title: Tumors about the knee misdiagnosed as athletic injuries.
abstract: BACKGROUND
  Musculoskeletal tumors may originally mimic a traumatic condition, and, on the basis of an erroneous diagnosis of an athletic injury, an invasive diagnostic or therapeutic procedure may be performed. We determined the number of such cases treated at our institution, and we analyzed the initial and final diagnoses as well as the changes in the indicated oncologic surgical technique due to the initial erroneous diagnosis.
  
  
  METHODS
  Twenty-five patients who had a bone or soft-tissue tumor about the knee that originally had been diagnosed as an athletic injury were referred to our institution. The complete clinical, radiographic, and pathological records were reviewed. Studies that had been performed prior to the invasive procedure and at the time of admission to our institution were evaluated to determine differences in the tumor stage and the oncologic treatment that was indicated at each time.
  
  
  RESULTS
  Of 667 knee tumors diagnosed in our institution, twenty-five (3.7%) previously had been treated with an intra-articular procedure as a result of a misdiagnosis of an athletic injury. The final diagnoses made at our institution were a benign tumor in eleven patients and a malignant tumor in fourteen. Oncologic surgical treatment was affected in fifteen of the twenty-five patients.
  
  
  CONCLUSIONS
  When a knee tumor is initially misdiagnosed as an athletic injury, treatment may be adversely affected by the delay in diagnosis or an inappropriate invasive procedure that results in extension of the tumor. Initial poor-quality radiographs and an unquestioned original diagnosis despite persistent symptoms were the most frequent causes of an erroneous diagnosis.
authors.affiliation: Institute of Orthopedics Carlos E. Ottolenghi, Italian Hospital of Buenos Aires, Argentina. vgaiteiro@hitalba.edu.ar
authors.forename: D Luis
authors.initials: DL
authors.lastname: Muscolo
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Ayerza
authors.forename: Arturo
authors.initials: A
authors.lastname: Makino
authors.forename: Matías
authors.initials: M
authors.lastname: Costa-Paz
authors.forename: Luis A
authors.initials: LA
authors.lastname: Aponte-Tinao
mesh_terms: D000293:Adolescent; D000328:Adult; D000671:Amputation, Surgical; D001175:Arthrography; D001182:Arthroscopy; D001265:Athletic Injuries / Q000175:diagnosis*; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000628:therapy; D015984:Causality; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000009:adverse effects / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007717:Knee; D007718:Knee Injuries / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012017:Referral and Consultation; D012189:Retrospective Studies; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000628:therapy; D000070600:Tibial Meniscus Injuries; D013997:Time Factors; D016896:Treatment Outcome