Cancellous screw fixation for subcapital femoral neck fractures.

Experience in treating 80 subcapital femoral neck fractures by AO/ASIF cancellous screws is reported. Immediate full-weight bearing was allowed routinely. The mean follow-up was 28 months. Non-union occurred in 2% and late segmental collapse in 12% of patients with undisplaced fractures. Non-union occurred in 16.7% and late segmental collapse in 30% of patients for displaced fractures. Regression of screws occurred in 30% of patients, all of which were detected within the first month after the operation. It was associated with a significantly higher risk of non-union and late segmental collapse for both undisplaced (P < 0.01) and displaced (P < 0.001) fractures.