An Association of Extent of Osteonecrosis of Femoral Head by Kerboul Angle with Functional Status: A Cross-Sectional Study

Background: Osteonecrosis of the femoral head (ONFH) is a debilitating condition that can lead to severe functional impairment. The Kerboul angle, measured on magnetic resonance imaging (MRI), has been used to assess the extent of necrosis in ONFH. However, the relationship between the Kerboul angle and functional status remains unclear. Objectives: This study aimed to evaluate the extent of ONFH using the Kerboul angle and investigate its correlation with functional status, as assessed by the Harris Hip Score (HHS). Methods: A cross-sectional study was conducted among 140 adult patients with ONFH. The Kerboul angle was measured on MRI, and functional status was assessed using the HHS. The correlation between the Kerboul angle and HHS was analyzed using Pearson’s correlation test. Results: The mean age of the study subjects was 41.57±15.76 years, with a male predominance (70.7%). The mean duration of pain was 9.52±6.94 months. The mean HHS was 64.49±15.38, with 61.43% of subjects having a poor score (<70). The mean Kerboul angle was 177.28±47.88. A highly significant negative correlation (r=-0.647, p<0.01) was observed between the Kerboul angle and HHS. Conclusion: This study demonstrates a significant negative correlation between the extent of necrosis, as measured by the Kerboul angle, and functional status in patients with ONFH. The findings suggest that the Kerboul angle could be a valuable tool for predicting functional outcomes in ONFH and highlight the importance of early diagnosis and intervention.