Upper limb bone health: Cadaveric, imaging and clinical studies with special emphasis on peripheral quantitative computed tomography

Introduction. Osteoporotic fractures are a major health care problem. A radial fracture is an important risk factor for osteoporosis that should initiate the assessment of bone health.

Purpose. (1) To validate pQCT measures of bone in aged cadaveric radii. (2) To examine side-side differences in radial bone variables after disuse. (3) To test a novel intervention for secondary prevention of osteoporosis after an index radial fracture.

Methods. Study Design: Part I: Parts IA and IB are descriptive cadaveric studies. Part 2: Cross-sectional observational studies of bone response to disuse; Part 3: Part 3A is a 6-month intervention of secondary prevention of osteoporosis following a fragility fracture. Part 3B uses a questionnaire to ascertain barriers to investigation after fracture.

Participants. Part I: Cadaveric specimens from women (73 to 88 years) for Parts IA and IB. Part 2A: Women (52-87 years) who sustained a distal radius fracture and Part 2B: Women and men (52 to 79 years) who had suffered a stroke. Part 3A : Women and men (50-90 years) with a fragility fracture; and Part 3B: Physicians in British Columbia.

Results. Part I: With different pQCT acquisition-analysis protocols, total bone area varied by 3-34%; cortical area varied by 3-30% and total content by 6-45% from a criterion standard. Total bone content of the distal radius explained between 74 and 81% of bone strength, Part 2: There was a significant decrease in bone strength in participants who had upper limb disuse because of stroke or fracture. Part 3: A patient and physician intervention improved bone health investigation rate by a factor of 3.1 times (RR) after fragility fracture. BC doctors reported few barriers to investigating osteoporosis.

Summary. Peripheral QCT acquisition and analysis protocols significantly influenced outcome variables. Patients do not have "normal" bone strength after fracture or stroke. In particular, there is an increased risk for non-dominant radial fractures to have lower bone strength and be associated with poorer limb function, compared with a dominant radial fracture. Physicians report no barriers to investigation after a fragility radial fracture and a systematic intervention may best address secondary prevention of osteoporosis.