Abstract
Purpose: Massive allografts have been used in orthopaedic surgery for many years. Early results have generally been encouraging, but the risk of long-term resorption remains to be evaluated. We analysed resorption of 39 allografts implanted more than 10 years earlier.
Material and methods: Thirty-nine massive allografts implanted to sheath hip, knee or shoulder prostheses were studied a mean 13 years (range 10 – 17) after implantation. These allografts had been prepared in the same manner: preservaton at −30°C, sterilisation by 25000 Gy before implantation. A radiological scale was used to class graft resorption as minor (less than 5 mm in depth and less than 1 cm in length), moderate, or major (concerning the entire thickness of the allograft over three quarters of the circumference, irrespective of the length involved. These allografts measured more than 15 cm and were used for revision of loosened total hip arthroplasties, or reconstruction after tumour resection (tibia, femur, humerus). Among the 39 patients, 21 had received postoperative chemotherapy alone or in combination with radiotherapy.
Results: The allograft healed within the first or second postoperative year. Peripheral resorption was only observed at last follow-up. Among the 39 massive allografts assessed more than 10 years after implantation, 28 exhibited radiologically visible resorption. Among these 28, resorption was minimal for 15, moderate for nine and major for four. The first factor favouring resorption was complementary treatment, particularly local radiotherapy after carcinological resection. To a lesser degree, chemotherapy, given alone, also favoured resorption. None of the allografts implanted during a revision procedure for loosened total hip arthroplasty exhibited signs of absorption 10 years later. Two patients who had undergone resection of a chondrosarcoma with no complementary treatment exhibited only minor allograft resorption. Minor and moderate resorption was observed preferentially in the upper portions of the tibia and humerus, compromising the implant (three loosenings at more than 10 years. Peripheral resorption of the allograft appeared generally between the third and seventh postoperative year. Beyond that time, resorption did not appear to occur or increase. Evident polyethyl-ene wear observed in several patients operated on more than 10 years earlier was not associated with endosteal osteolysis of the subjacent allograft.
Discussion: Resorption of massive allografts is preferentially observed in the upper portions of the humerus and tibia, and generally occurs in patients who have undergone carcinological resection of a tumour followed by complementary treatment. Resorption is exceptional for allografts inserted during total prosthesis revision.
The abstracts were prepared by Docteur Jean Barthas. Correspondence should be addressed to him at Secrétariat de la Société S.O.F.C.O.T., 56 rue Boissonade, 75014 Paris.
