title: Risk factors for surgical site infection after posterior fixation surgery and intraoperative radiotherapy for spinal metastases.
abstract: OBJECTIVE
  Posterior surgery with intraoperative radiotherapy for spinal metastases offers effective therapy, as we have reported previously. However, the procedure involves transfer from the operating room to the radiotherapy room, and as these patients are somewhat immunocompromised, the risk of postoperative surgical site infection (SSI) may be increased. The aim of our study was to identify risk factors and patient characteristics associated with postoperative SSI following posterior fixation surgery and intraoperative radiotherapy for spinal metastases.
  
  
  METHODS
  Participants comprised 279 patients who underwent IORT for the treatment of spinal metastases between August 2004 and June 2013. Patients who suffered SSI within 1 month after surgery were categorized as infected, and all others were categorized as non-infected. We compared factors of age, sex, use of pre-operative corticosteroid, medical history of diabetes, prognosis scores (Tomita, Tokuhashi, and Katagiri), pre- and postoperative Frankel scale scores, site of tumor origin, administration of pre-operative radiotherapy, operation time, intraoperative blood loss, intraoperative irradiation dose, and pre- and postoperative performance status between groups.
  
  
  RESULTS
  SSI occurred in 41 patients (14.7%). Katagiri's and Tokuhashi's prognostic scores (P < 0.05 each), postoperative Frankel scale score (P < 0.01), administration of pre-operative radiotherapy (P < 0.05), and postoperative performance status (P < 0.05) all correlated significantly with occurrence of SSI. Multivariate analysis using those factors revealed administration of pre-operative radiotherapy as a factor independently associated with SSI (P < 0.05).
  
  
  CONCLUSIONS
  Patient prognosis, postoperative ambulatory function, and pre-operative radiotherapy were risk factors for SSI in patients with spinal metastases. Duration of surgery and intraoperative blood loss were not associated with occurrence of SSI.
authors.affiliation: Department of Orthopaedic Surgery and Musculoskeletal Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22, Honkomagome, Bunkyo-ku, Tokyo, 113-8677, Japan. ssugita-tky@umin.ac.jp.
authors.forename: Shurei
authors.initials: S
authors.lastname: Sugita
authors.affiliation: Department of Orthopaedic Surgery and Musculoskeletal Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22, Honkomagome, Bunkyo-ku, Tokyo, 113-8677, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hozumi
authors.affiliation: Department of Orthopaedic Surgery and Musculoskeletal Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22, Honkomagome, Bunkyo-ku, Tokyo, 113-8677, Japan.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Yamakawa
authors.affiliation: Department of Orthopaedic Surgery and Musculoskeletal Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22, Honkomagome, Bunkyo-ku, Tokyo, 113-8677, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Goto
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Metropolitan Tama Medical Center, Tokyo, Japan.
authors.forename: Taiji
authors.initials: T
authors.lastname: Kondo
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013123:Spinal Fusion / Q000009:adverse effects*; D013125:Spinal Neoplasms / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery / Q000628:therapy*; D013530:Surgical Wound Infection / Q000209:etiology*
keywords: Intraoperative radiotherapy; Posterior surgery; Risk factors; Spinal metastasis; Surgical site infection