Surgical treatment of medial patellar luxation without femoral trochlear groove deepening procedures in dogs: 91 cases (1998-2009).

OBJECTIVE: To assess signalment, outcomes, and complications for dogs surgically treated for medial patellar luxation (MPL) with a combination of lateral retinacular imbrication and tibial crest transposition procedures without femoral trochlear groove deepening techniques, and to determine whether osteoarthritis progressed in these patients during the 8-week period following surgery. DESIGN: Retrospective case series. Animals-91 dogs. PROCEDURES: Medical records were reviewed for information on signalment, clinical history, unilateral versus bilateral disease, preoperative and postoperative MPL grades, duration of follow-up, and perioperative and postoperative complications. Radiographs obtained preoperatively and during 8-week follow-up examinations were reviewed and assigned degenerative joint disease (DJD) scores (range, 0 to 3). Data were analyzed to determine factors influencing outcomes. Kaplan-Meier curves were constructed for recurrence of MPL. RESULTS: Minor postoperative complications were reported for 31 of 91 (34.1%) dogs. Patellar reluxation occurred in 18 of 91 (19.8%) dogs. Reluxation or complications for which additional surgery was recommended developed in 6 of 91 (6.6%) dogs. At last clinical follow-up, 10 of 91 (11.0%) dogs had at least occasional lameness. No difference was revealed between preoperative and postoperative (8-week follow-up) radiographic DJD scores. CONCLUSIONS AND CLINICAL RELEVANCE: Results of surgical treatment of MPL without femoral trochlear groove deepening procedures were comparable to those in studies of surgical treatment that included groove deepening procedures. Radiographic indices of DJD did not increase during the 8 weeks following surgery. These results suggest that trochlear groove deepening procedures are not always necessary, and patients that undergo these techniques should be carefully selected.