Allograft-prosthetic composite reconstruction of the proximal part of the tibia. An analysis of the early results.

BACKGROUND

Allograft-prosthetic composite reconstruction of the proximal part of the tibia is one option following resection of a skeletal tumor. Previous studies with use of this technique have found a high prevalence of complications, including fracture, infection, extensor mechanism insufficiency, and loosening. To address some of these problems, we adopted certain measures, including muscle flap coverage, meticulous tendon reconstruction, rigid implant fixation, and careful rehabilitation. The goal of the present study was to evaluate the functional outcome and complications in patients undergoing allograft-prosthetic composite reconstruction of the proximal part of the tibia.

METHODS

Twelve patients who underwent allograft-prosthetic composite reconstruction of the proximal part of the tibia after tumor resection were retrospectively evaluated at a median follow-up of forty-nine months. Clinical records and radiographs were reviewed to evaluate patient outcome, healing at the allograft-host junction, function, construct survival, and complications.

RESULTS

Nine patients had no extensor lag, and three patients had 5 degrees to 15 degrees of extensor lag. The mean amount of knee flexion was 103 degrees (range, 60 degrees to 120 degrees ). The mean Musculoskeletal Tumor Society score was 24.3 (81%) of a maximum of 30. Complete bone union occurred in nine patients, and partial union occurred in three patients. At the time of writing, no secondary bone-grafting procedures had been required to achieve union, and no revision or removal of the reconstruction had been performed. Rotational or free flaps provided satisfactory wound coverage in all patients. A deep infection occurred in one patient whose allograft and prosthesis were successfully retained after treatment with surgical débridement and intravenous antibiotics.

CONCLUSIONS

After osteoarticular resection of destructive tumors of the proximal part of the tibia, an allograft-prosthetic composite reconstruction can provide consistently good functional results with an acceptably low complication rate. Technical aspects of the procedure that may favorably affect outcome include soft-tissue coverage with muscle flaps and rigid fixation with a long-stemmed implant.