Objective—To determine long-term outcome of distal femoral osteotomy as a component of treatment for distal femoral varus and medial patellar luxation in large-breed dogs.
Design—Retrospective case series.
Animals—12 dogs (16 stifle joints).
Procedures—Medical records and radiographs were reviewed to identify large-breed dogs with medial patellar luxation (grade ≥ 2) and femoral varus angle ≥ 12° treated with distal femoral osteotomy, with a minimum follow-up (by a veterinarian) of 18 months. Signalment, weight, medial patellar luxation and lameness grade, pre- and postoperative femoral varus angle, surgical technique, time to radiographic bone union, and complications were recorded. Follow-up with owners via questionnaire was performed > 18 months after surgery.
Results—16 corrective distal femoral osteotomies were performed with ancillary medial patellar luxation procedures in 12 dogs; 4 dogs had staged bilateral procedures. Mean ± SD preoperative and postoperative femoral varus angles were 16.3 ± 4.3° and 3.9 ± 2.5°, respectively. Mean ± SD time to radiographic union of the distal femoral osteotomy was 52.6 ± 13 days. One dog had Kirschner wire migration from the tibial tuberosity. Patellar luxation was not detected after surgery in any dog. Mean ± SD follow-up by a veterinarian was 1,335 ± 410 days and by use of an owner questionnaire was 1,497 ± 464 days. All 10 variables of owner-observed patient comfort and function were significantly improved.
Conclusions and Clinical Relevance—Distal femoral osteotomy in combination with traditional treatment provided predictable osteotomy healing, patellar stabilization, and long-term improvement in patient comfort and function when used to treat combined distal femoral varus and medial patellar luxation in large-breed dogs.
Objective—To compare the mechanical behaviors of a semicontoured, locking compression plate–rod (LCP-rod) construct and an anatomically contoured, limited-contact dynamic compression plate–rod (LC–DCP-rod) construct applied to experimentally induced gap fractures in canine femora.
Sample Population—16 femora from 8 cadaveric dogs.
Procedures—8 limbs from 8 dogs were assigned to the LCP-rod construct group or the LC–DCP-rod construct group. In each femur, a 39-mm mid-diaphyseal ostectomy was performed at the same plate location and the assigned construct was applied. Construct stiffness and ostectomy gap subsidence were determined before and after cyclic axial loading (6,000 cycles at 20%, 40%, and 60% of live body weight [total, 18,000 cycles]). Three constructs from each group further underwent 45,000 cycles at 60% of body weight (total, 63,000 cycles). Following cyclic loading, mode of failure during loading to failure at 5 mm/min was recorded for all constructs.
Results—After 18,000 or 63,000 cycles, construct stiffness did not differ significantly between construct groups. No implant failure occurred in any construct that underwent 63,000 cycles. In both construct groups, ostectomy gap subsidence similarly increased as axial load increased but did not change after 18,000 cycles. Mean ± SEM loads at failure in the LCP-rod (1,493.83 ± 200.12 N) and LC–DCP-rod (1,276.05 ± 156.11 N) construct groups were not significantly different. The primary failure event in all constructs occurred at the screw hole immediately distal to the ostectomy.
Conclusions and Clinical Relevance—Biomechanically, the semicontoured LCP-rod construct is similar to the anatomically contoured LC–DCP-rod system.
To compare mechanical properties (stiffness, yield load, failure load, and deformation at failure) of 2 pearl-type locking plate system (PLS) constructs (PLS 1 and PLS 2) in a simulated fracture gap model and to compare screw push-out forces of the 2 PLSs with and without plate contouring.
40 PLS constructs.
Mechanical properties of uncontoured PLS 1 (n = 8) and PLS 2 (8) constructs were evaluated in synthetic bone-plate models under axial compression. Screw push-out forces were evaluated in 6 uncontoured and 6 contoured PLSs of each type. Variables of interest were compared between PLS groups and between contoured and uncontoured plates by statistical methods.
Yield and failure loads were higher in the PLS 1 group than in the PLS 2 group, but stiffness did not differ significantly between groups. All constructs failed by plate bending, with greater deformation in the PLS 2 group. Push-out force to screw-plate uncoupling was higher in the PLS 2 group than in the PLS 1 group for uncontoured and contoured plates. Locking mechanism failure of PLS 1 specimens was through screw-thread stripping. The PLS 2 specimens failed by node deformation followed by screwhead stripping.
CONCLUSIONS AND CLINICAL RELEVANCE
Distinct mechanical differences were identified between the 2 PLSs. The clinical relevance of these differences is unknown. Further research including cyclic fatigue testing is needed to reveal more clinically pertinent information.
Objective—To identify risk factors for development of excessive tibial plateau angle (TPA) in large-breed dogs with cranial cruciate ligament disease (CCLD).
Animals—58 dogs with excessive TPAs (ie, TPA ≥ 35°; case dogs) and 58 dogs with normal TPAs (ie, TPA ≤ 30°; control dogs).
Procedures—Medical records and radiographs were reviewed and owners were interviewed to identify potential risk factors for excessive TPA.
Results—Case dogs were 3 times (95% confidence interval, 1.2 to 8.0) as likely to have been neutered before 6 months of age as were control dogs. Case dogs with TPA ≥ 35° in both limbs were 13.6 times (95% confidence interval, 2.72 to 68.1) as likely to have been neutered before 6 months of age as were control dogs with TPA ≤ 30° in both limbs. Case dogs were significantly younger at the onset of hind limb lameness than were control dogs.
Conclusions and Clinical Relevance—Results suggested that early neutering was a significant risk factor for development of excessive TPA in large-breed dogs with CCLD. Further research into the effects of early neutering on TPA and the pathophysiology of CCLD is warranted.
OBJECTIVE To compare owner satisfaction between custom-made stifle joint orthoses and tibial plateau leveling osteotomy (TPLO) for the management of medium- and large-breed dogs with cranial cruciate ligament disease (CCLD).
DESIGN Owner survey.
SAMPLE 819 and 203 owners of dogs with CCLD that were managed with a custom-made stifle joint orthosis or TPLO, respectively.
PROCEDURES Client databases of an orthosis provider and veterinary teaching hospital were reviewed to identify potential survey respondents. An online survey was developed to evaluate owner-reported outcomes, complications, and satisfaction associated with the nonsurgical (orthosis group) and surgical (TPLO group) interventions. Survey responses were compared between groups.
RESULTS The response rate was 25% (203/819) and 37% (76/203) for the orthosis and TPLO groups, respectively. The proportion of owners who reported that their dogs had mild or no lameness and rated the intervention as excellent, very good, or good was significantly greater for the TPLO group than for the orthosis group. However, ≥ 85% of respondents in both groups reported that they would choose the selected treatment again. Of 151 respondents from the orthosis group, 70 (46%) reported skin lesions associated with the device, 16 (11%) reported that the dog subsequently underwent surgery, and 10 (7%) reported that the dog never tolerated the device.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated high owner satisfaction rates for both interventions. Owners considering nonsurgical management with an orthosis should be advised about potential complications such as persistent lameness, skin lesions, patient intolerance of the device, and the need for subsequent surgery.