Effect of a locking triple pelvic osteotomy plate on screw loosening in 26 dogs.

OBJECTIVE: To evaluate the complication rate of the double (DPO) and triple pelvic osteotomy (TPO) procedure (unilateral and bilateral) with a locking purpose-specific plate. STUDY DESIGN: Retrospective case series ANIMALS: Dogs (n = 26; 38 hips) MATERIALS: Medical records (January 2007-January 2011) of dogs that had unilateral or bilateral DPO or TPO were evaluated. Signalment, age, body weight, estimated preoperative subluxation and reduction angles, lameness, and complications were evaluated. Follow-up radiographs were evaluated for implant loosening or failure, femoral head coverage (FCH), pelvic dimensions, and radiographic evidence of healing. RESULTS: Screw loosening occurred in 1 of 266 (0.4%) screws placed and in 1 of 38 hips (2.6%). The rate of screw loosening was significantly lower than previously reported. Only 1 hip (2.6%) developed a major complication. Minor complications involving implants occurred in 2 hips (5.3%). Three to 5 locking screws were used per plate. There was a significant increase in FCH and Norberg angle (NA) compared with preoperative values. No clinically significant change in pelvic canal dimensions measured at 3 locations was identified. CONCLUSION: Locking 7-hole TPO plates with 3-5 locking screws resulted in a lower rate of major and minor implant associated complications than the reported complication rate for conventional 6-hole plates. En bloc pullout of the caudal aspect of the plate is an infrequent but repeatable complication associated with the locking TPO implant.

Radiographic evaluation of the anconeal process in skeletally immature dogs.

OBJECTIVE: To determine if a secondary center of ossification (SCO) of the anconeal process is present in skeletally immature dogs that do not develop an ununited anconeal process (UAP). STUDY DESIGN: Case series. ANIMALS: Dogs 77-154 days of age with conditions other than developmental disease of the elbow (n=78 dogs; total elbows=100). METHODS: Mediolateral radiographic projections of the elbow were reviewed for presence or absence of a SCO of the anconeal process. RESULTS: A SCO was radiographically evident in 16% of elbows from breeds that have been reported to be affected by UAP. The appearance of the SCO was different to an UAP fragment. None of the elbows with SCO of the anconeal process developed UAP. A SCO was not present in any small breed dogs. CONCLUSIONS: A SCO of the anconeal process is uncommon in medium and large breed dogs and the presence of a SCO does not indicate that UAP will develop. CLINICAL RELEVANCE: Because radiographic diagnosis of a SCO of the anconeal process and UAP lesions have distinct appearances, an earlier diagnosis of UAP is possible.

Radiographic and ultrasonographic evaluation of the patellar ligament following tibial plateau leveling osteotomy.

Objective evaluation of patellar ligament changes following tibial plateau leveling osteotomy (TPLO) for cranial cruciate ligament injury has not been published to date. In this study, the patellar ligament was evaluated using radiographs and high-resolution ultrasound in 31 stifles (29 dogs) preoperatively and at 1 month (n=31), 2 months (n=18), and 6 months (n=13) postTPLO. A ratio of the thickness of the proximal to distal patellar ligament was determined for all radiographs evaluated. Ultrasound evaluation included proximal, middle, and distal mid-sagittal thickness and transverse thickness, and transverse area measurements. Subjective grading (0 being normal through a scale of 3) of the ultrasound changes was also performed at each evaluation. Significant thickening of the distal patellar ligament was noted postoperatively as evidenced by thickness and area measurements and a decreased radiographic ratio (P < 0.01). Preoperative patellar ligament thickness and area were similar at the proximal, middle and distal sites. Ultrasound-derived thickness and area measurements of the distal patellar ligament were increased at 1 and 2 months (P < 0.01). The radiographic ratio was significantly decreased at 1, 2 and 6 months (P < 0.01). Subjectively, all patellar ligaments scored a 0 preoperatively and 16/31 received a score of 2 or 3 during follow-up evaluation. Additionally, these dogs had ultrasonographic and radiographic changes consistent with distal patellar ligament thickening. Body weight (kg) and postoperative TPLO angle had a significant influence on 1-month postoperative distal patellar ligament area using a stepwise logistic model (P < 0.05). Patellar ligament desmitis is a common postoperative sequela to the TPLO procedure, however its clinical significance (i.e., correlation with a residual lameness) was not evaluated in this study.