Surgical versus conservative treatment of primary patellar dislocation. A systematic review and meta-analysis

Purpose: The purpose of this study was to determine the efficacy of surgical and conservative treatment in the prevention of recurrence after primary patellar dislocation. Methods: Studies were searched on MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and CINHAL from their inception to April 2015. All randomized controlled clinical trials comparing surgical versus conservative treatment after first patellar dislocation were included. Primary outcomes were: recurrent dislocation, subluxation, overall instability and subsequent surgery. Secondary outcomes included imaging, and subjective and objective clinical assessment tools. Methodological quality of the studies was assessed using Cochrane Collaboration's "Risk of Bias" tool. Pooled analyses were reported as risk ratio (RR) using a random effects model. Continuous data were reported as standardized mean difference (SMD) and 95 % confidence intervals (CIs). Heterogeneity was assessed using I². Results: Nine studies were included in the meta-analyses. Methodological quality of the studies was moderate to low. Meta-analyses showed that surgical treatment significantly reduces the redislocation rate (RR = 0.62; 95% CI = 0.39, 0.98, p = 0.04) and provides better results on Hughston VAS score (SMD = -0.32; 95% CI = -0.61, -0.03; p = 0.03) and running (OR = -0.52; 95% CI = 0.31, 0.88; p = 0.01). Conservative treatment showed less occurrence of minor complications (OR = 3.46; 95% CI = 2.08, 5.77; p = 0.01) and better results in the figure-of-8 run test (SMD = 0.42; 95% CI = 0.06, 0.77; p = 0.02) and in the squat down test (SMD = -0.45; 95% CI = -0.81, -0.10; p < 0.00001). No other significant differences could be found. Conclusions: Based on the available data, surgical treatment of primary patella dislocation significantly reduces the risk of patella redislocation.