Poster 359: Anorexia Nervosa and Bulimia Nervosa Diagnoses Are Associated with Increased Risk of Lower Extremity Soft Tissue Injury and Orthopaedic Surgery Requirements

OBJECTIVES: An abundance of literature exists demonstrating the link between eating disorders and fracture risk. However, no studies to our knowledge have investigated the impact of an eating disorder diagnosis on risk for ligamentous injury or the need subsequent orthopedic surgery. The aim of this study was therefore to elucidate this link and determine if pre-existing eating disorder diagnoses are associated with increased incidence of lower extremity connective tissue-related orthopaedic injuries and surgeries. We hypothesized that eating disorders, specifically anorexia nervosa and bulimia nervosa, lead to an increased risk of ligamentous injuries and need for surgery on injured ligaments. METHODS: Patients with a diagnosis of anorexia nervosa or bulimia nervosa were identified using International Classification of Diseases (ICD) -9 and -10 codes using the PearlDiver Mariner insurance claims data set. These patients were matched by age, gender, Charlson Comorbidity Index, record dates, and geographical region to respective control groups without anorexia nervosa or bulimia nervosa. Instances of ligamentous injuries were identified through ICD-9 and ICD-10 codes within the time period of 2010-2020 available within the Mariner dataset. Instances of ligamentous orthopaedic surgery procedures in these patients were identified through Current Procedural Terminology (CPT) codes. Rates of ligamentous injury and orthopaedic surgery among experimental and control cohorts were analyzed using chi-squared analysis. RESULTS: The anorexia nervosa cohort and its matched control group contained a total of 2,475 patients each. Patients with a diagnosis of anorexia nervosa were significantly more likely to sustain a meniscus tear (RR=1.57, p=0.001) or deltoid ligament sprain (RR=1.83, p=0.025), and to undergo anterior cruciate ligament (ACL) reconstruction (RR=2.83, p=0.037). They were less likely to sustain a tibiofibular ligament sprain (RR=0.64, p=0.012). The bulimia nervosa cohort and its matched control group contained a total of 2,375 patients each. Patients with a diagnosis of bulimia nervosa were significantly more likely to sustain a meniscus tear (RR=1.98, p <0.001), medial collateral ligament (MCL) sprain (RR=3.07, p<0.001), any cruciate ligament tear (RR=2.14, p=0.004), unspecified ankle sprain (RR=1.56, p<0.001), and any ankle ligament sprain (RR=1.27, p=0.008), and to undergo partial meniscectomy (RR=1.80, p=0.002). CONCLUSIONS: Diagnosis of an eating disorder is associated with an increased risk of certain ankle and knee ligamentous injuries and surgeries. Orthopaedic surgeons should be aware of the effects these disorders have on soft tissue injury and surgery rates. Furthermore, patients presenting to orthopaedic surgery clinics should be informed of increased risks associated with their eating disorder diagnoses and provided with information on resources promoting recovery to help prevent further injury.