title: [Conservative surgery as an alternative treatment of a knee osteosarcoma in the presence of a pathological fracture].
abstract: BACKGROUND
  classical osteosarcoma is defined as a very malignant spindle cell sarcoma, characterized by the production of osteoid matrix, it is the most common primary malignant bone tumor. It is most common among males in their twenties. Factors involved include those related with the skeletal growth and development, pathological fractures, and very young patients who are still growing. Conservative surgery is inappropriate; however, preoperative chemotherapy and a good choice of conservative treatment are an alternative.
  
  
  METHODS
  a 15-year-old male patient presented at the orthopedics service with a diagnosis of a pathological fracture in the distal third of the right femur and a tumor in the lateral aspect of the knee, with pain and limitation of gait. Based on X-rays, a bone scan and a biopsy, the diagnosis of a fibroblastic osteosarcoma, an Enneking IIB lesion, was made. Treatment consisted of conservative surgery with broad tumor resection involving 18 cm of the femur, resection of the vastus medialis and vastus lateralis, release of the femoral bundle, the popliteal and sciatic nerves, as well as placement of a modular stryker tumor prosthesis, with knee replacement.
  
  
  RESULTS
  the clinical and radiological course was appropriate. After a 3-week rehabilitation period the patient was able to walk and the lower limb was salvaged. At 5 months there is no evidence of tumor relapse, the patient can walk properly and has recovered the strength.
  
  
  CONCLUSIONS
  this is a case salvage surgery to treat a pathological fracture resulting from a malignant bone tumor. We think that staging is essential to select the treatment. In the case presented herein a comprehensive management is fundamental to the success of conservative treatment.
authors.affiliation: Hospital Angeles Mocel, Calle Gelati Núm. 29, Colonia San Miguel Chapultepec, Delegación Miguel Hidalgo, DF México. alexps77@hotmail.com
authors.forename: Alejandro G
authors.initials: AG
authors.lastname: Pérez Serna
authors.forename: Luis Felipe
authors.initials: LF
authors.lastname: Moreno Hoyos
authors.forename: Salvador
authors.initials: S
authors.lastname: Ramírrez Valdivia
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D005266:Femoral Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D005598:Fractures, Spontaneous; D005684:Gait; D006801:Humans; D007720:Knee Prosthesis; D023821:Limb Salvage; D008297:Male; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D052097:Quadriceps Muscle / Q000601:surgery; D011859:Radiography; D012737:Sex Factors; D016896:Treatment Outcome