Calcaneal Bone Morphology in Association with Bone Mineral Density Status: A Cadaveric Study

Category: Basic Sciences/Biologics; Ankle; Other Introduction/Purpose: Displaced intra-articular calcaneal fractures are mostly treated by reduction and internal fixation. The calcaneal cortical thickness and regional bone density play an important role in the stability of the fixation construct. This study aims to assess the relationship between calcaneal bone morphology and bone mineral density (BMD) status. Methods: Seventeen fresh cadaveric specimens underwent a BMD scan at the femoral neck and were later classified according to WHO criteria into three groups, including normal five specimens, osteopenic six specimens, and osteoporotic groups six specimens. The calcaneus bone of each specimen was then dissected and evaluated for the bone morphology. The sustentaculum tali of the calcaneus was divided into anterior, middle, and posterior segment. The superior, inferior, and posterior cortices of the calcaneus were equally divided from medial to lateral into five segments and from anterior to posterior into three segments (Figure 1). The cortical thickness (mm) was measured at the center of each divided fragment. The calcaneal bone density (g/cm 3 ) was quantified at three regions of interest (ROI), including superior, inferior, and posterior ROI (Figure 2). Results: The calcaneal cortical thickness and calcaneal bone density of each fragment or each ROI were demonstrated as the median and interquartile range (IQR) (Table 1-5, Figure 3). The overall cortical thickness and calcaneal bone density values were significantly lower in the osteopenic or osteoporotic group when compared with the normal BMD group. Notably, the cortical thickness of the normal group at the lateral one-fifth and/or lateral two-fifth fragment of the superior, posterior, and inferior cortices of the calcaneus were not significantly different when compared with the osteopenic or osteoporotic group. When focusing at the sustenaculum tali, the posterior cortical thickness was significantly different only when compared between the normal and osteoporotic groups. Inter and intra-rater reliability of the outcome measurements were all excellent (>0.80). Conclusion: The cortical thickness of the posterior aspect of the sustenaculum tali, as well as the cortical thickness of the lateral one-fifth and lateral two-fifth of the calcaneus, were less likely effected by the decrease in BMD status. However, the anterior part of sustenaculum tali, anteromedial area of superior and inferior cortex and inferomedial area of posterior cortex are thicker than others.