In proximal humerus reconstructions, osteoarticular massive allograft (OA) allows a biologic reattachment of tendineous structures of the host providing stability and functional recovery. Allograft-prosthesis composites (APC) are more technically demanding, but functional advantages with new prosthetic design are expected with lower fracture and failure rate with time. We compared the outcome of patients treated with OA reconstruction (group A) and patients treated with an APC (group B) after humerus resection for bone tumours.

Thirty six patients treated between 1996 and 2009 were included in the study (18 group A; 18 group B). The diagnosis was a malignant bone tumour in 28 cases, an aggressive benign bone tumour in 6 and a bone metastasis in 2. Three total humerus resections were performed (two in group A and one in group B). Three different type of prosthesis were used (conventional, reverse and resurfacing). In group A, at an average follow-up of 66 months (2-116), 16 patients were continuously disease free.

Ten patients (56%) had no complication; in 6 cases (33%) we observed a fracture of the graft and in 3 cases (17%) a pseudoarthrosis. In group B, at an average follow up of 44 months (3-164), 16 patients were continuously disease free.

Thirteen patients (72%) had no complication, in 2 cases (11%) stem loosening, in 2 cases (11%) dislocation, in 1 case pseudoarthrosis and in 1 case resorption and detachment of allograft's great tuberosity was observed. Functional outcome was evaluated using MSTS scoring system: a mean score of 24 (13-30) in group A and 23 (15-27) in group B was observed.

In our experience, proximal humerus APC showed functional results comparable to OA allograft with lower complication rate.

In conclusion, in biologic reconstruction of the proximal humerus, APC seems to provide a more reliable solution than OA allograft at long term

Modular endoprostheses are commonly used for reconstruction of proximal tibia defects after bone tumor resection and patellar tendon reattachment directly on the prosthesis represent an issue frequently ending in extension lag. Allograft-prosthesis composite implants theoretically provide the advantages of prosthetic implants (joint stability, mechanical resistance and long term durability) and the advantages of massive allograft reconstruction (bone stock mantainance and biologic reattachment of patellar tendon). 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 mid-term follow-up.