The Outcomes of Isolated Distal Realignment Procedures in Patellofemoral Instability: A Systematic Review and Meta-analysis.

Distal realignment procedures are now commonly performed routinely with proximal realignment procedures. Despite so, only a limited number of publications exist that have looked into the efficacy of isolated distal realignment procedures, and whether there is indeed a need for routine proximal realignment procedures to be added to the distal realignment procedures. The current systematic review and meta-analysis aims to evaluate the outcomes of isolated distal realignment procedures in the management of patellofemoral instability. The review was conducted using the preferred reporting items for systematic reviews and meta-analyses (PRSIMA) guidelines. All studies that reported the outcomes of isolated distal realignment procedures for patellofemoral instability were included. A total of six publications were included, with 347 knees. All studies consistently reported a decrease in the rates of patellofemoral instability or maltracking (odds ratio [OR]: < 0.01; 95% confidence interval [CI]: < 0.01-0.01) and an increase in the odds of having a good outcome (OR: 0.01; 95% CI: < 0.01-0.02) after distal realignment procedures. A total of 24 out of 306 patients (7.8%) had postoperative instability or maltracking, and a total of 220 out of 303 patients (72.6%) were rated to have good or excellent outcomes postoperatively. Isolated distal realignment procedures can lead to good outcomes when used in the management of patellofemoral instability. These include a significantly decreased rate of patellofemoral instability or maltracking and a significantly increased number of patients with excellent or good outcomes postoperatively. Comparisons between patients with and without additional proximal realignment procedures suggest that additional proximal realignment procedures do not definitely improve the outcomes of distal realignment procedures and, therefore, should not be routinely performed in all patients undergoing distal realignment procedures. The Level of Evidence for this study is IV.