To compare the advantages and disadvantages of posterior interbody fusion by intermuscular approach and oblique lateral interbody fusion combined with posterior pedicle screw fixation for treating lumbar spondylolisthesis (degree Ⅰ-Ⅱ).

A prospective study was conducted on 115 patients who underwent surgical treatment for lumbar spondylolisthesis from June 2016 to June 2018. These patients include 33 males and 82 females, ranging in age from 41 to 72 years, with a mean of (57±7) years. 56 cases (posterior interbody fusion group) were treated by intermuscular approach and 59 cases (oblique lateral interbody fusion group) were treated by oblique lateral approach and posterior pedicle screw fixation. The operative time, intraoperative blood loss, imaging results, clinical results and complications were compared between the two groups.

All patients were followed up with an average of (27±3) months (range from 12 to 48 months). The operative time and intraoperative blood loss of oblique lateral interbody fusion group were significantly less than posterior interbody fusion group (P<0.05). There was no incision infection and nerve injury were observed in two groups. Besides, the VAS score at 72 h after surgery of oblique lateral interbody fusion group (1.10±0.08) were significantly less than posterior interbody fusion group (1.51±0.15). According to the analysis of variance with repeated measures design, the difference between the posterior group and the oblique lateral fusion group was statistically significant in terms of lumbar lordosis angle and spondylolisthesis rate at postoperation and the last follow-up (P<0.05). There was no statistically significant difference between different groups in spondylolisthesis angle, sacral inclination angle and intervertebral space height. Both the two groups showed significant improvement in ODI during the final follow-up (P<0.05), but the difference between the two groups was not statistically significant. The incidence of complications in the posterior fusion group was significantly higher than in the oblique lateral fusion group (P<0.05). The fusion rate of posterior interbody fusion group was 96.4% and 94.9% in oblique lateral interbody fusion group, while the difference was not statistically significant (P>0.05). During the follow-up, loosening, displacement, breakage of pedicle screw, displacement of intervertebral cages or obvious degeneration of adjacent segments were not observed.

The posterior interbody fusion by intermuscular approach and the oblique lateral interbody fusion combined with posterior pedicle screw fixation take well clinical results for treating lumbar spondylolisthesis (degree Ⅰ-Ⅱ ). Oblique lateral interbody fusion combined with posterior pedicle screw fixation through intermuscular approach takes advantages of quick operation, less trauma, less bleeding, high safety, quick recovery and no interference to spinal canal, which can be a good choice for treatment of lumbar spondylolisthesis (degree Ⅰ-Ⅱ).