Endoprostheses in the Treatment of Femoral Neck Fractures

Abstract

Summary Primary treatment of an acute femoral neck fracture should be by a method that gives the lowest morbidity and mortality yet produces a good result in the majority of cases. This method would seem to be closed stable reduction and, if it fails, eventually open reduction followed by adequate internal fixation. Certain types of fractures are exceptions in which primary femoral head replacement seems to be the treatment of choice. Other indications for femoral head replacement are the complications of femoral neck fractures, that is, avascular necrosis with late segmental collapse and nonunion when significantly symptomatic. The use of scintimetry in the early recognition and evaluation of these complications certainly will play an increasing role as more experience is gained with its use. When deciding upon a femoral head replacement, the surgeon must always keep in mind the multiple associated complications that can occur at the time of surgery or later in the postoperative period. Deep infection is one of the most serious. If recognized early, it may be controlled by adequate antibiotic and surgical treatment, avoiding femoral head replacement. Nevertheless the long term results tend to be poorer than in uninfected cases. Irreparable damage is done to soft tissues and bone by delay or failure to recognize and fully diagnose the infection and resulting postponement of proper corrective treatment. Many such cases, however, may be salvaged later by adequate antibiotic therapy and further surgical revision, including the use of cemented total hip replacement in selected cases. As a general rule, the more elaborate the reconstructive procedure selected, the better the functional result will be but the greater the risk of recurrence or continuation of the infection. The efficacy of cementing the femoral head prosthesis with methyl-methacrylate is under current study. A smooth stemmed prosthesis should be used and placed in an acetabulum that has normal articular cartilage. Loosening and migration of the femoral stem are significantly reduced by cementing, although an increase in the erosion of the acetabular cartilage seems to occur. Total hip replacement in acute femoral neck fractures should be limited to cases in which the acetabulum is diseased or in which there is cartilage damage. The best long term results in the treatment of acute femoral neck fractures seem still to lie in the method that yields healing of the fracture with the patient's own viable femoral head.