Retrospective study of dogs with medial patellar luxation surgically treated

The aim of this study was to evaluate retrospectively 48 medium to toy breed dogs with developmental medial patellar luxation submitted to corrective surgical procedures. In the grade 1 limbs, 46.7% were treated by lateral retinacular overlap and 53.3% by lateral retinacular overlap and deepening of the femoral groove with no complications. In the grade 2 limbs (n=35) were used the techniques of deepening of the femoral groove and lateral retinacular overlap (100% of the cases), medial desmotomy (28.6%), fabello-patellar sutures (2.8%) with 14.3% of reluxation. The last evaluation varied from 3 to 9 months, and clinical signs of lameness were still observed in 20% of the limbs. In all grade 3 cases (n=11) were performed deepening of the femoral groove, lateral retinacular overlap, partial quadriceps released, medial desmotomy and lateral transposition of the tibial tuberosiy that was fixated with Kirschner wire or screw. Reluxation occurred in 27.3% of the limbs that were reoperated. In this group 72.7% of the limbs had absence of lameness. In the grade 4 limbs (n=10) were used the same techniques of grade 3, but it was also necessary the femoral corrective osteotomy in 4 limbs. Reluxation was observed in 30% of the limbs that were reoperated. Although 60% of the limbs showed a positive evolution of the locomotion after 5.2 months of evaluation, in general the dogs showed a posture with the hind limbs in a semi-flexed position, due to the inability to fully extend the stifle. In conclusion, the surgical procedures used allowed an improvement of the locomotion, but except to grade 1, the patellar reluxation may occur in the other degrees suggesting the necessity of other protocols.