title: Symptomatic retethering of the spinal cord after section of a tight filum terminale.
abstract: BACKGROUND
  Section of a tight filum terminale is a minimally invasive procedure compared with cord untethering procedures used for more complex spinal abnormalities. Anecdotal evidence suggests, however, that the risk of symptomatic retethering resulting from scarring might be higher than previously thought.
  
  
  OBJECTIVE
  To determine the frequency of symptomatic retethering after section of a tight filum terminale and to explore possible risk factors.
  
  
  METHODS
  We reviewed databases at 2 pediatric neurosurgery centers for all patients who had surgery for a suspected tight filum terminale between January 1982 and June 2009.
  
  
  RESULTS
  We identified 152 patients. The median length of follow-up was 78 months. Thirteen patients (8.6%) went on to retether symptomatically at a median time of 23.4 months after the initial procedure. Eight had early retethering (within 2 years) and 5 had late retethering (after 7 years). Compared with late retetherers, early retetherers were older at initial surgery (median, 9.4 vs 0.9 years of age), had a higher level of the conus (median, L1/L2 vs L3/L4), had more arachnoiditis after initial surgery, and required more repeat untethering procedures. Late retetherers were younger at initial surgery than those who did not retether (median, 0.9 vs 4.5 years of age).
  
  
  CONCLUSIONS
  Symptomatic retethering is not uncommon after a simple filum snip, and long-term follow-up is warranted. Two distinct patterns of retethering were observed. Arachnoiditis caused by infection or a cerebrospinal fluid fistula may predispose to early retethering, whereas early surgery for prevention of tethered cord symptoms may predispose to late retethering.
authors.affiliation: Division of Pediatric Neurosurgery, British Columbia Children's Hospital and University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Raymund L
authors.initials: RL
authors.lastname: Yong
authors.forename: Tracey
authors.initials: T
authors.lastname: Habrock-Bach
authors.forename: Mariko
authors.initials: M
authors.lastname: Vaughan
authors.forename: John R
authors.initials: JR
authors.lastname: Kestle
authors.forename: Paul
authors.initials: P
authors.lastname: Steinbok
mesh_terms: D000293:Adolescent; D000369:Aged, 80 and over; D002420:Cauda Equina / Q000473:pathology / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009436:Neural Tube Defects / Q000601:surgery*; D019635:Neurosurgical Procedures; D012008:Recurrence; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult