Veterinary and Comparative Orthopaedics and Traumatology最新文献

Objectives:  Gracilis myopathy is a well-recognized syndrome of weight-bearing gait abnormality; however, detailed description of computed tomography (CT) and magnetic resonance imaging (MRI) features of gracilis myopathy is lacking in the literature. This study aims to describe in detail CT and MRI features of gracilis myopathy.

Study design:  This is a retrospective study. Medical records of dogs with characteristic gait and available pelvic limb MRI or CT, presenting to four referral institutions, were reviewed.

Results:  Seven cases with MRI (3/7) or CT (4/7) were included, all German Shepherd dogs. MRI findings in all cases included a well-defined, T1-/T2-/proton density-weighted hypointense band along the axial margin of the gracilis muscle, shorter affected muscles, thickening and T2W/STIR hyperintensity with contrast enhancement at the symphyseal tendon, and concurrent focal indentation of the axial border of the gracilis muscle. CT findings included a hyperattenuating band (4/4), single instances of contrast enhancement at the origin of the muscle, thickening of the tendon at the origin and insertion, and concurrent thickening at the musculotendinous muscle.

Conclusion:  CT and MRI can present advantages in correctly identifying the specific muscles affected within the gracilis-semitendinosus muscle complex. Both modalities can localize anatomically lesions in detail, for instance at the origin or insertion of the muscle, which could present advantages in novel treatment strategies for this condition.

Objective:  To evaluate the in vitro mechanical properties of basilar fractures of the femoral neck stabilized with two or three titanium-cannulated screws in dogs.

Study design:  Ex vivo study.

Sample population:  Cadaveric canine femur (n = 21).

Methods:  The bones were divided as follows: Group 1: control (no osteotomy); Group 2: osteotomy and stabilization with two cannulated screws; and Group 3: osteotomy and stabilization with three cannulated screws. All groups were tested with destructive axial compression with load applied to the femoral head. The stiffness, load, and displacement were evaluated at the failure of Group 1, and the yield load and displacement of Groups 2 and 3.

Results:  The placement of the three cannulated screws was more demanding than two cannulated screws because of the risk of cortical perforation, especially in the trochanteric fossa area. The smaller the width of the femoral neck, the higher the risk of cortical bone wall perforation. The intact control bones were stiffer (674 N/mm) than both the two-screw repair (90 N/mm) and three-screw repair (120 N/mm) groups (p < 0.05). The failure load was greatest for Group 1 (2692 N). The yield loads for Groups 3 and 2 were 586 and 303 N, respectively. There was no difference between groups for displacement.

Conclusion:  In vitro cadaveric models of femoral neck basilar fractures repaired with three cannulated screws were significantly stronger than two cannulated screws, but the clinical efficacy must be evaluated by comparing them in vitro with noncannulated stainless steel screws.

Objectives:  The aims of this study are to describe a computed tomographic (CT) measurement method of feline femoral, tibial, and patellar conformation, and to compare these measurements between a cat population diagnosed with medial patellar luxation (MPL) and cats without MPL.

Materials and methods:  Eleven measurements were performed by two observers, including anatomical lateral distal femoral angle (aLDFA), femoral trochlear width (FTW) and femoral trochlear depth (FTD), anteversion angle of the femoral neck, patellar length, patellar width, patellar height, patellar volume, mechanical medial proximal tibial angle, tibial torsion angle, and tibial tuberosity displacement. Mean and standard deviation differences between the groups were statistically assessed. Intraobserver and interobserver interclass correlation coefficients (ICCs) were calculated.

Results:  The aLDFA was significantly higher in the MPL II compared with the control and MPL III. The FTW was significantly larger in the MPL III than in the control or the MPL II group. The FTD in the control group was significantly larger than in the MPL II and III groups. The TTA of the control group was significantly smaller than the MPL II and III. The intraobserver ICC was high at 64%, and the interobserver ICC was high at 36% of the measurements.

Clinical significance:  This study identified shallower FTD and increased TTA in cats diagnosed with MPL. The TTA difference was less than 5 degrees and FTD was less than 1 mm. The findings provide information on feline pelvic limb morphology. However, the differences between the two populations are small.

Objective:  To assess the data of high-rise syndrome (HRS) cases and determine the relationship between Animal Trauma Triage Score (ATTS), height, injury profile, and survival rate of patients.

Study design:  Retrospective study evaluating cats with HRS within a 4-year period.

Results:  A logistic regression analysis which included height, ground type, and ATTS variables was performed to predict survival rate of patients. Only ATTS was significant among these variables (p < 0.001) and each point increase in ATTS increased the nonsurvival by 0.46 times (95% confidence interval [CI]: 0.347-0.624). The receiver operating curve indicates that ATTS is good at predicting mortality (area under the curve: 0.857; 95% CI: 0.788-0.926; p < 0.001).

Conclusion:  The height of the fall, injury type, or ground type do not seem to be accurate in estimating the survival rate in HRS patients. Established scoring systems such as ATTS should be used to determine survival rates in future HRS studies.

Objective:  The aim of this study was to (1) compare 5-point and 10-point bone healing radiographic scoring systems using postoperative tibial plateau levelling osteotomy (TPLO) radiographs and (2) determine whether Boxer osteotomy healing time differs from age-matched Labrador Retrievers.

Study design:  This was a multicentre retrospective study. Fifty-eight client-owned dogs undergoing TPLO (29 Boxers and 29 Labrador Retrievers) were included. Five board-certified surgeons evaluated the radiographs three independent times. Osteotomy healing approximately 8 weeks postoperatively was graded using previously reported 5-point and 10-point scoring systems and immediate postoperative radiographs were assessed for the presence of an osteotomy gap of ≥1 mm.

Results:  Both scoring systems had good consistency among observers. Intraobserver consistency was good in three out of five observers using the 5-point system and in four out of five observers using the 10-point system. Boxers had significantly lower radiographic healing scores at 8 weeks postoperatively compared with Labrador Retrievers using both scoring systems (p ≤ 0.001). The presence of an osteotomy gap postoperatively resulted in significantly lower healing scores at 8 weeks using both scoring systems (p < 0.001) in both breeds.

Conclusion:  No difference was found in inter- and intraobserver variability between scoring systems. Boxer dogs had lower healing scores at 8 weeks after TPLO compared with Labrador Retrievers. An osteotomy gap of ≥1 mm was associated with lower healing scores.

Objective:  The aim of the study was to compare the stiffness and cyclic fatigue of locking compression plate constructs from three manufacturers, DePuy Synthes (DPS), Knight Benedikt (KB), and Provet Veterinary Instrumentation (Vi), under cyclic torsion.

Methods:  The constructs of DPS, KB, and Vi were assembled by fixing a 10-hole 3.5-mm stainless steel locking compression plate 1 mm away from a validated bone model with a fracture gap of 47 mm. The corresponding drill guides and locking screws were used. Three groups of six constructs were tested in cyclic torsion until failure.

Results:  There was no significant difference in initial stiffness between DPS constructs (28.83 ± 0.84 N·m/rad) and KB constructs (28.38 ± 0.81 N·m/rad), and between KB constructs and Vi constructs (27.48 ± 0.37 N·m/rad), but the DPS constructs were significantly stiffer than the Vi constructs. The DPS constructs sustained the significantly highest number of cycles (24,833 ± 2,317 cycles) compared with KB constructs (16,167 ± 1,472 cycles) and Vi constructs (19,833 ± 4,792 cycles), but the difference between KB and Vi constructs was not significant. All constructs failed by screw damage at the shaft between the plate and the bone model.

Conclusion:  DPS constructs showed superior initial torsional stiffness and cyclic fatigue life than Vi constructs, whereas KB and Vi constructs shared comparable results. Further investigation is required to assess the clinical significance of these biomechanical differences.

Objective:  Patellar luxation (PL) is commonly diagnosed in dogs and cats; however, a traumatic cause is poorly reported in the literature. The aim of this study was to report the clinical presentation, surgical treatment, and outcome in dogs and cats surgically treated for traumatic PL.

Study design:  This is a retrospective study. Medical records of dogs and cats operated for traumatic PL were reviewed. Short- and long-term follow-ups were assessed with medical records and telephone interviews with owners and referring veterinarians. Data on signalment, lameness, PL characteristics, surgery, complications, and outcome were recorded.

Results:  Eleven dogs and 5 cats were included. Both species had a median lameness grade of 4/5 and a median PL grade of 3/4. PL was medial in most cases (13/16). Joint capsule lesions were identified in 15 cases, 4 cases had trochlear ridge cartilage damage. All cases had a capsular imbrication, 12 cases had a fabello-patellar suture (FPS). Mean long-term follow-up time was 70.8 ± 42.5 months in 9 dogs and 4 cats. Ten cases out of 13 had no lameness at the 2-month follow-up, and 11/13 cases had no long-term lameness. Eleven cases out of 13 had no PL at the 2-month follow-up. No long-term PL was reported by owners. Complications were mild in 5 cases, moderate in 1, severe in 3. Functional outcome was full in 10 cases and acceptable in 3.

Conclusion:  Soft tissue techniques and FPS were effective in the surgical treatment of traumatic PL in dogs and cats, resulting in acceptable to full long-term function in all cases, with limited severe complications.

Intramedullary nails are specialized metal rods inserted into the medullary cavity of a fractured bone and secured to reduce load on the fracture site, provide stability, and permit healing. The purpose of this review is to highlight the biomechanics of orthopaedic intramedullary nailing, as well as discuss the biomechanical considerations that have shaped implant design and fixation technique in veterinary and human medicine. Relevant studies were included from the PubMed database and Google Scholar for discussion on the basic science and nail design of intramedullary nails. Implant design and implementation continues to progress, with new innovative designs currently under investigation. A lack of consensus remains on the superior implant material. Recent studies, particularly in human populations, have supported the use of reaming based on reoperation rates, nonunion rates, and dynamization. Design modifications, such as the expandable intramedullary nails and angle-stable interlocking designs, have been investigated as methods of improving cortical contact and resisting torsional stress. Intramedullary nailing is a valuable stabilization technique for long bone fractures across a variety of species. The technology continues to undergo design improvements in both veterinary and human medicine.