Does Operative Treatment of First-Time Patellar Dislocations Lead to Increased Patellofemoral Stability? A Systematic Review of Overlapping Meta-analyses.

PURPOSE: To conduct a systematic review of meta-analyses comparing nonoperative and operative treatment of patellar dislocations to elucidate the cause of the variation and to determine which meta-analysis provides the current best available evidence. METHODS: A systematic review of the literature to identify meta-analyses was performed. Data were extracted for patient outcomes and recurrent dislocations. Meta-analysis quality was assessed using the Oxman-Guyatt and Quality of Reporting of Meta-analyses systems. The Jadad algorithm was then applied to determine which meta-analysis provided the highest level of evidence. RESULTS: Four meta-analyses met the eligibility criteria: 1 Level I evidence, 2 Level II evidence, and 1 Level III evidence. A total of 1,984 patients were included (997 underwent surgery whereas 987 underwent conservative treatment). Three meta-analyses found a lower subsequent patellar dislocation rate in patients managed operatively compared with nonoperatively, whereas one did not find a difference in recurrent dislocation rates between the operative and nonoperative groups. When the results of all the studies were combined, the overall redislocation rate was 29.4% and the rate of recurrent instability episodes was 32.8%. Patients treated operatively had a 24.0% rate of repeat patellar dislocation and a 32.7% rate of recurrent patellar instability, whereas patients treated nonoperatively had a 34.6% rate of repeat patellar dislocation and a 33.0% rate of recurrent instability. In addition, 1 meta-analysis found a significantly higher rate of patellofemoral osteoarthritis in the operative group. No differences in functional outcomes scores were seen between treatments. Two meta-analyses had low Oxman-Guyatt scores (<4), indicative of major flaws. CONCLUSIONS: According to the best available evidence, operative treatment of acute patellar dislocations may result in a lower rate of recurrent dislocations than nonoperative treatment but does not improve functional outcome scores. LEVEL OF EVIDENCE: Level III, systematic review of Level I, II, and II studies.