The micro-hardness distribution in human talus bone

Abstract

Objective To explore the distribution of microhardness of human talus bone. Methods All the talus bones included in this study were collected from the Anatomy Department of Hebei Medical University, and 3 fresh frozen corpses aged above 40 years old, no chronic medical history were selected. All the right talus was taken and the soft tissue was dissected. With the base of the talus neck as the boundary, the talus was divided into the talus head-neck and the talus body using a slow-speed saw. Both the talus head-neck and talus body were bisected into the medial and lateral parts along the longitudinal axis and then the talus body was bisected into the anterior and posterior parts along the transverse axis. The bones were made into several 3 mm thick bone tissue sections and sanded with sandpaper. A microindenter fitted with a Vickers indenter point was used to measure the Vickers hardness in cortical bone and trabecular bone in different regions. The indentation load and dwell time was set to 50 g and 12 s for both the cortical and cancellous tissues in this study. For each site or region, 5 valid values were recorded and averaged as the Vickers hardness for this site or region. Results Totally, 18 bone tissue sections and 180 indentations at different bones and anatomic sites were involved in our result. The overall bone Vickers hardness of the talus bone was (36.70±5.77)HV, including (37.68±5.22) HV in the talus head-neck and (36.20±5.99) HV in the talus body. The Vickers hardness of the talus head-neck was similar to the talus body(t=1.624, P>0.05). There was no significant difference in the Vickers hardness between the medial[(38.60±5.17)HV] and lateral site[(36.76±5.19) HV] of the talus head-neck(t=1.376, P=0.174). Whereas in the talus body, the Vickers hardness in the medial site[(37.78±5.23)HV] of the talus body was higher than that of the lateral site[(34.63±6.32)HV](t=2.971, P 0.05). Conclusions This study reports for the first time the distribution of Vickers hardness of human talus bone. There was no significant difference in the Vickers hardness between the talus head-neck and talus body. The Vickers hardness in medial site of the talus body is higher than that of the lateral site, matching the high stress on the medial site of the talus body, which were eligible to physiological function of human body. Key words: Talus; Hardness tests; Vickers hardness; Microhardness; Skeleton