A COMPARISON OF ELDERLY PATIENTS WITH PROXIMAL FEMORAL FRACTURES AND A NORMAL ELDERLY POPULATION - A CASE CONTROL STUDY

Aim: to assess the importance of bone density and other risk factors in elderly subjects with hip fractures. Method: thirty-six subjects with femoral neck fracture were compared with 72 community controls in this case control study. Variables compared included: history of falls, previous fracture, body mass index, hand grip strength, blood pressure, medication use, cigarette smoking, alcohol intake, visual acuity, age at menopause, mental status quotient, mobility index and mid thigh circumference. Bone mineral density was measured at the hip (DPA absorptiometer) in the 36 subjects with hip fracture and 36 community controls. Results: fracture patients had significantly (p < 0.01) reduced bone mineral density at femoral neck (0.64 vs 0.74 g/cm2) and trochanteric regions (0.55 vs 0.66 g/cm2). They also had significantly (p < 0.05) lower body mass index, weaker hand grip strength, smaller mid thigh circumference, reduced mobility and more previous fractures. After controlling for age and sex stepwise logistic regression identified handgrip strength, mobility status and falls in that ranking as risk factors for fracture. Bone mineral density was correlated with mobility status and grip strength. Conclusion: patients with hip fracture have lower bone mineral density than controls. Mobility, grip strength and muscle bulk appear to be important in fracture aetiology and could operate either through bone density or risk of falling.