title: Subdural lumbar facet joint fistula secondary to dural tear case report.
abstract: METHODS
  A case report.
  
  
  OBJECTIVE
  To report a rare complication associated with lumbar decompression surgery.
  
  
  BACKGROUND
  Decompression surgery for lumbar degenerative canal stenosis is one of the most commonly performed spinal procedures. A dural tear is a common troublesome complication of the surgery. Occasionally, dural tear can lead to cerebrospinal fluid (CSF) fistula. However, there is no report of a CSF fistula between the subdural space and a facet joint.
  
  
  METHODS
  A 79-year-old woman underwent lumbar decompression surgery at L3-L5 level. During the surgery, a minimal dural tear was detected although the arachnoid membrane was intact. Because of the absence of CSF leakage and small size of the torn area, repair was not performed. After surgery, she complained of intermittent left buttock pain after ambulation. Her magnetic resonance imaging showed enlarged subdural space and tethering of the dura at L3-L4. CSF aspiration from subdural space was conducted during myelography. However, pain relief was only temporary. CSF fistula between subdural space and facet joint was detected on computed tomographic myelography (CTM). She subsequently underwent second surgery.
  
  
  RESULTS
  After separation of the adhesion between the dural tear and the facet joint, CSF leakage was observed. Water-tight sutures, free fat graft, and fibrin glue were applied for repair. She demonstrated complete resolution of her preoperative symptoms at 1 year after surgery. Follow-up magnetic resonance imaging showed no recurrence of the fistula and an adequately decompressed lumbar canal.
  
  
  CONCLUSIONS
  Computed tomographic myelography was essential to diagnose the rare complication after dural tear. Even in cases of minimal dural tears without arachnoid tear, we suggest repair in order to prevent the rare case of fistula formation.
authors.affiliation: Department of Orthopedic Surgery, Chubu Rosai Hospital, Nagoya, Japan. hirospine0527@yahoo.co.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakashima
authors.forename: Yasutsugu
authors.initials: Y
authors.lastname: Yukawa
authors.forename: Keigo
authors.initials: K
authors.lastname: Ito
authors.forename: Masaaki
authors.initials: M
authors.lastname: Machino
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Kato
mesh_terms: D000368:Aged; D002555:Cerebrospinal Fluid; D019299:Decompression, Surgical / Q000009:adverse effects / Q000379:methods; D004388:Dura Mater / Q000293:injuries*; D005260:Female; D005402:Fistula / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008159:Lumbar Vertebrae; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology; D013130:Spinal Stenosis / Q000601:surgery; D013355:Subdural Space / Q000473:pathology; D021801:Zygapophyseal Joint / Q000473:pathology*