Clinical Observation of Diminished Bone Quality and Quantity through Longitudinal HR-pQCT-derived Remodeling and Mechanoregulation

ABSTRACT Current clinical methods used to evaluate bone quality and quantity are insufficient for clinical evaluation of microstructural bone health, which is relevant in early diagnosis of bone disease. High resolution peripheral quantitative computed tomography (HR-pQCT) has recently emerged as a potential clinical tool for quantifying volumetric bone mineral density and microarchitecture. When combined with a longitudinal imaging protocol and finite element analysis, HR-pQCT can be used to assess bone remodeling and mechanoregulation at the tissue level. Herein, 25 patients with a contralateral distal radius fracture were imaged with HR-pQCT at baseline and 9-12 months follow-up: 16 patients were prescribed Calcium and/or Vitamin D supplement with indication of diminishing (n=9) or poor (n=7) bone quantity and 9 were not. To evaluate the sensitivity of this imaging protocol to microstructural changes, HR-pQCT images were registered for quantification of bone remodeling and image-based micro-finite element (micro-FE) analysis was then used to predict local bone strains and derive rules for bone mechanoregulation. Remodeling was predicted by both trabecular and cortical thickness and bone mineral density (R 2 >0.8), whereas mechanoregulation was affected by dominance of the arm and group classification (p<0.05). Overall, longitudinal HR-pQCT proved value in long-term patient evaluation and management of bone health.