Prosthetic replacement in the management of unstable femoral neck fractures in the elderly. Analysis of the mechanical complications noted in 778 fractures.

From 1987 to 1996, 778 unstable fractures of the femoral neck Garden type III or IV in 736 patients over 70 years of age have been treated surgically. Based on age and functional preinjury status, 477 patients were treated with a hemiarthroplasty; a total hip prosthesis was implanted in another 301 patients. The overall mortality rate at one year was 20%. Of the 472 surviving patients pre-operatively classified as "independent", 68% regained an independent active level; in the remaining 32%, the femoral neck fracture caused an important additional impairment. One also has to admit that the complications after prosthetic replacement are not harmless: dislocation (2%) requiring an early revision arthroplasty in about half of the cases; deep infection (< 1%) leading to a Girdlestone situation and sometimes even to death. It is generally accepted that, if prosthetic surgery is chosen, the best implant for this category of patients is a bipolar system. Despite good functional results observed after total hip arthroplasty for fractures, we recommend this technique only in selected cases. The risk for prosthetic loosening is also much higher after replacement for fracture than after replacement for osteoarthritis (at least 14% within 5 years). Nevertheless, we prefer a total prosthesis implant in patients with a good life expectancy and good functional condition, aged between 70 and 80 years, presenting a severely displaced unstable fracture.