Early results of the use of tantalum femoral cones for revision total knee arthroplasty

Background: The optimum treatment method for large femoral bone defects during revision knee replacement has not been established. The purpose of the present study was to determine the initial results associated with the use of porous tantalum metaphyseal cones for the treatment of severe femoral bone loss at the time of revision total knee arthroplasty. Methods: Porous tantalum metaphyseal cones were implanted during twenty-four revision total knee replacements. The study group included thirteen women and eleven men with a mean age of sixty-four years at the time of the procedure. The indications for the revision procedure included aseptic loosening of the femoral component (eleven patients), second-stage reimplantation for the treatment of deep infection (seven patients), severe osteolysis around a well-fixed femoral component (three patients), periprosthetic femoral fracture (two patients), and severe knee instability (one patient). Results: The patients were followed for an average of thirty-three months (range, twenty-four to fifty months). Overall, the average Knee Society clinical score improved from 55 points preoperatively to 81 points at the time of the latest follow-up. Radiographic evaluation was completed for twenty patients after a mean duration of follow-up of thirty-five months. All femoral cones appeared well fixed radiographically, with no evidence of complications related to the cone. Conclusions: At the time of short-term follow-up, the porous tantalum metaphyseal femoral cones effectively provided structural support for the femoral implants of a revision total knee arthroplasty in this series. The potential for long-term biologic fixation may provide durability for reconstructions. Long-term follow-up and comparison with alternative reconstructive techniques will be required to evaluate the true effectiveness of this implant. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.