ISOLATED MPFL RECONSTRUCTION VS. TIBIAL TUBERCLE OSTEOTOMY AND MEDIAL RETINACULAR PLICATION FOR RECURRENT PATELLAR INSTABILITY: A MATCHED, COHORT ANALYSIS OF CLINICAL OUTCOMES COMPARING TWO TECHNIQUES

Abstract

Background:Historically, the most commonly utilized technique to address recurrent patellofemoral instability (PFI) was a combined proximal and distal realignment, specifically the tibial tubercle osteotomy (TTO) with a proximal medial retinacular plication/reefing/tightening/repair (MRP). Rising interest in the medial patellofemoral ligament reconstruction (MPFLR) over the last decade, now frequently performed as a more powerful isolated proximal realignment procedure, has prompted debate over the optimal technique to treat this common condition.Hypothesis/Purpose:The study hypothesis was that no difference would be detected in recurrent PFI rates or revision surgery rates between patients who underwent TTO-MRP vs. MPFLR.Methods:With cohorts derived from a large, single-center PFI database of 523 patients who underwent a variety of stabilization procedures, 114 eligible MPFLR patients were matched to 109 TTO patients based on age, gender, BMI, and TT-TG distance. Propensity score matching was conducted using logistic regression models to produce 1:1 matching, and a caliper of 0.2 standard deviations of the estimated propensity score was used to for the nearest neighbor matching algorithm. Final matching procedure resulted in 84 MPFLR patients and 84 TTO patients. These were compared on demographics and post-operative clinical results.Results:Demographic and radiologic comparisons of the cohorts are shown in Table 1, with the only difference between groups being an expected higher rate of patients with open physes in the MPFLR cohort. Table 2 shows the TTO-MRP group had longer follow up times, but comparable rates of return to sports. The MPFLR group had a higher rate of recurrent instability, but not to a significant degree, and a significantly higher incidence of revision patellar stabilization surgery (p<0.001). The TTO group had a higher rate of additional knee surgery, the majority of which were implant removal for TTO screws.Conclusion:The TTO-MRP shows equivalent or superior results to the MPFLR for treatment of PFI. However, implant removal may be common with TTO, though this may be somewhat technique-dependent. In the current landscape of increasing interest and utilization of MPFLR as an all-encompassing PFI surgery, the influence of distal bony realignment to minimize recurrence should not be underappreciated.Tables/Figures: