BACKGROUND: Classic fusion methods include posterolateral fusion (PLF), posterior lumbar interbody fusion (PLIF), PLF combined with PLIF. Many studies have reported the advantage, technical requirements, clinical efficacy and complications of several fusion methods, but it is difficult to select the best fusion method.
OBJECTIVE: To compare the outcomes of PLF, PLIF, and PLF+PLIF and to find the optimal method.
METHODS: A total of 167 patients who underwent 1 or 2-level fusion surgery because of degenerative lumbar disease were studied. Minimum follow-up period was 3 years. The patients were randomized into three treatment groups: group 1 (PLF; n=62); group 2 (PLIF; n=57); and group 3 (PLF+PLIF; n=48). A visual analog scale, the Oswestry Disability Questionnaire, and Kirkaldy-Willis criteria were used to measure low back pain, leg pain, and disability. For radiologic evaluation, disc height, lumbar lordosis, segmental angle, and bone union were examined. Postoperative complications were also analyzed.
RESULTS: At the last follow-up, good or excellent results were obtained in 50 cases of PLF (80.7%), 50 cases of PLIF (87.8%), and 41 cases of PLF+PLIF (85.5%). No statistical differences were found among the three groups (P=0.704). All methods indicated significant improvement in the disc height (P < 0.05), with PLF having the highest loss in disc height. Lumbar lordosis and segmental angle increased significantly, and improvement of the segmental angle in the three fusion methods had statistically significant differences. The nonunion rates at the last follow-up in the three fusion groups were not statistically significant, with 8% in group 1, 5% in group 2, and 4% in group 3 (P > 0.05). Complications included deep infection in 3 cases, transient nerve palsy in 4, permanent nerve palsy in 1, and donor site pain in 6. No significant differences in clinical results and union rates were found among the 3 fusion methods. PLIF had better sagittal balance than PLF. PLIF had advantages of the elimination of donor site pain, shorter operating time, and less blood loss.