title: Reoperation after primary posterior instrumentation and fusion for idiopathic scoliosis. Toward defining late operative site pain of unknown cause.
abstract: METHODS
  Retrospective case series.
  
  
  OBJECTIVE
  To determine the frequency and categorize the indications for reoperation in three implant systems (Harrington, Cotrel-Dubousset [C-D], and Isola). To define late operative site pain (LOSP) of no apparent cause as an indication for implant removal and determine the success of implant removal in relieving LOSP.
  
  
  BACKGROUND
  Late operative site pain of no apparent cause has been discussed briefly in the literature but has not been investigated as a major indication for implant removal.
  
  
  METHODS
  One hundred eighty-two of 190 consecutive patients with idiopathic scoliosis (96%) who underwent primary surgery between January 1, 1981, and December 31, 1992, by one surgeon in one hospital, with use of Harrington, C-D, or Isola instrumentation were studied an average of 9 years after surgery to determine the indications for and frequency of reoperation.
  
  
  RESULTS
  The overall frequency of reoperation for all instrumentation types combined was 19%: Harrington, 19%; C-D, 24%; and Isola, 14%. By 6 years' follow-up the cumulative risk of reoperation by Kaplan-Meier analysis was Harrington, 14%; C-D, 21%; and Isola, 14%. (statistically nonsignificant difference). The most frequent indication for reoperation was LOSP of no apparent cause: 8% (14 patients) for all instrumentation types combined. The average interval between the initial operation and reoperation for LOSP was 46 months (range, 20-97 months). The frequency of each implant type was Harrington, 6%; C-D, 12%; and Isola, 6%. By 6 years' follow-up, the cumulative Kaplan-Meier risk for reoperation due to LOSP was Harrington, 5%; C-D, 13%; and Isola, 8% (statistically non-significant difference). Of the 14 patients who had instrumentation removal for LOSP, 10 (71%) had successful relief of pain after implant removal.
  
  
  CONCLUSIONS
  Occurring regardless of implant type, LOSP of no apparent cause after posterior instrumentation of scoliosis is a distinct clinical entity and is relieved by implant removal in most patients.
authors.affiliation: Section of Orthopedic Surgery, University of Kansas Medical Center, Kansas City, USA.
authors.forename: S
authors.initials: S
authors.lastname: Cook
authors.forename: M
authors.initials: M
authors.lastname: Asher
authors.forename: S M
authors.initials: SM
authors.lastname: Lai
authors.forename: J
authors.initials: J
authors.lastname: Shobe
mesh_terms: D000293:Adolescent; D000328:Adult; D001416:Back Pain / Q000503:physiopathology; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009984:Orthopedic Fixation Devices; D011183:Postoperative Complications / Q000503:physiopathology*; D012086:Reoperation; D012600:Scoliosis / Q000503:physiopathology / Q000601:surgery*; D013123:Spinal Fusion; D013530:Surgical Wound Infection / Q000503:physiopathology