Altered bone geometry of the radius and tibia among stroke survivors

Stroke is a major cause of disability, with muscle weakness, balance deficits, spasticity, and sensory loss being some of the most common physical impairments observed in stroke survivors. The skeleton also undergoes considerable change after stroke, which includes secondary bone loss. This not only leads to changes in bone mineral density but also causes substantial alterations in long bone cross-sectional geometry. Bone geometry is an important determinant of bone strength and fracture risk. It is thus highly relevant to study bone geometry among individuals living with stroke, as this population has a much higher risk of fragility fractures than age-matched reference populations. Peripheral quantitative computed tomography (pQCT), a relatively new bone imaging technology, enables researchers to evaluate bone geometric properties at different skeletal sites. Recent pQCT studies of chronic stroke patients revealed that both the radius and tibia on the hemiparetic side had significantly altered geometric properties, which resulted in lower estimated bone strength than on the unaffected side. These studies also showed that muscle strength, degree of functional recovery, and severity of spasticity were closely associated with long bone geometry. Further research is required to determine the temporal changes in geometric properties at different skeletal sites and their determinants among stroke survivors. Such information is essential for developing effective intervention strategies that enhance bone geometry, and hence reduce fracture risk in this vulnerable population.