title: Operative failure of percutaneous endoscopic lumbar discectomy: a radiologic analysis of 55 cases.
abstract: METHODS
  A retrospective study.
  
  
  OBJECTIVE
  To determine the range of lumbar disc herniation that can be addressed effectively using current endoscopic techniques.
  
  
  BACKGROUND
  The current technical limitation of the procedure in terms of the location and size of the herniation has not been fully documented in previous studies.
  
  
  METHODS
  The inclusion was an intracanal lower lumbar disc herniation in which subsequent surgery was performed because of the presence of remnant fragments. All 1586 cases, including 55 failed cases, were classified according to the size, location, and extent of migration.
  
  
  RESULTS
  In the nonmigrated herniations, the central located high-canal compromised (>50%) herniations showed the highest rate of failure (15%), and the rate was significantly different from the low and high-canal compromise group (1.9% and 11.1%, respectively, P < 0.001). There was no significant difference in the failure rate between the nonmigrated herniations and low-grade migration group (2.7% and 3.7%, respectively). However, the high-grade migration group (beyond the measured height of the posterior marginal disc space) showed a significantly high-incidence of failure (15.7%, P < 0.001).
  
  
  CONCLUSIONS
  Based on these results, open surgery may be considered for herniations with high-canal compromise and high-grade migration. On the other hand, percutaneous endoscopic lumbar discectomy can be considered to be a surgical option in the remaining intracanal disc herniations.
authors.affiliation: Department of Neurosurgery, Wooridul Spine Hospital, Kangnam-gu, Seoul, Korea.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Byung Uk
authors.initials: BU
authors.lastname: Kang
authors.forename: Yong
authors.initials: Y
authors.lastname: Ahn
authors.forename: Gun
authors.initials: G
authors.lastname: Choi
authors.forename: Young-Geun
authors.initials: YG
authors.lastname: Choi
authors.forename: Kwang Up
authors.initials: KU
authors.lastname: Ahn
authors.forename: Song-Woo
authors.initials: SW
authors.lastname: Shin
authors.forename: Ho-Yeong
authors.initials: HY
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D019299:Decompression, Surgical; D017587:Diskectomy, Percutaneous / Q000379:methods*; D004724:Endoscopy / Q000379:methods; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012086:Reoperation; D012189:Retrospective Studies; D017211:Treatment Failure