Fixation of displaced femoral neck fractures with a sliding screw plate and a cancellous screw or two Olmed screws. A prospective, randomized study of 225 elderly patients with a 3-year follow-up

Abstract

Background and aims: To analyse the importance of fixation method in displaced femoral neck fractures and to identify factors predictive of failure of the fixation.

Material and methods: Two hundred and twenty-five patients were included in a prospective, randomised study and operated on for a displaced, subcapital fracture of the femoral neck with either a sliding screw plate and a parallel cancellous screw (SSP), or two Olmed screws. The median follow-up time was 39 (22-51) months, excluding reoperated and dead patients.

Results and conclusions: Operation and anaesthesia time was considerably longer for the SSP system. The risk of failure was significantly increased (odds ratio 6.6) for patients operated with SSP outside ordinary working time. Poor reduction was recognized as a risk factor of failure for both types of fixation (odds ratio 3.1). The rate of reoperation within 3 months was 18.5% in the SSP group and 9.4% in the Olmed screw group. The rates of nonunion were 6.2% and 8.5%, respectively. The rates of late segmental collapse, 18.0% and 19.5% of all united fractures, respectively, decreased with increasing age (odds ratio 0.88). Salvage operations (replacement with bipolar or total hip prosthesis) were made in 30.6% and 26.5% of the cases, and the total rates of reoperation were 37.0% and 29.1%, respectively. We conclude that both treatment methods result in an unacceptably high rate of failures and reoperations, and that alternative treatment, prosthesis replacement, should be considered in selected cases.