Veterinary and Comparative Orthopaedics and Traumatology最新文献

Objective:  Medial patellar luxation (MPL) is prevalent in small dogs; however, the causes vary, and few studies have reported tibial deformities. We aimed to conduct a detailed morphological investigation of internal tibial torsion and internal foot rotation and compare the results between MPL grades to better understand the pathogenesis of MPL.

Study design:  We performed a morphological study of the tibia and comparison with MPL grade, and established a new parameter, metatarsal orientation relative to the orientation of the tibial tuberosity, the proximal tibia metatarsal angle (PTMTA). The distal tibia metatarsal angle was also established, and tibial torsion angle (TTA), mechanical medial proximal tibial angle, medial distance of the tibial tuberosity/proximal tibial width, and crural rotation angle were compared among the grades of MPL.

Results:  The PTMTA was significantly higher in grades 3 and 4 than in the normal group. TTA, medial distance of the tibial tuberosity/proximal tibial width, and mechanical medial proximal tibial angle were significantly higher in grade 4 than in the other grades, which is consistent with previous reports. A correlation was also observed between the PTMTA and the TTA.

Conclusion:  The PTMTA functioned as a parameter that included elements of the distal tibia metatarsal angle, TTA, and medial distance of the tibial tuberosity/proximal tibial width, and is considered clinically useful because it can be visually ascertained during palpation. Our results may play a major role in surgical decision-making in the treatment of MPL.

Objectives:  To evaluate the outcome and complications in dogs with medial patellar luxation (MPL) undergoing tibial tuberosity transposition (TTT) with a locking plate and pin fixation (Plate-Pin).

Methods:  This retrospective multicenter study included 65 consecutive MPL stifle surgeries using tibial tuberosity (TT) fixation with a 5-hole locking plate and a pin. The median weight of the dogs was 6.2 kg. The grade of luxation was 2/4 in 50 stifles and 3/4 in 15 stifles. Outcomes were assessed during follow-up examinations 33 to 648 days after surgery with clinical examination and radiography. Canine Orthopedic Index questionnaires were sent to owners 6 to 39 months after surgery.

Results:  Complications were reported in 14/65 stifles, of which 8/14 were minor and 6/14 were major. After treatment of the major complications, lameness was resolved in all cases and the MPL was resolved in 64/65 stifles.

Clinical significance:  When the surgery was performed as described in this article, Plate-Pin fixation for TT during MPL surgery is a feasible technique with a lower incidence of luxation recurrence, TT avulsion, and fractures compared with recent retrospective studies with pin and tension band wire TT fixation. Further development of the locking plate TT fixation is indicated to resolve pin-related complications and to determine if fixation including a pin is necessary.

Objective:  To assess the biomechanical parameters of intact tibiotarsi (INT) and tibiotarsi with a 5-mm segmental diaphyseal defect repaired using four osteosynthesis techniques: a locking plate (LP), a plate-rod combination, an external skeletal fixator (one end-threaded positive-profile pin per fragment) with an intramedullary pin tie-in (TIF 1), and an external skeletal fixator (two end-threaded positive-profile pins per fragment) with an intramedullary pin tie-in (TIF 2).

Study design:  Sixty tibiotarsi from 30 adult laying hens were allocated into five groups for nondestructive dynamic torsion and four-point bending tests, followed by failure tests. Nondestructive dynamic tests evaluated stiffness over time in torsion and bending. Torsion destructive tests provided maximum torque and rotation values, whereas the four-point bending tests provided the yield load, maximum bending load, and maximum displacement.

Results:  The INT group showed higher torsional stiffness and maximum torque but similar bending stiffness, torsional strength, and bending strength in one or more groups. LP and TIF 2 exhibited the highest similarity frequencies among the treatment groups, whereas the TIF 1 group displayed lower stiffness and strength for most of the evaluated parameters.

Conclusion:  Similar results for LP and TIF-2 groups suggest the biomechanical equivalence of these methods for tibiotarsal osteosynthesis in adult hens.

Objective:  The objective of this study was to assess the stability of the femoral component of a hip resurfacing arthroplasty prosthesis in canine cadaveric bone using a biomechanical test.

Study design:  Twenty adult dog cadavers were utilized, from which both femoral bones were extracted and preserved for experimentation. For each pair of femurs from the same animal, one femur underwent implantation of the hip resurfacing arthroplasty prosthesis, while the contralateral femur remained intact. All femoral specimens underwent flexo-compression biomechanical testing, with variables including maximum load (ML), load at collapse (LC), displacement at maximum load (DML), displacement at collapse (DC), and stiffness (k) being analysed. Subsequent to the biomechanical evaluation, the femoral specimens were radiographed to assess failure behaviour.

Results:  The prosthesis group showed a reduction of 22% (p ≤ 0.050) for the ML variable and 27% (p ≤ 0.05) for LC values. The prosthetic group supported a mean ML equivalent to six times the body weight of the animals whose bones were tested. No significant disparities were detected between the groups for the other analysed variables (DML, DC, and k). Similar failure patterns, such as fractures in the femoral neck region, were observed in specimens from both groups.

Conclusion:  The hip resurfacing arthroplasty prosthesis demonstrated biomechanical performance with no differences in DML, DC, and k but showed inferior performance in ML and LC when compared with intact femurs in the ex vivo setting.

Objective:  To determine the effect of locking head inserts (LHI) on plate strain, stiffness, and deformation when applied to a 3.5-mm broad locking compression plate (LCP) in an open fracture-gap model.

Study design:  Six, 13-hole, 3.5-mm broad LCP were secured to epoxy bone models with a 10 mm central defect and 1 mm plate offset. Two peripheral locking screws were placed in each segment, with the remaining screw holes left unfilled. Three strain gauges were glued to each LCP at anticipated regions of maximum strain. Constructs underwent cyclic uniaxial loading at a rate of 20 mm/min to 400 N in three different configurations (Configuration 1: no LHI, Configuration 2: 3 LHI, Configuration 3: 9 LHI). LHI were tightened to 4 Nm of torque. A data acquisition system was used to collect implant strain during testing. Construct stiffness and deformation were recorded by the biomechanical testing machine.

Results:  Maximum implant strain was recorded at the central screw hole directly over the simulated fracture gap in all configurations (Mdn 1,837.3 µε [interquartile range: 1,805.1-1,862.0]). There was no difference in implant peak-to-peak strain with addition of LHI at all three gauges (Gauge 1 [p = 0.847], Gauge 2 [p = 0.847], Gauge 3 [p = 0.311]). Similarly, peak-to-peak displacement (p = 0.069) and axial construct stiffness (p = 0.311) did not change with the addition of LHI.

Conclusion:  The addition of LHI to a 3.5-mm broad LCP construct was not shown to have an effect on plate strain, stiffness, or deformation.

Objective:  The aim of this cadaveric study was to compare the biomechanical outcomes of three methods of stabilization for tibial tuberosity transposition to treat medial patellar luxation: a complete osteotomy with a two-pin and tension band wire (TBW) fixation (TBW group), a partial osteotomy with a two-pin fixation (2 Pin group), and a partial osteotomy with a spacer pin fixation (Spacer Pin group).

Study design:  Thirty medium to large-sized canine cadaveric tibiae were dissected and randomly assigned to one of three groups: TBW, 2 Pin, and Spacer Pin groups. The patellar ligaments were loaded in tension until ultimate failure. Ultimate failure force and mode of failure were documented, stiffness was calculated, and the results were compared statistically between the three treatment groups.

Results:  There were not any significant differences in ultimate failure force or stiffness between groups. All groups predominantly failed by patellar ligament failure, with distal tibial crest fracture/displacement being the second-most common mode in the 2 Pin and Spacer Pin groups.

Conclusion:  The mechanical properties of the spacer pin stabilization were not different from the TBW and 2 Pin groups. The spacer pin technique could be an alternative way to stabilize tibial tuberosity following tibial tuberosity transposition with a partial osteotomy based on this cadaveric load-to-failure model.

Objectives:  The aim of this retrospective study was to report the magnitude of the craniocaudal angulation of the proximal tibia (CCAPT) quantified by the angle between the anatomical axis (AA) and the mechanical axis (MA), called the AMA angle, and the tibial plateau angle (TPA) in dogs >50 kg that were treated by cranial closing wedge osteotomy based on the AMA angle (AMA-based CCWO). Furthermore, the percentage of dogs in which the AA and MA could be aligned postoperatively and the rate of surgical site infection (SSI) were reported.

Study design:  Medical records (between January 2016 and September 2023) were reviewed for 204 dogs that had AMA-based CCWO stabilized with a double locking plate (DLP) fixation with or without joint exploration plus a Robert Jones bandage (RJB) and were given postoperative antibiotics.

Results:  The median (range) preoperative AMA angle and TPA were 3.1° (0-5.1°) and 30° (22-49.6°), respectively, and the postoperative AMA angle and TPA were 0° (-2.4 to 1.6°) and 9.2° (4-15°), respectively. The AA and MA were aligned in 82% of dogs. Grade 4 healing occurred in all osteotomies by 8 weeks postoperatively. Except for one dog, no SSIs were recorded.

Conclusion:  Concerning the magnitude of CCAPT in dogs >50 kg and the low SSI rate, AMA-based CCWO stabilized with a DLP fixation plus an RJB and postoperative antibiotics should be considered for treating cranial cruciate ligament-deficient stifles in this subset of dogs.

To compare the exposure of the craniolateral approach (CLA) with craniomedial approach (CMA) of the radius in dogs. To make general observations of each approach that may affect the ease of fracture repair.Six canine cadavers were used in the study to compare the exposed surface area, length, and width of radius with CLA and CMA (n = 12).The CLA exposed a larger surface area of the radius compared with the CMA (p = 0.01). The CLA of the radius had greater proximal width compared with the CMA (p = 0.01). There was no significant difference in the length of exposed radii with either approach.The CLA provided greater exposure for internal fixation of the radius in dogs.

Objective:  To introduce a novel universal guide design for distal femoral osteotomy (DFO) to treat femoral deformities and other hindlimb orthopaedic diseases, and to compare its accuracy to the patient-specific guide in vitro and ex vivo on X-ray and computed tomography (CT).

Methods:  Thirteen anatomic specimens of canine femurs and 13 3D-printed femoral bone models were subjected to DFO using a patient-specific and a universal guide. The anatomical lateral distal femoral angle and anteversion angle were measured on radiographic and CT images before and after surgical procedure and used to compare the accuracy of the surgical guides in treating uniplanar or biplanar deformities. Bone models were used to compare the accuracy with ex vivo models.

Results:  The mean correction errors were -1.18° to 0.72° on X-ray and -1.91° to 0.53° on CT scan. The analysis showed no statistically significant difference in the mean error between the groups based on type of guide used, nor in the mean error between groups based on whether anteversion correction was performed based on both the CT and X-ray imaging data.

Conclusion:  Both the patient-specific and universal guides can produce accurate results in DFO surgery, and the universal guide shows potential as a useful surgical tool.