Comparison of Clinical and Radiographic Results Between Posterior Pedicle-Based Dynamic Stabilization and Posterior Lumbar Intervertebral Fusion for Lumbar Degenerative Disease: A 2-Year Retrospective Study.

OBJECTIVE: To compare outcomes between K-rod dynamic stabilization system (KDSS) and posterior lumbar intervertebral fusion (PLIF) for lumbar degenerative disease.

METHODS: This study retrospectively reviewed 98 patients who underwent lumbar surgery from March 2012 to June 2014, including 48 in the KDSS group and 50 in the PLIF group. All patients were followed up for at least 2 years. Duration of operation, blood loss, hospital stay, complications, and patient satisfaction were recorded and analyzed. Clinical outcomes were evaluated by visual analog scale and Oswestry Disability Index. Radiographic results including disk height index, foraminal height, and range of motion (ROM) were compared between groups.

RESULTS: Compared with PLIF group, KDSS group had shorter duration of operation and less blood loss (P < 0.001). There were no differences in hospital stay, complications, and patient satisfaction. Both groups demonstrated significant improvement in visual analog scale back and leg pain and Oswestry Disability Index. No significant difference was found between groups at any time point (P > 0.05). Postoperative disk height index and foraminal height increased significantly compared with preoperatively (P < 0.05). Although disk height index and foraminal height in KDSS group were smaller than PLIF group values, there were no significant differences between groups. ROM of total lumbar and implanted segment was decreased compared with preoperative ROM in both groups (P < 0.05), but the 2 values were higher in KDSS group (P < 0.05).

CONCLUSIONS: Both KDSS and PLIF can improve clinical and radiographic outcomes for early-stage lumbar degenerative disease. Compared with PLIF, KDSS has better operative time, less blood loss, and better preservation of ROM, but prospective, randomized, controlled trials with larger sample size and longer follow-up are required.