BONE CONSERVING HIP REVISION OF FAILED HIP RESURFACINGS

Abstract

We present the early results of a bone conserving implant, the Thrust Plate Prosthesis (TPP) used for the revision of failed resurfacings of the hip in nine patients.

Four revisions were for fractured neck of femurs. The original implant in this fracture group was a McMinn resurfacing. The original acetabular component was retained. Five revisions were due to aseptic loosening. Four of the original implants in this group were Beuchal Pappas (BP) resurfacings and one was a Cormet2000 resurfacing.

In the fracture group the average age was 46yrs (34–70). The time from primary to revision surgery was 5.8 months (3–11). The Harris hip scores improved in all patients to their pre fracture level of 90 (83–99).

In the aseptic loosening group the average age was 62yrs (53–67). The time from primary to revision surgery was 121 months for the BP resurfacings and 19 months for the Cormet. The Harris hip scores also improved in this group to an average of 73.8 (50–100).

Hip resurfacing presents an attractive option for the younger patient. It is a bone conserving procedure with the added benefit of increased stability by using a large diameter head. Fracture of the femoral neck is a specific early complication. The usual treatment of this complication has been revision to a more traditional design, loosing the benefits of bone conservation.

The TPP is a bone preserving implant that has metaphyseal fixation of the proximal femur. It has satisfactory long term results (Huggler, 1993). The use of the TPP for revision of failed resurfacings has proved to be straight forward. Our early results are promising in the fracture group, but revision for aseptic loosening did not correlate with a high hip score. It remains to be proven that revision of a bone conserving hip replacement will maintain a high quality function. For the younger patient with a failed resurfacing, revision with a TPP can offer continued bone conservation.