Summary

This study analyzed the comparison of time and return to sport between patients with recurrent patellofemoral instability undergoing isolated medial patellofemoral ligament reconstruction (MPFL-R) and patients undergoing MPFL-R and concomitant TTO (MPFL-TTO).

Abstract

Purpose

Significant debate exists regarding the optimal treatment of recurrent lateral patellar dislocation due to the multifactorial nature of the pathology. The purpose of this study is to compare time to return to sport between patients undergoing isolated medial patellofemoral ligament reconstruction (MPFL-R) and patients undergoing MPFL-R and concomitant TTO (MPFL-TTO) for recurrent patellofemoral instability.

Methods

A retrospective chart review of prospectively collected data was conducted to identify consecutive patients who underwent primary isolated MPFL-R or MPFL-TTO. Exclusion criteria included concomitant cruciate ligament surgery, multi-ligament surgery, failed previous surgery, and <1 year follow-up. Patient demographic information, surgical data, radiographic data, return to sport, and redislocation rates were recorded. Pre-operative and post-operative functional outcome scores (Kujala, IKDC), activity level (Pedi-FABS), and health-related quality of life (KOOS-PS, KOOS-QOL) were compared. Statistical analysis was performed using independent samples t-tests to compare the continuous variables (and Shapiro-Wilks tests confirmed the assumption of normality was met for these variables). Chi-square and Fisher’s exact tests were used for the categorical variables. Significance was set at p<0.05 for all tests.

Results

178 patients were included in the study. 119 patients (74% female) underwent isolated MPFL-R and 59 patients (85% female) underwent MPFL-TTO. Patients who underwent MPFL-R returned to sport at 9.5 ± 3.9 months and patients who underwent MPFL-TTO returned to sport at 13.0 ± 11.0 months (p = 0.011). Patients who underwent isolated MPFL-R had a significantly higher return to the same or higher level of sport compared to MPFL-TTO (85% vs 66%, p = 0.030). When comparing whether the presence of cartilage lesion affected outcomes between groups, there was no significant difference in rates of return to sport. There was a significant difference in level of return to sport between MPFL without cartilage lesion versus TTO without cartilage lesion (13%, 31%, p = 0.033) and MPFL with cartilage procedure versus TTO with cartilage procedure (15%, 47%, p = 0.002). However, testing pairs within each procedure group revealed that the statistical difference was driven by procedure type and not the presence of a cartilage lesion. Both cohorts showed significant improvement in KOOS, IKDC, and Kujala scores at 1,2, and 5-year follow-up (p<0.001), with patients undergoing isolated MPFL reporting higher scores compared to those undergoing concomitant TTO at 1 and 5 years.

Conclusion

Patients who underwent both isolated MPFL-R and MPFL-TTO had excellent return to sport rates, with isolated MPFL-R patients reporting significantly higher rates of return to the same or higher level of sport. The MPFL-R group returned to sport faster than those who had a concomitant TTO, with no difference in rates of recurrent instability. Patient reported outcomes for both groups were significantly improved at 5-years postoperatively.