The Experts below are selected from a list of 2733 Experts worldwide ranked by ideXlab platform
M D Mckee - One of the best experts on this subject based on the ideXlab platform.
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treatment of osteopenic humeral shaft nonunion with Compression plating humeral cortical allograft struts and bone grafting
Journal of Orthopaedic Trauma, 2005Co-Authors: Andrew P Van Houwelingen, M D MckeeAbstract:Surgical stabilization of humeral shaft nonunions can be difficult to achieve if severe osteopenia or loss of bone stock is present. We present a technique whereby a 4.5-mm standard Dynamic Compression Plate is used in conjunction with a humeral cortical allograft strut and bone grafting to stabilize humeral shaft nonunions complicated by severe bone loss. Six patients with established nonunion of the humeral shaft underwent this technique. Union was achieved at an average of 3.4 months (range 2-6 months). Our method using onlay allograft struts can provide an effective alternative in the management of humeral shaft nonunion complicated by severe osteopenia of various etiologies.
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fixation of fractures of the shaft of the humerus by Dynamic Compression Plate or intramedullary nail a prospective randomised trial
Journal of Bone and Joint Surgery-british Volume, 2000Co-Authors: R G Mccormack, R E Buckley, M D Mckee, D. O'brien, J. Powell, Emil H SchemitschAbstract:We randomised prospectively 44 patients with fractures of the shaft of the humerus to open reduction and internal fixation by either an intramedullary nail (IMN) or a Dynamic Compression Plate (DCP). Patients were followed up for a minimum of six months. There were no significant differences in the function of the shoulder and elbow, as determined by the American Shoulder and Elbow Surgeons’ score, the visual analogue pain score, range of movement, or the time taken to return to normal activity. There was a single case of shoulder impingement in the DCP group and six in the IMN group. Of these six, five occurred after antegrade insertion of an IMN. In the DCP group three patients developed complications, compared with 13 in the IMN group. We had to perform secondary surgery on seven patients in the IMN group, but on only one in the DCP group (p = 0.016). Our findings suggest that open reduction and internal fixation with a DCP remains the best treatment for unstable fractures of the shaft of the humerus. Fixation by IMN may be indicated for specific situations, but is technically more demanding and has a higher rate of complications.
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Fixation of fractures of the shaft of the humerus by Dynamic Compression Plate or intramedullary nail
J Bone Joint Surg [Br], 2000Co-Authors: M D Mckee, Associate E Professor H Schemitsch, R G Mccormack, R E Buckley, Associate Professor, D. O'brien, J. Powell, Emil H SchemitschAbstract:W e randomised prospectively 44 patients with fractures of the shaft of the humerus to open reduction and internal fixation by either an intramedullary nail (IMN) or a Dynamic Compression Plate (DCP). Patients were followed up for a minimum of six months. There were no significant differences in the function of the shoulder and elbow, as determined by the American Shoulder and Elbow Surgeons' score, the visual analogue pain score, range of movement, or the time taken to return to normal activity. There was a single case of shoulder impingement in the DCP group and six in the IMN group. Of these six, five occurred after antegrade insertion of an IMN. In the DCP group three patients developed complications, compared with 13 in the IMN group. We had to perform secondary surgery on seven patients in the IMN group, but on only one in the DCP group (p = 0.016). Our findings suggest that open reduction and internal fixation with a DCP remains the best treatment for unstable fractures of the shaft of the humerus. Fixation by IMN may be indicated for specific situations, but is technically more demanding and has a higher rate of complications.
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the application of the limited contact Dynamic Compression Plate in the upper extremity an analysis of 114 consecutive cases
Injury-international Journal of The Care of The Injured, 1995Co-Authors: M D Mckee, John G Seiler, Jesse B JupiterAbstract:We sought to assess the clinical effectiveness of a new Plate design which offers improved biological and biomechanical features, the limited contact Dynamic Compression (LCDC) Plate. We analysed 114 LCDC Plates applied consecutively for upper extremity fractures or reconstruction in 94 patients. Three patients were lost to follow-up, leaving 111 Plates in 91 patients followed to definitive fracture/osteotomy outcome. Thirty-seven Plates were applied for reconstruction in 35 patients, including 11 where standard implants had failed. Fifty-six patients had 74 Plates applied for acute fractures including 12 open fractures, 23 multiply injured patients, 26 patients with concomitant fractures and seven associated neurovascular injuries. All patients were followed to definitive outcome. Union was achieved at an average of 10.7 weeks in 105 platings, while three delayed unions eventually united without further intervention, an overall union rate of 108/111, or 97.3 per cent. There were no mechanical failures of the Plates or screws. In this large series a union rate of 97.3 per cent with no implant failures confirms its clinical application for traumatic and reconstructive problems in this area. Improved contouring, easier screw placement, decreased interference with cortical bone blood flow and excellent union rates are definite short-term advantages. Theoretical long-term benefits of decreased stress-shielding and lower refracture rates will require longer follow up.
Emil H Schemitsch - One of the best experts on this subject based on the ideXlab platform.
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biomechanical evaluation of periprosthetic femoral fracture fixation
Journal of Bone and Joint Surgery American Volume, 2008Co-Authors: Rad Zdero, Richard Walker, James P Waddell, Emil H SchemitschAbstract:Background: A variety of methods are available for the fixation of femoral shaft fractures after total hip arthroplasty. However, few studies in the literature have quantified the performance of such repair constructs. The aim of this study was to evaluate biomechanically four different constructs for the fixation of periprosthetic femoral shaft fractures following total hip arthroplasty. Methods: Twenty synthetic femora were tested in axial Compression, lateral bending, and torsion to determine initial stiffness, as well as stiffness following fixation of a simulated femoral midshaft fracture with and without a bone gap. Four fracture fixation constructs (five specimens per group) were assessed: construct A was a Synthes locked Plate (a twelve-hole broad Dynamic Compression Plate) with locked screws; construct B, a Synthes locked Plate (a twelve-hole broad Dynamic Compression Plate) with cables and locked screws; construct C, a Zimmer nonlocking (eight-hole) cable Plate with cables and nonlocked screws; and construct D, a Zimmer nonlocking (eight-hole) cable Plate with allograft strut, cables, and nonlocked screws. Axial stiffness, lateral bending stiffness, and torsional stiffness were assessed with respect to baseline intact specimen values. Axial load to failure was also measured for the specimens. Results: Construct D demonstrated either equivalent or superior stiffness in all testing modes compared with the other constructs in femora with both a midshaft fracture and a bone gap. A comparison of constructs A, B, and C demonstrated equivalent stiffness in all test modes (with one exception) in femora with a midshaft fracture and a bone gap. Conclusions: A combination of a nonlocking Plate with an allograft strut (construct D) resulted in the highest stiffness of the constructs examined for treating a periprosthetic fracture around a stable femoral component of a total hip replacement. Clinical Relevance: A locked Plate (constructs A and B) should be used with caution as a stand-alone treatment for the fixation of a periprosthetic femoral shaft fracture following total hip arthroplasty, particularly with good bone stock.
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fixation of fractures of the shaft of the humerus by Dynamic Compression Plate or intramedullary nail a prospective randomised trial
Journal of Bone and Joint Surgery-british Volume, 2000Co-Authors: R G Mccormack, R E Buckley, M D Mckee, D. O'brien, J. Powell, Emil H SchemitschAbstract:We randomised prospectively 44 patients with fractures of the shaft of the humerus to open reduction and internal fixation by either an intramedullary nail (IMN) or a Dynamic Compression Plate (DCP). Patients were followed up for a minimum of six months. There were no significant differences in the function of the shoulder and elbow, as determined by the American Shoulder and Elbow Surgeons’ score, the visual analogue pain score, range of movement, or the time taken to return to normal activity. There was a single case of shoulder impingement in the DCP group and six in the IMN group. Of these six, five occurred after antegrade insertion of an IMN. In the DCP group three patients developed complications, compared with 13 in the IMN group. We had to perform secondary surgery on seven patients in the IMN group, but on only one in the DCP group (p = 0.016). Our findings suggest that open reduction and internal fixation with a DCP remains the best treatment for unstable fractures of the shaft of the humerus. Fixation by IMN may be indicated for specific situations, but is technically more demanding and has a higher rate of complications.
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Fixation of fractures of the shaft of the humerus by Dynamic Compression Plate or intramedullary nail
J Bone Joint Surg [Br], 2000Co-Authors: M D Mckee, Associate E Professor H Schemitsch, R G Mccormack, R E Buckley, Associate Professor, D. O'brien, J. Powell, Emil H SchemitschAbstract:W e randomised prospectively 44 patients with fractures of the shaft of the humerus to open reduction and internal fixation by either an intramedullary nail (IMN) or a Dynamic Compression Plate (DCP). Patients were followed up for a minimum of six months. There were no significant differences in the function of the shoulder and elbow, as determined by the American Shoulder and Elbow Surgeons' score, the visual analogue pain score, range of movement, or the time taken to return to normal activity. There was a single case of shoulder impingement in the DCP group and six in the IMN group. Of these six, five occurred after antegrade insertion of an IMN. In the DCP group three patients developed complications, compared with 13 in the IMN group. We had to perform secondary surgery on seven patients in the IMN group, but on only one in the DCP group (p = 0.016). Our findings suggest that open reduction and internal fixation with a DCP remains the best treatment for unstable fractures of the shaft of the humerus. Fixation by IMN may be indicated for specific situations, but is technically more demanding and has a higher rate of complications.
Tatsuo Yokoi - One of the best experts on this subject based on the ideXlab platform.
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CASE REPORT Bilateral Galeazzi fracture-dislocations: a case report of early rehabilitation
2016Co-Authors: Shingo Komura, Hidehiko Nonomura, Takashi Satake, Tatsuo YokoiAbstract:Abstract A 24-year-old man had bilateral Galeazzi fracture-dislocations due to a motorcycle accident. The right radius fracture was a simple fracture and was fixed with a limited contact Dynamic Compression Plate. The left radius fracture was a comminuted fracture and was fixed with a long locking Compression Plate in the bridging Plate fashion while maintaining reduction with a temporary external fixator. Postoperative computed tomography under passive rotation of both forearms showed acceptable con-gruency of the distal radioulnar joints, and early rehabili-tation of forearm rotation was started at 2 weeks after the operation. At 13-month follow-up, bone union of both fractures was achieved, and forearm motion was almost restored to normal. Moreover, no subluxation or dislocation of either distal radioulnar joint was observed
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Bilateral Galeazzi fracture-dislocations: a case report of early rehabilitation
Strategies in Trauma and Limb Reconstruction, 2012Co-Authors: Shingo Komura, Hidehiko Nonomura, Takashi Satake, Tatsuo YokoiAbstract:A 24-year-old man had bilateral Galeazzi fracture-dislocations due to a motorcycle accident. The right radius fracture was a simple fracture and was fixed with a limited contact Dynamic Compression Plate. The left radius fracture was a comminuted fracture and was fixed with a long locking Compression Plate in the bridging Plate fashion while maintaining reduction with a temporary external fixator. Postoperative computed tomography under passive rotation of both forearms showed acceptable congruency of the distal radioulnar joints, and early rehabilitation of forearm rotation was started at 2 weeks after the operation. At 13-month follow-up, bone union of both fractures was achieved, and forearm motion was almost restored to normal. Moreover, no subluxation or dislocation of either distal radioulnar joint was observed.
George S Martin - One of the best experts on this subject based on the ideXlab platform.
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a mechanical comparison of equine proximal interphalangeal joint arthrodesis techniques an axial locking Compression Plate and two abaxial transarticular cortical screws versus an axial Dynamic Compression Plate and two abaxial transarticular cortica
Veterinary Surgery, 2011Co-Authors: Gary A Sod, Laura M Riggs, Colin F Mitchell, George S MartinAbstract:Objectives: To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow locking Compression Plate (ELCP) using 5.0 mm locking screws and 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (ELCP–TLS) with an axial 3-hole, 4.5 mm narrow Dynamic Compression Plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP–TLS) for equine proximal interphalangeal (PIP) joint arthrodesis. Design: Experimental. Animal Population: Cadaveric adult equine forelimbs (n=18 pairs). Methods: For each forelimb pair, 1 PIP joint was stabilized with an axial ELCP using 5.0 mm locking screws and 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 PIP joint with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion. Six matching pairs of constructs were tested in single cycle to failure under axial Compression, 6 construct pairs were tested for cyclic fatigue under axial Compression, and 6 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Results: Mean yield load, yield stiffness, and failure load under axial Compression, single cycle to failure, of the DCP–TLS fixation were significantly greater than those of the LCP–TLS fixation. There was no significant difference between the mean number of cycles to failure in axial Compression of the LCP–TLS and the DCP–TLS fixations. Mean yield load, yield stiffness, and failure load under torsion, single cycle to failure, of the LCP–TLS fixation were significantly greater than those of the DCP–TLS fixation. Conclusion: The DCP–TLS construct provided significantly greater stability under axial Compression in single cycle to failure than the ELCP–TLS construct, the ELCP–TLS construct provided significantly greater stability under torsional loading in single cycle to failure than the DCP–TLS construct, and there was no significant difference in stability between the 2 constructs for cyclic loading under axial Compression.
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an in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques an axial positioned Dynamic Compression Plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion
Veterinary Surgery, 2010Co-Authors: Gary A Sod, Laura M Riggs, Colin F Mitchell, Jeremy D Hubert, George S MartinAbstract:Objectives— To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow Dynamic Compression Plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis. Study Design— Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Sample Population— Cadaveric adult equine forelimbs (n=15 pairs). Methods— For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial Compression, 5 construct pairs were tested for cyclic fatigue under axial Compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Results— Mean yield load, yield stiffness, and failure load under axial Compression and torsion, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial Compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation. Conclusion— The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue. Clinical Relevance— The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.
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in vitro biomechanical comparison of locking Compression Plate fixation and limited contact Dynamic Compression Plate fixation of osteotomized equine third metacarpal bones
Veterinary Surgery, 2008Co-Authors: Gary A Sod, Colin F Mitchell, George S Martin, Jeremy D Hubert, Marjorie S GillAbstract:Objective— To compare monotonic biomechanical properties and fatigue life of a broad locking Compression Plate (LCP) fixation with a broad limited contact Dynamic Compression Plate (LC-DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones. Study Design— In vitro biomechanical testing of paired cadaveric equine MC3 with a mid-diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. Animal Population— Cadaveric adult equine MC3 bones (n=12 pairs). Methods— MC3 were divided into 3 groups (4 pairs each) for: (1) 4-point bending single cycle to failure testing; (2) 4-point bending cyclic fatigue testing; and (3) torsional single cycle to failure testing. The 8-hole, 4.5 mm LCP was applied to the dorsal surface of 1 randomly selected bone from each pair. One 8-hole, 4.5 mm LC-DCP) was applied dorsally to the contralateral bone from each pair. All Plates and screws were applied using standard ASIF techniques. All MC3 bones had mid-diaphyseal osteotomies. Mean test variable values for each method were compared using a paired t-test within each group. Significance was set at P<.05. Results— Mean yield load, yield bending moment, composite rigidity, failure load and failure bending moment, under 4-point bending, single cycle to failure, of the LCP fixation were significantly greater than those of the LC-DCP fixation. Mean cycles to failure for 4-point bending was significantly greater for the LCP fixation compared with LC-DCP fixation. Mean yield load, mean composite rigidity, and mean failure load under torsional testing, single cycle to failure was significantly greater for the broad LCP fixation compared with the LC-DCP fixation. Conclusion— The 4.5 mm LCP was superior to the 4.5 mm LC-DCP in resisting the static overload forces (palmarodorsal 4-point bending and torsional) and in resisting cyclic fatigue under palmarodorsal 4-point bending. Clinical Relevance— The results of this in vitro study may provide information to aid in the selection of a biological Plate for the repair of equine long bone fractures.
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in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques prototype equine spoon Plate versus axially positioned Dynamic Compression Plate and two abaxial transarticular cortical screws inserted in lag fashion
Veterinary Surgery, 2007Co-Authors: Gary A Sod, Colin F Mitchell, George S Martin, Jeremy D Hubert, Marjorie S GillAbstract:Objectives— To compare in vitro monotonic biomechanical properties of an equine spoon Plate (ESP) with an axial 3-hole, 4.5 mm narrow Dynamic Compression Plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws (DCP-TLS) inserted in lag fashion for equine proximal interphalangeal (PIP) joint arthrodesis. Study Design— Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Animal Population— Cadaveric adult equine forelimbs (n=18 pairs). Methods— For each forelimb pair, 1 PIP joint was stabilized with an ESP (8 hole, 4.5 mm) and 1 with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion. Six matching pairs of constructs were tested in single cycle to failure under axial Compression with load applied under displacement control at a constant rate of 5 cm/s. Six construct pairs were tested for cyclic fatigue under axial Compression with cyclic load (0–7.5 kN) applied at 6 Hz; cycles to failure were recorded. Six construct pairs were tested in single cycle to failure under torsional loading applied at a constant displacement rate (0.17 radians/s) until rotation of 0.87 radians occurred. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Results— Mean yield load, yield stiffness, and failure load for ESP fixation were significantly greater (for axial Compression and torsion) than for DCP-TLS fixation. Mean (± SD) values for the ESP and DCP-TLS fixation techniques, respectively, in single cycle to failure under axial Compression were: yield load 123.9 ± 8.96 and 28.5 ± 3.32 kN; stiffness, 13.11 ± 0.242 and 2.60 ± 0.17 kN/cm; and failure load, 144.4 ± 13.6 and 31.4 ± 3.8 kN. In single cycle to failure under torsion, mean (± SD) values for ESP and DCP-TLS, respectively, were: stiffness 2,022 ± 26.2 and 107.9 ± 11.1 N m/rad; and failure load: 256.4 ± 39.2 and 87.1 ± 11.5 N m. Mean cycles to failure in axial Compression of ESP fixation (622,529 ± 65,468) was significantly greater than DCP-TLS (95,418 ± 11,037). Conclusion— ESP was superior to an axial 3-hole narrow DCP with 2 abaxial transarticular screws inserted in lag fashion in resisting static overload forces and cyclic fatigue. Clinical Relevance— In vitro results support further evaluation of ESP for PIP joint arthrodesis in horses. Its specific design may provide increased stability without need for external coaptation support.
Gary A Sod - One of the best experts on this subject based on the ideXlab platform.
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a mechanical comparison of equine proximal interphalangeal joint arthrodesis techniques an axial locking Compression Plate and two abaxial transarticular cortical screws versus an axial Dynamic Compression Plate and two abaxial transarticular cortica
Veterinary Surgery, 2011Co-Authors: Gary A Sod, Laura M Riggs, Colin F Mitchell, George S MartinAbstract:Objectives: To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow locking Compression Plate (ELCP) using 5.0 mm locking screws and 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (ELCP–TLS) with an axial 3-hole, 4.5 mm narrow Dynamic Compression Plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP–TLS) for equine proximal interphalangeal (PIP) joint arthrodesis. Design: Experimental. Animal Population: Cadaveric adult equine forelimbs (n=18 pairs). Methods: For each forelimb pair, 1 PIP joint was stabilized with an axial ELCP using 5.0 mm locking screws and 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 PIP joint with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion. Six matching pairs of constructs were tested in single cycle to failure under axial Compression, 6 construct pairs were tested for cyclic fatigue under axial Compression, and 6 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Results: Mean yield load, yield stiffness, and failure load under axial Compression, single cycle to failure, of the DCP–TLS fixation were significantly greater than those of the LCP–TLS fixation. There was no significant difference between the mean number of cycles to failure in axial Compression of the LCP–TLS and the DCP–TLS fixations. Mean yield load, yield stiffness, and failure load under torsion, single cycle to failure, of the LCP–TLS fixation were significantly greater than those of the DCP–TLS fixation. Conclusion: The DCP–TLS construct provided significantly greater stability under axial Compression in single cycle to failure than the ELCP–TLS construct, the ELCP–TLS construct provided significantly greater stability under torsional loading in single cycle to failure than the DCP–TLS construct, and there was no significant difference in stability between the 2 constructs for cyclic loading under axial Compression.
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an in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques an axial positioned Dynamic Compression Plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion
Veterinary Surgery, 2010Co-Authors: Gary A Sod, Laura M Riggs, Colin F Mitchell, Jeremy D Hubert, George S MartinAbstract:Objectives— To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow Dynamic Compression Plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis. Study Design— Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Sample Population— Cadaveric adult equine forelimbs (n=15 pairs). Methods— For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial Compression, 5 construct pairs were tested for cyclic fatigue under axial Compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Results— Mean yield load, yield stiffness, and failure load under axial Compression and torsion, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial Compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation. Conclusion— The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue. Clinical Relevance— The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.
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in vitro biomechanical comparison of locking Compression Plate fixation and limited contact Dynamic Compression Plate fixation of osteotomized equine third metacarpal bones
Veterinary Surgery, 2008Co-Authors: Gary A Sod, Colin F Mitchell, George S Martin, Jeremy D Hubert, Marjorie S GillAbstract:Objective— To compare monotonic biomechanical properties and fatigue life of a broad locking Compression Plate (LCP) fixation with a broad limited contact Dynamic Compression Plate (LC-DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones. Study Design— In vitro biomechanical testing of paired cadaveric equine MC3 with a mid-diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. Animal Population— Cadaveric adult equine MC3 bones (n=12 pairs). Methods— MC3 were divided into 3 groups (4 pairs each) for: (1) 4-point bending single cycle to failure testing; (2) 4-point bending cyclic fatigue testing; and (3) torsional single cycle to failure testing. The 8-hole, 4.5 mm LCP was applied to the dorsal surface of 1 randomly selected bone from each pair. One 8-hole, 4.5 mm LC-DCP) was applied dorsally to the contralateral bone from each pair. All Plates and screws were applied using standard ASIF techniques. All MC3 bones had mid-diaphyseal osteotomies. Mean test variable values for each method were compared using a paired t-test within each group. Significance was set at P<.05. Results— Mean yield load, yield bending moment, composite rigidity, failure load and failure bending moment, under 4-point bending, single cycle to failure, of the LCP fixation were significantly greater than those of the LC-DCP fixation. Mean cycles to failure for 4-point bending was significantly greater for the LCP fixation compared with LC-DCP fixation. Mean yield load, mean composite rigidity, and mean failure load under torsional testing, single cycle to failure was significantly greater for the broad LCP fixation compared with the LC-DCP fixation. Conclusion— The 4.5 mm LCP was superior to the 4.5 mm LC-DCP in resisting the static overload forces (palmarodorsal 4-point bending and torsional) and in resisting cyclic fatigue under palmarodorsal 4-point bending. Clinical Relevance— The results of this in vitro study may provide information to aid in the selection of a biological Plate for the repair of equine long bone fractures.
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in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques prototype equine spoon Plate versus axially positioned Dynamic Compression Plate and two abaxial transarticular cortical screws inserted in lag fashion
Veterinary Surgery, 2007Co-Authors: Gary A Sod, Colin F Mitchell, George S Martin, Jeremy D Hubert, Marjorie S GillAbstract:Objectives— To compare in vitro monotonic biomechanical properties of an equine spoon Plate (ESP) with an axial 3-hole, 4.5 mm narrow Dynamic Compression Plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws (DCP-TLS) inserted in lag fashion for equine proximal interphalangeal (PIP) joint arthrodesis. Study Design— Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Animal Population— Cadaveric adult equine forelimbs (n=18 pairs). Methods— For each forelimb pair, 1 PIP joint was stabilized with an ESP (8 hole, 4.5 mm) and 1 with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion. Six matching pairs of constructs were tested in single cycle to failure under axial Compression with load applied under displacement control at a constant rate of 5 cm/s. Six construct pairs were tested for cyclic fatigue under axial Compression with cyclic load (0–7.5 kN) applied at 6 Hz; cycles to failure were recorded. Six construct pairs were tested in single cycle to failure under torsional loading applied at a constant displacement rate (0.17 radians/s) until rotation of 0.87 radians occurred. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Results— Mean yield load, yield stiffness, and failure load for ESP fixation were significantly greater (for axial Compression and torsion) than for DCP-TLS fixation. Mean (± SD) values for the ESP and DCP-TLS fixation techniques, respectively, in single cycle to failure under axial Compression were: yield load 123.9 ± 8.96 and 28.5 ± 3.32 kN; stiffness, 13.11 ± 0.242 and 2.60 ± 0.17 kN/cm; and failure load, 144.4 ± 13.6 and 31.4 ± 3.8 kN. In single cycle to failure under torsion, mean (± SD) values for ESP and DCP-TLS, respectively, were: stiffness 2,022 ± 26.2 and 107.9 ± 11.1 N m/rad; and failure load: 256.4 ± 39.2 and 87.1 ± 11.5 N m. Mean cycles to failure in axial Compression of ESP fixation (622,529 ± 65,468) was significantly greater than DCP-TLS (95,418 ± 11,037). Conclusion— ESP was superior to an axial 3-hole narrow DCP with 2 abaxial transarticular screws inserted in lag fashion in resisting static overload forces and cyclic fatigue. Clinical Relevance— In vitro results support further evaluation of ESP for PIP joint arthrodesis in horses. Its specific design may provide increased stability without need for external coaptation support.
