Spontaneous subcapital femoral neck fracture after healed trochanteric fracture.

Two hundred thirty-three patients with an unstable trochanteric hip fracture were randomized prospectively for stabilization with a fixed angle blade plate or a compression hip screw. Twenty patients had the implant removed after the fracture was healed (average, 20.5 months; range, 12-42 months). In seven of these 20 patients, a spontaneous fracture of the femoral neck occurred at an average of 19 days after implant removal. Four of the seven patients had been treated with the fixed angle blade plate and three with the sliding screw plate. The histologic examination of three specimens was inconclusive. The authors have not observed subcapital fracture among patients whose implants were not removed. The mechanism behind this complication is unknown.