Measuring Whole and Tissue Level Bone Strength in men

Abstract Most patients who fracture have non-osteoporotic bone mineral density. Often, the result of a fracture is devastating and results in substantial morbidity and health care costs. One cause of fragility in these patients is poor bone quality that subsequently contributes to higher risk for fracture. Yet few techniques are available to accurately assess bone quality in the clinic. Dual energy x-ray absorptiometry (DXA) is the most used clinical surrogate for fracture risk, but DXA does not account for bone quality and thus overestimates bone health. OsteoProbe® Reference Point Indenter enables the measurement of bone quality in human patients and has been used safely on over 7,000 individuals. The OsteoProbe® quantifies bone material quality as a measure termed bone material strength index (BMSi). Measurements are made in a routine exam on the midshaft of the tibia by a safe and rapid microindentation process. A significant and predictive relationship has been demonstrated between tibial BMSi and fracture occurrence at multiple skeletal sites in published studies and in our Phase II study. Since fragility fractures occur most often at the hip, wrist, and the spine, this renewal will allow us to confirm the predictive relationship between OsteoProbe measurements at the tibia and bone strength at these clinically relevant skeletal sites on male cadavers. As in our original Phase II, we hypothesize that tibial OsteoProbe® measurements will predict bone strength at the whole bone and tissue levels at the hip, wrist, and spine for both males and females. At each of these skeletal sites, OsteoProbe measurements, BMD, and whole bone and tissue level mechanical testing will be performed. The renewal proposal aims to: (1) establish and confirm the mechanistic basis by which a clinically relevant surrogate of in vivo bone strength could be accurately measured at the hip, wrist, and spine for males; (2) develop OsteoProbe into a more manufacturable device that can be produced and supported in volume; and (3) provide pivotal data for an FDA 510(k) approval of a new, commercially attractive, and reimbursable marketing claim for OsteoProbe.