Poor outcome at 7.5 years after Stanisavljevic quadriceps transposition for patello-femoral instability.

INTRODUCTION

Congenital dislocation of the patella and recurrent symptomatic dislocation in adolescents are difficult pathologies to treat. Stanisavljevic described an extensive release procedure essentially involving medializing the entire lateral quadriceps and medial soft tissue stabilization. There are no significant series reporting the success of this method. This procedure has been performed in our institution over several years and we report our results.

METHOD: Retrospective case series. Between 1990 and 2007, 20 knees in 13 children and adolescents (mean age 12.8 years; 4-17, 7 female) with recurrent or congenital dislocation of the patella (8 knees) underwent this procedure after failed conservative treatment (mean follow-up 7.5 years; 4-16). All were immobilized in a long leg cast for 6 weeks.

RESULTS

Five knees in five patients (20 %, 1 congenital dislocation) reported their knees as improved without further dislocations. Out of the 15 knees with failures (80 %) 12 in six patients (60 %) were revised due to redislocation. Three knees in two patients (15 %) still had dislocations or subluxations, but any revision was refused. Three knees in three patients caused pain and discomfort during daily activity. Redislocation first developed after a mean of 21.3 months (4-72) postoperatively. Only one patient had returned to sport at the 12-month follow-up.

DISCUSSION: The Stanisavljevic procedure produces a mediocre success rate with our long-term follow-up series showing a failure rate up to 80 %. We therefore recommend more specific procedures dealing with the anatomical deformity such as trochleaplasty to produce superior success rates.