Intraoperative use of impact microindentation to assess distal radius bone quality

Impact microindentation is a new technique that measures the resistance of a patient's bone to micro-indentation but has not yet been implemented in an intraoperative setting. To assess the technique's safety and utility, we acquired microindentation measurements of bone material strength index (BMSi) using the OsteoProbe prior to distal radius fixation with a volar locking plate. Subsequently, the patients received a dual-energy x-ray absorptiometry scan to measure the areal bone mineral density of the proximal femur, lumbar spine, and contralateral distal radius. By assigning the patients to low-energy, fragility fracture (n = 17) and high-energy fracture (n = 11) groups based on clinical history, we investigated whether intraoperative BMSi was sensitive to osteoporosis. Impact microindentation added a maximum of 10 min of operative time and did not result in any intraoperative or postoperative complications. There were, however, no significant differences in BMSi at the radius between these two groups. This study demonstrates the feasibility of performing intraoperative impact microindentation to directly assess a patient's bone quality, but additional research is necessary to establish whether intraoperative microindentation can identify patients with inferior bone matrix quality.