Graft Choice in Isolated Medial Patellofemoral Ligament Reconstruction: A Systematic Review With Meta-analysis of Rates of Recurrent Instability and Patient-Reported Outcomes for Autograft, Allograft, and Synthetic Options

Abstract

Purpose: To determine whether graft selection or patient age affects the following after isolated medial patellofemoral ligament (MPFL) reconstruction: (1) rates of recurrent instability, (2) rates of postoperative complications (other than instability), and (3) subjective symptom improvement.

Methods: A systematic search identified studies reporting outcomes for isolated MPFL reconstruction. Rates of recurrent instability, subjective Kujala knee function scores, and complications were tabulated. Symptom improvement was defined as change in Kujala score (preoperative evaluation to final follow-up).

Results: Forty-five studies were included with 27 documented cases of recurrent instability among 1,504 patients (1.8%); instability rates ranged from 0% to 20.0% overall; among autograft in adults, 0% to 11.1% (1.4%, 18/1,260); among autograft in adolescents, 0% to 20% (10.0%, 8/80); among allograft, 0% (0/65 cases); and among synthetic, 0% to 3.3% (1.3%, 1/76). Among autograft choices in adults, rates of recurrent instability were low; recurrence with gracilis ranged from 0% to 11.1% (0.9%, 1/116); with semitendinosus, 0% to 6.3% (0.6%, 4/676); with quad or patellar tendon, 0% (0/65); and with adductor tendon, 5.6% to 8.3% (6.7%, 2/30). Complication rates ranged from 0% to 34.4%. All included studies reported significant improvement in Kujala scores after surgery (P < .01). There was significant heterogeneity in effect size and evidence of reporting bias among small studies, precluding reliable pooled analysis of treatment effect.

Conclusions: Autograft is not superior to allograft or synthetic grafts for isolated reconstruction of the MPFL, and rates of recurrent instability are generally low. Isolated MPFL reconstruction can provide significant symptom relief regardless of graft selection, although there is a bias toward reporting better than expected results among smaller studies. Pediatric patients and patients treated with adductor tendon autograft have higher recurrent instability rates. While caution should be used in making definitive recommendations secondary to the small number of allograft and synthetic studies, selection of graft type based on surgeon preference, comfort, and prior experience remains appropriate.

Level of evidence: Level IV, systematic review of Level I to IV studies.