Premature failure is the main complication of a hip joint resurfacing procedure. Loosening of the implant and fracture of the femoral neck are the two most common causes of early failure.
A recent study by orthopedic surgeons using the hip resurfacing technique may help us understand what's going on. It seems that the round head of the femur that fits into the hip socket doesn't have a very good blood supply normally.
Hip resurfacing requires the surgeon to dislocate the hip joint. Then the head of the femur is smoothed with a tool called a cylindrical reamer. The reamer prepares the femoral head for a smooth metal cap that is fit over the bone.
During this process of dislocation, preparation, and reaming of the femoral head, the blood supply to the head is decreased by as much as 70 per cent. This loss of blood flow is a major risk factor for loosening of the implant or fracture of the bone.
Although it's not common, enough cases have been reported to bring this to the attention of orthopedic surgeons using this technique. Future studies will help surgeons identify ways to prevent this from happening.