Multidimensional long-term outcome analysis after single-level lumbar microdiscectomy: a retrospective single-centre study

OBJECTIVE: To present multidimensional long-term results after mono-segmental microdiscectomy for lumbar disc herniation (LDH) in a large adult cohort treated at a tertiary care centre.

METHODS: Retrospective study design with Oswestry Disability Index (ODI) questionnaire employed at follow-up. All patients undergoing surgical treatment for single-level LDH between 2003 and 2009 were identified. Electronic patient records and imaging data were analysed.

RESULTS: A total of 939 patients underwent single-level lumbar MD at our institution. Three hundred and seven complete ODI forms (32.7%) were returned at a median follow-up of 48 months. Mean ODI score was 24.04, and mean age was 58 years. Females reported slightly higher ODI scores (25.52 vs. 22.68). Age and ODI score showed statistically significant correlation. Early surgery yielded lower ODI scores with patients faring significantly worse if symptoms persisted for a year or longer (one-way ANOVA, p < 0.001). ODI scores increased sharply even among those operated later than 1 week after symptom onset. Sequestered herniations were associated with significantly lower ODI scores than contained discs on MRI (21.96 vs. 39.89). Surgical complications occurred in 17 cases (5.6%), 82 patients (26.7%) required additional surgery, 58 (18.9%) of those for recurrent disc herniations.

CONCLUSION: Our findings suggest better outcomes with early surgical treatments. Time limits for conservative treatments should be set to avoid the chronification of pain and the worse overall outcomes that go along with belated surgery. Particularly in those with acute onset of pain, sequestered herniations and only mild degrees of immobilization good outcomes are common and surgical treatment appears best if indicated early.