Veterinary and Comparative Orthopaedics and Traumatology最新文献

Objective:  The aim of this study was to describe the development of a total elbow replacement (TER) technique in swine and report the outcome of TER in a Kunekune sow (61 kg) with severe elbow osteoarthritis.

Methods:  The technique was developed by operating on three pig cadavers (Yorkshire 40-50 kg). The TATE Elbow implant fit was confirmed with modeling to the patient's computed tomography imaging. Patient-specific instrumentation was printed for attempted use. Total elbow replacement was performed using a lateral approach, including lateral epicondylar osteotomy, careful retraction of the radial nerve, and preservation of the lateral collateral ligament. Postoperative care included controlled exercise and physical therapy.

Results:  A lateral approach to the pig elbow for TATE TER was successfully developed. The bulk of the lateral head of the triceps muscle precluded use of the patient-specific instrumentation; the procedure was performed using standard instrumentation. Radiographic evidence up to 9 months postoperatively showed adequate implant alignment and satisfactory osteointegration of humeral and radioulnar components. There were not any postoperative complications and the patient's comfort was improved by 6 months and sustained at 18 months.

Conclusion:  A lateral approach for TATE TER in a pig with advanced elbow osteoarthritis proved feasible and effective. With the expansion of the TATE Elbow line, it is possible that a larger range of pigs could be treated. This report suggests that a lateral approach for TATE TER in dogs could represent a suitable alternative to the medial approach currently used.

Objective:  The aim of the study was to determine the effect of a short and long working length screw configuration on construct stiffness and plate strain in a synthetic, short fragment, small gap fracture model stabilized with a 12-hole 3.5-mm locking compression plate (LCP).

Study design:  Six replicates of short and long working length constructs on a short fragment, small gap fracture model underwent four-point bending. Construct stiffness and plate strain were compared across working length and along the plate.

Results:  With the LCP on the compression surface (compression bending), the short working length had a significantly higher construct stiffness and lower plate strain than the long working length. Conversely, with the LCP on the tension surface (tension bending), transcortical contact between 150 and 155 N induced load sharing at the fracture gap, which significantly increased construct stiffness and decreased plate strain in the long working length. At 100 N (precontact), the short working length had a significantly higher construct stiffness and lower plate strain than the long working length, comparable with our compressing bending results.

Conclusion:  In compression bending, and before transcortical contact occurred in tension bending, the short working length had a significantly higher construct stiffness and lower plate strain than the long working length. Load sharing due to transcortical contact observed in our model in tension bending will vary with fracture gap, working length, and loading condition. These results must be interpreted with caution when considering clinical relevance or potential in vivo biomechanical advantages.

Our study aims to describe the surgical technique for temporary transarticular immobilization of the stifle joint using a locking plate and evaluate complications and outcomes.The medical records of dogs and cats that underwent transarticular immobilization of the stifle joint using a locking plate in two institutions from August 2018 to January 2024 were retrospectively evaluated.After managing the primary injury, a locking plate was contoured to fit the medial surface of the distal femur and proximal tibia, limiting the implant to the distal third of the femur and proximal third of the tibia, with immobilization at a 135 to 145-degree angle.Temporary transarticular immobilization of the stifle joint was performed in 16 stifle joints in 14 patients, with two dogs undergoing bilateral surgery. The transarticular implants were removed at a mean time of 55,86 ± 18,05 days postoperatively (median: 58, range: 27-96 days). No intraoperative complications were recorded. One major complication was recorded in a Galgo Espanol with a patellar fracture and patellar ligament lesion in which plate breakage was recorded 19 days after surgery, requiring early plate removal and application of an orthosis for 3 weeks. Four minor complications were recorded.Preliminary results suggest that a transarticular locking plate is effective for temporary stifle immobilization, with a low morbidity and complication rate. Dedicated implants should be developed to decrease the risk of plate failure.

Objective:  The aim of this study was to identify risk factors for refracture after radial union in small-breed dogs.

Study design:  In our retrospective study, medical records of radial-ulnar fracture cases in small dogs treated with plates and screws were reviewed. General information and postoperative course (days until confirmed radial fracture healing, with or without ulnar union, time to final follow-up, with or without plate removal and refracture) were recorded. The fracture line location, screw positions, radial thickness and width, and pixel values throughout the postoperative periods were obtained from the radiographs. The affected limbs were classified into non-plate removal (P) and plate removal (R) groups.

Results:  Refracture occurred in 5 of the 141 limbs at the most distal screw in the P group and 5 of the 40 limbs at the same site as the initial fracture in the R group. Multivariate analysis indicated that refracture was linked to the amount of relative change with growth in the position of the most distal screw in the P group, with pixel value and radial thickness ratios at the same site as the initial fracture in the R group.

Conclusion:  Reducing the screw diameter relative to the radial width to the appropriate extent may be considered in cases where the screw positioned at the most distal end of the radius is expected to be relatively proximal as the distal radius grows; not removing the plate may be considered in cases with a decreased radial thickness or bone mineral density beneath the plate during plate removal.

Objective:  The aim of this study was to compare the bending properties of String of Pearls plate-bone substitute constructs with and without bending tees in the nodes over a simulated fracture gap. It is hypothesized that the constructs with tees will have higher bending stiffness.

Study design:  Acetal polymer tubes and 12-hole, 3.5-mm String of Pearls plates were used to create plate-bone substitute constructs simulating stabilization in a bridging fashion over a 45-mm gap. Twenty-four constructs were made with 12 containing tees in the nodes over the fracture gap. Single-cycle load-to-failure 4-point bending was performed in mediolateral and craniocaudal planes. Bending stiffness was compared with a t-test (p < 0.05).

Results:  All plate-bone substitute constructs had a permanent loss of structural integrity via plastic deformation of the plate. The bending stiffness (mean ± standard deviation) of the craniocaudal group was 59.11 ± 1.98 N/mm with tees and 59.25 ± 1.69 N/mm without tees (p = 0.88). In the mediolateral group, the bending stiffness was 43.17 ± 0.75 N/mm with tees and 41.09 ± 0.91 N/mm without tees (p = 0.0042).

Conclusion:  In 4-point bending, the plate-bone substitute constructs with tees had equivalent bending stiffness in the craniocaudal plane and increased bending stiffness in the mediolateral plane. However, with a small absolute difference in values, the clinical significance is unclear. Future studies for cyclic bending, torsional, and axial compression tests should be performed to further investigate the value of tees in the nodes over a comminuted or gap fracture repaired in a bridging fashion.

Objective:  The aim of this study was to report complications and outcomes of a cementless total hip arthroplasty (THA) system with a second-generation selective laser-melted screw cup (SCSL).

Study design:  All THA using the SCSL performed at a single institution between January 2017 and November 2022 were retrospectively evaluated. Patients with a minimum follow-up period of 12 months and complete medical records were included and analyzed for radiographic and clinical outcomes.

Results:  Thirty THA with SCSL in 23 dogs were included in this study. Complications were observed in seven hips, comprising two minor and five major complications, with two hips experiencing two major complications. Among these seven major complications, six were associated with the femoral implant and one involved cup luxation. Of the 30 THA, 4 were explanted, while 26 remained in place for a median follow-up of 17.5 months (range, 12-38 months).

Conclusion:  No cases of late aseptic loosening were observed with SCSL. THA using SCSL helps reduce cup-associated complications and is appropriate for THA surgery, and the overall complication rate is comparable with that of other single-implant systems. Nevertheless, four hips were explanted.

Objective:  The aim of this study was to determine the effect of double pelvic osteotomy (DPO) on dorsolateral subluxation (DLS) of the femoral head in a weight-bearing position.

Study design:  Retrospective observational study with treatment effect analysis. Twenty-four client-owned dogs that underwent DPO due to hip dysplasia.

Methods:  Computed tomography (CT) studies were performed on 24 dogs that underwent a DPO between 2015 and 2021. The patients were positioned with the femora in a weight-bearing position. The DLS score was measured pre-DPO, immediately post-DPO, and at follow-up to determine if DPO resulted in an increase in the DLS score.

Results:  A total of 21 dogs underwent single-stage bilateral DPO and 3 dogs underwent unilateral DPO resulting in 45 hip joints available for analysis. Follow-up CT was available for 29 of these at a median of 51 days (range: 35-482 days). The mean DLS score was 36.1% ± 14.6 preoperatively, 71.4% ± 12.5 post-DPO, and 70.0% ± 15.3 at follow-up. The increase between the pre- and postoperative measurement was significant (p < 0.001).

Conclusion:  DPO results in reduced subluxation of the femoral head in a weight-bearing position.

Clinical significance:  The in vivo results suggest that DPO will result in reduced femoral subluxation during weight-bearing.

Objective:  To evaluate the effect of 3.5-mm locking compression plate (LCP) length on construct stiffness and plate and bone model strain in a synthetic, short-fragment, fracture-gap model.

Study design:  Six replicates of 6-hole, 8-hole, 10-hole, and 12-hole LCP constructs on a short-fragment, tubular Delrin fracture gap model underwent four-point compression and tension bending. Construct stiffness and surface strain, calculated using three-dimensional digital image correlation, were compared across plate length and region of interest (ROI) on the construct.

Results:  The 12-hole plates (80% plate-bone ratio) had significantly higher construct stiffness than 6-hole, 8-hole, and 10-hole plates and significantly lower plate strain than 6-hole plates at all ROIs. Strain on the bone model was significantly lower in constructs with 10-hole and 12-hole plates than 6-hole plates under both compression and tension bending.

Conclusion:  Incremental increases in construct stiffness and incremental decreases in plate strain were only identified when comparing 6-hole, 8-hole, and 10-hole plates to 12-hole plates, and 6-hole to 12-hole plates, respectively. Strain on the bone model showed an incremental decrease when comparing 6-hole to 10-hole and 12-hole plates. A long plate offered biomechanical advantages of increased construct stiffness and reduced plate and bone model strain, over a short plate in this in vitro model.