Recovery of modifiable risk factors at four years following distal radius fracture and their role as predictors of bone mineral density, subsequent falls and osteoporotic fractures

Abstract

Distal radius fracture (DRF) is one of the most common fall-related osteoporotic (OP) fracture and is an early predictor of subsequent falls and OP fractures among people with DRF. The majority of older people with DRF present with low bone mineral density (BMD) and there is often transition to reduced muscle strength, poor balance, fear of falling and physically inactive lifestyle after fall-related DRF. This thesis consists of three manuscripts which are aimed to explore the recovery patterns and the role of modifiable risk factors in predicting subsequent falls, OP fractures and BMD in patients with DRF. The first manuscript explores the recovery patterns in modifiable risk factors for falls and OP fractures over four years in patients with DRF. Our study findings showed that patients with DRF experienced both short-term (6 months) and long-term (4 years) improvement in fracture specific pain/disability, physical activity, fear of falling, BMD and general health status; although the majority of the recovery was achieved at six months after DRF. The second manuscript is a cross-sectional study identifying modifiable risk factors for BMD in patients with DRF. The unaffected hand grip strength was identified as the independent predictor of BMD explaining 17% and 12% of total variability in the BMD-femoral neck and BMD-total hip, respectively. Among age-stratified women with DRF, balance and unaffected hand grip strength were identified as independent determinants of BMD explaining 10% and 32% of the total variability in BMD-femoral neck among 50-64 year and 65-80 year old, respectively. The third manuscript is a longitudinal study identifying modifiable risk factors for subsequent falls and OP fractures at four years after DRF. The results suggest that nearly 24% of patients reported one or more subsequent falls (in the last six months) and 19% of patients experienced at least one subsequent OP fracture after DRF. Patients with poor balance, low BMD, fracture specific pain/disability of >81 points on patient-rated wrist evaluation questionnaire and presence of a prior history of multiple falls (≥2) had three times higher odds of subsequent falls. When adjusted for BMD, age and gender, only prior falls was identified as a significant independent predictor of subsequent falls. We were not fully powered to explore association of various modifiable and non-modifiable risk factors with subsequent fractures. However, we found that patients with osteopenia or osteoporosis had clinically four times higher odds of subsequent OP fractures than patients with normal BMD.