Lower Mental Component Scores are Associated with Lower Return-to-Work Rates after Patellofemoral Autologous Chondrocyte Implantation

Abstract

Objectives:Autologous chondrocyte implantation (ACI) is a well established treatment for articular cartilage defects of the knee. However, few studies have examined return-to-work rates among ACI patients, and even fewer have investigated the effect of mental health on postoperative outcomes. The purpose of this study was to examine the effect of preoperative mental health on return to work and patient-reported outcomes.Methods:From our IRB-approved prospective outcomes registry, we identified 109 ACI patients (mean age = 34.5 years, mean follow-up = 2.8 years) with pre- and postoperative clinical data. Patients were stratified into those with preoperative VR-12 Mental Component Scores in the bottom quartile (LOW MCS) and in the top 3 quartiles (HIGH MCS) based on normative values. Patients with patellar and/or trochlear lesions were placed in the patellofemoral (PF) group, and all other patients were placed in the tibiofemoral (TF) group. Return to work, IKDC scores, and Lysholm scores were individually compared between the LOW MCS and HIGH MCS groups that had undergone either PF or TF ACI. Fisher’s exact tests were used to compare the return to work rates and frequency of IKDC and Lysholm improvements greater than the minimal clinically important difference. One-way ANOVAs were used to examine magnitude of change of IKDC and Lysholm scores.Results:Preoperatively, 14/55 (25.5%) TF patients and 17/54 (31.5%) PF patients were included in the LOW MCS group. For PF patients, return to work rates were significantly lower for the LOW MCS group (p=.0005). Return to work rates did not differ in the TF group (p>0.99). Changes in IKDC and Lysholm scores did not differ between the LOW MCS and HIGH MCS groups in TF or PF patients (Table 1).Conclusion:Lower preoperative mental component scores were more common in PF ACI patients and were associated with decreased return to work rates in PF ACI patients. The results of this study underscore the need to preoperatively quantify mental health status for this specific patient group in order to set realistic postoperative expectations.Table 1.Comparison of postoterative outcomes between patients with either low or high preoperative VR-12 mental component scores (MCS), separated by the location of the lesion (patellofemoral or tibiofemoral). *MCID: Minimal Clinically Important DifferencePatellofemoral ACITibiofemoral ACILOW MCSHIGH MCSPLOW MCSHIGH MCSPNumber of patients1737-1437-Return to Work (%)29.4%81.1%0.000557.1%60.9%>0.99IKDC change > MDIC (%)73.3%45.7%0.1235%43.9%0.76Mean IKDC Improvement14.1221.870.91710.135.770.35Lysholm Change > MDIC (%)81.3%62.9%0.3314.3%46.2%0.53Mean Lysholm Improvement16.71%19.060.71911.920.650.631