The June 2012 Oncology Roundup. 360. looks at: avoiding pelvic hemipelvectomy; proximal femoral metastasis; extendible prostheses; rotationplasty; soft-tissue sarcomas; osteosarcoma of the pelvis; recurrent chondrosarcoma ; MRI and the differentiation between benign and malignant lesions; and malignant fibrous histiocytoma

Aim. To evaluate outcome and complications of knee arthrodesis with a modular prosthetic system (MUTARS(r) Implantcast), as primary and revision implants in musculoskeletal oncology. Method. Between 1975 and 2009, 24 prostheses were used for knee arthrodesis. Nineteen in oncologic cases: 6 osteosarcomas, chondrosarcoma, synovial sarcoma and metastatic carcinoma 3 each, 2 pigmented villonodular synovitis (PVNS), malignant fibrous hystiocitoma and giant cell tumour 1 each. Patients were grouped into: A) primary implants, B) revision implants. Group A included 9 patients: 8 arthrodeses after extra-articular resection with major soft tissue removal, 1 after primary resection following multiple excisions of locally recurrent PVNS. Group B included 15 patients: 12 arthrodeses for infection (5 infected TKAs, 7 infected megaprostheses), 2 for failures of temporary arthodesis with Kuntscher nail and cement, 1 for recurrent chondrosarcoma in previous arthrodesis. Results. Oncologic outcome ata mean follow-up of 6 years (ranging 1 to 26), showed 13 NED (68.4%), 2 NED after treatment of relapse (10.5%), 1 alive with metastases (5.3%), 2 dead with disease (10.5%) and one dead of other disease (5.3%). Complications causing failure were observed in 12 patients (50%): 11 infections at mean of 14 months (6 in arthrodeses as revision for previous infections, 5 in group A), 1 femoral stem breakage at 4.8 years (in group B). Treatment of infections was: amputation in 6, “one stage” in 1, “two stage” with new arthrodesis in 4 (1 subsequently amputated for recurrent infection). The breakage was revised, had further traumatic breakage at 2 years and a second revision. Conclusion. Arthrodesis with modular prosthetic system is indicated after major extra-articular resection or in revisions of severely failed previous reconstructions. High infection rate should be prevented with good soft tissue coverage, by flaps if needed

Introduction: Pelvic and acetabular reconstruction following tumor resections are often difficult and fraught with complications. This is the first report of a reconstruction utilizing sacral implantation of an acetabular component, a relatively simple procedure. Materials and Methods: A 74 year-old man developed recurrent low-grade chondrosarcoma in his ilium. Prior resections had included total hip reconstruction with massive cemented acetabular components. A combined Type I and II internal hemipelvectomy with endoprosthetic reconstruction were performed. Following resection, his sacrum and a small fragment of remaining ilium at the sacroiliac joint was reamed to accept a 48 mm porous coated acetabular component. It was press- fit into place and further secured with two central and three rim screws. A constrained cup liner was used. A proximal femoral endoprosthesis was constructed from a commercially available modular oncology system. Additional resection of the superior and inferior pubic ramie was required to minimize the likelihood of endoprosthetic impingement and leverage-induced dislocation. A soft tissue reconstruction of the abductors was accomplished. Results: He remains free of recurrence 15 months post-operative. He ambulates full weight bearing with crutches. His leg is neurovascularly intact and he is pleased with his results. A videotape, demonstrating his gait, will be shown. Discussion: The author knows of one similar reconstruction that was performed at another center (unpublished data). That other patient suffered acetabular component dislodgement. The intraoperative leverage-induced dislocation of the hip was the important determination. Pubic rami resection may be required to prevent femoral impingement and instability. The use of multiple fixation screws also improved component fixation. Conclusion: Placement of a well fixed, constrained, acetab-ular component into a retained sacrum at the level of the SI joint provides an alternative limb salvage technique

The October 2015 Oncology Roundup³⁶⁰ looks at: Radiotherapy for the radioresistant; Multiple hereditary exostosis; The total femur as a limb salvage option; Survival prediction in osteosarcoma; What happens when chondrosarcoma recurs?; Thumbs up for vascularised fibular graft; Radiotherapy and survival; Musculoskeletal tumours in pregnancy