Veterinary and Comparative Orthopaedics and Traumatology最新文献

Objectives:  The aim of the study was to investigate the contact mechanics and kinematic changes in the stifle in different standing angles.

Study design:  We performed a biomechanical ex vivo study using pairs of canine cadaver hindlimbs. Motion sensors were fixed to the tibia and the femur for kinematic data acquisition. Pressure mapping sensors were placed between the femur and both menisci. Thirty percent bodyweight was applied to the limbs with the stifle in 125, 135, or 145 degrees of extension.

Results:  Stifle flexion angle influences femoromeniscal contact mechanics significantly. The load on both menisci was significantly higher for 125 and 135 degrees in comparison to 145 degrees. Additionally, the center of force was located significantly more caudal when comparing 125 to 145 degrees in the medial meniscus as well as in both menisci combined.

Conclusion:  The angle of knee flexion significantly impacts the contact mechanics between the femur and the meniscus. As the knee flexes, the load on both menisci increases.

Objective:  The aim of this study was to report (1) the prevalence of contralateral humeral intracondylar GAP/HIF (HIF) in French Bulldogs with humeral condylar fractures (HCF) and (2) treatment and short- and long-term outcome in French Bulldogs with HCF.

Materials and methods:  Medical records of French Bulldogs treated surgically for HCF between January 2011 and November 2022 were reviewed. Perioperative imaging, surgical technique, complications, and long-term outcome were assessed.

Results:  Eighty-nine dogs with HCF were included and 36/89 were diagnosed with HIF. Surgical repair was performed in all HCF and a prophylactic transcondylar screw was placed in 20/36 HIF. For prophylactic transcondylar screw placement, two dogs required immediate revision surgery. Complications occurred in 12/89 HCF, and there were major complications in 6/89 HCF. Long-term outcome evaluated by owner questionnaire (n = 27) was rated as being excellent in 18/27 dogs, good in 8/27 dogs, and fair in 1/27 dogs.

Clinical significance:  Forty percent of French Bulldogs with HCF had a contralateral HIF. HIF as a cause of HCF should be considered in the French Bulldog, and a computed tomography (CT) scan of both elbows may be advisable prior to HCF repair. The complication rate of HCF surgery in the French Bulldog is significant.

Objective:  To report the use of a Lateral Epicondylar Anatomical Plate for the management of humeral condylar fractures (HCF) in dogs.

Study design:  Medical records of dogs with HCF stabilized using the Lateral Epicondylar Anatomical Plate at six UK veterinary referral centres between April 2018 and February 2021 were reviewed. Long-term follow-up (>6 months) was obtained via owner questionnaire, which incorporated the Liverpool Osteoarthritis in Dogs clinical metrology instrument.

Results:  Sixty-two HCF were treated in 61 dogs (44 lateral condylar fractures [LCF] and 18 intracondylar (T/Y) fractures [ICF]). Fifty-one dogs were Spaniels or Spaniel crossbreeds. Intraoperative contouring of the plate was required for one dog-a French Bulldog. Postoperative complications occurred in 14/42 LCF and 6/18 ICF; overall there were 14 minor, 8 major, and 2 catastrophic complications. On final follow-up imaging, there was evidence of partial or complete osseous continuity of the condylar part of the fracture 32/53 HCF (24/39 LCF and 8/14 ICF) and lateral epicondylar part of the fracture in 53/53 HCF (39/39 LCF and 14/14 ICF). At final reexamination, 20/28 dogs with LCF and 5/13 dogs with ICF were not lame and the remaining dogs demonstrated mild lameness. According to the owner questionnaire, 17/17 dogs with LCF and 8/10 dogs with ICF returned to full limb use and median Liverpool Osteoarthritis in Dogs scores were 2/52 for LCF and 6.5/52 for ICF.

Conclusion:  The Lateral Epicondylar Anatomical Plate can be used successfully for the surgical stabilization of HCF in dogs.

Objective:  The aim of this study was to determine if variations in Hounsfield units (HU) are present within the elbow between asymptomatic dogs of two breeds of dogs susceptible to elbow dysplasia.

Study design:  Guide Dogs and Border Collies that presented for routine computed tomography (CT) screening for elbow dysplasia prior to breeding were evaluated. All dogs had no documented history of lameness. Dogs diagnosed with CT as being free of elbow dysplasia were included. The CT images were randomized and assessed by three blinded observers. A standardised approach to CT image reconstruction to create consistent image planes was used. Hounsfield units were measured within a standardised region of interest (ROI) at the humeral trochlea and medial coronoid process. The minimum, mean and maximum HU within each ROI was recorded.

Results:  Eighty-six elbows were included in the study with 32 Guide Dogs, and 11 Border Collies. Guide Dogs had significantly higher minimum (99.75 HU, 95% confidence interval [CI]: 15.02-184.48, p = 0.022), mean (115.09 HU, 95% CI: 80.53-149.64, p < 0.01) and maximum (74.00 HU, 95% CI: 44.58-103.42, p < 0.01) difference in HU within the medial coronoid process ROI, and significantly higher mean (146.49 HU, 95% CI: 100.12-192.87, p < 0.01) and maximum (147.77 HU, 95% CI: 102.57-192.97, p < 0.01) difference in HU within the humeral trochlea ROI.

Conclusion:  In this dataset breed variations in elbow HU were present between asymptomatic Guide Dogs and Border Collies. This needs to be considered in breeding screening programmes to avoid over-interpretation of elbow sclerosis, in the absence of elbow pathology.

The aim of this study was to describe three dogs with permanent fibular nerve injury following tibial plateau levelling osteotomy (TPLO). Fibular nerve injury following TPLO led to atrophy of the cranial tibial muscle, absent hock flexion and a mild lameness. Fibular nerve injury was confirmed in one case with electrodiagnostics. All three cases had a drill tract in the same location, on the caudal aspect of the tibia, immediately distal to the tibial osteotomy. Permanent fibular nerve injury following TPLO occurred with a more caudally positioned plate and care should be taken when drilling the tibia from medial to lateral in the region described. Careful gait assessment at routine follow-up was required to identify this complication.

Objective:  The aim of this study was to evaluate the stress changes in the radii beneath the locking plates (LP) of dogs implanted with LP using finite element analysis (FEA).

Study design:  The study included radii harvested from eight dogs. After computed tomography (CT) scans of the forelimb, the articular surface of the radius was fixed using resin. Material tests were conducted to identify the yield and fracture points and for verification with FEA. The CT data of the radius were imported into FEA software. The radii were classified into three groups based on the placement of the LP (nonplate placement, intact group; 1 mm above the radial surface, LP + 1 mm group; 3 mm above the radial surface, LP + 3 mm group). Equivalent, maximum, and minimum principal stresses and minimum principal strain were measured after FEA at the radial diaphysis beneath the plate.

Results:  In shell elements, the LP + 1 mm and LP + 3 mm groups showed a significantly lower maximum principal stress compared with the intact group. In solid elements, the LP + 1 mm and LP + 3 mm groups showed a significantly higher equivalent stress and a significantly lower maximum principal stress compared with the intact group.

Conclusion:  When an axial load is applied to the radius, LP placement reduces the tension stress on the cortical bone of the radius beneath the plate, possibly related to implant-induced osteoporosis and bone formation in the cortical bone beneath the plate.

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 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:  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.