Spine Volume 34, Number 1, 2009 Min Seok Kim; Kun-Woo Park; Changju Hwang; Young-Kyun Lee; Ki Hyoung Koo; Bong-Soon Chang; Choon-Ki Lee; Dong-Ho Lee
Abstract Study Design: A retrospective clinical study. Objective: To estimate the recurrence rate of lumbar disc herniation after open discectomy in active young men using survival analysis. Summary of Background Data: 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. Conclusion: Survival analysis provides a more accurate estimation of true recurrence rate. Protruded discs are more likely to show recurrence than other types.