Arthroscopic surgery for primary traumatic patellar dislocation: a prospective, nonrandomized study comparing patients treated with and without acute arthroscopic stabilization with a median 7-year follow-up

Abstract

Background: No data exist whether patients with primary traumatic patellar dislocation benefit from initial arthroscopic medial repair surgery.

Purpose: To compare long-term outcomes of patients treated with acute arthroscopic stabilization for patellar dislocation with those treated nonoperatively except for removal of loose bodies.

Study design: Cohort study; Level of evidence, 2.

Methods: The study group included 76 consecutive military recruits (72 men, 4 women), with a median age of 20 years (range, 19-22) at the time of dislocation. Thirty patients (group 1) underwent initial arthroscopic medial retinacular repair, and 46 patients (group 2) were treated without stabilizing surgery, including 11 who had osteochondral fragments arthroscopically removed. Patients with previous patellar dislocations or instability were excluded. Aftercare was identical in both groups. Redislocations, subjective symptoms, and functional limitations were evaluated after a median 7-year follow-up.

Results: Sixty-one (80%) patients participated in a follow-up examination. At final follow-up, 8 (23%) redislocations occurred in group 2 and 5 (19%) in group 1 (P = .84). Eight (23%) patients in group 2 and 3 (12%) in group 1 reported patellar subluxations (P = .18). In group 1, 81% regained their preinjury activity level compared with 56% in group 2 (P = .05). Functional outcomes were good in both groups (Kujala scores: 87 for group 1 and 90 for group 2) (P = .22). Regarding the presence of osteoarthritic characteristics in the patellofemoral joint, no statistically significant differences were found between the groups.

Conclusions: Initial arthroscopic medial retinacular repair was not followed by improved patellar stability nor reduced incidence of redislocations compared with nonoperative (except for removal of loose bodies) treatment. Acute arthroscopic medial retinacular repair allowed patients to better regain preinjury activity level than in patients not undergoing retinacular repair. The decision to stabilize the patella by initial arthroscopic surgery should be made with caution.