Role of MRI in staging of avascular necrosis of the hip: A study of 50 cases

Open Access

Abstract

Background: Avascular necrosis (AVN) of the hip causes osteocyte death through a loss of blood supply, and leaves the femoral head at risk of collapse. Staging is crucial for prognosis and treatment, which can include core decompression, osteotomy or arthroplasty. MRI is highly sensitive in early AVN, but is not commonly used. Aim of the study: The purpose of the study was to assess the utility of MRI in staging AVN of the hip by comparing the MRI findings with Ficat and Arlet staging system and calculating the sensitivity and specificity of its diagnosis. Methods & Materials: This was a prospective cohort study, performed in the Department of Radiology & Imaging of Combined Military Hospital at Cumilla, between December 2024 to December 2025. A purposive sample of 50 patients with a clinical suspicion of hip AVN was included. The subjects had non-contrast MRI of the hip done on a 1.5 Tesla machine. SPSS version 23.0 was used for statistical analysis. Results: MRI successfully staged all 50 cases: Stage I (n=9, 18.0%), Stage II (n=19, 38.0%), Stage III (n=15, 30.0%), and Stage IV (n=7, 14.0%). Hip AVN was staged as stages I and II demonstrated marrow edema and the double-line sign, and stages III and IV showed femoral head collapse and joint effusion. The inter-observer agreement was excellent (κ=0.91). Conclusion: MRI is a reliable and accurate imaging modality for staging hip AVN and is well tolerated by patients. It should be considered an essential component of pre-therapeutic assessment, providing critical information for staging-guided surgical planning.