Thomas HodoTulane University , USA
Title: Increased likelihood of low energy knee dislocation after tka in the morbidly obese patient
Introduction: The incidence of total knee arthroplasty (TKA) and obesity in the United States continues to increase annually. Knee dislocations (KD) occur when an external mechanical force over comes the restraints of the knee. Previous studies have linked increased risk of KD due to obesity in native knees. This study aimed to identify the increased risk of elevated BMI in low energy KD after TKA in efforts to stratify risks for potential changes in management of obese patients with TKA.
Methods: Patient records from 2007-2017 were queried from an administrative claims database to investigate the rates of KD after TKA. Exclusion criteria included conditions that would lead to ligamentous laxity, fall from height and motor vehicle collisions. Dislocation rates were compared with multivariate logistic regression adjusting for age, gender and presence of diabetes or rheumatoid arthritis.
Results: Patients with >35 BMI had a significantly higher risk of KD after TKA compared to nonobese patients (BMI <30). An increased association with KD after this threshold with increasing BMI (BMI 40-50, OR: 1.55, 95% CI: 1.11-2.15; BMI >50, OR 2.5, 95% CI: 1.61-3.77).
Conclusion: Obese individuals are at a higher risk of dislocation following TKA. Patients with BMI >35 have a significantly higher risk of dislocation with up to a 2.5 greater likelihood at BMI >50. Providers should have an increased suspicion of KD in this group of patients and be readily able to assess for neurovascular compromise related to knee dislocation.
Thomas Hodo is current resident at Tulane University in New Orleans, Louisiana, USA. He received his medical education at the Medical College of Georgia at Augusta University and received training in biomedical research at Meharry Medical Colleege in Nashville, Tennessee where he focused on Cancer Immunotherapy. He will be subspecializing in Musculoskeletal Oncology but also has interest in Arthroplasty and Trauma.