Veterinary and Comparative Orthopaedics and Traumatology最新文献

Objective:  Rock-back is a reported complication following tibial plateau levelling osteotomy (TPLO), whereby tibial plateau angle (TPA) increases postoperatively. The mechanism of rock-back is not fully understood, although a recent ex vivo investigation demonstrated that osteotomy exit cut angle (ECA) and inclination of the plate in the sagittal plane might be risk factors. The purpose of this study was to explore these relationships in a clinical dog population. We hypothesized that dogs with rock-back would have a higher degree of plate inclination and downward ECA compared with those without rock-back.

Materials and methods:  Medical records and radiographs of dogs that underwent TPLO between January 2021 and January 2022 were retrospectively reviewed. TPA was recorded preoperatively, postoperatively, and at follow-up. Plate inclination, ECA, and descriptive data were collected. Observers measuring TPA were blinded to other variables. Rock-back was defined as a change in TPA ≥ 2.

Results:  Ninety-five TPLO procedures met the inclusion criteria (n = 87 dogs). Rock-back was identified in 21% of TPLOs (n = 20/95). The mean increase in TPA in the rock-back group was 3.2 ± 2.6. Plate inclination and ECA were not correlated with the presence of rock-back. Descriptive variables did not have a significant correlation with rock-back.

Conclusion:  Plate inclination and ECA did not have a relationship with rock-back when defined as a postoperative TPA change ≥2 degrees, in this clinical retrospective study.

Objective:  The aim of this study was to measure the mechanical properties and failure mode of an ex vivo model of proximal interphalangeal arthrodesis in horses with different methods of proximal screw fixation using a locking compression plate.

Study design:  Pastern joint arthrodesis with a 3-hole 4.5-mm narrow locking compression plate was performed on 20 forelimbs of equine cadavers, randomized into four groups based on the fixation method and type of proximal screw used: unicortical cortex, bicortical cortex, unicortical locking, bicortical locking. Single-cycle axial compression testing was conducted until failure. The frequency of implant plastic deformation was recorded. Bone failure analysis was performed through computed tomography examinations and fractal analysis.

Results:  There were no differences in the analysed mechanical variables and fractal dimension among the groups. Transarticular screws showed a higher frequency of deformation (75%) regardless of the group. Both unicortical locking and bicortical locking groups deformed the plate more frequently.

Conclusion:  The type of screw used in the proximal hole of the locking compression plate and its method of anchoring in the proximal phalanx do not affect the mechanical properties of pastern arthrodesis in equine cadavers subjected to single-cycle axial compression tests until failure.

Objective:  To describe a modification of the tibial plateau leveling osteotomy technique wherein a double cut is made in the same plane to level the tibial plateau (double-cut tibial plateau leveling osteotomy [DCTPLO]) for treating dogs with cranial cruciate ligament (CrCL) and excessive tibial plateau angle (eTPA) diseases.

Study design:  The DCTPLO technique was performed on 18 stifles in dogs with CrCL and an eTPA (>34°). This study evaluated the accuracy of preoperative planning, feasibility of the technique, postoperative clinical outcomes, radiographic examinations at the postoperative follow-up for the first 120 days, evolution of the tibial plateau angle (TPA), time of union of the osteotomy, apposition of the implants, and possible complications.

Results:  The described technique proved to be feasible for clinical application, with reproducibility from preoperative planning. An effective reduction in the eTPA levels was observed. The mean preoperative and postoperative TPA values were 39.4° (36°-43.5°) and 6.3° (3°-13°), respectively. Radiographic healing time was 60 days in 17/18 of stifles. Minor complications (not requiring surgical review or clinical treatment) were observed in 4/18 of stifles.

Conclusion:  The DCTPLO technique was effective for treating CrCL disease with TPA of up to 43.5° in dogs.

Objective:  The aim of our study was to investigate a degradable polylactide-collagen scaffold (COPLA) in the treatment of shoulder osteochondritis dissecans (OCD) in dogs.

Study design:  The study was a controlled, randomized, blinded clinical trial with a parallel group design with a 1.5-year follow-up. Twenty dogs with uni- or bilateral shoulder OCD (29 shoulders) were randomized to receive a COPLA or arthroscopic debridement only (Control). The outcome of treatment was assessed with gait and stance analysis, passive range of motion measurement, pain and lameness evaluation, Helsinki Chronic Pain Index, and computed tomography (CT).

Results:  Eighteen dogs (25 shoulders) completed the study. The clinical outcome variables improved significantly from baseline in COPLA and Control groups after treatment but no significant differences emerged between groups. Significantly fewer COPLA than Control shoulders had osteoarthritis (OA) in CT at 6 months (p = 0.019) but the difference was not significant at 1.5 years. At 1.5 years, all dogs were sound and pain-free in joint palpation, but OA was diagnosed in 13/18 dogs (18/25 shoulders) with CT.

Conclusion:  The results suggest that COPLA scaffold slowed down the development of OA at 6 months but it did not improve the clinical recovery or prevent OA in dogs with shoulder OCD in long-term follow-up at 1.5 years compared with arthroscopic debridement only. Regardless of the treatment method, clinical recovery was good, but OA developed in the majority of dogs.

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.

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.

The aim of this study was to describe the physeal pathology of the proximal radius in four skeletally immature male Pugs. Physical examination, radiography, and computed tomography (CT) of the thoracic limbs were performed in all four dogs. Two Pugs were available for long-term follow-up and two Pugs were euthanatized after the diagnostic imaging results. Four male Pugs, aged between 6 and 7 months, were presented with a history of thoracic limb lameness lasting 2 to 3 months. Radiography and CT of the thoracic limbs showed irregularity of the proximal radial physes with varying degrees of radiolucency within the adjacent metaphyses. The pathology was associated with elbow joint incongruity and angular deformity of the antebrachium. Two dogs were euthanatized, one of which was autopsied, and histopathology of the proximal radius revealed bilateral physeal dysplasia. At long-term follow-up of the two surviving dogs, lameness had resolved. Radiography and CT scans of the thoracic limbs revealed normal bone opacity within the proximal radius and resolution of the radiolucent areas of the proximal radial physes. However, incongruity of the radioulnar joint remained. In this report, the resolution of identified physeal pathology at the proximal radius in juvenile Pugs demonstrates the potential for spontaneous remission despite the presence of notable radiographic changes.

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.

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.