Surface replacement of the hip has become established as an alternative treatment to total hip replacement in the younger, active, male patient. By the very nature of preserving the femoral head and neck, there may be failures due to femoral neck fracture and femoral component loosening. Additionally, revisions of hip resurfacing for acetabular loosening may be necessary. Other scientific papers have described problems that may arise as a result of the metal-on-metal bearing either due to excess metal production or an immunologic-mediated reaction to the metal debris. Grammatopolous et al. describe poor results of revisions of surface replacements due to massive tissue destruction at the time of revision surgery, persistent pain, and swelling. In my experience with hip resurfacing, this complication is extremely rare. In my series of 925 resurfacings with a minimum of 2 year follow up, 12 revisions (1.3%) have been performed. Of these revisions, only 3 (0.3%) were for complications related to the metal-on-metal bearing; 2 for edge-loading and excess metal production, and 1 for metal hypersensitivity. None of the revision cases have had abductor destruction, or nerve/vascular involvement. Reconstruction of the joint was carried out with standard and revision components; post-operative function of these patients has been comparable to that of a primary total hip replacement. With careful monitoring of the post-operative resurfacing patient, problems can be identified early and
It has been proposed that a major advantage of surface replacement is that it is easy to revise and that the outcome of such revisions is good. This seems logical as the femoral head can easily be removed, the acetabular component can be cut out and a primary hip replacement can be inserted. Indeed a number of studies have shown good outcome following revision, particularly for femoral neck fracture. When we initially reviewed the results of our revisions we found that the operations were straight forward and the results were good provided the reasons for revision were neck fractures, loosening, infection and causes other than soft tissue reactions. When the reason for revision was soft tissue reaction, otherwise known as pseudotumour, the outcome was unsatisfactory with poor hip scores, and high rates of complications, revisions and recurrences. These were generally a manifestation of the soft tissue damage caused by the pseudotumours. We therefor recommended that early revisions should be considered with soft tissue reaction. By undertaking revisions earlier we have found that the results have improved but there are still cases with poor outcomes.
