title: Partial epiphyseal preservation and intercalary allograft reconstruction in high-grade metaphyseal osteosarcoma of the knee.
abstract: BACKGROUND
  The purpose of this study was to analyze a series of patients with a high-grade metaphyseal osteosarcoma of the knee who had been treated with a transepiphyseal resection, with preservation of the distal femoral and the proximal tibial (articular) portions of the epiphysis, and an intercalary allograft reconstruction.
  
  
  METHODS
  The cases of thirteen patients with a high-grade metaphyseal osteosarcoma around the knee who had transepiphyseal resection and reconstruction with an intercalary allograft were retrospectively reviewed at a mean of sixty-three months. Complications, disease-free survival of the patient, final preservation of the limb and epiphysis, and functional results according to the Musculoskeletal Tumor Society scoring system were documented at the time of the latest follow-up.
  
  
  RESULTS
  At the final follow-up examination, eleven of the thirteen patients continued to be disease-free. One patient died of bone and pulmonary metastases with no evidence of local recurrence, and the remaining patient had no evidence of disease after resection of a local recurrence of the tumor in the soft tissues. No patient had a local recurrence in the remaining epiphysis. Seven patients had complications that included a fracture (three patients), diaphyseal nonunion (two), deep infection (one), and a local recurrence in the soft tissues (one). The allograft was removed in only four of these patients. At the latest follow-up examination, twelve patients were alive with preserved limbs. In one patient, the epiphysis, which originally had been preserved, was resected because of a metaphyseal fracture, and the limb was reconstructed with an osteoarticular allograft. The patients with a preserved epiphysis had an average functional score of 27 points (maximum, 30 points).
  
  
  CONCLUSIONS
  Preservation of the epiphysis in high-grade metaphyseal osteosarcoma at the knee is an alternative in carefully selected patients. Crucial factors needed to obtain local tumor control and achieve an acceptable functional result are a positive response to chemotherapy, accurate preoperative assessment of tumor extension to the epiphysis, and appropriate fixation techniques for intercalary allografts.
  
  
  METHODS
  Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.
authors.affiliation: Institute of Orthopedics "Carlos E. Ottolenghi," Italian Hospital of Buenos Aires, Potosí 4215, (1199) Buenos Aires, Argentina. luis.muscolo@hospitalitaliano.org.ar
authors.forename: D Luis
authors.initials: DL
authors.lastname: Muscolo
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Ayerza
authors.forename: Luis A
authors.initials: LA
authors.lastname: Aponte-Tinao
authors.forename: Maximiliano
authors.initials: M
authors.lastname: Ranalletta
mesh_terms: D000293:Adolescent; D000328:Adult; D001178:Arthroplasty / Q000379:methods*; D001859:Bone Neoplasms / Q000175:diagnosis / Q000601:surgery*; D016025:Bone Transplantation; D002648:Child; D004838:Epiphyses / Q000601:surgery; D005260:Female; D005266:Femoral Neoplasms / Q000175:diagnosis / Q000601:surgery; D005269:Femur / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D012516:Osteosarcoma / Q000175:diagnosis / Q000601:surgery*; D011859:Radiography; D013977:Tibia / Q000601:surgery*; D014184:Transplantation, Homologous