Medial patellar retinaculum plasty versus medial capsule reefing for patellar dislocation in children and adolescents.

ABSTRACT

INTRODUCTION: The purpose of this study was to evaluate the clinical effect of medial patellar retinaculum plasty for children and adolescent patients with patellar dislocation. MATERIALS AND METHODS: A prospective study was performed between October 2005 and December 2009. Sixty-one cases of children and adolescent patients with patellar dislocation were admitted to our study. Twenty-nine patients received medial capsule reefing, of which 13 patients also received lateral retinacular release (LRR) (Group I). Thirty-two patients received medial patellar retinaculum plasty, of which 12 patients also received LRR (Group II). Preoperatively, all patients received magnetic resonance imaging (MRI) to evaluate the injury of medial patellofemoral ligament. And all patients received computed tomography (CT) scans on which the congruence angle (CA) and patellar lateral shift (PLS) could be evaluated with 30° knee flexion. Physical apprehension tests were examined and the redislocation was recorded. In addition, knee function was evaluated using the Kujala score and subjective questionnaires. RESULTS: Patients were followed up for a mean period of 50 months (25-75 months). For the comparison between the preoperative and postoperative results, the Kujala score improved significantly from 52.3 ± 2.9 to 78.1 ± 3.6 in Group I and from 53.5 ± 3.4 to 82.2 ± 3.4 in Group II (P < 0.05). There was significant difference of CA on CT scans and PLS with a statistical difference between the two groups (P < 0.05). Results of the apprehension test showed that nine patients had patellar lateral shift exceeding 1.5 cm with a soft end point in Group I and two patients had patellar lateral shift exceeding 1.5 cm with a hard end point in Group II (P < 0.05). Moreover, the subjective questionnaire revealed a significant difference of subjective effects between two groups (P < 0.05), including 7 excellent, 10 good and 12 fair in Group I and 18 excellent, 9 good, and 5 fair in Group II. CONCLUSION: The medial retinaculum plasty was better than medial capsule reefing in improving the subjective effects and decreasing the rate of patellar instability postoperatively in children and adolescent patients.