Porous-coated femoral components in a canine model for revision arthroplasty.

UNLABELLED

Six dogs had a total hip arthroplasty during which the femoral component was coated with methacrylate and inserted in the femoral canal, after the canal had been reamed to a larger diameter than that of the femoral stem (including the coating). Thus, the implant was loose and motion was present between it and the femur in each animal. Five dogs had a revision to a prosthesis with a porous polysulfone-coated stem. This prosthesis was not cemented in place. One dog was killed before the revision for the purpose of histological examination. Although bone was present in the porous surface of all five stems at the revision, the amount was scant in three.

CLINICAL RELEVANCE

A model is described for the study of cemented hip-replacement prostheses that have failed. Although variable amounts of ingrowth of bone were observed after the revision to the porous-coated prostheses without bone cement, further study is needed to determine whether adequate ingrowth of bone occurs in this model.