Dynamic evolution of osseous structure in osteonecrosis of the femoral head and dynamic collapse risks: a preliminary CT image study

BACKGROUND: Collapse risk of osteonecrosis of the femoral head (ONFH) is estimated mainly based on static indicators, including lesion size and lesion location, but bone repairing is a dynamic process that lasts for years. The present study attempted to analyze the dynamic evolution of the osseous structure and its correlation with radiographic progression. METHODS: This retrospective study included 50 hips with ONFH from 50 patients. Participants were divided into the non-collapse group (n = 25) and the collapse group (n = 25). Original files of the initial computed tomography (CT) images were imported into imaging processing software for morphology analysis. The volume of sclerotic bone, the volume of soft tissue, and bone mineral density (BMD) were calculated. The linear correlations between the aforementioned indicators and the disease duration were estimated. The logistic regression analysis was conducted to evaluate the correlation of these indicators with the radiographic progression. Receiver operating characteristic (ROC) analysis was used to evaluate these indicators’ prediction performance. RESULTS: The volume of sclerotic bone and the BMD grew with disease duration, but the volume of soft tissue decrease. The logistic regression analysis found that the volume of sclerotic bone and the BMD were statistically associated with radiographic progression. The ROC analysis found that the regression model, which integrated the volume of sclerotic bone and the BMD, had satisfactory performance in predicting radiographic progression. CONCLUSION: The present study suggested a dynamic evolution of the osseous structure and a dynamic variation trend of the collapse risk in ONFH. The volume of sclerotic bone and the BMD might serve as further prognostic indicators when estimating the collapse risk.