J Korean Knee Soc.  2006 Jun;18(1):91-95.

Results of Recurrent Patellar Instability after Trauma According to Anatomical Predisposing Factors

• Kyung JS
• Oh CW
• Park BC
• Cha KB
• Lee SW

Abstract

PURPOSE
We analyzed the results of lateral retinacular release(LRR) and proximal realignment for recurrent patellar instability after trauma according to the anatomical predisposing factors.
MATERIALS AND METHODS
Twelve patients of fifteen cases of recurrent patellar instability had been evaluated. Clinical assessment were performed by Q-angle, apprehension test, passive patellar tilt test and general joint laxity. The anatomical predisposing factors assessed by plain radiographs included patella alta, sulcus angle, femoral trochlear dysplasia, genu valgum and patellar dysplasia. Clinical results were assessed by Kujala scoring system. Radiographic results were assessed by congruence angle. The results were analyzed according to the predisposing factors.
RESULTS
Patella alta was observed in eight, increased sulcus angle in six, trochlear dysplasia in twelve, genu valgum in five and patella dysplasia in four cases. The result of treatment (Kujala score / congruence angle) was 85.8 / 9.7degrees in group A(predisposing factors > or = 3) and 91.4 / -5.3degrees in group B (predisposing factors<3)(p=0.036). We had 4 cases of recurrence after operation and genu valgum was related with recurrence rate.
CONCLUSION
The clinical results of LRR and proximal realignment for recurrent patellar instability developed after trauma were worse in cases with more anatomical predisposing factors.

Keyword

Recurrent patellar instability; Anatomical predisposing factor

MeSH Terms

Causality*
Genu Valgum
Humans
Joint Instability
Patella
Recurrence