Influence of Psychiatric Comorbidities on Postoperative Outcomes Following Pediatric Medial Patellofemoral Ligament Reconstruction

Purpose To compare postoperative complications, rehabilitation outcomes, and health care utilization in children undergoing primary medial patellofemoral ligament reconstruction for patellofemoral instability with and without a pre‐existing mental illness. Methods The TriNetX U.S. Collaborative Network was queried to identify patients younger than 18 years old undergoing medial patellofemoral ligament reconstruction for patellar instability in the United States between 2000 and 2020. Patients were then separated into those with a pre‐existing mental illness (PMI Group) and those without (Control Group). After propensity score matching for patient demographics, chronic pain, and obesity, postoperative complication rates, rehabilitation outcomes, and health care utilization of both groups were compared across 1 year. Results After propensity score matching, each group consisted of 223 patients for a total cohort of 446 patients. The PMI Group showed significantly greater rates of postoperative knee pain (51.5% vs 41.0%, P = .004, risk ratios (RR): 1.40), opioid analgesic use (42.2% vs 31.4%, P = .018, RR: 1.34), nonopioid analgesic use (34.5% vs 22.0%, P = .006, RR: 1.27), emergency department visits (22.0% vs 4.9%, P < .001, RR: 4.46), and physical therapy treatment sessions (61.4% vs 51.1%, P = .028, RR: 1.20). Conclusions Children with pre‐existing mental illness exhibit significantly greater rates of persistent knee pain, higher opioid consumption, and increased health care utilization following medial patellofemoral ligament reconstruction. Level of Evidence Level III, retrospective comparative study.