title: Prognostic effect of erroneous surgical procedures in patients with osteosarcoma: evaluation using propensity score matching.
abstract: BACKGROUND
  Little is known concerning erroneous surgical procedures of malignant bone tumors, and the prognostic effect of erroneous surgical procedures in osteosarcoma has not been determined.
  
  
  METHODS
  We retrospectively reviewed 240 patients with initially non-metastatic high-grade osteosarcoma of the pelvis and extremities and, of these, identified twenty-six who had undergone previous less appropriate surgical procedures due to misdiagnosis followed by adequate treatment at our institution. We evaluated the clinicopathologic characteristics of these twenty-six patients compared with the remaining 214 patients treated with regular protocol. Subsequently, thirty-eight patients (nineteen in the matched case group and nineteen in the matched control group) were matched for multiple different variables using propensity score matching, and the oncologic results in terms of event-free survival and overall survival were analyzed.
  
  
  RESULTS
  The patients undergoing erroneous surgical procedures were typically older, with small, non-osteoblastic-type tumors that were in an unusual location, showed an osteolytic pattern on radiographs, had a tendency toward marginal or intralesional excision with positive histologic margin, and had not been treated with neoadjuvant chemotherapy (all p < 0.05). After adjustment of confounding variables by propensity score matching, there was no significant difference between matched groups with regard to event-free survival (p = 0.46) and overall survival (p = 0.99).
  
  
  CONCLUSIONS
  Distinct differences existed in the clinicopathologic characteristics of the patients who underwent erroneous surgical procedures due to misdiagnosis. We failed to detect a prognostic relevance of the presence of previous erroneous procedures followed by adequate treatment.
authors.affiliation: Department of Orthopaedic Surgery, Konkuk University School of Medicine, Konkuk University Hospital, 120-1 Neungdong-ro, Gwangjin-gu, Seoul 143-729, Republic of Korea. E-mail address: smilecsw@gmail.com.
authors.forename: Seok Won
authors.initials: SW
authors.lastname: Chung
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea. E-mail address for I. Han: hik19@snu.ac.kr. E-mail address for H.-S. Kim: han.
authors.forename: Ilkyu
authors.initials: I
authors.lastname: Han
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 166 Goomi-ro, Bungdang-gu, Seongnam-si, Gyeonggi-do 463-707, Republic of Korea. E-mail address for J.H. Oh: ohjh1@snu.ac.kr. E-ma.
authors.forename: Joo Han
authors.initials: JH
authors.lastname: Oh
authors.affiliation: Department of Orthopaedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Republic of Korea. E-mail address: tumorshin@gmail.com.
authors.forename: Seung Han
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 166 Goomi-ro, Bungdang-gu, Seongnam-si, Gyeonggi-do 463-707, Republic of Korea. E-mail address for J.H. Oh: ohjh1@snu.ac.kr. E-ma.
authors.forename: Hwan Seong
authors.initials: HS
authors.lastname: Cho
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea. E-mail address for I. Han: hik19@snu.ac.kr. E-mail address for H.-S. Kim: han.
authors.forename: Han-Soo
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000601:surgery*; D003951:Diagnostic Errors; D005121:Extremities / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D019300:Medical Errors; D009364:Neoplasm Recurrence, Local; D012516:Osteosarcoma / Q000175:diagnosis* / Q000601:surgery*; D010384:Pelvic Bones / Q000601:surgery; D011379:Prognosis; D057216:Propensity Score; D012189:Retrospective Studies; D016019:Survival Analysis; D055815:Young Adult