Lumbar disc herniation treated by microendoscopic discectomy : Prognostic predictors of long-term postoperative outcome

Abstract

Purpose: Microendoscopic discectomy (MED) is becoming an established and effective minimally invasive surgical method for the treatment of lumbar disc herniation (LDH); however, the absence of prognostic factors for long-term outcomes after MED results in a lack of specific criteria for appropriate patient selection. Therefore, we evaluated the long-term outcomes and associated predictors in patients who underwent MED for LDH.

Material and methods: Baseline and follow-up data for 664 LDH patients who suffered from sciatica and underwent primary MED were reviewed retrospectively. Variables at baseline that were analyzed as potential prognostic factors included sociodemographic characteristics, clinical findings, and imaging features. Follow-up data including improvements in the Visual Analog Scale (VAS) score and Oswestry Disability Index (ODI), postoperative low back pain (LBP), reoperation, and excellent/good results according to the modified MacNab criteria were set as outcome variables for univariate and further multivariate logistic regression analyses.

Results: The mean follow-up period was 63.8 ± 20.0 months (range 24-96 months). On average, sufficient improvements in both the VAS score (72.8%) and ODI (63.4%) were observed. In addition, a low postoperative LBP rate (23.9%), low reoperation rate (7.1%), and high rate of excellent/good clinical outcomes (89.9%) were achieved. A multivariate analysis indicated that older age, shorter disease duration, higher preoperative VAS score, lower preoperative ODI, shorter surgical time, lower severity of disc and adjacent disc degeneration, and lower severity of lumbar multifidus atrophy contributed to superior clinical outcomes.

Conclusion: Excellent long-term outcomes after primary MED were achieved and specific sociodemographic, clinical, and imaging variables were identified as prognostic factors that can be used to guide patient selection and clinical decision making.

Keywords: Low back pain; Minimally invasive surgery; Retrospective study; Surgical procedures; Visual analog scale.