Coxarthrosis and femoral neck fracture.

A retrospective cross-sectional study of the roentgenograms of 300 hip fracture patients and 300 age- and gender-matched controls was performed to determine the relationship between fracture type, femoral neck trabecular bone integrity (as measured by the Singh index), osteoarthrosis, and age. Coxarthrosis was associated with a low incidence of intracapsular fracture but unchanged rates of extracapsular fracture. Singh grade declined with age in all groups of patients, although the rate of decline was reduced in control female patients with coxarthrosis compared with other diagnostic groups. When the coxarthrosis patients were included, the mean Singh grade for the female fracture patients was significantly reduced in patients compared with controls with or without age adjustment (3.88 versus 4.17). When patients with coxarthrosis were excluded from the analysis, this effect disappeared. It is suggested that the differences in Singh grades observed previously between femoral fracture patients and controls may have resulted from an undetected negative association between coxarthrosis and retention of trabecular integrity with aging.