4.P.06 ALLOGRAFT-PROSTHESIS COMPOSITE RECONSTRUCTION AFTER INTRA-ARTICULAR PROXIMAL TIBIA RESECTION FOR BONE TUMORS

Proximal tibia reconstruction after oncologic resection is challenging due to bone stock and extensor mechanism restoration. From 1997 to 2007 19 patients (mean age: 39±16 years old) underwent proximal tibia oncologic intra-articular resection with wide margins. Primary diagnosis included giant cell tumor, osteosarcoma, chondrosarcoma and a failed osteoarticular allograft in 10, 4, 3 and 2 patients respectively. Tibial resection length was 10.4±3.4 cm in 18 knees. In one patient with chondrosarcoma the entire tibia was resected. Three patients received preoperative and postoperative chemotherapy, one only postoperative. Reconstruction was performed with an allograft-prosthesis composite implant and direct suture of the host patellar tendon to the allograft one. Fresh frozen allograft and modular Link prosthesis were used for reconstruction. Five to six weeks of knee immobilization in extension followed the operation. A transient peroneal nerve palsy was observed in three patients. Two patients with a stiff knee underwent an open release after less than one year from index surgery. One patient had a local recurrence from osteosarcoma and underwent an above knee amputation. No patient developed distant metastasis at follow-up. After 59±37 months none of the patients had implant revision for mechanical complications. One patient had 2-stage implant revision for deep infection. A minor allograft resorption with aseptic drain was observed in one patient who underwent surgical debridement. One other patient had a moderate allograft resorption. Knee flexion was 96±12 degrees. All the patients but two could reach complete knee extension and only two had a minor extensor lag (less than 15 degrees). In conclusion intrarticular tibia resection and allograft-prosthesis composite replacement ensures satisfactory oncologic and functional results at a midterm follow-up.