ALLOGRAFT RECONSTRUCTION FOR MALIGNANT BONE TUMORS IN THE GROWING CHILD

Abstract

Allograft reconstruction of large defects after resection of malignant tumors is one option besides use of artificial and other biologic material. Allografts allow for a 1:1 reconstruction of the defect, while endoprosthetic reconstruction for its anchorage usually needs resection of more bone or joint structures and thus more loss of growth plates. Tibial allografts used in adults according to the literature and our own experience has been rather diasappointng – while in our experience in children they seem to function better.

Patients and Methods: In 6 children with open growth plates 8 reconstructions with massive fresh frozen cry-preserved allografts have been performed. Age at surgery was 7, 8 (2 children), 9, 11 and 13 years. 4 osteoarticular reconstructions were performed (1 distal tibia, 2 proximal tibia), the others were proximal tibia epiphysis sparing reconstructions after transepiphysial proximal tbia resections.

Results: All reconstructions between the recipient and allograft fused, except in one patient developing pseud-arthrosis at diaphysial level after irradiation. The joint function in 2 patients with osteoarticular allografts is excellent at 10 and 6 years f/u. One patient with an osteoarticular allograft died after 2 years from metastases, one needed replacement of the allograft because of a fracture at 4 years and at 6 y f/u of the second allograft is scheduled for resurfacing of the knee joint because of cartilage degeneration. In 4 transepiphyseal resectio-nas and reconstructions the joint fuction continues to be excellent at 1 to 5 year f/u

Conclusion: Allograft reconstructions of the tibia in growing children may have better results than in adults. This may be due to better incorporation. They may allow for partial or complete joint sparing and the growth plate of the joint partner . Good results definitely depend on the appropriate indication, choice of allograft and surgical Technique.