with a minimum follow up of one year. Gustilo III open fractures and type C fractures of the AO classification (complete articular Stroke were excluded. The sample comprised 35 patients remained. The follow-up was 29.2 months. We evaluated the time of consolidation, malunion and complications. The functional results were described according to the AOFAS score. Results Of the 35 patients with fracture of the distal third of the tibia all of them presented fracture healing. The average time to union was 17.2 weeks (range: 11-26. Of the total sample, 5 patients had delayed union, requiring dynamic nail on average at 12 weeks. The malunion was present in 4 (11.4% patients. We found no  difference (p = 0.201 in the time to union between fractures associated with fractures of the fibula treated (13sem or not (17sem. The AOFAS score was 86 points. Conclusion Intramedullary nailing with multiple distal locks like a good alternative treatment for distal tibia fractures AO type A or B, with low complication rate and a high rate of consolidation.

  17. Medical Expulsive Therapy for Distal Ureteral Stones

    NARCIS (Netherlands)

    Tzortzis, Vassilios; Mamoulakis, Charalampos; Rioja, Jorge; Gravas, Stavros; Michel, Martin C.; de La Rosette, Jean J. M. C. H.

    2009-01-01

    Although minimally invasive treatments for ureteral stones are efficacious, they are not free of complications and are associated with high cost. Medical expulsive therapy (MET) has recently emerged as an alternative strategy for the initial management of small distal ureteral stories. A MEDLINE

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

    African Journals Online (AJOL)

    2014-03-01

    Mar 1, 2014 ... Methods: 11 consecutive patients (7 women, 4 men, mean age of 49.2 years) with ruptured distal PICA aneurysms were studied retrospectively. All had onset of acute intraventricular or cerebellar haemorrhage, and subarachnoid hemorrhage. (SAH). Hunt-Hess (HH) grades were H-H I in 1 patient, H-H II in ...

  19. 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: ...

  20. Double Plating of Distal Fibula Fractures.

    Science.gov (United States)

    Vance, Danica D; Vosseller, J Turner

    2017-12-01

    Distal fibula fractures are common orthopaedic injuries that often require open reduction internal fixation (ORIF) to anatomically reduce the fracture and minimize the risk of posttraumatic arthritis. In certain clinical situations, stouter fixation may be advantageous to decrease the risk of fixation failure. In this study, the authors report on 12 patients who underwent distal fibula ORIF with 2 one-third tubular plates. Twelve consecutive patients who underwent distal fibula ORIF with 2 one-third tubular plates were retrospectively reviewed. Clinical and radiographic outcomes were reviewed, and functional outcomes were obtained using the Foot and Ankle Outcome Score (FAOS). Institutional review board approval was obtained. All 12 fractures healed clinically and radiographically. One patient was lost to follow-up after healing of the fracture. One patient had removal of fibular hardware at 15 months after surgery. Ten patients had no hardware related pain and good ankle function. FAOS scores were obtained at a mean of 25.6 months after surgery and were as follows: pain (87.6, SD = 9.5), activities of daily living (90.4, SD = 14.5), symptoms (93.3, SD = 9.5), sports (89.5, SD = 18.1), and quality of life (57.4, SD = 21.3). Double plating of distal fibula fractures is a viable technique for problem fractures that potentially provides a readily accessible, low-cost alternative to other means of enhancing fixation. Level IV.

  1. Computed tomography diagnosis of distal radioulnar subluxation

    International Nuclear Information System (INIS)

    Wechsler, R.J.; Rifkin, M.D.; Edeiken, J.; Branch, H.M.

    1987-01-01

    Eight patients with suspected diagnosis of distal radioulnar joint (DRUJ) subluxation underwent computed tomographic (CT) scans of the wrist. Five underwent surgery and had DRUJ subluxation or dislocation; CT scans revealed subluxation in four. Three CT criteria for the evaluation of DRUJ subluxation are discussed and compared in this manuscript. (orig.)

  2. The effect of select pulp cavity conditions on stress field development in distal abutments in two types of fixed dental prostheses.

    Science.gov (United States)

    Manda, Mirianthi; Galanis, Christos; Venetsanos, Dimitrios; Provatidis, Christofer; Koidis, Petros

    2011-01-01

    Insufficient coronal tooth structure may require restoration of endodontically treated (ET) teeth with cast posts and cores (CPCs). The prognosis for these teeth is a matter of scientific debate, especially if they serve as distal abutments in cantilever fixed dental prostheses (FDPs). The purpose of this study was to study stress field development in distal abutments in two types of FDPs with different pulp cavity conditions. The methodology involved the development of four digital models in which the right mandibular premolars were splinted via an FDP with: (1) no cantilever and a vital distal abutment, (2) no cantilever and an ET CPC distal abutment, (3) a single-unit cantilever and a vital distal abutment, and (4) a single-unit cantilever with an ET CPC distal abutment. The models were analyzed using a three-dimensional finite element program, and von Mises stress values and patterns were evaluated. The results revealed that although the stress distribution patterns in dentin were dissimilar, the von Mises stress values registered for the vital and ET CPC distal abutment were not considerably different. However, higher stress values were detected in the dentin area surrounding the post-gutta-percha interface after CPC placement. The addition of the cantilever resulted in a considerable increase in stress on the dental tissue structures. CPCs appear to create a risk of potential fracture that is initiated in the dentin at the apex of the post. The type of restoration appears to have a much more serious impact on the stress pattern developed in the distal abutment, and the addition of a cantilever appears to biomechanically compromise both biologic and restorative structures.

  3. Ulnar shortening osteotomy for distal radius malunion.

    Science.gov (United States)

    Kamal, Robin N; Leversedge, Fraser J

    2014-08-01

    Background Malunion is a common complication of distal radius fractures. Ulnar shortening osteotomy (USO) may be an effective treatment for distal radius malunion when appropriate indications are observed. Methods The use of USO for treatment of distal radius fracture malunion is described for older patients (typically patients >50 years) with dorsal or volar tilt less than 20 degrees and no carpal malalignment or intercarpal or distal radioulnar joint (DRUJ) arthritis. Description of Technique Preoperative radiographs are examined to ensure there are no contraindications to ulnar shortening osteotomy. The neutral posteroanterior (PA) radiograph is used to measure ulnar variance and to estimate the amount of ulnar shortening required. An ulnar, mid-sagittal incision is used and the dorsal sensory branch of the ulnar nerve is preserved. An USO-specific plating system with cutting jig is used to create parallel oblique osteotomies to facilitate shortening. Intraoperative fluoroscopy and clinical range of motion are checked to ensure adequate shortening and congruous reduction of the ulnar head within the sigmoid notch. Results Previous outcomes evaluation of USO has demonstrated improvement in functional activities, including average flexion-extension and pronosupination motions, and patient reported outcomes. Conclusion The concept and technique of USO are reviewed for the treatment of distal radius malunion when specific indications are observed. Careful attention to detail related to surgical indications and to surgical technique typically will improve range of motion, pain scores, and patient-reported outcomes and will reduce the inherent risks of the procedure, such as ulnar nonunion or the symptoms related to unrecognized joint arthritis.  Level IV.

  4. Biomechanical, anthropometrical and physical profile of elite ...

    African Journals Online (AJOL)

    Literature indicates that deficiencies of certain parameters such as biomechanics, anthropometry, physical and motor abilities, may influence a netball players susceptibility to injury, as well as the players physical performance during a game. The primary aim of this study was to determine the physical profile of elite netball ...

  5. 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...

  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. Biomechanical Concepts for the Physical Educator

    Science.gov (United States)

    Strohmeyer, H. Scott

    2004-01-01

    The concepts and principles of biomechanics are familiar to the teacher of physical science as well as to the physical educator. The difference between the two instructors, however, is that one knows the language of science and the other provides an experientially rich environment to support acquisition of these concepts and principles. Use of…

  8. Biomechanical pulping : a mill-scale evaluation

    Science.gov (United States)

    Masood. Akhtar; Gary M. Scott; Ross E. Swaney; Mike J. Lentz; Eric G. Horn; Marguerite S. Sykes; Gary C. Myers

    1999-01-01

    Mechanical pulping process is electrical energy intensive and results in low paper strength. Biomechanical pulping, defined as the fungal treatment of lignocellulosic materials prior to mechanical pulping, has shown at least 30% savings in electrical energy consumption, and significant improvements in paper strength properties compared to the control at a laboratory...

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

    Indian Academy of Sciences (India)

    Prakash

    2009-10-29

    Oct 29, 2009 ... Bone is an important tissue in paleontological studies as it is a commonly preserved element in most fossil vertebrates, and can often allow its ... biomechanical studies now tend to use FEA. However, despite its use in .... the cross sectional area of each concentric annular region,. i.e. lamella, increases with ...

  10. The biomechanical interaction between horse and rider

    NARCIS (Netherlands)

    Cocq, de P.

    2012-01-01

    The forces exerted by a rider on a horse have a direct influence on the mechanical load experienced by the horse and consequently on its motion pattern. The aim of this thesis is to explore the biomechanical interaction between rider, saddle and horse in order to get insight in the loading of

  11. Incidence of Bacterial Pathogens following Biomechanical ...

    African Journals Online (AJOL)

    A correlation exists between endodontic microflora in pulpal disease and endodontic treatment failure. This study presents data on the recoverable bacterial pathogens following biomechanical treatment of infected root canals. Standard endodontic procedure were used to access tooth pulp cavity, processed and fluid ...

  12. In vivo biomechanics of cruciate ligament injuries

    NARCIS (Netherlands)

    Van de Velde, S.K.

    2016-01-01

    Measuring biomechanics of the knee with an acceptable degree of accuracy is difficult. When the in vivo knee joint motion is analyzed in all its six degrees-of-freedom without compromising on physiological loading conditions, the task becomes even more challenging. This thesis offers a brief

  13. A Biomechanical Analysis of the Karate Chop.

    Science.gov (United States)

    Cavanagh, Peter R.; Landa, Jean

    Although the sport of karate has been somewhat neglected by scientists, the following two isolated biomechanical studies exist in literature: (1) tracings of a karate chop in two planes were presented, but no data was given concerning the rates of movement of the limb segments, and (2) pre- and postimpact phenomena of five subjects were studied,…

  14. 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.

  15. 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.…

  16. 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

  17. Injury incidence and selected biomechanical, postural and ...

    African Journals Online (AJOL)

    The strongest predictors for lower extremity injuries (I>0.3) were uneven hips, pronated feet, tight hamstrings, anatomical leg length differences, gait pronation and a tall stature. It was concluded that certain postural and biomechanical imbalances in the lower extremities could contribute to injury among rugby union players.

  18. 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

  19. 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 ...

  20. Biomechanics and mechanobiology in functional tissue engineering.

    Science.gov (United States)

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

    2014-06-27

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. 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.

  2. Does computer use affect the incidence of distal arm pain?

    DEFF Research Database (Denmark)

    Mikkelsen, Sigurd; Lassen, Christina Funch; Vilstrup, Imogen

    2012-01-01

    To study how objectively recorded mouse and keyboard activity affects distal arm pain among computer workers.......To study how objectively recorded mouse and keyboard activity affects distal arm pain among computer workers....

  3. Biomechanical model produced from light-activated dental composite resins: a holographic analysis

    Science.gov (United States)

    Pantelić, Dejan; Vasiljević, Darko; Blažić, Larisa; Savić-Šević, Svetlana; Murić, Branka; Nikolić, Marko

    2013-11-01

    Light-activated dental composites, commonly applied in dentistry, can be used as excellent material for producing biomechanical models. They can be cast in almost any shape in an appropriate silicone mold and quickly solidified by irradiation with light in the blue part of the spectrum. In that way, it is possible to obtain any number of nearly identical casts. The models can be used to study the behavior of arbitrary structure under mechanical loads. To test the technique, a simple mechanical model of the tooth with a mesio-occluso-distal cavity was manufactured. Composite resin restoration was placed inside the cavity and light cured. Real-time holographic interferometry was used to analyze the contraction of the composite resin and its effect on the surrounding material. The results obtained in the holographic experiment were in good agreement with those obtained using the finite element method.

  4. 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.      

  5. Distal Fibula Fractures in National Football League Athletes

    OpenAIRE

    Werner, Brian C.; Mack, Christina; Franke, Kristina; Barnes, Ronnie P.; Warren, Russell F.; Rodeo, Scott A.

    2017-01-01

    Background: Despite the frequency of distal fibula fractures in elite athletes and the significant potential impact on the athletes’ season and future careers, little data exist characterizing the epidemiology of these injuries or, more importantly, return to competition. Purpose: To (1) evaluate the incidence of acute distal fibula fractures in National Football League (NFL) athletes, including isolated distal fibula and combined ankle fracture patterns; (2) analyze distal fibula fracture ra...

  6. 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

  7. 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.

  8. 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

  9. Carpal alignment in distal radial fractures

    Directory of Open Access Journals (Sweden)

    Jain Pankaj

    2002-05-01

    Full Text Available Abstract Background Carpal malalignment following the malunited distal radial fracture is described to develop as an adaptation to realign the hand to the malunion. It worsens gradually after healing of the fracture due to continued loading of the wrist. It is also reported to develop during the immobilization itself rather than after fracture healing. The present work was aimed to study the natural course and the quantitative assessment of such adaptive carpal realignment following distal radial fracture. Methods In a prospective study, 118 distal radial fractures treated with different modalities were followed-up with serial radiographs for a year for assessment of various radiological parameters. Results Two patterns of carpal malalignment were identified depending upon the effective radio-lunate flexion (ERLF measured on pre-reduction radiographs. The midcarpal malalignment was seen in 98 radial fractures (83% with the lunate following the dorsiflexed fracture fragment and a measured ERLF of less than 25°. The second pattern of radio-carpal malalignment showed the fracture fragment to dorsiflex without taking the lunate with a measured ERLF of more than 25°. The scaphoid did not follow the fracture fragment in both the patterns of malalignment. Conclusion It is better to assess distal radial fractures for any wrist ligamentous injury on the post-reduction film with the restored radial anatomy than on the pre-reduction film since most carpal malalignments get corrected with the reduction of the fracture. Similar carpal malalignment reappear with the redisplacement of the fracture as seen in pre-reduction radiographs and develops during the immobilization rather than as a later compensatory mechanism for the malunion.

  10. Ideal Characteristics of a Laser-Protected Endotracheal Tube: ABEA and AHNS Member Survey and Biomechanical Testing.

    Science.gov (United States)

    Friedman, Aaron D; Gerber, Mark E; Bhayani, Mihir K; Kuchta, Kristine; Kumar, Kanav; Ma, Aobo; Ren, Yupeng; Zhang, Li-Qun

    2018-04-01

    To determine the characteristics of laser-protected endotracheal tubes (LPETs) valued by otolaryngologists performing transoral laser surgery in the head and neck and to measure LPET stiffness. An online questionnaire was completed by American Broncho-Esophagological Association (ABEA) and American Head and Neck Society (AHNS) members. LPET distal end compliance was measured in a biomechanics laboratory. A total of 228 out of 2109 combined ABEA and AHNS members completed the survey. The following LPET characteristics, which were properties of the Medtronic Laser-Shield II tube (MLST), were highly valued: softness and flexibility, surface smoothness, and a tight-to-shaft balloon (all P < .01). Prior to industry-driven discontinuation of the MLST, 52% of surgeons (78% of fellowship-trained laryngologists [FTLs]) reported using it; afterward, 58% reported using the stainless steel, Mallinckrodt Laser-Flex tube (MLFT). Forty-six percent of all respondents (69% of FTLs) did not consider cost being a factor in LPET choice. Biomechanical testing revealed the distal end of the MLST to be 3.45 times more compliant than the MLFT ( P < .01). Members of the ABEA and AHNS, particularly FTLs, highly value distinguishing properties of the now discontinued MLST. Manufacturers should consider this in the design of new LPETs.

  11. Dermoscopic features of distal lateral subungual onychomycosis

    Directory of Open Access Journals (Sweden)

    Thansiha Nargis

    2018-01-01

    Full Text Available Background: Onychomycosis is a very common disease and accounts for upto 50% of the diseases affecting the nail apparatus. Diagnosis of onychomycosis is usually confirmed with the help of a potassium hydroxide (KOH mount and fungal culture. Onychoscopy can be a handy and additional tool for the diagnosis. Aims and Objectives: To determine the dermoscopic findings in distal lateral subungual onychomycosis (DLSO. Materials and Methods: A prospective study of 60 nails with a clinical and mycological diagnosis (KOH with Chicago sky blue positive of DLSO. Dermoscopic examination was performed using a Heine delta 20 plus dermatoscope and the features were recorded. Results: Longitudinal striae and jagged proximal edges seen in all 60 (100% patients. Intermittent spiked pattern was seen in 47 nails (78.3%. Chromonychia and distal irregular termination were noticed in 23 (38.3% and 7 (11.7% nails, respectively. Conclusions: Onychoscopy can be used as an important diagnostic tool while evaluating nail disease, especially in DLSO. Limitations: Small study sample and lack of comparison with other nail diseases that manifests with distal onycholysis.

  12. Miastenia grave distal: relato de caso

    Directory of Open Access Journals (Sweden)

    Scola Rosana Herminia

    2003-01-01

    Full Text Available Relatamos o caso de uma mulher de 30 anos com quadro de fraqueza muscular nos membros inferiores com predomínio distal com início há 7 anos. Na evolução apresentou fraqueza muscular nos membros superiores. O exame físico mostrava nervos cranianos sem alterações, hipotrofia bilateral de quadriceps e interósseos dos pés, redução da força muscular mais intensa em tibiais anteriores e interósseos dorsais dos pés e reflexos tendinosos globalmente hipoativos. Foi realizado teste de estimulação repetitiva que mostrou decremento maior que 10% no nervo fibular e ulnar. A dosagem de anticorpos anti-receptor de acetilcolina foi positiva. Tomografia computadorizada de tórax foi normal. Dosagem de hormônios tireoidianos mostrou evidências laboratoriais de hipertireoidismo, porém sem manifestações clínicas. Foi iniciado tratamento com piridostigmina havendo melhora importante do quadro clínico. A fraqueza distal é um sintoma inicial raro na miastenia grave (MG. Contudo, a MG deve entrar no diagnóstico diferencial de doenças que cursam com fraqueza muscular distal de membros superiores ou inferiores.

  13. 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.

  14. Annular ligament reconstruction with the superficial head of the brachialis: surgical technique and biomechanical evaluation.

    Science.gov (United States)

    Hackl, Michael; Wegmann, Kilian; Ries, Christian; Lappen, Sebastian; Scaal, Martin; Müller, Lars Peter

    2017-06-01

    The purpose of this study was to perform biomechanical testing of annular ligament (AL) reconstruction using the superficial head of the brachialis tendon (SHBT) as a distally based tendon graft. We hypothesized that posterior translation of the radial head following AL reconstruction with an SHBT graft does not significantly differ from intact specimens. Six fresh-frozen elbow specimens were used. The stability of the radial head against posterior translation forces (30 N) was evaluated in 0°, 45°, 90° and 120° of elbow flexion. Posterior translation was obtained for the intact AL, the sectioned AL and the reconstructed AL. Cyclic loading (100 cycles) in 90° of elbow flexion was performed for the intact and the reconstructed AL. Posterior translation of the radial head decreased during elbow flexion in native specimens. Sectioning of the AL significantly increased instability over the full range of motion. AL reconstruction with the SHBT restored the stability of the proximal radius but-other than the native AL-was not influenced by elbow flexion. In 120° of flexion the native AL provided significantly more stability when compared to the reconstructed AL. Cyclic loading did not provide significant differences between native and reconstructed specimens. We provide a feasible technique for AL reconstruction using the SHBT. The biomechanical results obtained in this study confirm the efficacy of the procedure. AL reconstruction restores the stability of the proximal radius, yet it cannot fully mimic the complex features of the intact AL.

  15. 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.

  16. Biomechanical research in artistic gymnastics: a review.

    Science.gov (United States)

    Prassas, Spiros; Kwon, Young-Hoo; Sands, William A

    2006-07-01

    Biomechanical research into artistic gymnastics has grown substantially over the years. However, most research is still skill oriented with few tries at generalization. Consequently, our understanding of the principles and bases of the sport, although improved, is still marginal with gaps in knowledge about technique attributes throughout the sport. For that reason, this review begins with an attempt to identify important variables contributing to successful performance. The review is presented in clusters of work in similar apparatuses culminating in Tables offering an 'at a glance' summary of knowledge in each cluster. The last section of the review tries to give some direction to future biomechanical research in gymnastics in issues relating to data collection--two-dimensional or three-dimensional, image size, frame rate--and analysis, such as descriptive or explanatory, simulation and optimization, and statistical issues.

  17. 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.

  18. 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

  19. 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.

  20. Biomechanics/risk management (Working Group 2)

    DEFF Research Database (Denmark)

    Sanz, Mariano; Naert, Ignace; Gotfredsen, Klaus

    2009-01-01

    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......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...

  1. 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.

  2. 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.

  3. Topographic matching of distal radius and proximal fibula articular surface for distal radius osteoarticular reconstruction.

    Science.gov (United States)

    Zhang, H; Chen, S; Wang, Z; Guo, Y; Liu, B; Tong, D

    2016-07-01

    During osteoarticular reconstruction of the distal radius with the proximal fibula, congruity between the two articular surfaces is an important factor in determining the quality of the outcome. In this study, a three-dimensional model and a coordinate transformation algorithm were developed on computed tomography scanning. Articular surface matching was performed and parameters for the optimal position were determined quantitatively. The mean radii of best-fit spheres of the articular surfaces of the distal radius and proximal fibula were compared quantitatively. The radial inclination and volar tilt following reconstruction by an ipsilateral fibula graft, rather than the contralateral, best resembles the values of the native distal radius. Additionally, the ipsilateral fibula graft reconstructed a larger proportion of the distal radius articular surface than did the contralateral. The ipsilateral proximal fibula graft provides a better match for the reconstruction of the distal radius articular surface than the contralateral, and the optimal position for graft placement is quantitatively determined. © The Author(s) 2015.

  4. 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

    (1.1%) had complete distal renal tubular acidosis and 14 (15.5%) incomplete distal renal tubular acidosis. Our results confirm that distal renal tubular acidification defects are associated with a more severe form of stone disease and make distal renal tubular acidosis one of the most frequent...... metabolic disturbances in renal stone formers. Distal renal tubular acidosis (dRTA) was relatively more common in female stone formers and most often found in patients with bilateral stone disease (36%). Since prophylactic treatment in renal stone formers with renal acidification defects is available...

  5. 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

  6. 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...

  7. [Fundamental biomechanic problems on osteosynthesis (author's transl)].

    Science.gov (United States)

    Labitzke, R

    1976-02-26

    By means of compression plate osteosynthesis, of the lateral tension band and of the treatment with external chucks the main demand for stability of osteosynthesises is derivated: by adjustified, in the resultant axial tension of the metal implantats is to produce only pressure in the entire fracture zone without detrimental osteosynthesis induced excentric powers. The joint biomechanic aspects of the three methods are worked out.

  8. Biomechanical Factors in Planning of Periacetabular Osteotomy

    Directory of Open Access Journals (Sweden)

    Noushin eNiknafs

    2013-12-01

    Full Text Available This study addresses the effects of cartilage thickness distribution and compressive properties in the context of optimal alignment planning for periacetabular osteotomy (PAO. The Biomechanical Guidance System (BGS is a computer-assisted surgical suite assisting surgeon’s in determining the most beneficial new alignment of a patient’s acetabulum. The BGS uses biomechanical analysis of the hip to find this optimal alignment. Articular cartilage is an essential component of this analysis and its physical properties can affect contact pressure outcomes. Patient-specific hip joint models created from CT scans of a cohort of 29 dysplastic subjects were tested with four different cartilage thickness profiles (one uniform and threenonuniform and two sets of compressive characteristics. For each combination of thickness distribution and compressive properties, the optimal alignment of the acetabulum was found; the resultant geometric and biomechanical characterization of the hip were compared among the optimal alignments. There was an average decrease of 49.2 +/- 22.27% in peak contact pressure from the preoperative to the optimal alignment over all patients. We observed an average increase of 19 +/- 7.7 degrees in center-edge angle and an average decrease of 19.5 +/- 8.4 degrees in acetabular index angle from the preoperative case to the optimized plan. The optimal alignment increased the lateral coverage of the femoral head and decreased the obliqueness of the acetabular roof in all patients. These anatomical observations were independent of the choice for either cartilage thickness profile, or compressive properties. While patient-specific acetabular morphology is essential for surgeons in planning PAO, the predicted optimal alignment of the acetabulum was not significantly sensitive to the choice of cartilage thickness distribution over the acetabulum. However, in all groups the biomechanically predicted optimal alignment resulted in decreased

  9. Integrative Structural Biomechanical Concepts of Ankylosing Spondylitis

    OpenAIRE

    Alfonse T. Masi; Kalyani Nair; Brian J. Andonian; Kristina M. Prus; Joseph Kelly; Jose R. Sanchez; Jacqueline Henderson

    2011-01-01

    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...

  10. Biomechanics of the pelvic floor musculature

    OpenAIRE

    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 very complex muscular structure. It is largely responsible for supporting both pelvic and abdominal organs and acts synergistically with the striated muscle of the anterior abdominal wall to generate ...

  11. 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...

  12. Basic biomechanic principles of knee instability.

    Science.gov (United States)

    Zlotnicki, Jason P; Naendrup, Jan-Hendrik; Ferrer, Gerald A; Debski, Richard E

    2016-06-01

    Motion at the knee joint is a complex mechanical phenomenon. Stability is provided by a combination of static and dynamic structures that work in concert to prevent excessive movement or instability that is inherent in various knee injuries. The anterior cruciate ligament (ACL) is a main stabilizer of the knee, providing both translational and rotatory constraint. Despite the high volume of research directed at native ACL function, pathogenesis and surgical reconstruction of this structure, a gold standard for objective quantification of injury and subsequent repair, has not been demonstrated. Furthermore, recent studies have suggested that novel anatomic structures may play a significant role in knee stability. The use of biomechanical principles and testing techniques provides essential objective/quantitative information on the function of bone, ligaments, joint capsule, and other contributing soft tissues in response to various loading conditions. This review discusses the principles of biomechanics in relation to knee stability, with a focus on the objective quantification of knee stability, the individual contributions of specific knee structures to stability, and the most recent technological advances in the biomechanical evaluation of the knee joint.

  13. Morphology and biomechanics of human heart

    Science.gov (United States)

    Chelnokova, Natalia O.; Golyadkina, Anastasiya A.; Kirillova, Irina V.; Polienko, Asel V.; Ivanov, Dmitry V.

    2016-03-01

    Object of study: A study of the biomechanical characteristics of the human heart ventricles was performed. 80 hearts were extracted during autopsy of 80 corpses of adults (40 women and 40 men) aged 31-70 years. The samples were investigated in compliance with the recommendations of the ethics committee. Methods: Tension and compression tests were performed with help of the uniaxial testing machine Instron 5944. Cardiometry was also performed. Results: In this work, techniques for human heart ventricle wall biomechanical properties estimation were developed. Regularities of age and gender variability in deformative and strength properties of the right and left ventricle walls were found. These properties were characterized by a smooth growth of myocardial tissue stiffness and resistivity at a relatively low strain against reduction in their strength and elasticity from 31-40 to 61-70 years. It was found that tissue of the left ventricle at 61-70 years had a lower stretchability and strength compared with tissues of the right ventricle and septum. These data expands understanding of the morphological organization of the heart ventricles, which is very important for the development of personalized medicine. Taking into account individual, age and gender differences of the heart ventricle tissue biomechanical characteristics allows to rationally choosing the type of patching materials during reconstructive operations on heart.

  14. following Wide Resection of Giant Cell Tumour of Distal Ulna

    Directory of Open Access Journals (Sweden)

    Elango Mariappan

    2013-01-01

    Full Text Available Giant cell tumour of the bone (GCT is a rare locally aggressive primary bone tumour with an incidence of 3% to 5% of all primary bone tumours. The most common location for this tumour is the long bone metaepiphysis especially of the distal femur, proximal tibia, distal radius, and the proximal humerus. Involvement of distal ulna is rare accounting for 0.45% to 3.2%. Considering local aggressive nature and high recurrence, wide resection is the treatment recommended. Instability of ulnar stump and ulnar translation of the carpals are known complications following resection of distal ulna. To overcome these problems, we attempted a newer technique of distal ulna reconstruction using proximal fibula and TFCC reconstruction using palmaris longus tendon following wide resection of giant cell tumour of distal ulna in a 44-year-old male. This technique of distal radioulnar joint reconstruction has excellent functional results with no evidence of recurrence after one-year followup.

  15. 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.

  16. The role of hand-assisted laparoscopic distal gastrectomy for distal gastric cancer.

    Science.gov (United States)

    Kim, Y W; Bae, J M; Lee, J H; Ryu, K W; Choi, I J; Kim, C G; Lee, J S; Rho, J Y

    2005-01-01

    The aim of this study was to evaluate the role of hand-assisted distal gastrectomy (HALDG) for gastric cancer. This study prospectively enrolled 16 patients who underwent HALDG for early gastric cancer and matched them individually by sex, age, and body mass index to patients who underwent laparoscopically assisted distal gastrectomy (LADG) or open distal gastrectomy (ODG). Surgical outcomes were compared among the surgical methods. The mean operating time was the longest for the HALDG group, whereas wound size of the HALDG group was intermediate between that of the LADG and the ODG groups. The other surgical outcomes, such as the number of harvested lymph nodes, were not different among the groups. According to the findings, HALDG may not be as beneficial for patients with early gastric cancer as has been previously suggested. However, because of easier hand-eye coordination, HALDG may be an excellent bridge learning technique as a surgeon gains experience in laparoscopic gastrectomy.

  17. Biomechanical Studies and Optical Digitizer Development for Enhanced Orthopedic Footwear

    National Research Council Canada - National Science Library

    Houston, Vern

    2001-01-01

    .... Custom designed and manufactured orthopedic footwear is also an essential component in treatment and rehabilitative care of persons with neuromusculoskeletal foot/ankle pathologies, biomechanical...

  18. The biomechanics of soccer: a review.

    Science.gov (United States)

    Lees, A; Nolan, L

    1998-04-01

    This review considers the biomechanical factors that are relevant to success in the game of soccer. Three broad areas are covered: (1) the technical performance of soccer skills; (2) the equipment used in playing the game; and (3) the causative mechanisms of specific soccer injuries. Kicking is the most widely studied soccer skill. Although there are many types of kick, the variant most widely reported in the literature is the maximum velocity instep kick of a stationary ball. In contrast, several other skills, such as throwing-in and goalkeeping, have received little attention; some, for example passing and trapping the ball, tackling, falling behaviour, jumping, running, sprinting, starting, stopping and changing direction, have not been the subject of any detailed biomechanical investigation. The items of equipment reviewed are boots, the ball, artificial and natural turf surfaces and shin guards. Little of the research conducted by equipment manufacturers is in the public domain; this part of the review therefore concentrates on the mechanical responses of equipment, player-equipment interaction, and the effects of equipment on player performance and protection. Although the equipment has mechanical characteristics that can be reasonably well quantified, the player-equipment interaction is more difficult to establish; this makes its efficacy for performance or protection difficult to predict. Some soccer injuries may be attributable to the equipment used. The soccer boot has a poor protective capability, but careful design can have a minor influence on reducing the severity of ankle inversion injuries. Performance requirements limit the scope for reducing these injuries; alternative methods for providing ankle stability are necessary. Artificial surfaces result in injury profiles different from those on natural turf pitches. There is a tendency for fewer serious injuries, but more minor injuries, on artificial turf than on natural turf pitches. Players adapt to

  19. OUTCOME OF FRACTURE OF INTRAARTICULAR DISTAL FEMUR TREATED WITH DISTAL FEMUR LOCKING COMPRESSION PLATE

    Directory of Open Access Journals (Sweden)

    Swapna Pran Saikia

    2017-10-01

    Full Text Available BACKGROUND The most challenging fractures faced by orthopaedic surgeons are the distal fractures of femur, especially the intraarticular distal femoral fractures. These fractures have been classified according to Orthopaedic Trauma Association (OTA 33-C3. Distal femoral fractures account to 4-7% of all femoral fractures and are less common compared to hip fractures. The aim of the study is to study the functional outcome of fracture of intraarticular distal femur treated with distal femur locking compression plate. MATERIALS AND METHODS This study is a prospective study, which comprised of 30 patients of intraarticular distal femur fracture AO classification 33-C3 who were treated by locking compression plate at Jorhat Medical College and Hospital, Jorhat, Assam. This study was conducted during February 2015 to April 2017. The functional outcome was studied using Neer’s score, outcome of radiology and complication with fracture fixation using LCP. RESULTS Out of 30 patients, 22 were males (73.3% and 8 were females (26.7%. 18 patients had fracture right hand side and 12 patients had left-handed fractures. A 19 years old was the youngest patient and 72 years was the oldest patient. About 70% patients had sustained road traffic accidents and 10% had sustained fall from a height. Four days was the average trauma to operative interval, 22 patients were operated extensile lateral approach and 8 patients were operated by swashbuckler approach. 12 weeks was the average weightbearing duration, 21 weeks was average time for fracture healing. 10 patients had C1 (33.3%, 12 patients had C2 (40% and 8 patients had C3 (26.7% type of fracture according to AO classification. Among 30 patients, 13 patients have shown excellent results, 7 patients have good results, 5 fair results and 5 poor results. Primary bone grafting was done in 4 patients for severely comminuted type C3 fracture. Secondary bone grafting was done in 2 patients who had delayed union at 4

  20. Repair of distal biceps brachii tendon ruptures.

    Science.gov (United States)

    Bell, R H; Wiley, W B; Noble, J S; Kuczynski, D J

    2000-01-01

    This study consisted of 26 male patients with distal biceps tendon ruptures, 2 of whom had bilateral injuries, making the total number of ruptures 28. The average age at injury was 45 years. The treatment groups were the following: 3 were treated without surgery, 4 were repaired with brachialis tenodesis, and 21 were reattached to the radial tuberosity by the 2-incision Boyd-Anderson approach. Patients underwent follow-up a minimum of 14 months after surgery, with the average being 43 months. Outcome was evaluated based on the physical examination, isokinetic testing of strength and endurance of flexion and supination, and radiographic analysis.

  1. 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.)

  2. Periosteal osteoblastoma of the distal femur

    International Nuclear Information System (INIS)

    Nakatani, Tetsuya; Yamamoto, Tetsuji; Akisue, Toshihiro; Marui, Takashi; Hitora, Toshiaki; Kawamoto, Teruya; Nagira, Keiko; Yoshiya, Shinichi; Kurosaka, Masahiro; Fujita, Ikuo; Matsumoto, Keiji

    2004-01-01

    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.)

  3. 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.

  4. Distal radius fracture after proximal row carpectomy

    OpenAIRE

    Igeta, Yuka; Naito, Kiyohito; Sugiyama, Yoichi; Obata, Hiroyuki; Aritomi, Kentaro; Kaneko, Kazuo; Obayashi, Osamu

    2015-01-01

    Introduction: We encountered a patient with distal radius fracture (DRF) after proximal row carpectomy (PRC). The mechanism of the DRF after PRC is discussed in this report. Presentation of case: The patient was a 73-year-old female who had undergone PRC due to Kienböck disease before. The wrist range of motion was: 45° on dorsiflexion and 20° on flexion. DRF has occurred at 3 years after PRC. The fracture type was extra-articular fracture. Osteosynthesis was performed using a volar lockin...

  5. Biomechanical Comparison of Transoral and Transbuccal Lateral ...

    African Journals Online (AJOL)

    2018-01-24

    Jan 24, 2018 ... All testings were performed on a servo‑hydraulic testing ... Plate Fixation for the Management of Mandibular Angle Fractures .... the fracture line. All of the osteotomies were performed on a standard basis. The superior border of the osteotomy was set. 3 mm distal to the last molar of the mandible, and a.

  6. STUDY OF FUNCTIONAL OUTCOME OF DISTAL FEMORAL FRACTURES MANAGED WITH LOCKING COMPRESSION PLATE

    Directory of Open Access Journals (Sweden)

    Majji Chandrasekharam Naidu

    2017-12-01

    uniformly successful. This paper includes detailed study on behaviour of fractures of distal femur after internal fixation and an attempt is made to manage these fractures with early ambulation and least disability. Technique of open reduction and fixation of LCP provides biomechanically stable construct. Several clinical studies have established with LCP as a biologically friendly and technically sound methods of fixation.

  7. 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.

  8. 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.

  9. 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

  10. Distal radius fracture after proximal row carpectomy.

    Science.gov (United States)

    Igeta, Yuka; Naito, Kiyohito; Sugiyama, Yoichi; Obata, Hiroyuki; Aritomi, Kentaro; Kaneko, Kazuo; Obayashi, Osamu

    2015-01-01

    We encountered a patient with distal radius fracture (DRF) after proximal row carpectomy (PRC). The mechanism of the DRF after PRC is discussed in this report. The patient was a 73-year-old female who had undergone PRC due to Kienböck disease before. The wrist range of motion was: 45° on dorsiflexion and 20° on flexion. DRF has occurred at 3 years after PRC. The fracture type was extra-articular fracture. Osteosynthesis was performed using a volar locking plate. No postoperative complication developed, the Mayo score was excellent at 6 months after surgery, and the daily living activity level recovered to that before injury. Since the wrist range of motion decreased and the lunate fitted into the joint surface after PRC, making the forearm join with the hand like a single structure, pressure may have been loaded on the weak distal end of the radius from the dorsal side, causing volar displacement and fracture. The pressure distribution and range of motion of the radiocarpal joint after PRC are different from those of a normal joint, and the mechanism of fracture also changes due to PRC. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. [Carpal malalignment following distal radius fracture].

    Science.gov (United States)

    Coulet, B; Gauci, M-O; Lazerges, C; Chammas, M

    2016-12-01

    Adaptive carpal malalignment is the consequence of malunion of the distal radius. Since the radial metaphysis and capitate have to be aligned, any disorientation of the radial epiphysis will force the proximal carpal row to adapt, as it is the only mobile element. There are two types of adaptation depending where the compensative occurs: (1) midcarpal - leading to flexion between the lunate and capitate, with the lunate maintaining a normal relationship with the radial epiphysis axis; (2) radiocarpal - combining flexion and dorsal displacement of the lunate relative to the axis of the radial epiphysis, with the midcarpal joint remaining aligned. Clinically, adaptive carpal malalignment is not the first reason for consultation in cases of distal radius malunion. It occurs in cases of moderate deformity with preserved pronation-supination in a young patient who has good mobility. It generates dorsal pain that may be associated with a snapping sensation. The diagnosis requires strict lateral X-ray views. Over time, the wrist becomes stiff but analgesic and is often well tolerated functionally. This type of deformity has not been shown to lead to osteoarthritis. Osteotomy to correct the malunion is the only way to treat adaptive carpal malalignment in active young patients who have a mobile but painful wrist. Copyright © 2016 SFCM. Published by Elsevier Masson SAS. All rights reserved.

  12. 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.

  13. Clinical profile of distal renal tubular acidosis

    Directory of Open Access Journals (Sweden)

    Ratan Jha

    2011-01-01

    Full Text Available To determine the clinical profile and progression of renal dysfunction in distal renal tubular acidosis (dRTA, we retrospectively studied 96 consecutive cases of dRTA diagnosed at our center. Patients with unexplained metabolic bone disease, short stature, hypokalemia, re-current renal stones, chronic obstructive uropathy or any primary autoimmune condition known to cause dRTA were screened. Distal RTA was diagnosed on the basis of systemic metabolic acidosis with urine pH >5.5 and positive urine anion gap. In those patients who had fasting urine pH >5.5 with normal baseline systemic pH and bicarbonate levels (incomplete RTA, acid load test with ammonium chloride was done. A cause of dRTA could be established in 53 (54% patients. Urological defect in children (22/44 and autoimmune disease in adults (11/52 were the commonest causes. Hypokalemic paralysis, proximal muscle weakness and voiding difficulty were the common modes of presentation. Doubling of serum creatinine during the study period was noted in 13 out of 27 patients who had GFR 60 mL/min (P <0.005. In conclusion, urological disorders were the commonest cause of dRTA in children while autoimmune disorders were the commonest asso-ciation in adults. Worse baseline renal function, longer duration of disease and greater frequency of nephrolithiasis/nephrocalcinosis and urological disorders were noted in those who had wor-sening of renal dysfunction during the study period.

  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. Comparison of Jones jig molar distalization appliance with extraoral traction.

    Science.gov (United States)

    Haydar, S; Uner, O

    2000-01-01

    In this study, 20 patients were evaluated. Ten were treated with intraoral distalization followed by fixed appliance therapy, and 10 were treated with extra oral traction followed by fixed appliance therapy. Molar relationship correction was achieved in 2.5 months with intraoral distalization and in 10.7 months with extraoral distalization. A significant anterior movement of the anchorage unit (P <.001) was observed with the intraoral distalization and a significant distal drift of premolars was observed in the headgear group (P <.05). Palatal plane was found to tip downward significantly in the headgear group (P <.05). Total outcome of the 2 methods were discussed evaluating the advantages and disadvantages of the 2 distalization methods.

  17. The Supination-Pronation Test for Distal Biceps Tendon Rupture.

    Science.gov (United States)

    Metzman, Louis S; Tivener, Kristin A

    2015-10-01

    Prompt diagnosis of a distal biceps tendon complete rupture increases the ability to perform a primary repair and to restore motion and strength. When examining an acute injury, it is important to isolate the biceps brachii tendon from the lacertus fibrosus and the brachialis because the examiner may mistakenly miss a distal tendon rupture by not isolating supination and pronation. The supination-pronation test can be performed easily in the acute setting and confirms attachment of the biceps tendon distally to the bicipital tuberosity of the radius. If the distal biceps tendon is intact, there is substantial change in the shape of the biceps as the arm is supinated (the biceps moves proximally), then pronated (the biceps moves distally). Clinically, the supination-pronation test has been found to be a reliable, pain-free test that should be incorporated in the physical examination to evaluate patients for distal biceps injury.

  18. 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...... (1.1%) had complete distal renal tubular acidosis and 14 (15.5%) incomplete distal renal tubular acidosis. Our results confirm that distal renal tubular acidification defects are associated with a more severe form of stone disease and make distal renal tubular acidosis one of the most frequent...... metabolic disturbances in renal stone formers. Distal renal tubular acidosis (dRTA) was relatively more common in female stone formers and most often found in patients with bilateral stone disease (36%). Since prophylactic treatment in renal stone formers with renal acidification defects is available...

  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 study of the funnel technique applied in thoracic ...

    African Journals Online (AJOL)

    Background: Funnel technique is a method used for the insertion of screw into thoracic pedicle. Aim: To evaluate the biomechanical characteristics of thoracic pedicle screw placement using the Funnel technique, trying to provide biomechanical basis for clinical application of this technology. Methods: 14 functional spinal ...

  2. 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…

  3. Biomechanical effects of trees on soil and regolith: beyond treethrow

    Science.gov (United States)

    Jonathan D. Phillips; Daniel A. Marion

    2006-01-01

    Forest soils are profoundly influenced by the biomechanical as well as the chemical and biological effects of trees. Studies of biomechanical impacts have focused mainly on uprooting (treethrow), but this study shows that at least two other effects are significant: physical displacement of soil by root growth, and infilling of stump rot pits. Rocky soils in the...

  4. 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…

  5. Steven Vogel and His Theory of Comparative Biomechanics

    Indian Academy of Sciences (India)

    IAS Admin

    motivating examples of biological systems. Vogel's books are different. He truly talks about biomechanics or rather comparative bio- mechanics. The book is perfect for teaching biomechan- ics to biology students. It will surely sensitize them to mechanics. But what about engineer- ing students who presumably know mechan ...

  6. 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…

  7. 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.; Jones, C. M.; Cornell, C.; Crist, B. D.; van Deurzen, D. F. P.; Beingessner, D.; Rowland, D. J.; Della Rocca, G. J.; Eygendaal, D.; McKee, D. M.; Verbeek, D. O. F.; Kalainov, D. M.; Polatsch, D.; Barreto, C. J. R.; Merchant, M.; Brilej, D.; Bijlani, N.; Silva, D. M.; Maman, E.; Ibrahim, I. M.; Nyszkiewicz, R.; Henry, P. D. G.; Ruchelsman, D.; Vishwanath, I. M.; Scott, D. F.; Harvey, E.; Grosso, E.; Stojkovska, E.; Pemovska, N. N.; Tolo, E. T.; Schumer, E. D.; Suarez, F.; Frihagen, F.; Lopez-Gonzalez, F.; Rodríguez, F. M.; Caro, G. C. Zambrano; Garnavos, C.; Athwal, G. S.; DeSilva, G.; Dyer, G. S. M.; Babis, G. C.; Gradl, G.; Frykman, G. K.; Gaston, R. G.; Garrigues, G.; Bayne, G. J.; Merrell, G.; Hernandez, G. R.; Gadbled, G.; Campinhos, L. A. B.; Balfour, G. W.; van der Heide, H.; Nancollas, M.; Young, C.; Pess, G. M.; Goost, H.; Alonso, H.; Villamizar, N. N.; Awan, H.; Routman, H. D.; Kimball, H. L.; Hofmeister, E.; McGraw, I.; Erol, K.; Biert, J.; Goslings, J. C.; Di Giovanni, J. F.; Bishop, J.; Abzug, J. M.; Greenberg, J. A.; Ahn, J.; McAuliffe, J.; Fanuele, J. C.; Boretto, J. G.; Choueka, J.; Murachovsky, J.; Ribeiro Filho, J. E. G.; Isaacs, J.; Izzi, J. A.; Kellam, J.; Giuffre, J. L.; Conflitti, J. M.; Wolf, J. M.; Scheer, J. H.; Capo, J. T.; Rubio, J.; Taras, J.; Wint, J.; Wolkenfelt, J.; Kakar, S.; Chivers, K.; Zyto, K.; Keener, J. D.; Eng, K.; Jeray, K.; Lee, K.; Malone, K. J.; Kabir, K.; Kraan, G. A.; Radcliff, K.; Dickson, K.; Poelhekke, L. M. S. J.; Mica, L.; Weiss, L.; Adolfsson, L. E.; Borris, L. C.; Lasanianos, N. G.; Schulte, L. M.; Paz, L.; Felipe, N. E. L.; Verhofstad, N. N.; van de Sande, M. A. J.; Mormino, M.; Richard, M. J.; Bonczar, M.; Hammerberg, E. M.; Menon, M.; Mazzocca, A. D.; Bronkhorst, M. W. G. A.; McKee, M.; Soong, M.; Costanzo, R. M.; Wood, M. M.; Abdel-Ghany, M. I.; Baskies, M.; Behrman, M.; Quell, M.; Kessler, M. W.; Palmer, M. J.; Prayson, M.; Pirpiris, M.; Ragsdell, M. M.; Krijnen, M. R.; Tyllianakis, M.; Grafe, M. W.; Schep, N.; Nelson, E.; Akabudike, N. M.; Shortt, N. L.; Horangic, N. J.; Leung, N. L.; Gummerson, N. W.; Kanakaris, N. K.; Wilson, N.; Calandruccio, J.; Semenkin, O. M.; Omid, R.; Veillette, C. J. H.; Richardson, M.; Ortiz, J. A.; Forigua, J. E.; Brink, P. R. G.; Kloen, P.; van Eerten, P. V.; Prashanth, I.; Althausen, P.; Lygdas, P.; Parnes, N.; Martineau, P. A.; Benhaim, P.; Blazar, P.; Schandelmaier, N. N.; Petrisor, B.; Jebson, P.; Levin, P.; Batson, W. A.; García, F.; Owens, P. W.; Guenter, L.; Haverlag, R.; Peters, R. W.; de Bedout, R.; Shatford, R.; Rowinski, S.; Verhagen, R. A. W.; Babst, R. H.; Hauck, R.; Papandrea, R.; Gilbert, R. S.; Rizzo, M.; Jenkinson, R.; Hutchison, R. L.; Liem, R.; Smith, R. M.; Tashijan, R.; Zura, R. D.; Page, R. S.; Pesantez, R.; Wagenmakers, R.; Abrams, J.; Spruijt, S.; Kennedy, S. A.; Mehta, S.; Beldner, S.; Schmidt, A.; Mitchell, S.; Fischer, S. T.; Checchia, S. L.; Dodds, S.; Nolan, B. M.; Kaplan, S.; Kaar, S. G.; Kronlage, S.; Meylaerts, S. A.; Steinmann, S.; McCabe, S. J.; Streubel, P. N.; Omara, T.; Swiontkowski, M.; Gosens, T.; DeCoster, T.; Taitsman, L.; Baxamusa, T.; Dienstknecht, T.; Kaplan, F. T. D.; Siff, T.; Begue, T.; Higgins, T.; Mittlmeier, T.; Apard, T.; Hughes, T.; Havliček, T.; Wyrick, T.; Rozental, N. N.; Stackhouse, T. G.; Giordano, V.; Varecka, T. F.; Nikolaou, V. S.; Jokhi, V.; Philippe, V.; Wall, C. J.; Walsh, C. J.; Hammert, W. C.; Weil, Y.; Satora, W.; Wright, T.; Zalavras, C.

    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

  8. [Exposed distal radio-ulnar dislocation by dog bite. Reconstructive surgical technique using a soft tissue graft and a syndesmotic fixation implant. Case report].

    Science.gov (United States)

    Vélez-de Lachica, J C; Brambila-Botello, C A; Valdez-Jiménez, L A

    2015-01-01

    The main function of the forearm is the supination, which is achieved largely through the biomechanical characteristics and stability of the distal radio-ulnar joint. There are several surgical techniques for the treatment of distal radio-ulnar dislocations isolated or associated with a fracture. We report the case of a canine trainer who was bitten at the wrist and distal forearm that came to the emergency department in where distal ulnar dislocation with muscle tendon exposure was diagnosed. Due to the offending agent and multiple soft tissue injuries the treatment with standard techniques was impossible. We describe the technique of treatment of this patient by placing autologous gracilis tendon graft, platelet rich plasma and two anchoring systems for ankle syndesmosis. Immobilization was maintained for six weeks with a subsequent rehabilitation and posterior valuation at 12, 18 and 28 weeks by the scale of MAYO, PRWE and DASH and finding a good result which implies the return to work and daily activities of the patient with minimal pain and limitation.

  9. 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

  10. 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.

  11. Aquaporin-4 expression in distal myopathy with rimmed vacuoles

    OpenAIRE

    Hoshi, Akihiko; Yamamoto, Teiji; Kikuchi, Saeko; Soeda, Tomoko; Shimizu, Keiko; Ugawa, Yoshikazu

    2012-01-01

    Abstract Background Distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy is clinically characterized by the early involvement of distal leg muscles. The striking pathological features of the myopathy are muscle fibers with rimmed vacuoles. To date, the role of aquaporin-4 water channel in distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy has not been studied. Case presentation Here, we studied the expression of aquaporin-4 in muscle fibers of a patient...

  12. Refractory rickets caused by mild distal renal tubular acidosis

    OpenAIRE

    Ji-Ho Lee; Joo Hyun Park; Tae-Sun Ha; Heon-Seok Han

    2013-01-01

    Type I (distal) renal tubular acidosis (RTA) is a disorder associated with the failure to excrete hydrogen ions from the distal renal tubule. It is characterized by hyperchloremic metabolic acidosis, an abnormal increase in urine pH, reduced urinary excretion of ammonium and bicarbonate ions, and mild deterioration in renal function. Hypercalciuria is common in distal RTA because of bone resorption, which increases as a buffer against metabolic acidosis. This can result in intractable rickets...

  13. 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 around...... a synovial joint. Although a number of studies and systematic reviews have been performed to assess the association of various factors with the development of KOA, a comprehensive overview focusing on biomechanical factors that are associated with the development of KOA is not available. The aim...... of this review is (1) to identify biomechanical factors that are associated with (the development of) KOA and (2) to identify the impact of other relevant risk factors on this association. METHODS AND ANALYSIS: Cohort, cross-sectional and case-control studies investigating the association of a biomechanical...

  14. Distal Xq duplication and functional Xq disomy

    Directory of Open Access Journals (Sweden)

    Schluth-Bolard Caroline

    2009-02-01

    Full Text Available Abstract Distal Xq duplications refer to chromosomal disorders resulting from involvement of the long arm of the X chromosome (Xq. Clinical manifestations widely vary depending on the gender of the patient and on the gene content of the duplicated segment. Prevalence of Xq duplications remains unknown. About 40 cases of Xq28 functional disomy due to cytogenetically visible rearrangements, and about 50 cases of cryptic duplications encompassing the MECP2 gene have been reported. The most frequently reported distal duplications involve the Xq28 segment and yield a recognisable phenotype including distinctive facial features (premature closure of the fontanels or ridged metopic suture, broad face with full cheeks, epicanthal folds, large ears, small and open mouth, ear anomalies, pointed nose, abnormal palate and facial hypotonia, major axial hypotonia, severe developmental delay, severe feeding difficulties, abnormal genitalia and proneness to infections. Xq duplications may be caused either by an intrachromosomal duplication or an unbalanced X/Y or X/autosome translocation. In XY males, structural X disomy always results in functional disomy. In females, failure of X chromosome dosage compensation could result from a variety of mechanisms, including an unfavourable pattern of inactivation, a breakpoint separating an X segment from the X-inactivation centre in cis, or a small ring chromosome. The MECP2 gene in Xq28 is the most important dosage-sensitive gene responsible for the abnormal phenotype in duplications of distal Xq. Diagnosis is based on clinical features and is confirmed by CGH array techniques. Differential diagnoses include Prader-Willi syndrome and Alpha thalassaemia-mental retardation, X linked (ATR-X. The recurrence risk is significant if a structural rearrangement is present in one of the parent, the most frequent situation being that of an intrachromosomal duplication inherited from the mother. Prenatal diagnosis is performed by

  15. Refractory rickets caused by mild distal renal tubular acidosis

    Directory of Open Access Journals (Sweden)

    Ji-Ho Lee

    2013-09-01

    Full Text Available Type I (distal renal tubular acidosis (RTA is a disorder associated with the failure to excrete hydrogen ions from the distal renal tubule. It is characterized by hyperchloremic metabolic acidosis, an abnormal increase in urine pH, reduced urinary excretion of ammonium and bicarbonate ions, and mild deterioration in renal function. Hypercalciuria is common in distal RTA because of bone resorption, which increases as a buffer against metabolic acidosis. This can result in intractable rickets. We describe a case of distal RTA with nephrocalcinosis during follow-up of rickets in a patient who presented with clinical manifestations of short stature, failure to thrive, recurrent vomiting, dehydration, and irritability.

  16. Outcome in corrective osteotomy for malunited distal radius fractures.

    Science.gov (United States)

    Samson, Lucjan; Treder, Mariusz; Kolarz, Krzysztof; Lorczyński, Adam

    2007-01-01

    This article reports outcome in osteotomy for malunion of distal radius fractures. We evaluated 12 patients with distal radius malunion (mean age 54), who were treated with corrective osteotomy. Wrist motion and grip strength were evaluated, along with examination of pre and post osteotomy radiographs. The indications for corrections were degree of deformity, limitation of function, pain, and the appearance of the wrist. The radiographic evaluation proved that the restoration of the normal anatomic relationship between the distal radius and ulna leads to significant improvement of the function of the hand, as measured by range of motion and grip strength. Osteotomy of the distal radius in cases of malunion gives favorable outcomes.

  17. Computed tomography diagnosis of distal radioulnar joint subluxation

    International Nuclear Information System (INIS)

    Lu Laijin; Nakamura, Ryogo; Nakao, Etsuhiro; Hidaka, Yasuhiro; Shionoya, Kaori.

    1995-01-01

    Although computed tomography (CT) provides the most reliable diagnostic information about distal radioulnar joint dislocation and subluxation, the method for assessing distal radioulnar joint integrity on CT is controversial. We studied roentgenographic diagnosis and three methods of CT diagnosis in 20 patients with suspected distal radioulnar dislocation or subluxation. Sensitivity was 35% in roentgenographic diagnosis and 70 to 100% in CT diagnosis. Of the three methods of CT diagnosis, Mino's radioulnar line method showed 100% sensitivity to subluxation including dislocation. We believe Mino's method is the most reliable method for the diagnosis of distal radioulnar dislocation in unilateral CT. (author)

  18. Computed tomography diagnosis of distal radioulnar joint subluxation

    Energy Technology Data Exchange (ETDEWEB)

    Lu Laijin [Bethune (N.) Medical Univ., Changchun, JL (China); Nakamura, Ryogo; Nakao, Etsuhiro; Hidaka, Yasuhiro; Shionoya, Kaori

    1995-08-01

    Although computed tomography (CT) provides the most reliable diagnostic information about distal radioulnar joint dislocation and subluxation, the method for assessing distal radioulnar joint integrity on CT is controversial. We studied roentgenographic diagnosis and three methods of CT diagnosis in 20 patients with suspected distal radioulnar dislocation or subluxation. Sensitivity was 35% in roentgenographic diagnosis and 70 to 100% in CT diagnosis. Of the three methods of CT diagnosis, Mino`s radioulnar line method showed 100% sensitivity to subluxation including dislocation. We believe Mino`s method is the most reliable method for the diagnosis of distal radioulnar dislocation in unilateral CT. (author).

  19. 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

  20. Clinical impact of United versus nonunited fractures of the proximal half of the ulnar styloid following volar plate fixation of the distal radius.

    Science.gov (United States)

    Buijze, Geert A; Ring, David

    2010-02-01

    Distal radius fractures are often associated with a fracture of the ulnar styloid at its base. This study tested the null hypothesis that there is no difference in outcome between patients with union and nonunion of a fracture of the proximal half of the ulnar styloid 6 months after volar plate fixation of a fracture of the distal radius. A total of 36 consecutive patients with fractures of both distal radius and the proximal half of the ulnar styloid enrolled in 1 of 2 clinical trials evaluating volar plate fixation of the distal radius had no treatment of the ulnar styloid fracture. Six months after surgery, wrist function was assessed using the Mayo wrist score and the Gartland and Werley score system, and arm-specific health status was measured using the Disabilities of the Arm, Shoulder, and Hand questionnaire. Pain was assessed on a 10-point ordinal scale. Nonunion of the fracture of the proximal half of the ulnar styloid was defined as no signs of consolidation on 6-month postoperative radiographs. At the 6-month follow-up, patients were assessed for overall wrist function but not specifically for ulnar-sided wrist problems or stability. Sixteen ulnar styloid fractures had united, and 20 had not. There were no differences in demographic and injury characteristics. There were no significant differences in motion; strength; Gartland and Werley scores; Mayo scores; Disabilities of the Arm, Shoulder, and Hand scores; or pain scores 6 months after fracture. Nonunion of a fracture of the proximal half of the ulnar styloid has no effect on wrist function, pain, and upper extremity-specific health status 6 months after volar plate fixation of a fracture of the distal radius. Therapeutic III. Copyright 2010. Published by Elsevier Inc.

  1. 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.

  2. Biomechanical metrics of aesthetic perception in dance.

    Science.gov (United States)

    Bronner, Shaw; Shippen, James

    2015-12-01

    The brain may be tuned to evaluate aesthetic perception through perceptual chunking when we observe the grace of the dancer. We modelled biomechanical metrics to explain biological determinants of aesthetic perception in dance. Eighteen expert (EXP) and intermediate (INT) dancers performed développé arabesque in three conditions: (1) slow tempo, (2) slow tempo with relevé, and (3) fast tempo. To compare biomechanical metrics of kinematic data, we calculated intra-excursion variability, principal component analysis (PCA), and dimensionless jerk for the gesture limb. Observers, all trained dancers, viewed motion capture stick figures of the trials and ranked each for aesthetic (1) proficiency and (2) movement smoothness. Statistical analyses included group by condition repeated-measures ANOVA for metric data; Mann-Whitney U rank and Friedman's rank tests for nonparametric rank data; Spearman's rho correlations to compare aesthetic rankings and metrics; and linear regression to examine which metric best quantified observers' aesthetic rankings, p dance movements revealed differences between groups and condition, p brain combines sensory motor elements into integrated units of behaviour. In this representation, the chunk of information which is remembered, and to which the observer reacts, is the elemental mode shape of the motion rather than physical displacements. This suggests that reduction in redundant information to a simplistic dimensionality is related to the experienced observer's aesthetic perception.

  3. Biomechanics of running with rocker shoes.

    Science.gov (United States)

    Sobhani, Sobhan; van den Heuvel, Edwin R; Dekker, Rienk; Postema, Klaas; Kluitenberg, Bas; Bredeweg, Steef W; Hijmans, Juha M

    2017-01-01

    Load reduction is an important consideration in conservative management of tendon overuse injuries such as Achilles tendinopathy. Previous research has shown that the use of rocker shoes can reduce the positive ankle power and plantar flexion moment which might help in unloading the Achilles tendon. Despite this promising implication of rocker shoes, the effects on hip and knee biomechanics remain unclear. Moreover, the effect of wearing rocker shoes on different running strike types is unexplored. The aim of this study was to investigate biomechanics of the ankle, knee and hip joints and the role of strike type on these outcomes. Randomized cross-over study. In this study, 16 female endurance runners underwent three-dimensional gait analysis wearing rocker shoes and standard shoes. We examined work, moments, and angles of the ankle, knee and hip during the stance phase of running. In comparison with standard shoes, running with rocker shoes significantly (pshoes significantly increased the positive work (14%), extension moment peak (6%), and extension moment impulse (12%). These findings indicate that although running with rocker shoes might lower mechanical load on the Achilles tendon, it could increase the risk of overuse injuries of the knee joint. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  4. Integrative structural biomechanical concepts of ankylosing spondylitis.

    Science.gov (United States)

    Masi, Alfonse T; Nair, Kalyani; Andonian, Brian J; Prus, Kristina M; Kelly, Joseph; Sanchez, Jose R; Henderson, Jacqueline

    2011-01-01

    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.

  5. How few? Bayesian statistics in injury biomechanics.

    Science.gov (United States)

    Cutcliffe, Hattie C; Schmidt, Allison L; Lucas, Joseph E; Bass, Cameron R

    2012-10-01

    In injury biomechanics, there are currently no general a priori estimates of how few specimens are necessary to obtain sufficiently accurate injury risk curves for a given underlying distribution. Further, several methods are available for constructing these curves, and recent methods include Bayesian survival analysis. This study used statistical simulations to evaluate the fidelity of different injury risk methods using limited sample sizes across four different underlying distributions. Five risk curve techniques were evaluated, including Bayesian techniques. For the Bayesian analyses, various prior distributions were assessed, each incorporating more accurate information. Simulated subject injury and biomechanical input values were randomly sampled from each underlying distribution, and injury status was determined by comparing these values. Injury risk curves were developed for this data using each technique for various small sample sizes; for each, analyses on 2000 simulated data sets were performed. Resulting median predicted risk values and confidence intervals were compared with the underlying distributions. Across conditions, the standard and Bayesian survival analyses better represented the underlying distributions included in this study, especially for extreme (1, 10, and 90%) risk. This study demonstrates that the value of the Bayesian analysis is the use of informed priors. As the mean of the prior approaches the actual value, the sample size necessary for good reproduction of the underlying distribution with small confidence intervals can be as small as 2. This study provides estimates of confidence intervals and number of samples to allow the selection of the most appropriate sample sizes given known information.

  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. Forces and moments generated by removable thermoplastic aligners: incisor torque, premolar derotation, and molar distalization.

    Science.gov (United States)

    Simon, Mareike; Keilig, Ludger; Schwarze, Jörg; Jung, Britta A; Bourauel, Christoph

    2014-06-01

    The exact force systems as well as their progressions generated by removable thermoplastic appliances have not been investigated. Thus, the purposes of this experimental study were to quantify the forces and moments delivered by a single aligner and a series of aligners (Invisalign; Align Technology, Santa Clara, Calif) and to investigate the influence of attachments and power ridges on the force transfer. We studied 970 aligners of the Invisalign system (60 series of aligners). The aligners came from 30 consecutive patients, of which 3 tooth movements (incisor torque, premolar derotation, molar distalization) with 20 movements each were analyzed. The 3 movement groups were subdivided so that 10 movements were supported with an attachment and 10 were not. The patients' ClinCheck (Align Technology, Santa Clara, Calif) was planned so that the movements to be investigated were performed in isolation in the respective quadrant. Resin replicas of the patients' intraoral situation before the start of the investigated movement were taken and mounted in a biomechanical measurement system. An aligner was put on the model, the force systems were measured, and the calculated movements were experimentally performed until no further forces or moments were generated. Subsequently, the next aligners were installed, and the measurements were repeated. The initial mean moments were about 7.3 N·mm for maxillary incisor torque and about 1.0 N for distalization. Significant differences in the generated moments were measured in the premolar derotation group, whether they were supported with an attachment (8.8 N·mm) or not (1.2 N·mm). All measurements showed an exponential force change. Apart from a few maximal initial force systems, the forces and moments generated by aligners of the Invisalign system are within the range of orthodontic forces. The force change is exponential while a patient is wearing removable thermoplastic appliances. Copyright © 2014 American Association of

  8. [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.

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

    African Journals Online (AJOL)

    Introduction: Distal hypospadias is the most common genital anomaly, occurring in almost 65% of all hypospadias cases. Although there are several surgical techniques for the treatment of distal hypospadias, it is clear that none can be used to correct all forms of hypospadias. The aim of the study was to evaluate urethral ...

  10. Experience with Quartey's Distal Penile Island Skin Flap ...

    African Journals Online (AJOL)

    Objective: To evaluate our experience with Quartey's distal penile island skin flap urethroplasty in the treatment of urethral stricture in two tertiary hospitals in South Western Nigeria. Patients and Methods: Between June 2002 and May 2005, 18 patients with a mean age of 42.2 years (range: 25 – 75 years) underwent distal ...

  11. Distal radius fractures: what determines the outcome after surgery?

    NARCIS (Netherlands)

    Teunis, T.

    2016-01-01

    This thesis addresses current issues in the outcome of operatively treated distal radius fractures. The general aim was to determine factors associated with adverse events, loss of motion, functional limitations, and opioid use after surgery. Injury In 3D complete articular distal radius fracture

  12. Outcome of ureteroscopy for the management of distal ureteric calculi

    African Journals Online (AJOL)

    Objective: To review our 5 years' experience with ureteroscopy treatment of distal ureteric calculi. Patients and methods: We reviewed the medical records of 136 patients who underwent ureteroscopic procedures for the treatment of distal ureteric calculi from February 2007 to October 2012. Patient and stone characteristics, ...

  13. 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|info:eu-repo/dai/nl/134440455; 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,

  14. Current concepts in fractures of the distal femur.

    Science.gov (United States)

    Link, B-C; Babst, R

    2012-01-01

    This paper describes current treatment strategies of distal femoral fractures as well as their evidence based rationale. The treatment of distal femoral fractures has improved with the evolution of plating and nailing technologies. The commonly selected surgical approaches are outlined and surgical treatment techniques including both internal and external fixation are discussed.

  15. 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.)

  16. Complications of Minimally Invasive Percutaneous Plating for Distal Tibial Fractures

    OpenAIRE

    Muzaffar, Nasir; Bhat, Rafiq; Yasin, Mohammad

    2016-01-01

    Background The management of distal tibia fractures continues to remain a source of controversy and debate. Objectives The aim of this study was to evaluate the various complications of minimally invasive percutaneous plate osteosynthesis (MIPPO) using a locking plate for closed fractures of distal tibia in a retrospective study. Patients and Methods Twenty-five patients with dista...

  17. 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.

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

    African Journals Online (AJOL)

    We tried to highlight that postmenopausal distal radius fractures attributed to osteoporosis, are not given much of consideration when lot of funds and researches are being diverted to osteoporosis and related diseases. Methods: 60 elderly female patients with distal radius fracture were studied for outcome. The primary ...

  19. Distal Oblique Bundle Reinforcement for Treatment of DRUJ Instability

    NARCIS (Netherlands)

    Brink, P.R.G.; Hannemann, P.F.

    2015-01-01

    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

  20. Population-based epidemiology and incidence of distal femur fractures

    DEFF Research Database (Denmark)

    Elsoe, Rasmus; Ceccotti, Adriano Axel; Larsen, Peter

    2018-01-01

    The literature lacks recent epidemiological studies on the incidence, trauma mechanism and fracture classification of distal femur fractures. The aim of the present study was to provide up-to-date information concerning the incidence of distal femur fractures in a large and complete population...

  1. 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

  2. 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.

  3. 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.

  4. Proximal and distal muscle fatigue differentially affect movement coordination

    Science.gov (United States)

    Cowley, Jeffrey C.

    2017-01-01

    Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor) or distal (finger flexor) muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p fatigue caused small but significant changes in trunk angles (2°, p fatigue protocols (p fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks. PMID:28235005

  5. Carbon fiber reinforced PEEK Optima--a composite material biomechanical properties and wear/debris characteristics of CF-PEEK composites for orthopedic trauma implants.

    Science.gov (United States)

    Steinberg, Ely L; Rath, Ehud; Shlaifer, Amir; Chechik, Ofir; Maman, Eran; Salai, Moshe

    2013-01-01

    The advantageous properties of carbon fiber reinforced polyetheretherketone (CF-PEEK) composites for use as orthopedic implants include similar modulus to bone and ability to withstand prolonged fatigue strain. The CF-PEEK tibial nail, dynamic compression plate, proximal humeral plate and distal radius volar plate were compared biomechanically (by four-point bending, static torsion of the nail, and bending fatigue) and for wear/debris (by amount of the debris generated at the connection between the CF-PEEK plate and titanium alloy screws) to commercially available devices. Four-point bending stress of the tibial nail and dynamic and distal radius plates yielded characteristics similar to other commercially available devices. The distal volar plate bending structural stiffness of the CF-PEEK distal volar plate was 0.542 Nm2 versus 0.376 Nm2 for the DePuy's DVR anatomic volar plate. The PHILOS proximal humeral internal locking system stainless steel plate was much stronger (6.48 Nm2) than the CF-PEEK proximal humeral plate (1.1 Nm2). Tibial nail static torsion testing showed similar properties to other tested nails (Fixion, Zimmer and Synthes). All tested CF-PEEK devices underwent one million fatigue cycles without failure. Wear test showed a lower volume of generated particles in comparison to the common implants in use today. Thus, these tested implants were similar to commercially used devices and can be recommended for use as implants in orthopedic surgery. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. 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.

  7. 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.

  8. Contribution of the Pubofemoral Ligament to Hip Stability: A Biomechanical Study.

    Science.gov (United States)

    Martin, Hal D; Khoury, Anthony N; Schröder, Ricardo; Johnson, Eric; Gómez-Hoyos, Juan; Campos, Salvador; Palmer, Ian J

    2017-02-01

    To determine the isolated function of the pubofemoral ligament of the hip capsule and its contribution to hip stability in external/internal rotational motion during flexion greater than 30° and abduction. Thirteen hips from 7 fresh-frozen pelvis-to-toe cadavers were skeletonized from the lumbar spine to the distal femur with the capsular ligaments intact. Computed tomographic imaging was performed to ensure no occult pathological state existed, and assess bony anatomy. Specimens were placed on a surgical table in supine position with lower extremities resting on a custom-designed polyvinylchloride frame. Hip internal and external rotation was measured with the hip placed into a combination of the following motions: 30°, 60°, 110° hip flexion and 0°, 20°, 40° abduction. Testing positions were randomized. The pubofemoral ligament was released and measurements were repeated, followed by releasing the ligamentum teres. Analysis of the 2,106 measurements recorded demonstrates the pubofemoral ligament as a main controller of hip internal rotation during hip flexion beyond 30° and abduction. Hip internal rotation was increased up to 438.9% (P ligament was released and 412.9% (P ligament were released, compared with the native state. The hypothesis of the pubofemoral ligament as one of the contributing factors of anterior inferior hip stability by controlling external rotation of the hip in flexion beyond 30° and abduction was disproved. The pubofemoral ligament maintains a key function in limiting internal rotation in the position of increasing hip flexion beyond 30° and abduction. This cadaveric study concludes previous attempts at understanding the anatomical and biomechanical function of the capsular ligaments and their role in hip stability. The present study contributes to the understanding of hip stability and biomechanical function of the pubofemoral ligament. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All

  9. 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 ...

  10. Physiopathology and biomechanics of hip osteoarthritis

    Directory of Open Access Journals (Sweden)

    M. Cutolo

    2011-09-01

    Full Text Available Several factors seem to play a relevant role in the pathogenesis of hip osteoarthritis. Among these, an altered biomechanic and neuromuscular integrity of the hip joint should be considered. This is a review of the recent international literature concerning the role of loads and strengths acting on the hip joint, in order to better understand the pathogenesis and the physiopathology of the hip osteoarthritis. The study of these factors might be important to prevent the development of the osteoarthritis and might suggest the conservative treatment. In particular, the role of the balance among the muscles working in maintaining the equilibrium of the acting strengths is matter of discussion. The articular and neuromuscular dysfunction might induce an altered load distribution in the hip, particularly on the articular cartilage surface, and seems to favour the development of hip osteoarthritis...

  11. Biomechanics of posterior dynamic stabilization systems.

    Science.gov (United States)

    Erbulut, D U; Zafarparandeh, I; Ozer, A F; Goel, V K

    2013-01-01

    Spinal rigid instrumentations have been used to fuse and stabilize spinal segments as a surgical treatment for various spinal disorders to date. This technology provides immediate stability after surgery until the natural fusion mass develops. At present, rigid fixation is the current gold standard in surgical treatment of chronic back pain spinal disorders. However, such systems have several drawbacks such as higher mechanical stress on the adjacent segment, leading to long-term degenerative changes and hypermobility that often necessitate additional fusion surgery. Dynamic stabilization systems have been suggested to address adjacent segment degeneration, which is considered to be a fusion-associated phenomenon. Dynamic stabilization systems are designed to preserve segmental stability, to keep the treated segment mobile, and to reduce or eliminate degenerative effects on adjacent segments. This paper aimed to describe the biomechanical aspect of dynamic stabilization systems as an alternative treatment to fusion for certain patients.

  12. Biomechanics of Posterior Dynamic Stabilization Systems

    Directory of Open Access Journals (Sweden)

    D. U. Erbulut

    2013-01-01

    Full Text Available Spinal rigid instrumentations have been used to fuse and stabilize spinal segments as a surgical treatment for various spinal disorders to date. This technology provides immediate stability after surgery until the natural fusion mass develops. At present, rigid fixation is the current gold standard in surgical treatment of chronic back pain spinal disorders. However, such systems have several drawbacks such as higher mechanical stress on the adjacent segment, leading to long-term degenerative changes and hypermobility that often necessitate additional fusion surgery. Dynamic stabilization systems have been suggested to address adjacent segment degeneration, which is considered to be a fusion-associated phenomenon. Dynamic stabilization systems are designed to preserve segmental stability, to keep the treated segment mobile, and to reduce or eliminate degenerative effects on adjacent segments. This paper aimed to describe the biomechanical aspect of dynamic stabilization systems as an alternative treatment to fusion for certain patients.

  13. 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.

  14. Biomechanical research in dance: a literature review.

    Science.gov (United States)

    Krasnow, Donna; Wilmerding, M Virginia; Stecyk, Shane; Wyon, Matthew; Koutedakis, Yiannis

    2011-03-01

    The authors reviewed the literature, published from 1970 through December 2009, on biomechanical research in dance. To identify articles, the authors used search engines, including PubMed and Web of Science, five previous review articles, the Dance Medicine and Science Bibliography, and reference lists of theses, dissertations, and articles being reviewed. Any dance research articles (English language) involving the use of electromyography, forceplates, motion analysis using photography, cinematography or videography, and/or physics analysis were included. A total of 89 papers, theses/dissertations, and abstracts were identified and reviewed, grouped by the movement concept or specialized movements being studied: alignment (n = 8), plié (8), relevé (8), passé (3), degagé (3), développé (7), rond de jambe (3), grand battement (4), arm movements (1), forward stepping (3), turns (6), elevation work (28), falls (1), and dance-specific motor strategies (6). Several recurring themes emerged from these studies: that elite dancers demonstrate different and superior motor strategies than novices or nondancers; that dancers perform differently when using a barre as opposed to without a barre, both in terms of muscle activation patterns and weight shift strategies; that while skilled dancers tend to be more consistent across multiple trials of a task, considerable variability is seen among participants, even when matched for background, years of training, body type, and other variables; and that dance teachers recommend methods of achieving movement skills that are inconsistent with optimal biomechanical function, as well as inconsistent with strategies employed by elite dancers. Measurement tools and the efficacy of study methodologies are also discussed.

  15. 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.

  16. Development of a biomechanical energy harvester.

    Science.gov (United States)

    Li, Qingguo; Naing, Veronica; Donelan, J Maxwell

    2009-06-23

    Biomechanical energy harvesting-generating electricity from people during daily activities-is a promising alternative to batteries for powering increasingly sophisticated portable devices. We recently developed a wearable knee-mounted energy harvesting device that generated electricity during human walking. In this methods-focused paper, we explain the physiological principles that guided our design process and present a detailed description of our device design with an emphasis on new analyses. Effectively harvesting energy from walking requires a small lightweight device that efficiently converts intermittent, bi-directional, low speed and high torque mechanical power to electricity, and selectively engages power generation to assist muscles in performing negative mechanical work. To achieve this, our device used a one-way clutch to transmit only knee extension motions, a spur gear transmission to amplify the angular speed, a brushless DC rotary magnetic generator to convert the mechanical power into electrical power, a control system to determine when to open and close the power generation circuit based on measurements of knee angle, and a customized orthopaedic knee brace to distribute the device reaction torque over a large leg surface area. The device selectively engaged power generation towards the end of swing extension, assisting knee flexor muscles by producing substantial flexion torque (6.4 Nm), and efficiently converted the input mechanical power into electricity (54.6%). Consequently, six subjects walking at 1.5 m/s generated 4.8 +/- 0.8 W of electrical power with only a 5.0 +/- 21 W increase in metabolic cost. Biomechanical energy harvesting is capable of generating substantial amounts of electrical power from walking with little additional user effort making future versions of this technology particularly promising for charging portable medical devices.

  17. Development of a biomechanical energy harvester

    Directory of Open Access Journals (Sweden)

    Donelan J Maxwell

    2009-06-01

    Full Text Available Abstract Background Biomechanical energy harvesting–generating electricity from people during daily activities–is a promising alternative to batteries for powering increasingly sophisticated portable devices. We recently developed a wearable knee-mounted energy harvesting device that generated electricity during human walking. In this methods-focused paper, we explain the physiological principles that guided our design process and present a detailed description of our device design with an emphasis on new analyses. Methods Effectively harvesting energy from walking requires a small lightweight device that efficiently converts intermittent, bi-directional, low speed and high torque mechanical power to electricity, and selectively engages power generation to assist muscles in performing negative mechanical work. To achieve this, our device used a one-way clutch to transmit only knee extension motions, a spur gear transmission to amplify the angular speed, a brushless DC rotary magnetic generator to convert the mechanical power into electrical power, a control system to determine when to open and close the power generation circuit based on measurements of knee angle, and a customized orthopaedic knee brace to distribute the device reaction torque over a large leg surface area. Results The device selectively engaged power generation towards the end of swing extension, assisting knee flexor muscles by producing substantial flexion torque (6.4 Nm, and efficiently converted the input mechanical power into electricity (54.6%. Consequently, six subjects walking at 1.5 m/s generated 4.8 ± 0.8 W of electrical power with only a 5.0 ± 21 W increase in metabolic cost. Conclusion Biomechanical energy harvesting is capable of generating substantial amounts of electrical power from walking with little additional user effort making future versions of this technology particularly promising for charging portable medical devices.

  18. 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.

  19. Laryngeal biomechanics of the singing voice.

    Science.gov (United States)

    Koufman, J A; Radomski, T A; Joharji, G M; Russell, G B; Pillsbury, D C

    1996-12-01

    By transnasal fiberoptic laryngoscopy, patients with functional voice often demonstrate abnormal laryngeal biomechanics, commonly supraglottic contraction. Appropriately, such conditions are sometimes termed muscle tension dysphonias. Singers working at the limits of their voice may also transiently demonstrate comparable tension patterns. However, the biomechanics of normal singing, particularly for different singing styles, have not been previously well characterized. We used transnasal fiberoptic laryngoscopy to study 100 healthy singers to assess patterns of laryngeal tension during normal singing and to determine whether factors such as sex, occupation, and style of singing influence laryngeal muscle tension. Thirty-nine male and 61 female singers were studied; 48 were professional singers, and 52 were amateurs. Examinations of study subjects performing standardized and nonstandardized singing tasks were recorded on a laser disk and subsequently analyzed in a frame-by-frame fashion by a blinded otolaryngologist. Each vocal task was graded for muscle tension by previously established criteria, and objective muscle tension scores were computed. The muscle tension score was expressed as a percentage of frames for each task with one of the laryngeal muscle tension patterns shown. The lowest muscle tension scores were seen in female professional singers, and the highest muscle tension scores were seen in amateur female singers. Male singers (professional and amateur) had intermediate muscle tension scores. Classical singers had lower muscle tension scores than nonclassical singers, with the lowest muscle tension scores being seen in those singing choral music (41%), art song (47%), and opera (57%), and the highest being seen in those singing jazz/pop (65%), musical theater (74%), bluegrass/country and western (86%), and rock/gospel (94%). Analyzed also were the influences of vocal nodules, prior vocal training, number of performance and practice hours per week

  20. [BIOMECHANICS STUDY ON ACETABULAR POSTERIOR WALL FRACTURE].

    Science.gov (United States)

    Tang, Yang; Hu Xiaopeng; Lu, Xiongwei; Zhang, Yuntong; Zhang, Chuncai; Wang, Panfeng; Zhao, Xue

    2015-08-01

    To study the experimental biomechanics of acetabular posterior wall fractures so as to provide theoretical basis for its clinical treatment. Six formalin-preserved cadaveric pelvises were divided into groups A and B (n=3). The fracture models of superior-posterior wall and inferior-posterior wall of the acetabulum were created on both hips in group A; fractures were fixed with two interfragmentary screws and a locking reconstruction plate. The fracture models of superior-posterior wall of acetabulum were created on both hips in group B; fractures were fixed with two interfragmentary screws and a locking reconstruction plate at one side, and with acetabular tridimensional memory fixation system (ATMFS) at the other side. The biomechanical testing machine was used to load to 1 500 N at 10 mm/min speed for 30 seconds. The displacement of superior and inferior fracture sites was analyzed with the digital image correlation technology. No fracture or internal fixation breakage occurred during loading and measuring; the displacement valuess of the upper and lower fracture lines were below 2 mm (the clinically tolerable maximum value) in 2 groups. In group A, the displacement values of the upper and lower fracture lines at superior-posterior wall fracture site were significantly higher than those at inferior-posterior wall fracture site (P fracture line were significantly higher than those of lower fracture line (P fracture types. In group B, the displacement values of the upper and lower fracture lines at the side fixed with screws and a locking reconstruction plate were similar to the values at the side fixed with ATMFS, all being close to 2 mm; the displacement values of the upper fracture line were significantly higher than those of lower fracture line (P acetabulum is much greater than that of the inferior-posterior wall of acetabulum and they should be discriminated, which might be the reasons of reduction loss, femoral head subluxation, and traumatic arthritis

  1. 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) (ppedicle screws had failed during the reduction attempt with visible pullout of the screw. After reduction, decreased POS was observed in both normal (posteoporotic (pscrew resulted in no significant

  2. Biomechanical effects of fusion levels on the risk of proximal junctional failure and kyphosis in lumbar spinal fusion surgery.

    Science.gov (United States)

    Park, Won Man; Choi, Dae Kyung; Kim, Kyungsoo; Kim, Yongjung J; Kim, Yoon Hyuk

    2015-12-01

    Spinal fusion surgery is a widely used surgical procedure for sagittal realignment. Clinical studies have reported that spinal fusion may cause proximal junctional kyphosis and failure with disc failure, vertebral fracture, and/or failure at the implant-bone interface. However, the biomechanical injury mechanisms of proximal junctional kyphosis and failure remain unclear. A finite element model of the thoracolumbar spine was used. Nine fusion models with pedicle screw systems implanted at the L2-L3, L3-L4, L4-L5, L5-S1, L2-L4, L3-L5, L4-S1, L2-L5, and L3-S1 levels were developed based on the respective surgical protocols. The developed models simulated flexion-extension using hybrid testing protocol. When spinal fusion was performed at more distal levels, particularly at the L5-S1 level, the following biomechanical properties increased during flexion-extension: range of motion, stress on the annulus fibrosus fibers and vertebra at the adjacent motion segment, and the magnitude of axial forces on the pedicle screw at the uppermost instrumented vertebra. The results of this study demonstrate that more distal fusion levels, particularly in spinal fusion including the L5-S1 level, lead to greater increases in the risk of proximal junctional kyphosis and failure, as evidenced by larger ranges of motion, higher stresses on fibers of the annulus fibrosus and vertebra at the adjacent segment, and higher axial forces on the screw at the uppermost instrumented vertebra in flexion-extension. Therefore, fusion levels should be carefully selected to avoid proximal junctional kyphosis and failure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. A biomechanical comparison of proximal femoral nails and locking proximal anatomic femoral plates in femoral fracture fixation

    Science.gov (United States)

    Ozkan, Korhan; Türkmen, İsmail; Sahin, Adem; Yildiz, Yavuz; Erturk, Selim; Soylemez, Mehmet Salih

    2015-01-01

    Background: The incidence of fractures in the trochanteric area has risen with the increasing numbers of elderly people with osteoporosis. Although dynamic hip screw fixation is the gold standard for the treatment of stable intertrochanteric femur fractures, treatment of unstable intertrochanteric femur fractures still remains controversial. Intramedullary devices such as Gamma nail or proximal femoral nail and proximal anatomic femur plates are in use for the treatment of intertrochanteric femur fractures. There are still many investigations to find the optimal implant to treat these fractures with minimum complications. For this reason, we aimed to perform a biomechanical comparison of the proximal femoral nail and the locking proximal anatomic femoral plate in the treatment of unstable intertrochanteric fractures. Materials and Methods: Twenty synthetic, third generation human femur models, obtained for this purpose, were divided into two groups of 10 bones each. Femurs were provided as a standard representation of AO/Orthopedic Trauma Associationtype 31-A2 unstable fractures. Two types of implantations were inserted: the proximal femoral intramedullary nail in the first group and the locking anatomic femoral plate in the second group. Axial load was applied to the fracture models through the femoral head using a material testing machine, and the biomechanical properties of the implant types were compared. Result: Nail and plate models were locked distally at the same level. Axial steady load with a 5 mm/m velocity was applied through the mechanical axis of femur bone models. Axial loading in the proximal femoral intramedullary nail group was 1.78-fold greater compared to the plate group. All bones that had the plate applied were fractured in the portion containing the distal locking screw. Conclusion: The proximal femoral intramedullary nail provides more stability and allows for earlier weight bearing than the locking plate when used for the treatment of

  4. Ipsilateral olecranon and distal radius fracture: A case report.

    Science.gov (United States)

    Cengiz, Ömer; Polat, Gökhan; Karademir, Gökhan; Kara, Deniz; Erdil, Mehmet

    2015-01-01

    Concomitant ipsilateral olecranon and distal radius fracture are rare injuries. Their clinical presentation is unusual and investigation and management is poorly described. We present a 55-year-old woman patient who fell off sustaining a concomitant distal radius and olecranon fracture in the same extremity. On examination, there was gross swelling of the proximal and distal forearm and no neurovascular deficit. Radiographs confirmed distal radius and olecranon fracture. Patient was treated with open reduction and anatomic locking plate for olecranon and a closed reduction percuteneous K wire fixation with penning fixator for distal radius fracture. After physical therapy program, functional results were good and DASH score was 60. Several different combinations of fracture with dislocation have been described, but, to our knowledge, concurrent ipsilateral olecranon and distal radius fracture has not been reported before. In the literature review there are two similar cases in the English literature. Ipsilateral olecranon and distal radius fracture is a very rare injury due to different trauma mechanisms. However we should keep in mind that there may be adjacent joints and structures for concomitant injuries. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Relationship between osseointegration and superelastic biomechanics in porous NiTi scaffolds.

    Science.gov (United States)

    Liu, Xiangmei; Wu, Shuilin; Yeung, Kelvin W K; Chan, Y L; Hu, Tao; Xu, Zushun; Liu, Xuanyong; Chung, Jonathan C Y; Cheung, Kenneth M C; Chu, Paul K

    2011-01-01

    The superelastic nature of bones requires matching biomechanical properties from the ideal artificial biomedical implants in order to provide smooth load transfer and foster the growth of new bone tissues. In this work, we determine the biomechanical characteristics of porous NiTi implants and investigate bone ingrowth under actual load-bearing conditions in vivo. In this systematic and comparative study, porous NiTi, porous Ti, dense NiTi, and dense Ti are implanted into 5 mm diameter holes in the distal part of the femur/tibia of rabbits for 15 weeks. The bone ingrowth and interfacial bonding strength are evaluated by histological analysis and push-out test. The porous NiTi materials bond very well to newly formed bone tissues and the highest average strength of 357 N and best ductility are achieved from the porous NiTi materials. The bonding curve obtained from the NiTi scaffold shows similar superelasticity as natural bones with a deflection of 0.30-0.85 mm thus shielding new bone tissues from large load stress. This is believed to be the reason why new bone tissues can penetrate deeply into the porous NiTi scaffold compared to the one made of porous Ti. Histological analysis reveals that new bone tissues adhere and grow well on the external surfaces as well as exposed areas on the inner pores of the NiTi scaffold. The in vitro study indicates that the surface chemical composition and topography of the porous structure leads to good cytocompatibility. Consequently, osteoblasts proliferate smoothly on the entire implant including the flat surface, embossed region, exposed area of the pores, and interconnected channels. In conjunction with the good cytocompatibility, the superelastic biomechanical properties of the porous NiTi scaffold bodes well for fast formation and ingrowth of new bones, and porous NiTi scaffolds are thus suitable for clinical applications under load-bearing conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Keratoconus: A biomechanical perspective on loss of corneal stiffness

    Directory of Open Access Journals (Sweden)

    Abhijit Sinha Roy

    2013-01-01

    Full Text Available Keratoconus (KC is progressive disease of corneal thinning, steepening and collagen degradation. Biomechanics of the cornea is maintained by the intricate collagen network, which is responsible for its unique shape and function. With the disruption of this collagen network, the cornea loses its shape and function, resulting in progressive visual degradation. While KC is essentially a stromal disease, there is evidence that the epithelium undergoes significant thinning similar to the stroma. Several topographical approaches have been developed to detect KC early. However, it is now hypothesized that biomechanical destabilization of the cornea may precede topographic evidence of KC. Biomechanics of KC has been investigated only to a limited extent due to lack of in vivo measurement techniques and/or devices. In this review, we focus on recent work performed to characterize the biomechanical characteristics of KC.

  7. 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.

  8. 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 ...

  9. 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.

  10. Ex vivo evaluation of the biomechanical effect of varying monocortical screw numbers on a plate-rod canine femoral gap model.

    Science.gov (United States)

    Delisser, P J; McCombe, G P; Trask, R S; Etches, J A; German, A J; Holden, S L; Wallace, A M; Burton, N J

    2013-01-01

    To compare the biomechanical behaviour of plate-rod constructs with varying numbers of monocortical screws applied to an ex vivo canine femoral-gap ostectomy model. Twenty Greyhound dog cadaveric femurs. Bone mineral density (BMD) was assessed with dual x-ray absorptiometry. Bones were assigned to four groups. Bones had a 12-hole 3.5 mm locking compression plate with one bicortical non-locking cortical screw in the most proximal and distal plate holes and an intramedullary Steinmann pin applied across a 20 mm mid-diaphyseal ostectomy. Additionally, one to four monocortical non-locking cortical screws were then placed (Groups 1-4 respectively) in the proximal and distal fragments. Stiffness and axial collapse were determined before and after cyclic axial loading (6000 cycles at 20%, 40%, and 60% of mean bodyweight [total: 18000 cycles]). Constructs subsequently underwent an additional 45000 cycles at 60% of bodyweight (total: 63000 cycles). Loading to failure was then performed and ultimate load and mode of failure recorded. The BMD did not differ significantly between groups. Construct stiffness for group 1 was significantly less than group 4 (p = 0.008). Stiffness showed a linear increase with an increasing number of monocortical screws (p = 0.001). All constructs survived fatigue loading. Load-to-failure was not significantly different between groups. Mean load- to-failure of all groups was >1350N. Ex vivo canine large-breed femurs showed adequate stability biomechanically and gradually increasing stiffness with increasing monocortical screw numbers.

  11. Tratamento cirúrgico da tendinite distal da patela Surgical treatment of the distal patellar tendinitis

    Directory of Open Access Journals (Sweden)

    Marco Martins Amatuzzi

    2005-01-01

    Full Text Available A tendinite distal da patela é uma doença que acomete principalmente jovens esportistas e caracteriza-se por dor referida na extremidade distal da patela junto à inserção do ligamento patelar. O tratamento inicial preconizado é sempre conservador com fisioterapia. A grande maioria tem boa resposta a este tipo de conduta, mas em alguns raros casos os sintomas não regridem exigindo uma mudança de conduta. Para este grupo usamos o tratamento cirúrgico com técnica derivada de Trillat que se baseia na utilização de um enxerto de parte do tendão do músculo Grácil implantado dentro do ligamento patelar, inserido intra-ósseo na patela e fixado na tuberosidade anterior da tíbia. Foram operados seis pacientes, sendo que em dois casos a operação foi bilateral, totalizando oito joelhos. O seguimento mínimo foi de três anos, com avaliação final dentro do índice considerado como EXCELENTE, conforme a cotação ARPÉGE, para todos os joelhos.Distal patellar tendinitis is a young athlete's disease characterized by pain at the distal patellar pole, near the patellar ligament insertion. Early treatment recommended is generally conservative, with physical therapy. The great majority of patients present favorable responses to this approach, but, in some cases, the remission of symptoms does not occur, requiring a different approach. For this group, surgical treatment with a technique derived from that of Trillat was used, which is based on the use of a graft removed from a portion of gracillis muscle tendon into patellar ligament, intraosseously inserted in the patella and fixed at the tibial anterior tuberosity. Six patients were operated, bilaterally in two cases, totaling eight knees. The minimum follow-up time was three years, with all knees presenting an EXCELLENT score, according to ARPÉGE evaluation.

  12. New interspinous implant evaluation using an in vitro biomechanical study combined with a finite-element analysis.

    Science.gov (United States)

    Lafage, Virginie; Gangnet, Nicolas; Sénégas, Jacques; Lavaste, François; Skalli, Wafa

    2007-07-15

    A combined in vitro and finite-element analysis was completed to assess the biomechanical effect of a new interspinous implant on the lumbar spine. The aim was to investigate the effect of an interspinous implant on the biomechanical behavior of a vertebral segment. An in vitro study on L3-L5 segments from fresh human cadavers was conducted combined with a 3-dimensional finite-element analysis. Intact, injured, and instrumented states of L4-L5 were compared loaded in flexion-extension, lateral-bending, and torsion. The evaluated implant is an interspinous spacer fixed to the spine by 2 polyester braids looped around the proximal and distal spinous. The effect of the implant appeared mainly in flexion-extension: experimental results showed reduced range of motion of the instrumented spine regarding the injured and intact one; and finite-element analysis indicated a decrease of disc stresses and increase of loads transmitted to the spinous processes. In this in vitro and finite-element analysis, the role of the new interspinous implant appeared to reduce motion without suppressing it and to lower stress in the disc fibers and anulus matrix. Further in vivo investigations are necessary to draw definitive conclusions.

  13. Biomechanics Strategies for Space Closure in Deep Overbite

    OpenAIRE

    Harryanto Wijaya; Isnani Jenie; Himawan Halim

    2013-01-01

    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 tre...

  14. Hand biomechanics in skilled pianists playing a scale in thirds.

    Science.gov (United States)

    Lee, Sang-Hie

    2010-12-01

    Pianists, who attend to the integral relationship of their particular musculoskeletal characteristics to the piano technique at hand, discover an efficient path to technical advancement and, consequently, to injury prevention. Thus, a study of pianist's hand biomechanics in relation to different piano techniques is highly relevant, as hand features may influence various techniques in different ways. This study addressed relationships between pianists' hand biomechanics and the performance of a scale in thirds, as a part of an ongoing series of studies examining relationships between hand biomechanics and performance data of primary techniques. The biomechanics of hand length and width, finger length, hand span, hand and arm weights, and ulnar deviation at the wrist were compared with tempo, articulation, and dynamic voicing (tone balance between two notes of the thirds). Pearson correlation analysis showed a positive association between ulnar deviation and tempo; the other biomechanical features showed no relationships with any of the performance criteria. Qualitative cross-sectional observation of individual profiles showed that experienced pianists perform with a higher degree of synchrony in two-note descent while pianists with organ training background play with a lesser degree of synchrony. All biomechanical features were closely related among one another with one exception: wrist ulnar deviation was not associated with any other biomechanical features; rather, data suggest possible negative associations. This study underscores the importance of wrist mobility in piano skills development. Further research using a complete set of prototype piano techniques and multiple-level pianist-subjects could provide substantive biomechanical information that may be used to develop efficient pedagogy and prevention strategies for playing-related injuries as well as rehabilitation.

  15. Femoral derotation osteotomy in spastic diplegia. Proximal or distal?

    Science.gov (United States)

    Pirpiris, M; Trivett, A; Baker, R; Rodda, J; Nattrass, G R; Graham, H K

    2003-03-01

    We describe the results of a prospective study of 28 children with spastic diplegia and in-toed gait, who had bilateral femoral derotation osteotomies undertaken at either the proximal intertrochanteric or the distal supracondylar level of the femur. Preoperative clinical evaluation and three-dimensional movement analysis determined any additional soft-tissue surgery. Distal osteotomy was faster with significantly lower blood loss than proximal osteotomy. The children in the distal group achieved independent walking earlier than those in the proximal group (6.9 +/- 1.3 v 10.7 +/- 1.7 weeks; p spastic diplegia.

  16. 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.

  17. Adenoma of the distal common bile duct -a case report-

    International Nuclear Information System (INIS)

    Do, Young Soo; Lee, Hyun Gon; Han, Ho Seong; Ko, Gyung Hyuck; Kim, Jae Hyoung; Kim, Hyung Jin; Chung, Sung Hoon

    1991-01-01

    On rare occasions, Obstructive Jaundice may be caused by a benign tumor of the biliary tract. We describe a patient in whom the diagnosis of an adenoma of the distal common bile duct (CBD) was established. The CT showed a soft tissue density mass in the distal CBD and diffuse dilatation of the intrahepatic duct, gall the bladder, and CBD. Endoscopic retrograde cholangiopnacreatography showed an irregularly marginated polypoid mass in the distal CBD. The clinical, radiological, and histological features of this neoplasm are reviewed. The clinical, radiological and histological features of this neoplasm are reviewed

  18. Distal tibial interosseous osteochondroma with impending fracture of fibula ? a case report and review of literature

    OpenAIRE

    Wani, Iftikhar H; Sharma, Siddhartha; Malik, Farid H; Singh, Manjeet; Shiekh, Irfan; Salaria, Abdul Q

    2009-01-01

    Osteochondromas arising from the interosseous border of the distal tibia and involving distal fibula are uncommon. We present a 16 year old young boy with an impending fracture, erosion and weakness of the distal fibula, secondary to an osteochondroma arising from the distal tibia. Early excision of this deforming distal tibial osteochondroma avoided the future risk of pathological fracture of the distal fibula, ankle deformities and syndesmotic complications.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Results of preputial reconstruction in 77 boys with distal hypospadias

    NARCIS (Netherlands)

    Klijn, A. J.; Dik, P.; de Jong, T. P.

    2001-01-01

    There is growing interest in preputial reconstruction combined with hypospadias repair. We retrospectively analyzed its results for future developments and patient information. We evaluated 77 boys who underwent distal hypospadias repair combined with preputial reconstruction to determine

  4. 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.

  5. 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.

  6. 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

  7. Distal vertebral artery reconstruction when managing vertebrobasilar insufficiency

    OpenAIRE

    D. M. Galaktionov; A. V. Dubovoy; K. S. Ovsyannikov

    2017-01-01

    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....

  8. Update on the roles of distal airways in COPD

    Directory of Open Access Journals (Sweden)

    N. Roche

    2011-03-01

    Full Text Available This review is the summary of a workshop on the role of distal airways in chronic obstructive pulmonary disease (COPD, which took place in 2009 in Vence, France. The evidence showing inflammation and remodelling in distal airways and the possible involvement of these in the pathobiology, physiology, clinical manifestations and natural history of COPD were examined. The usefulness and limitations of physiological tests and imaging techniques for assessing distal airways abnormalities were evaluated. Ex vivo studies in isolated lungs and invasive measurements of airway resistance in living individuals have revealed that distal airways represent the main site of airflow limitation in COPD. Structural changes in small conducting airways, including increased wall thickness and obstruction by muco-inflammatory exudates, and emphysema (resulting in premature airway closure, were important determinants of airflow limitation. Infiltration of small conducting airways by phagocytes (macrophages and neutrophils, dendritic cells and T and B lymphocytes increased with airflow limitation. Distal airways abnormalities were associated with patient-related outcomes (e.g. dyspnoea and reduced health-related quality of life and with the natural history of the disease, as reflected by lung function decline and mortality. These data provide a clear rationale for targeting distal airways in COPD.

  9. Aquaporin-4 expression in distal myopathy with rimmed vacuoles.

    Science.gov (United States)

    Hoshi, Akihiko; Yamamoto, Teiji; Kikuchi, Saeko; Soeda, Tomoko; Shimizu, Keiko; Ugawa, Yoshikazu

    2012-04-27

    Distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy is clinically characterized by the early involvement of distal leg muscles. The striking pathological features of the myopathy are muscle fibers with rimmed vacuoles. To date, the role of aquaporin-4 water channel in distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy has not been studied. Here, we studied the expression of aquaporin-4 in muscle fibers of a patient with distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy. Immunohistochemical and immunofluorescence analyses showed that sarcolemmal aquaporin-4 immunoreactivity was reduced in many muscle fibers of the patient. However, the intensity of aquaporin-4 staining was markedly increased at rimmed vacuoles or its surrounding areas and in some muscle fibers. The fast-twitch type 2 fibers were predominantly involved with the strong aquaporin-4-positive rimmed vacuoles and TAR-DNA-binding protein-43 aggregations. Rimmed vacuoles with strong aquaporin-4 expression seen in the distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy patient were not found in control muscles without evidence of neuromuscular disorders and the other disease-controls. Aquaporin-4 might be crucial in determining the survival or degeneration of fast-twitch type 2 fibers in distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy.

  10. Distal biceps brachii tendon rupture resulting in acute compartment syndrome.

    Science.gov (United States)

    Grandizio, Louis C; Suk, Michael; Feltham, Glen T

    2013-11-01

    Distal biceps brachii tendon rupture is an uncommon injury. Compartment syndrome of the upper arm is rarely described in the literature. The diagnosis of upper arm compartment syndrome requires a high index of suspicion, and emergent surgical treatment with fasciotomy in the acute setting is necessary to avoid devastating neurovascular complications. This article reports a case of acute compartment syndrome of the anterior compartment of the upper arm after a complete rupture of the distal biceps brachii tendon. A healthy 45-year-old man presented with increasing arm pain; paresthesia in the lateral antebrachial cutaneous nerve distribution; and a tense, swollen anterior compartment of his upper arm. Side port catheter absolute pressure measurement was 83 mm Hg with a diastolic blood pressure of 92 mm Hg. The patient underwent an emergent fasciotomy and was found to have a complete rupture of his distal biceps brachii tendon. He subsequently underwent distal biceps tendon repair and delayed primary closure of his incision. Postoperatively, his paresthesia improved and he has no neurological deficit. There is a paucity of case reports describing compartment syndrome after rupture of either the proximal or distal end of the biceps brachii tendon, and none of the reports describe compartment syndrome of the upper arm after rupture of the distal biceps tendon. This article highlights an unusual complication of an uncommon injury and reviews diagnostic and treatment principles for the management of acute compartment syndrome of the upper arm. Copyright 2013, SLACK Incorporated.

  11. Endovascular treatment for ruptured distal anterior inferior cerebellar artery aneurysm.

    Science.gov (United States)

    Oh, Jae-Sang; Yoon, Seok-Mann; Shim, Jai-Joon; Bae, Hack-Gun; Yoon, Il-Gyu

    2014-03-01

    A 42-year-old woman presented with Hunt and Hess grade (HHG) III subarachnoid hemorrhage (SAH) caused by a ruptured left distal anterior inferior cerebellar artery (AICA) aneurysm. Computed tomography showed a thin SAH on the cerebellopontine angle cistern, and small vermian intracerebral hemorrhage and intraventricular hemorrhage in the fourth ventricle. Digital subtraction angiography revealed the aneurysm on the postmeatal segment of left distal AICA, a branching point of rostrolateral and caudomedial branch of the left distal AICA. Despite thin caliber, tortuous running course and far distal location, the AICA aneurysm was obliterated successfully with endovascular coils without compromising AICA flow. However, the patient developed left side sensorineural hearing loss postoperatively, in spite of definite patency of distal AICA on the final angiogram. She was discharged home without neurologic sequela except hearing loss and tinnitus. Endovascular treatment of distal AICA aneurysm, beyond the meatal loop, is feasible while preserving the AICA flow. However, because the cochlear hair cell is vulnerable to ischemia, unilateral hearing loss can occur, possibly caused by the temporary occlusion of AICA flow by microcatheter during endovascular treatment.

  12. 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.

  13. 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...

  14. Biomechanical origin of the Denonvilliers' fascia.

    Science.gov (United States)

    Bertrand, M M; Alsaid, B; Droupy, S; Benoit, G; Prudhomme, M

    2014-01-01

    Since 1836 and the first description of the recto-genital fascia by Charles Denonvilliers, many anatomists have shown interest in this subject. Recently, pelvic surgeons have in turn shown similar interest, for they consider that perfect knowledge of this anatomical domain is crucial for optimal nerve conservation during surgery. Thanks to new anatomical description techniques, fascia location and relationships with pelvic nerves now appear clearer. To describe and represent Denonvilliers' fascia and its relationships in the female foetus at different stages of gestation and in three-dimensional space (3D). Computer-assisted anatomical dissection technique was used. Serial histological sections were made from four human female foetuses. Sections were treated with conventional staining, as well as with nerve and smooth muscle immunostaining. Finally, the sections were digitalized and reconstructed in 3D. Denonvilliers' fascia was clearly located and visualized in three dimensions. It was present in the female foetus, being distinct from the fascia propria of the rectum. It appeared to be composed of multiple parallel layers situated between the vagina and the rectum. From a lateral view, it had an asymmetrical "Y-shaped" aspect that seemed to play the role of a protective sheet for the neurovascular bundles. This study betters our comprehension of the Denonvilliers' fascia in the female foetus and of its connections with pelvic nerves. It also provides a better understanding of safe planes during pelvic dissection. These findings also suggest a biomechanical theory for embryological origin of the Denonvilliers' fascia.

  15. Biomechanic Factors Associated With Orbital Floor Fractures.

    Science.gov (United States)

    Patel, Sagar; Andrecovich, Christopher; Silverman, Michael; Zhang, Liying; Shkoukani, Mahdii

    2017-07-01

    Orbital floor fractures are commonly seen in clinical practice, yet the etiology underlying the mechanism of fracture is not well understood. Current research focuses on the buckling theory and hydraulic theory, which implicate trauma to the orbital rim and the globe, respectively. To elucidate and define the biomechanical factors involved in an orbital floor fracture. A total of 10 orbits from 5 heads (3 male and 2 female) were used for this study. These came from fresh, unfixed human postmortem cadavers that were each selected so that the cause of death did not interfere with the integrity of orbital walls. Using a drop tower with an accelerometer, we measured impact force on the globe and rim of cadaver heads affixed with strain gauges. The mean impacts for rim and globe trauma were 3.9 J (95% CI, 3.4-4.3 J) and 3.9 J (95% CI, 3.5-4.3 J), respectively. Despite similar impact forces to the globe and rim, strain-gauge data displayed greater mean strain for globe impact (6563 μS) compared with rim impact (3530 μS); however, these data were not statistically significant (95% CI, 3598-8953 μS; P = .94). Our results suggest that trauma directly to the globe predisposes a patient to a more posterior fracture while trauma to the rim demonstrates an anterior predilection. Both the hydraulic and buckling mechanisms of fracture exist and demonstrate similar fracture thresholds. NA.

  16. 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.

  17. 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.

  18. An overview on plant cuticle biomechanics.

    Science.gov (United States)

    Domínguez, Eva; Cuartero, Jesús; Heredia, Antonio

    2011-08-01

    Plant biomechanics combines the principles of physics, chemistry and engineering to answer questions about plant growth, development and interaction with the environment. The epidermal-growth-control theory, postulated in 1867 and verified in 2007, states that epidermal cells determine the rate of organ elongation since they are under tension, while inner tissues are under compression. The lipid cuticle layer is deposited on the surface of outer epidermal cell walls and modifies the chemical and mechanical nature of these cell walls. Thus, the plant cuticle plays a key role in plant interaction with the environment and in controlling organ expansion. Rheological analyses indicate that the cuticle is a mostly viscoelastic and strain-hardening material that stiffens the comparatively more elastic epidermal cell walls. Cuticle stiffness can be attributed to polysaccharides and flavonoids present in the cuticle whereas a cutin matrix is mainly responsible for its extensibility. Environmental conditions such as temperature and relative humidity have a plasticizing effect on the mechanical properties of cuticle since they lower cuticle stiffness and strength. The external appearance of agricultural commodities, especially fruits, is of great economic value. Mechanical properties of the cuticle can have a positive or negative effect on disorders like fruit cracking, fungal pathogen penetration and pest infestation. Cuticle rheology has significant variability within a species and thus can be subjected to selection in order to breed cultivars resistant to pests, infestation and disorders. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  19. 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.

  20. Biomechanics of Nested Transforaminal Lumbar Interbody Cages.

    Science.gov (United States)

    Soriano-Baron, Hector; Newcomb, Anna G U S; Malhotra, Devika; de Tranaltes, Kaylee; Martinez-Del-Campo, Eduardo; Reyes, Phillip M; Crawford, Neil R; Theodore, Nicholas; Tumialán, Luis M

    2016-02-01

    Arthrodesis is optimized when the structural graft occupies most of the surface area within a disc space. The transforaminal corridor inherently limits interbody size. To evaluate the biomechanical implications of nested interbody spacers (ie, a second curved cage placed behind a first) to increase disc space coverage in transforaminal approaches. Seven lumbar human cadaveric specimens (L3-S1) underwent nondestructive flexibility and axial compression testing intact and after transforaminal instrumentation at L4-L5. Specimens were tested in 5 conditions: (1) intact, (2) interbody, (3) interbody plus bilateral pedicle screws and rods (PSR), (4) 2 nested interbodies, and (5) 2 nested interbodies plus PSR. Mean range of motion (ROM) with 1 interbody vs 2 nested interbodies, respectively, was: flexion, 101% vs 85%; extension, 97% vs 92%; lateral bending, 127% vs 132%; and axial rotation, 145% vs 154%. One interbody and 2 nested interbodies did not differ significantly by loading mode (P > .10). With PSR, ROM decreased significantly compared with intact, but not between interbody and interbody plus PSR or 2 interbodies plus PSR (P > .80). Mean vertical height during compressive loading (ie, axial compressive stiffness) was significantly different with 2 nested interbodies vs 1 interbody alone (P < .001) (compressive stiffness, 89% of intact vs 67% of intact, respectively). Inserting a second interbody using a transforaminal approach is anatomically feasible and nearly doubles the disc space covered without affecting ROM. Compressive stiffness significantly increased with 2 nested interbodies, and foraminal height increased. Evaluation of the clinical safety and efficacy of nested interbodies is underway.

  1. Biomechanical behavior of human crural fascia in anterior and posterior regions of the lower limb.

    Science.gov (United States)

    Pavan, Piero G; Pachera, Paola; Stecco, Carla; Natali, Arturo N

    2015-10-01

    The present work focuses on the numerical modeling of the mechanical behavior of the crural fascia, the deep fascia enwrapping the lower limb muscles. This fascia has an important biomechanical role, due to its interaction with muscles during contraction and its association with pathological events, such as compartment syndrome. The mechanical response of the crural fascia is described by assuming a hyperelastic fiber-reinforced constitutive model, with families of fibers disposed according to the spatial disposition of the collagen network, as shown in histological analyses. A two-dimensional finite element model of a lower limb transversal section has been developed to analyze deformational behavior, with particular attention on interaction phenomena between crural fascia and enwrapped muscles. The constitutive model adopted for the crural fascia well fits experimental data taken along the proximal-distal and medial-lateral directions. The finite element analysis allows for interpreting the relation between change in volume and pressure of muscle compartments and the crural fascia deformation.

  2. Endoprosthetic Reconstruction of distal Humerus following Resection of distal Humeral Giant Cell Tumours in Six Patients in Rural India

    Directory of Open Access Journals (Sweden)

    Balasubramanian N

    2017-07-01

    Full Text Available Giant cell tumour is a commonly occurring benign bone tumour in the Indian population. The common sites of involvement in descending order of frequency are distal femur, proximal tibia, distal radius and proximal humerus. The less commonly occurring sites are distal humerus, pelvis and proximal femur. We present six cases of giant cell tumour involving the distal humerus in rural India. After obtaining a tissue diagnosis by Trucut biopsy and classifying using Enneking's classification, we proceeded to perform wide resection followed by endoprosthetic reconstruction using custom mega prosthesis. We present here six patients (M: F: 2: 4 who were managed by us between 2008-2014. They presented to us with pain around the elbow and restriction in range of movements. They were each noted radiographically to have a lytic lesion involving the distal humerus with the likely diagnosis of giant cell tumour. Closed biopsy was done in all of them to obtain a definitive diagnosis. All patients underwent wide resection and reconstruction using distal humerus custom prosthesis. All patients were followed up at 6, 12, 18 and 24 weeks and thereafter six monthly until the last review. They were assessed using the DASH scoring system. All patients were well with no evidence of recurrence with good to fair functional outcome. We conclude that careful pre-operative planning with meticulous soft tissue dissection and good implant metallurgy and design, these tumours can be treated with good long term functional results.

  3. Off-axis loads cause failure of the distal radius at lower magnitudes than axial loads: A finite element analysis

    Science.gov (United States)

    Troy, Karen L.; Grabiner, Mark D.

    2014-01-01

    Distal radius (Colles’) fractures are a common fall-related injury in older adults and frequently result in long-term pain and reduced ability to perform activities of daily living. Because the occurrence of a fracture during a fall depends on both the strength of the bone and upon the kinematics and kinetics of the impact itself, we sought to understand how changes in bone mineral density (BMD) and loading direction affect the fracture strength and fracture initiation location in the distal radius. A three-dimensional finite element model of the radius, scaphoid, and lunate was used to examine changes of ±2% and ±4% BMD, and both axial and physiologically relevant off-axis loads on the radius. Changes in BMD resulted in similar percent changes in fracture strength. However, modifying the applied load to include dorsal and lateral components (assuming a dorsal view of the wrist, rather than an anatomic view) resulted in a 47% decrease in fracture strength (axial failure load: 2752 N, off-axis: 1448 N). Loading direction also influenced the fracture initiation site. Axially loaded radii failed on the medial surface immediately proximal to the styloid process. In contrast, off-axis loads, containing dorsal and lateral components, caused failure on the dorsal–lateral surface. Because the radius appears to be very sensitive to loading direction, the results suggest that much of the variability in fracture strength seen in cadaver studies may be attributed to varying boundary conditions. The results further suggest that interventions focused on reducing the incidence of Colles’ fractures when falls onto the upper extremities are unavoidable may benefit from increasing the extent to which the radius is loaded along its axis. PMID:17368466

  4. Tilted and short implants supporting fixed prosthesis in an atrophic maxilla: a 3D-FEA biomechanical evaluation.

    Science.gov (United States)

    Almeida, Erika O; Rocha, Eduardo P; Freitas Júnior, Amilcar C; Anchieta, Rodolfo B; Poveda, Ronald; Gupta, Nikhil; Coelho, Paulo G

    2015-01-01

    This study compared the biomechanical behavior of tilted long implant and vertical short implants to support fixed prosthesis in an atrophic maxilla. The maxilla model was built based on a tomographic image of the patient. Implant models were based on micro-computer tomography imaging of implants. The different configurations considered were M4S, four vertical anterior implants; M4T, two mesial vertical implants and two distal tilted (45°) implants in the anterior region of the maxilla; and M6S, four vertical anterior implants and two vertical posterior implants. Numerical simulation was carried out under bilateral 150 N loads applied in the cantilever region in axial (L1) and oblique (45°) (L2) direction. Bone was analyzed using the maximum and minimum principal stress (σmax and σmin ), and von Mises stress (σvM ) assessments. Implants were analyzed using the σvM . The higher σmax was observed at: M4T, followed by M6S/L1, M6S/L2, M4S/L2, and M4S/L1 and the higher σvM : M4T/L1, M4T/L2 and M4S/L2, M6S/L2, M4S/L1, and M6S/L1. The presence of distal tilted (all-on-four) and distal short implants (all-on-six) resulted in higher stresses in both situations in the maxillary bone in comparison to the presence of vertical implants (all-on-four). © 2013 Wiley Periodicals, Inc.

  5. Biomechanics of the Gastrointestinal Tract in Health and Disease

    DEFF Research Database (Denmark)

    Zhao, Jingbo; Liao, Donghua; Gregersen, Hans

    2010-01-01

    The gastrointestinal (GI) tract is functionally subjected to dimensional changes. Hence, biomechanical properties such as the stress-strain relationships are of particularly importance. These properties vary along the normal GI tract and remodel in response to growth, aging and disease. The biome......The gastrointestinal (GI) tract is functionally subjected to dimensional changes. Hence, biomechanical properties such as the stress-strain relationships are of particularly importance. These properties vary along the normal GI tract and remodel in response to growth, aging and disease....... 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...... in the tissue structure that determine a specific motor dysfunction. Therefore, biomechanical data on the GI wall are important to understand the pathogenesis to the GI motor-sensory function and dysfunction. Moreover, biomechanical studies of the GI tract pave the way for further mathematical and computational...

  6. Biomechanics and functionality of hepatocytes in liver cirrhosis.

    Science.gov (United States)

    Sun, Shan; Song, Zhenyuan; Cotler, Scott J; Cho, Michael

    2014-06-27

    Cirrhosis is a life-threatening condition that is generally attributed to overproduction of collagen fibers in the extracellular matrix that mechanically stiffens the liver. Chronic liver injury due to causes including viral hepatitis, inherited and metabolic liver diseases and external factors such as alcohol abuse can result in the development of cirrhosis. Progression of cirrhosis leads to hepatocellular dysfunction. While extensive studies to understand the complexity underlying liver fibrosis have led to potential application of anti-fibrotic drugs, no such FDA-approved drugs are currently available. Additional studies of hepatic fibrogenesis and cirrhosis primarily have focused on the extracellular matrix, while hepatocyte biomechanics has received limited attention. The role of hepatocyte biomechanics in liver cirrhosis remains elusive, and how the cell stiffness is correlated with biological functions of hepatocytes is also unknown. In this study, we demonstrate that the biomechanical properties of hepatocytes are correlated with their functions (e.g., glucose metabolism), and that hepatic dysfunction can be restored through modulation of the cellular biomechanics. Furthermore, our results indicate the hepatocyte functionality appears to be regulated through a crosstalk between the Rho and Akt signaling. These novel findings may lead to biomechanical intervention of hepatocytes and the development of innovative tissue engineering for clinical treatment to target liver cells rather than exclusively focusing on the extracellular matrix alone in liver cirrhosis. © 2013 Published by Elsevier Ltd.

  7. 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.

  8. 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

  9. BIOMECHANICAL MODEL OF THE SPRINT START

    Directory of Open Access Journals (Sweden)

    Milan Čoh

    2007-05-01

    Full Text Available The study analysed and identifi ed the major kinematic parameters of the phases of sprint start and block acceleration that infl uence the results of sprint running. The biomechanical measurements and kinematic analysis were performed on the best world’s best sprinters during his preparation for the European Athletics Championship in Geteborg 2006. In this competition Matic Osovnikar won the bronze medal in a 100- metre run set the Slovenian national record with 10.14 s. The kinematic parameters of the sprint start were established on the basis of a 2-D kinematic analysis, using a high-speed camera with a frequency of 200 F/s. The measurements of block acceleration were made by means of the OPTO TRACK technology and an infra-red photo cell system. The athlete performed fi ve, 20m low-start sprints in constant and controlled measurement conditions. The subject of the study was the set position from the point of view of the height of the total body centre of gravity (TBCG, the block time at the front and rear blocks, block velocity, the block face angle, the velocity of the TBCG in the fi rst three metres and the kinematic parameters of block acceleration in the fi rst ten steps. The study showed the following were the key performance factors in the two phases of sprint running: medium start block distance, block velocity, low block face angles, fi rst step length, low vertical rise in the TBCG in the fi rst three metres of block acceleration, contact phase/fl ight phase index in the fi rst ten steps and the optimal ratio between the length and frequency of steps.

  10. Biomechanical Behavior of the Dental Implant Macrodesign.

    Science.gov (United States)

    Lima de Andrade, Camila; Carvalho, Marco Aurélio; Bordin, Dimorvan; da Silva, Wander José; Del Bel Cury, Altair Antoninha; Sotto-Maior, Bruno Salles

    The aim of this study was to evaluate the influence of implant macrodesign when using different types of collar and thread designs on stress/strain distributions in a maxillary bone site. Six groups were obtained from the combination of two collar designs (smooth and microthread) and three thread shapes (square, trapezoidal, and triangular) in external hexagon implants (4 × 10 mm) supporting a single zirconia crown in the maxillary first molar region. A 200-N axial occlusal load was applied to the crown, and measurements were made of the von Mises stress (σ vM ) for the implant, and tensile stress (σ max ), shear stress (τ max ), and strain (ε max ) for the surrounding bone using tridimensional finite element analysis. The main effects of each level of the two factors investigated (collar and thread designs) were evaluated by one-way analysis of variance (ANOVA) at a 5% significance level. Collar design was the main factor of influence on von Mises stress in the implant and stresses/strain in the cortical bone, while thread design was the main factor of influence on stresses in the trabecular bone (P design able to produce more favorable stress/strain distribution was the microthreaded design for the cortical bone. For the trabecular bone, the triangular thread shape had the lowest stresses and strain values among the square and trapezoidal implants. Stress/strain distribution patterns were influenced by collar design in the implant and cortical bone, and by thread design in the trabecular bone. Microthreads and triangular thread-shape designs presented improved biomechanical behavior in posterior maxillary bone when compared with the smooth collar design and trapezoidal and square-shaped threads.

  11. Biomechanics and pathophysiology of flat foot.

    Science.gov (United States)

    Van Boerum, Drew H; Sangeorzan, Bruce J

    2003-09-01

    When the foot works properly it is an amazing, adaptive, powerful aid during walking, running, jumping, and in locomotion up or down hill and over uneven ground. Dysfunction of the foot can often arise from the foot losing its normal structural support, thus altering is shape. An imbalance in the forces that tend to flatten the arch and those that support the arch can lead to loss of the medial longitudinal arch. An increase in the arch-flattening effects of the triceps surae or an increase in the weight of the body will tend to flatten the arch. Weakness of the muscular, ligamentous, or bony arch supporting structures will lead to collapse of the arch. The main factors that contribute to an acquired flat foot deformity are excessive tension in the triceps surae, obesity, PTT dysfunction, or ligamentous laxity in the spring ligament, plantar fascia, or other supporting plantar ligaments. Too little support for the arch or too much arch flattening effect will lead to collapse of the arch. Acquired flat foot most often arises from a combination of too much force flattening the arch in the face of too little support for the arch. Treatment of the adult acquired flat foot is often difficult. The clinician should remember the biomechanics of the normal arch and respond with a treatment that strengthens the supporting structures of the arch or weakens the arch-flattening effects on the arch. After osteotomies or certain hindfoot fusions, the role of the supporting muscles of the arch, in particular the PTT, play less of a role in supporting the arch. Rebalancing the forces that act on the arch can improve function and lessen the chance for further or subsequent development of deformity.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. Suture anchor reinsertion of distal biceps rupture: clinical results and radiological assessment of tendon healing.

    Science.gov (United States)

    Gallinet, D; Dietsch, E; Barbier-Brion, B; Lerais, J-M; Obert, L

    2011-05-01

    The present study consisted in a clinical follow-up of patients with distal rupture of the biceps brachii tendon managed by suture anchor reinsertion to the radial tuberosity. Tendon apposition on the cortical bone is the least resistant reinsertion technique according to biomechanical studies. A parallel radiological (X-ray and MRI) study was therefore performed to assess the exact quality of tendon healing and its correlation to clinical results. Twenty-eight patients were followed up retrospectively at a mean 22 months (minimum FU: six months) with clinical examination (mobility, force, satisfaction, residual pain, and return to work) and radiological assessment (standard X-ray exploration for heterotopic ossification, and MRI for quality of healing of the tendon apposed to the cortical bone). Forty percent of cases showed complications (mainly neurological) which resolved without sequelae under medical treatment. Mobility was normal in all but eight patients who showed -5° to -20° supination loss. Force in flexion-supination was 91% of that on the contralateral side. On X-ray, only 46% of patients were free of ossification. On MRI, reinsertion was judged anatomic in 19 patients (70%), moderate in six and poor in two, with one iterative rupture. Statistical analysis revealed that the greater the number of suture tacks through the tendon, the greater the force in patients with less than two weeks' interval to surgery and satisfactory reinsertion on MRI. Many reinsertion techniques have been reported, giving clinical results similar to one another and to the present findings. The complications rate, in contrast, varies according to technique and surgical approach. Radiologically, 70% of reinsertions were satisfactory: healing with the tendon apposed on the cortical bone is thus a reliable technique. Heterotopic ossification is considered benign in the literature. The present radiological study refined this notion by identifying three types of ossification: pure

  17. Modeling and rational determination of the main biomechanical characteristics in javelin throwing.

    Directory of Open Access Journals (Sweden)

    Adashevskiy V.M.

    2011-06-01

    Full Text Available The possibilities of the use of biomechanical models in training athletes. The approaches in the construction of biomechanical models. A biomechanical model of throwing the javelin. An solution to the problem of dynamic influence on flight range spear absolute initial rate of departure, departure angle, height of release of the spear. The most important biomechanical characteristics of the "athlete-spear. " The possibilities of using individual features of the athlete to achieve better results.

  18. All-polyethylene tibial components in distal femur limb-salvage surgery: a finite element analysis based on promising clinical outcomes.

    Science.gov (United States)

    Tang, Fan; Zhou, Yong; Zhang, Wenli; Min, Li; Shi, Rui; Luo, Yi; Duan, Hong; Tu, Chongqi

    2017-04-04

    Whether all-polyethylene tibial (APT) components are beneficial to patients who received distal femur limb-salvage surgery lacks high-quality clinical follow-up and mechanical evidence. This study aimed to investigate the biomechanics of the distal femur reconstructed with APT tumor knee prostheses using finite element (FE) analysis based on our previous, promising clinical outcome. Three-dimensional FE models that use APT and metal-backed tibial (MBT) prostheses to reconstruct distal femoral bone defects were developed and input into the Abaqus FEA software version 6.10.1. Mesh refinement tests and gait simulation with a single foot both in the upright and 15°-flexion positions with mechanical loading were conducted. Stress distribution analysis was compared between APT and MBT at the two static positions. For both prosthesis types, the stress was concentrated on the junction of the stem and shaft, and the maximum stress in the femoral axis base was more than 100 Mpa. The stress on the tibial surface was relatively distributed, which was 1-19 MPa. The stress on the tibial bone-cement layer of the APT prosthesis was approximately 20 times higher than that on the MBT prosthesis in the same region. The stress on the proximal tibial cancellous bone and cortical bone of the APT prosthesis was 3-5 times greater than that of the MBT prosthesis, and it was more distributed. Although the stress of bone-cement around the APT component is relatively high, the stress was better distributed at the polyethylene-cement-bone interface in APT than in MBT prosthesis, which effectively protects the proximal tibia in distal femur tumor knee prosthesis replacement. These results should be considered when selecting the appropriate tibial component for a patient, especially under the foreseeable conditions of osteoporosis.

  19. 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.

  20. Complications of Minimally Invasive Percutaneous Plating for Distal Tibial Fractures.

    Science.gov (United States)

    Muzaffar, Nasir; Bhat, Rafiq; Yasin, Mohammad

    2016-07-01

    The management of distal tibia fractures continues to remain a source of controversy and debate. The aim of this study was to evaluate the various complications of minimally invasive percutaneous plate osteosynthesis (MIPPO) using a locking plate for closed fractures of distal tibia in a retrospective study. Twenty-five patients with distal tibial fractures, treated by minimally invasive percutaneous plate osteosynthesis, were evaluated in a retrospective study. We studied the rate, probable etiological factors and preventive and corrective measures of various complications associated with minimally invasive plating of distal tibia. Mean age of the patients was 41.16 years (range 22 - 65). There were 13 male and 12 female patients. All fractures united at an average duration of 16.8 weeks. There were two cases of superficial and two cases of deep infection, and deep infections required removal of hardware for cure. There were four cases of ankle stiffness, most of them occurring in intra-articular fractures, three cases of palpable implant, three cases of malunion, one case of loss of reduction and one patient required reoperation. The average AO foot and ankle score was 83.6. We found MIPPO using locking plate to be a safe and effective method for the treatment of distal tibial fractures in properly selected patients yet can result in a variety of complications if proper precautions before, during and after surgery are not taken care of.

  1. Recurrent Giant cell tumour in distal Humerus: A Case report

    Directory of Open Access Journals (Sweden)

    Y Bhanu Rekha

    2013-07-01

    Full Text Available Introduction: Giant cell tumour of bone (GCT is a common benign primary bone tumour, seen commonly in the distal Femur, proximal Tibia and distal Radius. Very few cases of GCT are reported in distal humerus. We report an unusual presentation of recurrent Giant cell tumour in a 25 year old male in the medial condyle and epicondyle of left Humerus. Case Report: Patient presented elsewhere with lytic lesion of left elbow three years ago. As it is an uncommon site for tumors, it was misdiagnosed as tuberculous osteomyelitis and was inadequately curetted. Patient presented to us with recurrence of tumor one year after the primary surgery. We did en-bloc resection of the tumour, with judicious removal of partial trochlea. Though reconstruction was planned, it was found to be not necessary as the elbow was stable per-operatively. Patient regained near normal movements of the elbow with no instability. His Mayo Elbow Performance score improved from 30 to 85.There is no recurrence or metastasis of the tumor in the two-year follow-up. Conclusion: Though bone tumors are rare in distal Humerus, biopsy is needed to confirm the diagnosis of any lytic lesion in this region for proper management. Keywords: Recurrent Giant cell tumor, resection of GCT, GCT distal Humerus.

  2. 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...

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

    Directory of Open Access Journals (Sweden)

    N.P. Batieieva

    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. 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.

  5. [Air transport biomechanical risk: reduced mobility passengers' handling].

    Science.gov (United States)

    Draicchio, F; Campoli, G; Silvetti, A; Badellino, E; Forzano, F; Ranavolo, A; Iavicoli, S; Campagna, G; Raffaele, G; Gismondi, M

    2012-01-01

    As the airport traffic increases there is a continuous increase of passengers with different motor disabilities. Disabled passenger's assistance causes a biomechanical overload in airport workers. Some disabled passengers are classified by IATA as WCHC (wheel chair in cabin or Charlie). Our study, was performed in one of the most important Italian airport on Charlie passengers (about 10% of all assistances). We identified four critical points: 1) wheelchair and baggage moving (unstable load), 2) inclined ramps with worker's backwards steps and braked wheelchair to prevent passenger tipping or falling, 3) transfer from standard wheelchair to bicycle wheelchair, specifically designed for the aisle; 4.) transfer from bicycle wheelchair to aircraft seat. The last two points required sometimes to lift passengers over the armrest and positioning them on a window side seat, causing a serious increase of biomechanical load. For each critical point we have proposed technical and organizational measures to reduce airport worker's biomechanical risk.

  6. 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.

  7. 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.

  8. Biomechanical Profile of Danish Elite and Sub-elite Soccer Goalkeepers

    DEFF Research Database (Denmark)

    Sørensen, Henrik; Thomassen, Martin; Zacho, Morten

    2008-01-01

    The purpose of this study was to define a biomechanical profile of the soccer goalkeeper. We tested whether the skill level of 6 goalkeepers correlated with a number of biomechanical tests. The skill level of each goalkeeper was defined as the league he played in. The biomechanical tests were...

  9. 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

  10. Biomechanically Excited SMD Model of a Walking Pedestrian

    DEFF Research Database (Denmark)

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

    2016-01-01

    of biomechanical forces, was used to model a pedestrian for application in vertical human-structure interaction (HSI). Tests were undertaken in a gait laboratory, where a three-dimensional motion-capture system was used to record a pedestrian's walking motions at various frequencies. The motion-capture system...... 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...

  11. 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.

  12. The modern biomechanics technology in practice of preparedness athletes.

    Directory of Open Access Journals (Sweden)

    Akhmetov R.F.

    2011-01-01

    Full Text Available The generalized information about directions of application of biomechanics technologies in modern sport is resulted. Some aspects of the use of biomechanics ergogenical tools of the moved delayed action in the system of preparation of athletes-jumpers are considered. Presents the possibility of using training complex «easy leading» for perfection of structure of motive actions of sportsmen, specialized in high jumps. The introduction of a vast arsenal of technical tools in practice the training process open new prospects associated with increased efficiency in the preparation of athletes.

  13. Biomechanical constraints and optimal posture of a human operator

    Energy Technology Data Exchange (ETDEWEB)

    Riffard, V.; Chedmail, P. [Ecole entrale de Nantes-LAN, Nantes Cedex (France)

    1995-12-31

    In complex mechanical systems, an important feature of concurrent engineering is to take into account the operators accessibility for assembly operations and maintenance checking in the earliest phases of assembly design. Accessibility can be viewed from geometric and biomechanical points of view. The first one was described in a previous paper. The object of this paper is to integrate the biomechanical aspects of finding optimal postures of a human operator in an encumbered environment. Research on mechanical modeling of human operators deals with (1) geometric and kinematics models; (2) inertial characterizations; (3) static and muscular efforts; and (4) human-gesture characterization.

  14. 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

  15. [Repair of distal biceps brachii tendon rupture: a case report].

    Science.gov (United States)

    Oztürk, Kahraman; Sahin, Vedat

    2002-01-01

    The rupture of the distal tendon of the biceps brachii muscle is a rarely encountered injury, causing flexion and supination losses. There are literature reports giving good results with the use of two-incision technique that fixes the distal biceps brachii tendon to the radial tuberosity. We used this technique in a 49-year-old male patient who had had left distal tendinous rupture of the biceps brachii muscle caused by lifting heavy weight. Functional evaluation at the end of 16 months with the use of the Cybex 350 test machine showed normal range of motions for flexion and extension in the left elbow. There was a 25 percent loss of strength and 5 percent loss of endurance in flexion, and 11 percent loss of endurance in pronation. No complications were observed and a very good functional result was achieved.

  16. [Proximal and distal rupture of the m. biceps brachii].

    Science.gov (United States)

    Lorbach, O; Kieb, M; Grim, C; Engelhardt, M

    2010-12-01

    Ruptures of the biceps tendon account for a high percentage of tendon ruptures. The aetiology of proximal ruptures of the long head of the biceps tendon is often degenerative and they are frequently associated with lesions of the rotator cuff. The clinical findings are often not specific and long lasting. Distal ruptures of the biceps tendon mostly occur during eccentric contraction of the biceps muscle.Clinical tests, the associated haematoma and a distalisation or proximalisation of the muscle belly in combination with ultrasound or MRI to rule out combined diseases lead to the diagnosis. The possible options include conservative and operative treatment. Tenotomy and tenodesis lead to comparable results in the literature. Therefore, conservative treatment is mostly recommended in proximal ruptures. Operative treatment is preferred in distal ruptures of the biceps tendon in order to achieve an anatomical reconstruction of the muscle function. Chronic ruptures of the distal biceps tendon can be successfully treated with free autografts or allografts.

  17. Surgical Management of Fossa Navicularis and Distal Urethral Strictures.

    Science.gov (United States)

    Daneshvar, Michael; Hughes, Michael; Nikolavsky, Dmitriy

    2018-04-17

    Urethral reconstruction has evolved in the last several decades with the introduction of various techniques including fasciocutaneous skin flaps and buccal mucosal grafts. However, distal urethral strictures have continued to be a reconstructive challenge due to tendency for adverse cosmetic outcomes, risks of glans dehiscence or fistula formation, and stricture recurrence. The surgical options for treatment of distal urethral strictures have changed throughout the years; however, there is no one universally accepted technique for their treatment. The current trend for treatment is shifting away from multi-staged procedures or the use of local skin flaps to single-stage transurethral procedures that utilize buccal mucosa with glans preservation. This chapter will describe the evolution of distal urethral stricture treatments tracking gradual improvements and modifications over time. The different interventions include transurethral approaches, such as dilations and visual urethrotomy, meatotomy, and meatoplasty/urethroplasty techniques including genital skin flaps and single- and double-stage repairs with buccal mucosal grafts.

  18. 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.

  19. Distal mycotic aneurysm of the AICA mimicking intracanalicular acoustic neuroma.

    Science.gov (United States)

    DiMaio, Salvatore; Mohr, Gérard; Dufour, Jean-Jacques; Albrecht, Steffan

    2003-11-01

    Among cases of cerebellopontine angle lesions, vascular lesions involving the internal auditory canal are extremely rare. We report a distal fusiform mycotic pseudoaneurysm of the anterior inferior cerebellar artery (AICA) that simulated an acoustic neuroma on presentation. A 60-year-old woman was investigated for recent onset of acute dizziness. Laboratory and radiographic investigations are presented, as well as the surgical management of the patient and pathological examination of the aneurysm. An exceptionally rare case of distal mycotic intracanalicular pseudoaneurysm of the AICA with intraluminal thrombus and fusiform anatomy is described. In our review of the literature (1966-present), only five other intracanalicular AICA-aneurysms were encountered, none of which were infectious in etiology. The possible pathophysiologic mechanisms of distal AICA-aneurysms are discussed along with the currently available literature.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. Current concepts in the treatment of distal radial fractures.

    Science.gov (United States)

    Ruch, David S; Weiland, Andrew J; Wolfe, Scott W; Geissler, William B; Cohen, Mark S; Jupiter, Jesse B

    2004-01-01

    Surgical indications for the treatment of distal radial fractures are evolving. It is important to identify the various articular fragments and their significance to facilitate optimal surgical treatment of these fragments from the standpoint of both internal and external fixation. New techniques in the visualization and stabilization of the articular surface and the treatment of defects in the metaphysis, including the use of cement to buttress the articular surface, have been brought to the forefront. A treatment algorithm for associated injuries to the distal radioulnar joint is also helpful.

  5. 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.

  6. Galeazzi fracture with volar dislocation of the distal radioulnar joint.

    Science.gov (United States)

    Kim, Suezie; Ward, James P; Rettig, Michael E

    2012-11-01

    Galeazzi fracture dislocations are fractures of the distal one-third of the radial diaphysis with traumatic disruption of the distal radioulnar joint (DRUJ). This injury results in subluxation or dislocation of the ulnar head. We present a case of a Galeazzi fracture with a volar dislocation of the DRUJ. Open reduction of the DRUJ with Kirschner wire fixation in pronation was necessary to reduce the joint and maintain anatomic alignment. Repair of the triangular fibrocartilage complex was also necessary to maintain stability of the DRUJ.

  7. External Fixation of Unstable Distal Radius Fracture. A Case Report

    OpenAIRE

    Yaniel Truffin Rodríguez; Rafael Esmandy Gámez Arregoitía; Indira L. Gómez Gil; José Julio Requeiro Morejón

    2014-01-01

    Unstable fracture of the distal radius is a common injury. If not properly treated, it can cause major disturbance in the radiocarpal joint and impaired hand function. A case of a 42-year-old patient of rural origin without a history of previous conditions treated at the Gustavo Aldereguía Lima Hospital in Cienfuegos is presented. He suffered a fall on the outstretched hand, which led to an unstable fracture of the left distal radius. Emergency surgery consisting of manual fracture reduction ...

  8. 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...

  9. 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.)

  10. 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. 

  11. 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.

  12. Imaging of the Proximal and Distal Radioulnar Joints.

    Science.gov (United States)

    Ehman, Eric C; Felmlee, Joel P; Frick, Matthew A

    2015-08-01

    The proximal and distal radioulnar joints form a unique articular arrangement between the radius and ulna, allowing pivot motion of the forearm and positioning the hand in space. Typically imaged in conjunction with the elbow, radiographs, computed tomography (CT), and MR imaging of the proximal radioulnar joint contribute unique diagnostic information. Because dysfunction of the distal radioulnar joint is often a result of instability, dynamic CT protocols stressing the joint in addition to anatomic imaging with radiographs and MR imaging is valuable. Detailed knowledge of the patient's clinical condition and careful selection of imaging protocols will maximize the benefits. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. 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...

  14. Left ventricular biomechanics in professional football players.

    Science.gov (United States)

    von Lueder, T G; Hodt, A; Gjerdalen, G F; Steine, K

    2018-01-01

    Chronic exercise induces adaptive changes of left ventricular (LV) ejection and filling capacities which may be detected by novel speckle-tracking echocardiography (STE) and tissue Doppler imaging (TDI)-based techniques. A total of 103 consecutive male elite Norwegian soccer players and 46 age-matched healthy controls underwent echocardiography at rest. STE was used to assess LV torsional mechanics and LV systolic longitudinal strain (LS). Diastolic function was evaluated by trans-mitral blood flow, mitral annular velocities by TDI, and LV inflow propagation velocity by color M-mode. Despite similar global LS, players displayed lower basal wall and higher apical wall LS values vs controls, resulting in an incremental base-to-apex gradient of LS. Color M-mode and TDI-derived data were similar in both groups. Peak systolic twist rate (TWR) was significantly lower in players (86.4±2.8 vs controls 101.9±5.2 deg/s, P<.01). Diastolic untwisting rate (UTWR) was higher in players (-124.5±4.2 vs -106.9±6.7 deg/s) and peaked earlier during the cardiac cycle (112.7±0.8 vs 117.4±2.4% of systole duration, both P<.05). Untwisting/twisting ratio (-1.48±0.05 vs -1.11±0.08; P<.001) and untwisting performance (=UTR/TW; -9.25±0.34 vs -7.38±0.40 s -1 , P<.01) were increased in players. Augmented diastolic wall strain (DWS), a novel measure of LV compliance in players, was associated with improved myocardial mechanical efficiency. The described myocardial biomechanics may underlie augmented exertional cardiac function in athletes and may have a potential role to characterize athlete's heart by itself or to distinguish it from hypertensive or hypertrophic cardiomyopathy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Physiological and biomechanical in different swimming intensities

    Directory of Open Access Journals (Sweden)

    Sebastião Iberes Lopes de Melo

    2004-06-01

    Full Text Available The objective of this study was to analyze the physiological and biomechanical responses of swimmers at different swimming intensities. The intentionally selected sample was composed by seven athletes with swimming times for qualifying on the Brazilian Swimming Championship. A series of 8x200 free style swimming at speeds of 80%, 85%, 90%, 95% and 100% of individual maximum effort was used as the task. A film camera of 60 Hz and an Accusport mMol lactimeter were used for data collection. Descriptive statistics, analysis of variance (ANOVA with “post-hoc” Tukey test and Spearman’s correlation were used for statistical analyses to identify the differences between athletes for the variables blood lactate, crawl stroke frequency (FB and dimension (BR at different intensities. The level of significance was set at 0.05. Based on the results, there were significant differences on swimming technique among effort intensities, for both the physiological and mechanical responses, especially at levels above 95% individual maximum effort. The high correlation between blood lactate and crawl stroke frequency and length, and between crawl stroke frequency and length, with the last two correlations being negative, indicated that the proposed series was adequate to analyze physiological and biomechanical response. It was concluded that as the intensity increases, there is a need for mechanical adjustments to enable the athletes to endure different speeds. It was also possible to establish the ideal swimming speed for each energetic zone, providing data for coaches and athletes to train both speed and technique within the specific energetic zones. RESUMO O objetivo deste estudo foi analisar as respostas fisiológicas e biomecânicas de nadadores em diferentes intensidades de nado. A amostra, intencionalmente escolhida, foi composta por sete atletas que possuíam índices de participação em campeonato brasileiro absoluto. Foi utilizada como tarefa de

  16. 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

  17. Biomechanical research on bowed string musicians: a scoping study.

    Science.gov (United States)

    Kelleher, Leila K; Campbell, Kody R; Dickey, James P

    2013-12-01

    Performing arts biomechanics is concerned with quantifying the musculoskeletal demands of artistic tasks. The growing body of related research has prompted this scoping study, solely focused on quantitative research, to summarize the state of the science, identify knowledge gaps, and identify opportunities for future research. To identify, summarize, and categorize quantitative research on the biomechanics of violin, viola, cello, and double bass players, using scoping study methodology. Established scoping study methodology was used to identify and categorize existing research. We identified 74 articles for review. Of these, 34 met our scoping study criteria and were included in this study. Twenty-one of the 34 articles that met the scoping criteria were published since 2000. Investigations using electromyography (16 studies) and kinematics (15 studies) comprise the bulk of the research. Two studies employed force transducers for data collection. Violinists were the most frequently studied musicians (22 studies) and double bass players were the least (1 study). Fewer than half of the studies used solely professional musicians as their subjects (13 studies). This scoping study confirmed that quantitative biomechanical research into bowed string musicians has been performed with increasing frequency and that there are voids in the research, particularly in investigating mechanisms of injury and protective strategies. Currently, arts biomechanics research is largely descriptive in nature. There are few studies that investigate protective strategies, although it is expected that the field will progress to incorporate this type of research.

  18. Steven Vogel and His Theory of Comparative Biomechanics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 5. Steven Vogel and His Theory of Comparative Biomechanics. Book Review Volume 21 Issue 5 May 2016 pp 467-471. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/021/05/0467-0471. Abstract ...

  19. 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...

  20. 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.

  1. 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…

  2. 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.

  3. How to Assess the Biomechanical Risk Levels in Beekeeping.

    Science.gov (United States)

    Maina, G; Rossi, F; Baracco, A

    2016-01-01

    Beekeepers are at particular risk of developing work-related musculoskeletal disorders, but many of the studies lack detailed exposure assessment. To evaluate the biomechanical overload exposure in a specific farming activity, a multitasking model has been developed through the characterization of 37 basic operational tasks typical of the beekeeping activity. The Occupational Repetitive Actions (OCRA) Checklist and the National Institute for Occupational Safety and Health (NIOSH) Lifting Index methodologies have been applied to these elementary tasks to evaluate the exposure, and the resulting risk indices have been time-weighted averaged. Finally, an easy access, computer-assisted toolkit has been developed to help the beekeepers in the biomechanical risk assessment process. The risk of biomechanical overload for the upper limbs ranges from acceptable (maintenance and recovery of woody material and honey packaging with dosing machine tasks) to high (distribution of the top supers) risk level. The risk for back injury is always borderline in women and increases with exposure time, whereas it ranges from acceptable to borderline in men. The definition of the biomechanical risk levels allows for planning of corrective actions aimed at preventing and reducing the risk of musculoskeletal disorders through engineering, administrative, and behavioral interventions. The methodology can be used for risk assessment in other mainly manual agricultural activities.

  4. 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

  5. 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…

  6. Biomechanics Curriculum: Its Content and Relevance to Movement Sciences

    Science.gov (United States)

    Hamill, Joseph

    2007-01-01

    While the National Association for Sport and Physical Education (NASPE) has outlined a number of learning outcomes for undergraduate biomechanics, there are a number of factors that can influence the curriculum in such courses. These factors create a situation that indeed can influence students and their attitude towards these classes.…

  7. 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

  8. 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.

  9. 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…

  10. 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

  11. 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.

  12. Steven Vogel and His Theory of Comparative Biomechanics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 5. Steven Vogel and His Theory of Comparative Biomechanics. Book Review Volume 21 Issue 5 May 2016 pp 467-471. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/021/05/0467-0471. Abstract ...

  13. 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

  14. Applied Biomechanics Research for the United States Ski Team.

    Science.gov (United States)

    Dillman, Charles J.

    1982-01-01

    Assisted by a team of physicians and sports scientists, the United States Ski Team has developed its own sports medicine program, the purpose of which is to assist coaches and athletes in controlling and optimizing factors which influence skiing performance. A number of biomechanical research projects which have been undertaken as part of this…

  15. 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.

  16. Corneal Biomechanical Changes and Tissue Remodeling After SMILE and LASIK.

    Science.gov (United States)

    Shetty, Rohit; Francis, Mathew; Shroff, Rushad; Pahuja, Natasha; Khamar, Pooja; Girrish, Molleti; Nuijts, Rudy M M A; Sinha Roy, Abhijit

    2017-11-01

    To evaluate transient corneal tissue healing and biomechanical changes between laser in situ keratomileusis (LASIK) and small incision lenticule extraction (SMILE) eyes. In each patient, one eye underwent LASIK and the other underwent SMILE. Optical coherence tomography (OCT) and dynamic Scheimpflug imaging (Corvis-ST) was used to assess tissue healing and biomechanics, respectively. Analyses of OCT scans yielded corneal speckle distribution (CSD) and Bowman's roughness index (BRI). Waveform analyses of deformation amplitude yielded corneal stiffness. Further, corneal force versus corneal deformation data helped compare the two procedures. BRI increased and then decreased transiently after both treatments (P < 0.05). However, SMILE eyes had BRI similar to that of their preoperative state compared to LASIK eyes at 6-month follow-up. CSD indicated a marked increase in the number of bright pixels and a decrease in the number of dark pixels after SMILE (1-month follow-up) and LASIK eyes (3-month follow-up), respectively. CSD returned to near preoperative state thereafter, respectively. Corneal stiffness change from preoperative state was similar between LASIK and SMILE eyes. However, deformation at discrete values of corneal force indicated some recovery of biomechanical strength after SMILE, but not in LASIK eyes. BRI and CSD indicated earlier tissue healing in SMILE eyes than in LASIK. CSD results may indicate delayed cell death in LASIK eyes and increased light scatter due to interface fluid in SMILE eyes. Corneal biomechanical strength remodeled better in SMILE. This may indicate some hydration-related recovery.

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

    African Journals Online (AJOL)

    2015-08-10

    Aug 10, 2015 ... Materials and Methods: Three different three-dimensional finite element models of the mandible were developed to simulate the biomechanical responses of titanium plates and screws. The fracture lines were fixed with double 4-hole straight, 4-hole square, and 5-hole Y plates with monocortical screws.

  18. Pathobiology of obesity and osteoarthritis: integrating biomechanics and inflammation

    Directory of Open Access Journals (Sweden)

    Rita I. Issa

    2012-05-01

    Full Text Available Obesity is a significant risk factor for developing osteoarthritis in weight-bearing and non-weight-bearing joints. Although the pathogenesis of obesity-associated osteoarthritis is not completely understood, recent studies indicate that pro-inflammatory metabolic factors contribute to an increase in osteoarthritis risk. Adipose tissue, and in particular infrapatellar fat, is a local source of pro-inflammatory mediators that are increased with obesity and have been shown to increase cartilage degradation in cell and tissue culture models. One adipokine in particular, leptin, may be a critical mediator of obesity-associated osteoarthritis via synergistic actions with other inflammatory cytokines. Biomechanical factors may also increase the risk of osteoarthritis by activating cellular inflammation and promoting oxidative stress. However, some types of biomechanical stimulation, such as physiologic cyclic loading, inhibit inflammation and protect against cartilage degradation. A high percentage of obese individuals with knee osteoarthritis are sedentary, suggesting that a lack of physical activity may increase the susceptibility to inflammation. A more comprehensive approach to understanding how obesity alters daily biomechanical exposures within joint tissues may provide new insight into the protective and damaging effects of biomechanical factors on inflammation in osteoarthritis.

  19. Biomechanical effects of pedicle screw fixation on adjacent segments.

    Science.gov (United States)

    Kyaw, Thein Aung; Wang, Zhuo; Sakakibara, Toshihiko; Yoshikawa, Takamasa; Inaba, Tadashi; Kasai, Yuichi

    2014-07-01

    Various biomechanical investigations have attempted to clarify the aetiology of adjacent segment disease (ASD). However, no biomechanical study has examined in detail the deformation behaviour of the adjacent segments when both pure torque and an angular displacement load are applied to the vertebrae along multiple segments. The purpose of this study is to investigate the biomechanical effects of pedicle screw fixation on adjacent segments. Ten cadaveric lumbar spines (L2-L5) of boars were used. Control and fusion models were prepared by disc damage and pedicle screw fixation of each specimen, and then, bending and rotation tests were performed using a six-axis material tester. In the biomechanical tests regulated by an angular displacement load, the range of motion (ROM) of the cranial and caudal adjacent segments in antero-posterior flexion and lateral bending was increased by about 20 % (p fusion surgery as a mechanism to compensate for the ROM lost due to excessive fusion by pedicle screw fixation, so that a large torque may be applied to adjacent segments within a physiologically possible range, and it might gradually lead to a degenerative intervertebral disc or progression of spondylolisthesis in the adjacent segments.

  20. 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.

  1. Biomechanical design considerations for transradial prosthetic interface: A review.

    Science.gov (United States)

    Sang, Yuanjun; Li, Xiang; Luo, Yun

    2016-03-01

    Traditional function and comfort assessment of transradial prostheses pay scant attention to prosthetic interface. With better understanding of the biomechanics of prosthetic interface comes better efficiency and safety for interface design; in this way, amputees are more likely to accept prosthetic usage. This review attempts to provide design and selection criteria of transradial interface for prosthetists and clinicians. Various transradial socket types in the literature were chronologically reviewed. Biomechanical discussion of transradial prosthetic interface design from an engineering point of view was also done. Suspension control, range of motion, stability, as well as comfort and safety of socket designs have been considered in varying degrees in the literature. The human-machine interface design should change from traditional "socket design" to new "interface design." From anatomy and physiology to biomechanics of the transradial residual limb, the force and motion transfer, together with comfort and safety, are the two main aspects in prosthetic interface design. Load distribution and transmission should mainly rely on achieving additional skeletal control through targeted soft tissue relief. Biomechanics of the residual limb soft tissues should be studied to find the relationship between mechanical properties and the comfort and safety of soft tissues. © IMechE 2016.

  2. Stability of the human spine: a biomechanical study

    NARCIS (Netherlands)

    Scholten, P.J.M.; Veldhuizen, A.G.; Grootenboer, H.J.

    1988-01-01

    The influences of curvatures and of physical properties on the mechanical stability of the spine were analysed by means of a three-dimensional, geometrical, nonlinear biomechanical model. According to the model, the initial buckling load decreases with increasing lordotic and kyphotic curvatures.

  3. Steven Vogel and His Theory of Comparative Biomechanics

    Indian Academy of Sciences (India)

    IAS Admin

    Bio-Cyber Physical Systems) or a suffix (e.g.,. Mathematical Biology). The traditional fields of biology and mechanics present a peculiar problem when they are combined together because biomechanics and mechanobiology are both used, the latter being much younger than the former. How is mechanobiology dif-.

  4. 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.

  5. 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 ...

  6. The History of Biomechanics in Total Hip Arthroplasty.

    Science.gov (United States)

    Houcke, Jan Van; Khanduja, Vikas; Pattyn, Christophe; Audenaert, Emmanuel

    2017-01-01

    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.

  7. Biomechanics of the Gastrointestinal Tract in Health and Disease

    DEFF Research Database (Denmark)

    Zhao, Jingbo; Liao, Donghua; Gregersen, Hans

    2010-01-01

    The gastrointestinal (GI) tract is functionally subjected to dimensional changes. Hence, biomechanical properties such as the stress-strain relationships are of particularly importance. These properties vary along the normal GI tract and remodel in response to growth, aging and disease. The biome...

  8. 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

  9. 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

  10. 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 footprint coverage of the simple suture and horizontal mattress suture groups was not significantly different ( P = .44). There were no significant differences in load to failure, cyclic displacement, or stiffness between the single-row and double-row groups or between the simple suture and horizontal mattress suture techniques. Likewise, there was no

  11. 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

  12. Propeller Flap for Complex Distal Leg Reconstruction: A Versatile ...

    African Journals Online (AJOL)

    have been described in the axilla, periolecranon, forearm, lower extremity,[1] hand,[6] and trunk.[7] In spite of the versatility of perforator‑based flaps, literature search reveals ... Anatomy of distal leg perforators. Perforators are small diameter vessels that originate from a main pedicle and perforate the fascia or muscle to ...

  13. A traction jig for reduction of distal radial fractures.

    Science.gov (United States)

    Wise, David; Coats, Tim; Persad, Ram

    2004-01-01

    A traction jig is described which facilitates the closed reduction of extra-articular distal radial fractures and which maintains the reduction whilst a plaster cast is applied. The jig is suitable for use by a single operator in an Accident and Emergency department setting.

  14. Comparative distalization effects of Jones jig and pendulum appliances.

    Science.gov (United States)

    Patel, Mayara Paim; Janson, Guilherme; Henriques, José Fernando Castanha; de Almeida, Renato Rodrigues; de Freitas, Marcos Roberto; Pinzan, Arnaldo; de Freitas, Karina Maria Salvatore

    2009-03-01

    In this study, we compared the dentoalveolar changes of Class II patients treated with Jones jig and pendulum appliances. The experimental group comprised 40 Class II malocclusion subjects, divided into 2 groups: group 1 consisted of 20 patients (11 boys, 9 girls) at a mean pretreatment age of 13.17 years, treated with the Jones jig appliance for 0.91 years; group 2 comprised 20 patients (8 boys, 12 girls) at a mean pretreatment age of 13.98 years, treated with the pendulum appliance for 1.18 years. Only active treatment time of molar distalization was evaluated in the predistalization and postdistalization lateral cephalograms. Molar, second premolar, and incisor angular and linear variables were obtained. The intergroup treatment changes in these variables were compared with independent t tests. The maxillary second premolars showed greater mesial tipping and extrusion in the Jones jig group, indicating more anchorage loss during molar distalization with this appliance. The amounts and the monthly rates of molar distalization were similar in both groups. The Jones jig group showed greater mesial tipping and extrusion of the maxillary second premolars. The mean amounts and the monthly rates of first molar distalization were similar in both groups.

  15. Distal skin vasodilation promotes rapid sleep onset in preterm neonates.

    Science.gov (United States)

    Barcat, Lucile; Decima, Pauline; Bodin, Emilie; Delanaud, Stephane; Stephan-Blanchard, Erwan; Leke, Andre; Libert, Jean-Pierre; Tourneux, Pierre; Bach, Veronique

    2017-10-01

    Although sleep is of paramount importance for preterm neonates, care of the latter in a neonatal intensive care unit does not favour sleep. Given that several studies in adults have described a 'vegetative preparedness to sleep' (in which distal skin vasodilation before lights-out promotes rapid sleep onset), we looked at whether or not this process operates in preterm neonates. Sleep propensity was assessed in terms of the duration of a spontaneous episode of wakefulness (W). Skin temperatures at six body sites (the abdomen, pectoral region, eye, hand, thigh and foot) were measured (using infrared thermography) during nocturnal polysomnography in 29 9-day-old preterm neonates (postmenstrual age: 209 ± 9 days). We then determined whether the duration of the W episode depended upon the local skin temperatures measured at the start, during and end of the episode. The W episode was shorter when distal skin temperatures (thigh, hand and foot) and the pectoral temperature were higher at the end of the episode (i.e. at sleep onset). The relationship with the duration of the W episode was not significant for temperatures measured at the start of the W episode. We observed gradual distal vasodilation at the pectoral region, the thigh, hand and foot (i.e. affecting most of the body's skin surface) during W episodes. Our results constitute initial evidence to show that distal vasodilation may have a key role in facilitating sleep onset in very preterm neonates. © 2017 European Sleep Research Society.

  16. Proximal and distal environmental correlates of adolescent obesity.

    Science.gov (United States)

    Nesbit, Kathryn C; Kolobe, Thubi A; Arnold, Sandra H; Sisson, Susan B; Anderson, Michael P

    2014-08-01

    The purpose of this study was to determine how proximal (home) and distal (neighborhood) environmental characteristics interact to influence obesity in early and middle adolescents. This was a descriptive, cross-sectional study using the 2007 National Survey of Children's Health (NCSH). Participants were 39,542 children ages 11 to 17 years. Logistic regressions were used to examine the relationship between adolescent obesity and environmental factors, the relative strength of these factors, and the influence of age and gender. Proximal environmental factors were stronger correlates of adolescent obesity than distal environmental factors. Sedentary behavior related to TV watching time at home was the strongest correlate of adolescent obesity overall (OR 1.13, 95% CI 1.11-1.15). Parks and playgrounds (OR 0.86, 95% CI 0.08-0.92), as well as recreation centers (OR 0.91, 95% CI 0.85-0.97) were significant distal environmental factor correlates. Girls and middle adolescents were at less risk for obesity than boys and early adolescents (OR 0.51, 95% CI 0.68-0.82; OR 0.75, 95% CI 0.68-0.96). The results of this study reveal the importance of proximal environmental characteristics on adolescent obesity relative to distal environmental characteristics. Obesity intervention strategies for adolescents should target sedentary behavior and opportunities for physical activity with a focus on early adolescents and boys.

  17. Surgical management of acute distal biceps tendon rupture ...

    African Journals Online (AJOL)

    Acute distal biceps tendon rupture constitute a rare lesion of biceps injuries, typically, easy to diagnosis after lifting a heavy object. Treatment is controversial, nonoperative for sedentary and elderly patients; surgical for young and active individuals. Many operative techniques are described, they all aim to restore an ...

  18. 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 ...

  19. Distal adding-on phenomenon in Lenke 1A scoliosis

    DEFF Research Database (Denmark)

    Wang, Yu; Hansen, Ebbe Stender; Høy, Kristian

    2011-01-01

    the instrumentation) from the CSVL (the vertical line that bisects proximal sacrum). Five methods for determining LIV were compared in both the adding-on group and no adding-on group. RESULTS: Out of the 278 patients reviewed, 45 met the inclusion criteria; 23 of these met the definition for distal adding...

  20. Distal biceps reconstruction 13 years post-injury.

    Science.gov (United States)

    Burrus, M Tyrrell; Chhabra, A Bobby

    2015-04-01

    Distal biceps tendon ruptures are relatively rare injuries most commonly caused by an eccentric contraction of the biceps brachii. The majority of complete ruptures receive early surgical intervention, however, some patients do present in a delayed fashion. There are many surgical options at this time for acute and chronic injuries, and this case report describes an Achilles allograft reconstruction in a male who sustained a complete tear 13 years prior to presentation. At 12-month follow up, he had regained full function of his dominant extremity as evidence by returning to work with no limitations and by a Disabilities of the Arm, Shoulder, and Hand (DASH) score of zero. We are unaware of a successfully surgically reconstructed distal biceps tendon of this chronicity. As the literature on this subject is sparse, this case report gives credence to the idea that certain patients with a chronic distal biceps rupture should be considered for operative reconstruction and not relegated to continued failed conservative treatment. Discussed are the surgical treatment options and controversies for chronic distal biceps ruptures, and we review various outcome studies using different surgical techniques.

  1. Bilateral ruptures of the distal biceps brachii tendon.

    Science.gov (United States)

    Schneider, Adam; Bennett, J Michael; O'Connor, Daniel P; Mehlhoff, Thomas; Bennett, James B

    2009-01-01

    The purpose of this study was to identify characteristics associated with bilateral ruptures of the distal biceps tendons. We present a retrospective case series of 25 patients who sustained non-simultaneous bilateral distal biceps brachii tendon ruptures that were repaired surgically, with follow-up available on 10 patients. The average age of the patients was 50 years (range 28-76). All patients were male. The mean time from the first tendon rupture to the contralateral tendon rupture was 2.7 years (range 0.5 - 6.3). Follow-up averaged 45 months (range 24-85). Patients with bilateral ruptures tended to be middle-aged men, who commonly participated in weight lifting, manual labor, or sports, and who had higher rates of nicotine (50%) and anabolic steroid use (20%) than the general population. After surgical repair of 9 of 10 patients, patients with bilateral distal biceps tendon ruptures had good to excellent outcomes. With the numbers available, outcomes were not statistically associated with manual labor, past medical history, prescription medications, prior tendon injury, body mass index, current activity in sports, use of nutritional supplements, or anabolic steroid use, although worker's compensation claims approached statistical significance (p = 0.059). Patients who sustained bilateral distal biceps tendon ruptures tended to be middle-aged men with higher rates of nicotine and anabolic steroid use than the general population.

  2. Distal Renal Tubular Acidosis, an Uncommonly diagnosed Cause of ...

    African Journals Online (AJOL)

    Five cases of distal renal tubular acidosis aged between 2½ weeks and 2½ months are described. The presenting features included lethargy, refusal to feed, high density of periodic respiration, vomiting and recurrent episodes of unexplained metabolic acidosis. A constant feature was failure to thrive despite caloric intakes ...

  3. Conservative management of distal leg necrosis in lung transplant recipients.

    Science.gov (United States)

    Aigner, F; Husmann, M; Huber, L C; Benden, C; Schuurmans, M M

    2017-05-01

    Critical limb ischemia (CLI) with distal leg necrosis in lung transplant recipients (LTR) is associated with a high risk for systemic infection and sepsis. Optimal management of CLI has not been defined so far in LTR. In immunocompetent individuals with leg necrosis, surgical amputation would be indicated and standard care. We report on the outcome of four conservatively managed LTR with distal leg necrosis due to peripheral arterial disease (PAD) with medial calcification of the distal limb vessels. Time interval from lung transplantation to CLI ranged from four years (n = 1) to more than a decade (n = 3). In all cases a multimodal therapy with heparin, acetylsalicylic acid, iloprost and antibiotic therapy was performed, in addition to a trial of catheter-based revascularization. Surgical amputation of necrosis was not undertaken due to fear of wound healing difficulties under long-term immunosuppression and impaired tissue perfusion. Intensive wound care and selective debridement were performed. Two patients developed progressive gangrene followed by auto-amputation during a follow-up of 43 and 49 months with continued ambulation and two patients died of unrelated causes 9 and 12 months after diagnosis of CLI. In conclusion, we report a conservative treatment strategy for distal leg necrosis in LTR without surgical amputation and recommend this approach based on our experience. Copyright © 2017 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  4. Propeller Flap for Complex Distal Leg Reconstruction: A Versatile ...

    African Journals Online (AJOL)

    Reverse sural artery fasciocutaneous flap has become a workhorse for the reconstruction of distal leg soft tissue defects. When its use is not feasible, perforator‑based propeller flap offers a better, easier, faster, and cheaper alternative to free flap. We present our experience with two men both aged 34 years who sustained ...

  5. 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

  6. 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

  7. 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.

  8. Stressfrakturer af distale fibula hos en patient med osteoporose

    DEFF Research Database (Denmark)

    Schwartz, Frederik; Heerfordt, Ida Marie

    2014-01-01

    We report a case of an 81-year-old osteoporotic woman, who suffered stress fractures of the distal fibula on both sides within a two-year period. The risk factors for stress fractures are reviewed and the importance of a high index of suspicion for stress fractures is emphasized. When a stress fr...

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

    African Journals Online (AJOL)

    2017-03-06

    Mar 6, 2017 ... treatment.[10] The percentage of GP-filled areas (PGFAs) has been used as a measure of the quality of the root filling.[7] Therefore, the aim of this study was to compare different filling techniques in the distal canals of lower molars, instrumented by different single-file systems, and the canal area in terms of ...

  10. Non-Vascularised Fibular Grafting After Resection of Distal Femoral ...

    African Journals Online (AJOL)

    Background: Vascularized fibular grafting, allografting, megaprosthesis and allograft-prosthesis composite are suitable limb salvage techniques after resection of ... the initial observation showed such a wide non-vascularized fibular grafting for arthrodesis of the knee after resection of the distal femoral tumours is a feasible ...

  11. 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 ...

  12. 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.

  13. 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.

  14. 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 ...

  15. 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.

  16. Endoprosthetic replacement of distal femoral tumors in Nigeria: A ...

    African Journals Online (AJOL)

    2015-08-12

    Aug 12, 2015 ... In this observational study, three consecutive patients who were treated for distal femur tumours using endoprosthetic replacement between June 2013 and June 2014 were studied. The patients were within the ages of 28-47 years at the time of surgery. All three patients had modular endoprosthesis ...

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

    African Journals Online (AJOL)

    There was an improvement of the preinjury function attributed to the osteotomy of the femoral diaphyseal, which alleviated the anterior thigh discomfort. Keywords: Amputation, Distal femur fracture, Femoral shaft fracture, Femur, Femur fractures, Fracture fixation, Fracture malunion, Fractures, Intramedullary nail, Knee ...

  18. 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.

  19. An electro-myographic study of the distal porcine ureter

    NARCIS (Netherlands)

    Roshani, H.; Dabhoiwala, N. F.; Dijkhuis, T.; Ongerboer de Visser, B. W.; Kurth, K. H.; Lamers, W. H.

    2000-01-01

    PURPOSE: The accumulation of urine in the renal pelvis causes depolarisation of non-specific muscular pace-maker cells. The wave of depolarisation spreads distally in the ureteric smooth muscle cells via gap junctions. This wave of excitation causes a coordinated peristaltic contraction which

  20. 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 ...