Abstract
Objective
was to review the experience of the Rizzoli with megaprosthetic reconstruction of the extremities in musculoskeletal oncology.
Material and methods
Between April 1983 and December 2007, 1036 modular uncemented megaprostheses of the lower limbs were implanted in 605 males and 431 females: 160 KMFTR(r), 633 HMRS(r) prostheses, 68 HMRS(r) Rotating Hinge and 175 GMRS(r). Sites: distal femur 659, proximal tibia 198, proximal femur 145, total femur 25, distal femur and proximal tibia 9. Histology showed 612 osteosarcomas, 113 chondrosarcomas, 72 Ewing's sarcoma, 31 metastatic carcinomas, 89 GCT, 36 MFH,68 other diagnoses.
Between 1975 and 2006 at Rizzoli 344 reconstructions of the humerus using prosthetic devices (alone or in association with allografts) were performed: 289 MRS(r), 37 HMRS(r), 2 Osteobridge(r), 4 composite prostheses, 8 Coonrad-Morrey(r), 4 custom made prostheses. Sites of reconstruction were: proximal humerus 311, distal humerus 19, diaphysis 5, total humerus 9. Histology showed 146 osteosarcomas, 56 chondrosarcomas, 23 Ewing's sarcoma, 67 metastatic carcinomas, 14 GCT, 10 MFH, 28 other diagnoses.
Patients were followed periodically in the clinic. Information were obtained from clinical charts and imaging studies with special attention to major complications requiring revision surgery. Major prostheses-related complications were analysed and functional results evaluated according to the MSTS system. Univariate analysis by Kaplan-Meier actuarial curves was used for studying implant survival to major complications.
Results
Major complications causing implants failure in lower limbs were 80 infections (7.7%), 64 aseptic loosening (6.2%) and 33 breakages (3.2%). In lower limbs infection occurred in 18 KMFTR(r), 47 HMRS(r), 5 HMRS(r) Rotating Hinge, 10 GMRS(r). Breakage of the prosthetic reconstruction occurred in 16 KMFTR(r), 16 HMRS(r), 1 HMRS(r) Rotating Hinge. Aseptic loosening occurred in 15 KMFTR(r), 28 HMRS(r), 18 HMRS(r) Rotating Hinge, 3 GMRS(r).
Major complications causing implants failure in upper limbs were 15 infections (4.3%), 8 aseptic loosening (2.3%) and 4 breakages (1.2%). In upper limbs infection occurred in 14 MRS(r) and 1 Coonrad-Morrey(r). Aseptic loosening in 8 cases MRS(r). Breakage in 4 cases MRS(r) prostheses. Most patients in both lower and upper extremities series showed satisfactory function (good or excellent) according to the MSTS evaluation system.
Implant survival to all major complications of lower limb megaprostheses evaluated with Kaplan-Meier curve was 80% at 10 years and 60% at 20 years. Implant survival for the newer designs (GMRS(r)) available only at middle term follow up showed an implant survival to major complications at about 90% at 5 years. Implant survival to all major complications was over 80% at 10 years and 78% at 20 years.
Conclusions
Megaprostheses are the most frequently used type of reconstruction after resection of the extremities, since they provide good function and a relatively low incidence of major complications. Both function and implant survival improved in the last decades with the introduction of newer designs and materials.
