Clinical outcomes after posterior dynamic transpedicular stabilization with limited lumbar discectomy: Carragee classification system for lumbar disc herniations

BACKGROUND The observed rate of recurrent disc herniation after limited posterior lumbar discectomy is highest in patients with posterior wide annular defects, according to the Carragee classification of type II (fragment-defect) disc hernia. Although the recurrent herniation rate is lower in both type III (fragment-contained) and type IV (no fragment-contained) patients, recurrent persistent sciatica is observed in both groups. A higher rate of recurrent disc herniation and sciatica was observed in all 3 groups in comparison to patients with type I (fragment-fissure) disc hernia. METHODS In total, 40 single-level lumbar disc herniation cases were treated with limited posterior lumbar microdiscectomy and posterior dynamic stabilization. The mean follow-up period was 32.75 months. Cases were selected after preoperative magnetic resonance imaging and intraoperative observation. We used the Carragee classification system in this study and excluded Carragee type I (fragment-fissure) disc herniations. Clinical results were evaluated with visual analog scale scores and Oswestry scores. Patients' reherniation rates and clinical results were evaluated and recorded at 3, 12, and 24 months postoperatively. RESULTS The most common herniation type in our study was type III (fragment-contained), with 45% frequency. The frequency of fragment-defects was 25%, and the frequency of no fragment-contained defects was 30%. The perioperative complications observed were as follows: 1 patient had bladder retention that required catheterization, 1 patient had a superficial wound infection, and 1 patient had a malpositioned transpedicular screw. The malpositioned screw was corrected with a second operation, performed 1 month after the first. Recurrent disc herniation was not observed during the follow-up period. CONCLUSIONS We observed that performing discectomy with posterior dynamic stabilization decreased the risk of recurrent disc herniations in Carragee type II, III, and IV groups, which had increased reherniation and persistent/continuous sciatica after limited lumbar microdiscectomy. Moreover, after 2 years' follow-up, we obtained improved clinical results.