Background: Surgeons performing revision arthroplasties of the hip
and knee are confronted with a growing number of patients with extensive loss
of bone stock. Implantation of a total femur prosthesis is a possible method
of treatment of such patients. The purpose of this study was to assess the
functional outcomes and the complications associated with total femur
replacements used in revision arthroplasty.
Methods: We evaluated the results associated with 100 total femur
prostheses that had been implanted during revision arthroplasty in 100
consecutive patients without infection. The mean duration of follow-up was
five years. The prosthesis was implanted because of a complication of a total
hip replacement in seventy-seven patients, because of a complication of a
total knee replacement in four, and because of a complication affecting the
diaphysis of the femur in nineteen. Thirty-nine patients had sustained a
periprosthetic fracture, usually in combination with loosening of the
prosthesis, before the revision. The radiographs made at the time of the
latest follow-up were evaluated for signs of loosening and material failure.
The preoperative and postoperative function of the hip and knee was assessed
according to the Enneking score. Five patients were lost to follow-up.
Results: Sixty-five patients (68%) had no complications. Deep
infection was found in twelve patients (13%); dislocation, in six (6%);
material failure, in three (3%); patellar problems, in two (2%); and peroneal
nerve palsy, in one (1%). The mean preoperative Enneking score for hip
function was 1.25 points, and it improved to 3.29 points postoperatively. The
mean Enneking score for knee function was 2.09 points preoperatively and 3.29
Conclusions: We believe that the total femur prosthesis is a useful
implant for patients with extensive bone loss at revision arthroplasty. While
the infection rate was high, the overall functional results for both the hip
and the knee were rated as better than good with the Enneking
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.