OBJECTIVE. The objective of our study was to compare subtrochanteric femur bone mineral density (BMD) and bone quality of long-term bisphosphonate (BP) users who sustained an atypical femoral fracture (AFF) with BP users who did not sustain a femoral fracture and BP-nave patients with no history of femoral fracture using quantitative CT (QCT). MATERIALS AND METHODS. Fourteen female BP users with an AFF (mean age, 72.6 years; mean duration of BP use, 6.2 years; mean body mass index, 21.9) who had undergone QCT before fracture events were sex-, age-, BP use duration-, and body mass index-matched to 14 BP users who did not sustain a fracture and 14 BP-naive patients. The lateral cortical thickness index (CTI) and the mean BMD (BMDmean) and SD of the BMD (BMDSD) within the lateral cortex and within the entire cross-sectional area of the subtrochanteric femur were measured on axial QCT. Femoral neck-shaft angles were measured on the QCT scout image. Parameters were analyzed using the Kruskal-Wallis test. RESULTS. Lateral CTIs were greater in the BP users with an AFF (median, 0.28) than in the BP users without a femoral fracture (median, 0.21) (p = 0.038) and the BP-naive group (median, 0.21) (p = 0.009). The lateral cortex BMDSD was significantly higher in the BP users with an AFF (median, 59.59 mg/cm3) than the BP users without a femoral fracture (median, 39.27 mg/cm3; p = 0.049) and the BP-naive group (median, 31.02 mg/cm3; p = 0.037). There was no significant difference among groups in lateral cortex BMDmean, BMDmean and BMDSD of the entire cross-sectional area, and femoral neck-shaft angle. CONCLUSION. Long-term BP users with a subsequent AFF had a thicker lateral cortex and higher lateral cortex BMDSD at the subtrochanteric area before the fracture on QCT than BP users who did not sustain a femoral fracture and BP-naive patients.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation (grant no. MSIP 2015R1A2A1A05001887), which is funded by the Ministry of Science, ICT and Future Planning of the Republic of Korea.
All Science Journal Classification (ASJC) codes
- Radiology Nuclear Medicine and imaging