title: Recurrence rate of lumbar disc herniation after open discectomy in active young men.
abstract: METHODS
  A retrospective clinical study.
  
  
  OBJECTIVE
  To estimate the recurrence rate of lumbar disc herniation after open discectomy in active young men using survival analysis.
  
  
  BACKGROUND
  There are few reports on the recurrence rate of lumbar disc herniation in young adults, even though this age group shows a higher incidence of disc herniation than the other age groups. In addition, most of the studies on the recurrence rate of disc herniation have reported percentages without regard to the effect of the time course.
  
  
  METHODS
  Medical records were retrospectively reviewed and phone call surveys were undertaken for 241 patients aged from 20 to 39 who had undergone open discectomies over a period of 14 years. A diagnosis of recurrence was based on the development of new symptoms and magnetic resonance imaging showing compatible lesions in the same segment as the initial diagnosis. The recurrence rate was calculated using a survival analysis based on the Kaplan-Meier product-limit method and the log-rank test was used to evaluate the effect of patient age, level of occurrence, and type of herniated disc on the recurrence rate.
  
  
  RESULTS
  The overall recurrence rate was 7.1% (17 patients) at a mean follow-up of 8.55 years, and the cumulative survival rate was 91.5% at a follow-up of 14 years. Survival analysis estimated a higher rate of recurrence at longer follow-up, although there was no recurrence after ninth year from the primary surgery. The recurrence rate was significantly higher for protruded discs compared with other types.
  
  
  CONCLUSIONS
  Survival analysis provides a more accurate estimation of true recurrence rate. Protruded discs are more likely to show recurrence than other types.
authors.affiliation: Department of Orthopaedic Surgery, Asan Medical Center, College of Medicine, Ulsan University, 388-1 Pungnap-dong, Songpa-gu, Seoul, Republic of Korea.
authors.forename: Min Seok
authors.initials: MS
authors.lastname: Kim
authors.forename: Kun-Woo
authors.initials: KW
authors.lastname: Park
authors.forename: Changju
authors.initials: C
authors.lastname: Hwang
authors.forename: Young-Kyun
authors.initials: YK
authors.lastname: Lee
authors.forename: Ki Hyoung
authors.initials: KH
authors.lastname: Koo
authors.forename: Bong-Soon
authors.initials: BS
authors.lastname: Chang
authors.forename: Choon-Ki
authors.initials: CK
authors.lastname: Lee
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Lee
mesh_terms: D000328:Adult; D017586:Diskectomy; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D007405:Intervertebral Disc Displacement / Q000175:diagnosis / Q000601:surgery*; D053208:Kaplan-Meier Estimate; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D012008:Recurrence; D012189:Retrospective Studies