Successful mid- to long-term outcome after reconstruction of the extensor apparatus using proximal tibia-patellar tendon composite allograft

Purpose The purpose of the study was to assess the outcomes of extensor mechanism reconstruction with proximal tibia-patellar tendon composite allograft. Methods 24 consecutive patients treated with allograft-prosthetic composite for proximal tibia tumour resection and a conventional total knee arthroplasty were included. Extensor mechanism reconstruction was performed with a proximal tibia-patellar tendon composite allograft and the suture of the donor tendon to the remnant native patellar tendon. Function was evaluated by the Musculoskeletal Tumor Society score (MSTS) and range of motion. Western Ontario and MacMaster University (WOMAC) and visual analogue scale for pain also were used. Results After a mean follow-up of 11.7 (range 3–15) years, mean MSTS score was 22.4 (range 20–30), mean flexion was 94.0° (range 84°–110°), and mean extension lag was 7.2° (range 0°–18°). The mean VAS-pain was 4.3 (range 2–6), and WOMAC score was 72.4 (range 58–100). There was no failure of the reconstructed extensor mechanism. Conclusion Patellar tendon reconstruction with allogeneic tissue from the proximal tibia allograft sutured to the recipient’s remnant patellar tendon provides the mechanical support needed for healing of the reconstructed extensor mechanism with a substantial functional benefit to stabilize active knee extension and successful reconstruction survival at long-term. Level of evidence III.