A Comparative Study of two Different Methods of Bone Grafting in the Treatment of Degenerative Lumbar Spondylolisthesis

Objective To compare the clinical efficacy of posterior cage interbody fusion or posterior lumbar circumferential fusion combined with pedicle screw fixation system in the treatment of degenerative lumbar spondylosisthesis. Methods 46 patients failed conservative treatment were divided into 2 groups based on fusion method: one group underwent posterior lumbar cage interbody fusion(group A, 26 cases), another group received posterior lumbar circumferential fusion(group B, 20 cases). Inervertebral space height, rates of lumbar spondylosisthesis reduction, fusion rate, as well as the clinical efficacy were compared between both groups. Results All the patients were followed up for 6~24 months with an average of 18 months. The difference in the fusion rate between group A and group B was not significant(P0.05) at the last follow up. According to Nakai criteria, the results of group A were excellent in 16 cases, good in 7 cases, fair in 3 cases, and poor in 0 case; the results of group B were excellent in 14 cases, good in 4 cases, fair in 2 cases, and poor in 0 case, the excellent and good rate of the two groups was 88.5% and 90% respectively, the difference was not statistically different(P0.05).There was significant difference with respect to intervertebral space height between preoperative and postoperative. At the last follow up, the loss of intervertebral space height in group B was more than that in group A with significant difference(P0.05). Conclusion Posterior cage interbody fusion or posterior lumbar circumferential fusion combined with pedicle screw fixation system are both effective methods for degenerative lumbar spondylosisthesis and with no sig-nificant difference in the short term.