Surgical Reconstruction of the Lateral Patellofemoral Restraint Complex for Medial Patellar Instability: A Systematic Review of Techniques and Clinical Outcomes

Abstract

Medial patellar instability is an uncommon, frequently iatrogenic complication after lateral retinacular release or other lateral-sided procedures. Multiple reconstructive techniques for the lateral patellofemoral restraint complex (LPFRC) have been described, but evidence remains heterogeneous. To characterize surgical techniques for LPFRC reconstruction and summarize associated clinical outcomes. Systematic review; Level of evidence, 4. A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)-compliant systematic review of MEDLINE, EMBASE, Scopus, and Web of Science was conducted from database inception through January 11, 2026, for studies describing surgical reconstruction of the LPFRC for medial patellar instability. Two reviewers independently extracted data on operative characteristics, rehabilitation, and clinical outcomes; the methodological quality was assessed using the MINORS (Methodological Index for Non-Randomized Studies) checklist. Findings were synthesized descriptively without meta-analysis due to heterogeneity in techniques and reporting. Twenty studies were included: 6 case series, 5 case reports, and 9 technical notes. Iatrogenic instability after prior lateral-sided surgery occurred in 15 studies (75%). Fourteen studies described anatomic ligament reconstruction, 5 pedicled soft-tissue reconstruction, and 3 retinacular imbrication or sling procedures (not mutually exclusive). MINORS scores among 6 eligible noncomparative studies ranged from 6 to 11 of 16 (mean, 8.8). Clinical outcomes were reported in 10 studies, with follow-up ranging from 12 to 99 months. Six studies reported numeric pre- and postoperative scores: the Knee injury and Osteoarthritis Outcome Score improved from 34.4 to 69.5 points ( P < .0001), the Lysholm score from 45.6 to 71.9 points ( P < .001), and, in another cohort, the Lysholm score improved from 36.4 to 86.1 while the visual analog scale-pain score decreased from 7.6 to 1.9 ( P < .001). Across the outcome-bearing studies, 7 recurrent instability events were reported, concentrated in 2 studies. Complication reporting was sparse and inconsistent. LPFRC reconstruction is described using technically diverse, predominantly low-level, noncomparative evidence. Although individual studies reported postoperative improvements, small cohort sizes, inconsistent reporting of outcomes, and methodological limitations preclude comparisons between techniques or definitive conclusions about efficacy. Prospective comparative studies with standardized outcome reporting are needed.