Abstract

Objectives: Medial patellofemoral ligament reconstruction (MPFLR) is a common procedure to treat recurrent patellofemoral instability, typically in a younger, active patient population. While many patients treated with MPFLR fall into this age group, patellar instability is encountered in older patients as well. Outcomes in older patient populations have been less frequently reported in the literature. We hypothesize that patients over 30 at the time of surgery will have poorer postoperative patient reported outcome measures (PROMs) following MPFLR than patients under age 30. Methods: Retrospective review was undertaken to identify patients who underwent isolated MPFLR between 2008 and 2020. Chart review was utilized to obtain patient demographic, anatomical, and surgical factors. Patients were contacted via mail and/or phone and patient-reported outcomes were recorded. PROMs included the knee injury and osteoarthritis injury outcome score (KOOS), Norwich patellar instability score, and Marx activity score. Differences between groups were evaluated by Mann-Whitney and Fisher-exact tests. KOOS and Norwich scores were also evaluated using a multivariable linear regression adjusting for the following variables selected a priori: sex, body mass index, Caton-Deschamps index, TT-TG distance, sulcus angle, and the presence or absence of ≥ Grade 2 cartilage damage. Results: A total of 228 patients underwent isolated MPFL reconstruction in the study period. 177 patients (78%) had data on repeat patellar dislocations at least 1 year postoperatively, with a median follow-up interval of 40.8 months (3.4 years) postoperative. Of these 177, 140 were under age 30 at time of surgery, 7 (5%) of whom had a repeat dislocation; of 37 patients at or over age 30 at time of surgery, 2 (6.6%) had a repeat dislocation. 147 patients further completed KOOS, Norwich, and Marx activity score surveys with a median follow-up of 45.3 months (3.8 years) post-operative. Patients ≥ 30 years old at surgery (n=31) had lower KOOS pain (82.1 vs 91.7; p=0.03), KOOS activities of daily living (94.1 vs 97.1; p=0.04), and Marx activity scores (1 vs 7; p<0.001) compared to the patients under age 30 (n=116) (Table 1). After adjusting for covariates, multivariable regression models for KOOS and Norwich scores showed only KOOS pain subscores were lower for patients ≥ 30 years (β= -4.2; 95% CI -8.3, -0.2; p=0.04). Conclusions: Patients over age 30 at the time of MPFLR demonstrated similar recurrence risk but lower KOOS pain and Marx activity scores at 3.8 years postoperative than patients under age 30 at the time of MPFLR. [Figure: see text]