Variability in the classification, management, and outcome reporting for avascular necrosis of the femoral head: A systematic review.

Introduction: There is no universally-utilized classification system for avascular necrosis of the femoral head (AVNFH), a debilitating condition that arises due to impaired blood supply resulting in cortical collapse. AVNFH may require early intervention to prevent irreversible damage leading to total hip arthroplasty. The purpose of this study is to assess the variability in classification, management, and outcomes reported in randomized controlled trials (RCTs) related to AVNFH. Methods: PubMed, Embase, and Medline were queried for RCTs on the treatment of AVNFH (2010-2023). The number of patients, number of femoral heads, minimum follow-up, AVNFH classification system, treatment interventions, and outcome measures were extracted. Variability in classification, management approach, and reporting of outcomes was evaluated. Results: A total of 30 RCTs met inclusion criteria, encompassing 1891 total patients. The mean number of patients in each study was 63 (SD = 41), with a mean minimum follow-up of 30 months (SD = 17). The Association Research Circulation Osseous classification system was utilized in 63 % (n = 19) of studies, Ficat and Arlet in 20 % (n = 6) of studies, Steinberg in 10 % (n = 3), Mitchell in 3 % (n = 1), and the China-Japan Friendship Hospital classifications in 3 % (n = 1). There were 61 treatment interventions, stratified into nine categories. Radiographic imaging was most commonly used to evaluate patients at follow-up. Conclusion: There are a variety of classification systems, treatments, and outcome measures utilized in the literature to categorize and quantify AVNFH. The utilization of a universally-accepted classification system and standardized outcome reporting may help to ensure reproducibility and accuracy given a continued lack of consensus.