Composite indices of femoral neck strength predicts the collapse of steroid-associated osteonecrosis of the femoral head: a retrospective study

Abstract Purposes The purpose of this study was to investigate the predictive effect exerted by composite indices of femoral neck strength (compressive strength index (CSI), bending strength index (BSI) and impact strength index (ISI) on the femoral head collapse in steroid-associated ONFH patients. Methods Nonoperative steroid-associated osteonecrosis of the femoral head (ONFH) patients from 2017 to 2019 were selected. The patients fell into the collapsed group and the non-collapsed group according to whether the femoral head collapsed. CSI, BSI and ISI were calculated. Moreover, bone turnover markers were measured. The statistical analysis was conducted on the predictive effects of composite indices of femoral neck strength and bone turnover index on ONFH collapse. Results A total of 62 patients were included. The mean CSI, BSI and ISI were significantly lower in the collapsed group than those in the non-collapsed group (P