Bone Abstracts

Objective: We aim to investigate gender similarities and differences in femoral neck (FN) structure of elderly population by bone investigational tookit (BIT) of quantitative computed tomography (QCT).

Material and methods: This cross-sectional study was part of China Action on Spine and Hip Status study, including 207 males aged 55–87 years and 400 females aged 55–96 years. QCT scans were performed in the hip for the subjects, and we used BIT software which directed automatically the lowest area of FN cross-section perpendicular to FN axis to measure cortical and trabecular bone in anatomic quadrants of FN. The measurements of cortical thickness (Cor.T), cortiacal vBMD (Cor.vBMD), trabecular vBMD (Tra.vBMD) and integral vBMD (Int.vBMD) at the FN were determined in BIT sectors. This resulted in four anatomical quadrants, Quadrant 1(Supero-anterior, SA), Quadrant 2 (Infero-anterior, IA), Quadrant 3 (Infero-posterior, IP), Quadrant 4 (Supero-posterior, SP). The study was approved by the ethics committee of Beijing Jishuitan Hospital.

Results: The greatest difference between genders after adjustment was in Cor.T of Quadrant SA, 27.3% lower in women (P=0.000). The differences in Cor.T of Quadrant IA and IP did not get statistical significance. There was no gender-related difference in Int.vBMD of Quadrant IA, IP and SP. However it was detected that elderly men had a higher vBMD in the trabecular bone compartment in same regions. With aging, Cor.T of superior FN declined significantly in both sexes, in contrast Cor.T of inferior region maintained in men different from that in women.

Conclusions: Our results indicate that women have thinner Cor.T in superior quadrants. With aging, Cor.T of cross-sectional FN declines significantly in women, in contrast Cor.T of Inferior region maintains in men.