Nonunion of the femoral neck: possibilities and limitations of the various treatment modalities.
Nowadays in cases of nonunions of the femoral neck, the surgeon is tempted to perform prosthetic replacement of the hip, more so if there is also evidence of avascular necrosis of the head of femur. This provides rapid pain relief and allows early mobilization. However, long-term results of hip arthroplasties, especially in younger people and in the presence of osteopenia, are not always as expected; and a less radical approach is worth considering. The intertrochanteric valgization osteotomy, described by Pauwels, is an excellent alternative for healthy patients up to 65 years of age with a nonunion of the femoral neck. A union rate of 80-90% of the nonunion is described by most authors. Leg length inequality, rotational and angular deformities can be corrected at the same time. During the period 1973-1995, we performed valgization osteotomy according to Pauwels in 66 patients of, 18-72 years old (mean 49.5 years). 24 (37%) of our patients died 4 months to 24 years (mean: 9.5 years) after the operation. Union of the femoral neck was achieved in 58 (88%) of the 66 patients; union of the osteotomy in 65 patients (99%). A good or excellent result was achieved in 62% (23 uneventful and 13 with healed, necrosis/arthrosis without need for further treatment) of our patients. However, the method has its limits. We feel if there is too little bone stock inside the femoral head, a valgization osteotomy does not give good result. The radiographic signs of avascular necrosis in patients over 30 years of age is considered a contraindication for an osteotomy. However our results show that it is worthwhile trying to save the joint of young patients even in case of a segmental collapse. In the race between revascularization and collapse, often revascularization is the winner. We deliberately give nature its chance and don't rely on the result of bleeding from drill holes in the head, nuclear scans and other methods to estimate vascularity. A secondary total hip replacement if necessary because of avascular necrosis or osteoarthritis is considerably postponed; and better milieu for hip replacement can be achieved by the development of sclerotic bone in the subchondral areas of the acetabulum and femoral head. Between 65 and 80 years of age, a total hip replacement is probably the best option for fit patients. We treat fresh femoral neck fractures with a hemiarthroplasty in patients over the biological age of 80 years. Logically the same choice will be made for patients with a nonunion. During the period 1973-1995 we performed hemiarthroplasty (n = 34) in patient with low general condition. Their mean age was 79 years. The average survival in these patients was less than three years and that explains probably the low late complication rate: in this group. Total hip replacement was performed in 37 younger patients with a mean age of 69 years. They were not considered for a valgization osteotomy because of age being over 70 years, severe osteoporosis or a total collapse of the femoral head. In this group, we observed one aseptic cup revision and two extractions of the prosthesis because of a deep infection.
Raaymakers
Ernst L F B
EL
Orthopaedic Department of the Academical Medical Centre, Amsterdam, Netherlands. fam.raaymakers@planet.nl
Marti
René K
RK