K-rod dynamic internal fixation versus microendoscopic discectomy for the treatment of single-segment lumbar disc herniation

Abstract

Purpose: This study compared the clinical outcome of K-rod dynamic internal fixation versus microendoscopic discectomy (MED) for the treatment of single-segment lumbar disc herniation. Methods: This retrospective study included 34 patients with L4-L5 single-segment lumbar disc herniation who underwent K-rod dynamic internal fixation (n = 18) or MED (n = 16). The pain was evaluated by the Oswestry disability index (ODI) and visual analogue scale (VAS). The neurological function was assessed by the Japanese Orthopaedic Association (JOA) scores. The height of intervertebral space was calculated using X-ray images, and the disc degeneration was evaluated based on Pfirrmann scores. The mean follow-up time was 31 months (range, 18–46 months). Results: In both groups, the ODI scores, VAS scores and JOA scores were significantly improved at the last follow-up compared with the preoperative values (p < 0.05). There was no significant difference in the improvement of ODI, VAS and JOA scores between the two groups (p > 0.05). The height of intervertebral space in the surgical segments, proximal segments and distal segments, was significantly greater in the K-rod group than in the MED group. The disc degeneration occurred more in the MED group than in the K-rod group (p < 0.05). Conclusion: K-rod internal fixation and MED produce satisfactory outcomes in the treatment of single-segment lumbar disc herniation. K-rod internal fixation is superior to MED in preventing adjacent segment degeneration.