Lower Extremity Injuries and Revision Surgery Rates are Increased in Patients With Anorexia Nervosa and Bulimia Nervosa Compared With Controls

Purpose To compare lower extremity soft tissue injury and revision surgery rates for patients with anorexia nervosa (AN) and bulimia nervosa (BN) compared with matched controls. Methods This retrospective cohort study used a deidentified claims database. Patients were included if they carried an International Classification of Diseases code for AN or BN. Respective matched cohorts for AN and BN were created using propensity score matching. Primary and revision surgeries for anterior cruciate ligament (ACL) reconstruction, posterior cruciate ligament reconstruction, knee collateral ligament reconstruction, meniscus repair or meniscectomy, and any ankle ligament reconstruction were identified by their CPT codes. Patients over the age of 40 and without a minimum 2‐year follow‐up after primary surgery were excluded. Differences in prevalence and revision rates were analyzed. Results A total of 56,146 patients with AN and 42,630 patients with BN were included in this study with equal numbers in respective matched cohorts. Patients with BN showed an increased risk of ACL injury (relative risk = 1.32, P = .019), medial collateral ligament injury (1.17, 0.04), calcaneofibular sprain (1.92, <0.001), deltoid sprain (1.41, 0.004), and unspecified ankle sprain (1.44, <0.001). Patients with AN showed an increased risk for calcaneofibular sprain (1.25, 0.007), deltoid sprain (1.28, 0.015), and unspecified ankle sprain (1.17, <0.001). Patients with BN were more likely to have revision ACL repair (1.89, 0.02), partial meniscus revision (3.44, <0.001) and any meniscus revision (4.74, <0.001) while patients with AN were more likely to have an ACL revision (2.81, <0.001), partial meniscus (4.37, <0.001), and any meniscus (4.52, <0.001). Conclusions In this study, patients with AN and BN had a significantly increased risk for various knee and ankle injuries and revision surgeries compared with matched controls. Additionally, patients with AN and BN who sustained these injuries were more likely to undergo a revision surgical procedure within the first 5 years of the primary procedure. Level of Evidence Level III, retrospective comparative study.