Etiological factors in the pathogenesis of femoral trabecular fatigue fractures.

Detailed histological evaluation of 72 femoral heads in terms of bone density, cartilagenous integrity and number of stress fractures in 3 different clinical groups of patients suggest that femoral trabecular fatigue fractures are largely determined by the degree of osteoporosis in all clinical states. The state of the hyaline cartilage also contibutes to the development of these fractures but only when the cartilage is degenerated to a severe degree as seen in rheumatoid arthritis. Both bone density and cartilage viability may be determining factors in the pathogenesis of trabecular stress fractures in rheumatoid hips.