Hip anteroposterior radiographic indices for effective osteoporosis screening in female patients undergoing total hip arthroplasty

Abstract

Osteoporosis in patients awaiting total hip arthroplasty remains undiagnosed. Although hip radiographic indices have been proposed for screening, they have not been compared. We compared the diagnostic accuracy of eight indices for osteoporosis. The canal–bone ratio measured 7 cm below the lesser trochanter may be a useful screening tool. Osteoporosis increases the risk of perioperative and postoperative fractures in patients undergoing total hip arthroplasty (THA). However, osteoporosis remains undiagnosed and untreated preoperatively. Several indices measured on hip anteroposterior radiographs have been proposed to screen for osteoporosis. Nevertheless, few studies have compared these indices, necessitating investigations to identify a practical and effective radiographic index. Osteoporosis prevalence was assessed in 317 female patients who underwent dual-energy X-ray absorptiometry before primary THA. The screening performance of eight radiographic indices was evaluated using anteroposterior hip radiographs for patients without previous diagnosis or treatment of osteoporosis: canal flare index (CFI), morphological cortical index (MCI), canal–bone ratio (CBR) at 2, 7, and 10 cm below the lesser trochanter and canal–bone area ratio (CBAR) measured at 2–7, 2–10, and 7–10 cm segments. Receiver operating characteristic analyses were performed, and the areas under the curve (AUCs) were calculated and compared among indices. Osteoporosis was identified in 129 patients (40.7%), of whom only 48 (37.2%) received treatment. The highest AUC values were observed for CBAR2–7 (0.801), CBAR7–10 (0.798), and CBR7 (0.798), followed by CBAR2–10 (0.785), CBR10 (0.766), CBR2 (0.740), CFI (0.696), and MCI (0.654). CBAR and CBR7 exhibited higher screening accuracy than other indices. The osteoporosis prevalence and treatment rates were 40.7% and 37.2%, respectively. Among the radiographic indices, CBR7 and CBARs demonstrated favorable screening performance, with CBR7 offering comparable accuracy and greater simplicity. CBR7 may serve as a practical and efficient screening tool for osteoporosis.