gms | German Medical Science

Objective: Simple fragment excision in cases of herniated lumbar discs has been repeatedly reported as an alternative to standard microdiscectomy with comparable clinical results. The aim of the present study was to assess disc morphology radiologically two years after surgery in a cohort of 84 prospectively randomized patients undergoing microdiscectomy (D) or sequestrectomy (S).

Methods: Follow-up MRI was performed in all attainable patients 2 years after surgery. Disc and nondisc characteristics such as disc desiccation, loss of disc height and endplate changes plus form, size and location of canal-compromising disc lesions were assessed by a blinded neuroradiologist. Pre- and postoperative radiological data were compared and correlated with clinical outcome.

Results: The incidence of postoperative protrusions/extrusions was 70.6% for group D compared to 94.6% in group S (p=0.009). There was no positive correlation between presence of protrusion/extrusion and low back pain (LBP) or sciatica. MRI analysis revealed significant loss of disc height in more patients after microdiscectomy than sequestrectomy (63.2% vs. 37.9%; p<0.05). 47.4% of patients demonstrated an increase in modic changes 2 years after microdiscectomy compared to 13.8% after sequestrectomy (p<0.05). Endplate changes correlated with increased low back pain.

Conclusions: In particular endplate changes seem to play an important role in the etiology of unfavorable clinical outcome following disc surgery. Sequestrectomy causes less degeneration of the endplates and less segmental height loss than microdiscectomy, which seems to prove beneficial in long-term follow-up. Thus, sequestrectomy appears to be an advantageous alternative to “standard” microdiscectomy.