Evaluating the Impact of Graft Tensioning and Leg Positioning in Medial Patellofemoral Ligament Reconstruction on Patellofemoral Pressure Profile: A Systematic Review and Meta-analysis.

Abstract

To systematically review the effects of pretension on patellofemoral pressure distribution and determine which flexion angle at fixation allows for the most reliable restoration of patellofemoral kinematics and mechanics. This systematic review and meta-analysis adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and included studies from PubMed, EMBASE, and Scopus from January 2000 to July 2024. We focused on cadaveric studies measuring patellofemoral pressure after medial patellofemoral ligament (MPFL) reconstruction. Two authors extracted data independently, and the risk of bias was assessed using the Quality Appraisal for Cadaveric Studies scale. Statistical analyses used fixed- and random-effect models to compare patellofemoral pressure at various flexion angles (30°, 60°, 90°) and pretension levels (2 N, 10 N, 10+ N). Thirteen studies met the inclusion criteria, with 8 qualifying for quantitative analysis. No significant difference in patellofemoral pressure was found between native and reconstructed knees across all flexion angles and pretension levels. Increased medial patellofemoral pressure was shown in the 10+ N pretension group, particularly at 90° of flexion; however, no statistically significant differences were found. Most studies reported graft fixation at 30° of knee flexion, effectively restoring native patellofemoral mechanics. MPFL reconstruction at various angles of knee flexion and pretension levels showed no statistically significant differences in patellofemoral pressure compared to the native state. Understanding the optimal graft pretension and knee flexion angle for MPFL reconstruction can help surgeons more accurately and reliably restore native patellofemoral biomechanics and kinematics.