Reduction and osteosynthesis of subcapital fractures of the femoral neck: possible repercussions on post-fracture hemarthrosis of the hip.

Intracapsular hip pressure was measured in undisplace or less displaced subcapital fractures of the femoral neck before and after open reduction and internal fixation with three-flanged nails. After reduction and osteosynthesis, intracapsular pressure increased in three out of five cases. The result is discussed in relation to the possible role of intracapsular pressure sustained by hemarthrosis in the pathogenesis of post-traumatic vascularity of the femoral head.