Comparative study of direct pars repair versus transforaminal lumbar interbody fusion for low grade isthmic spondylolisthesis: a retrospective analysis.

Spinal fusion has shown satisfactory efficacy in the treatment of adult patients with low-grade isthmic spondylolisthesis (LGIS), however, the efficacy of direct repair (DR) for LGIS has not been established, and there is as yet a few reports on it. To assess the clinical efficacy of DR with the pedicle screw-rod-hook (PSRH) fixation and transforaminal lumbar interbody fusion (TLIF) in adult patients with symptomatic LGIS. A total of 140 adult patients with LGIS were enrolled from April 2009 to December 2018, of whom, 69 cases underwent DR using the PSRH system and 71 cases underwent TLIF, with clinical efficacy evaluated comparatively using clinical and radiological assessments. The patients in both groups showed satisfactory pain relief efficacy and improvement in lumbar spine function. Bone fusion rate was 97.10% in the DR group vs. 100% in the TLIF group. The range of motion (ROM) of the surgical segment was significantly decreased from 13.72 ± 6.73 preoperatively to 11.60 ± 9.70 at the final follow-up (FFU) in the DR group and lost in the TLIF group, however, that of the upper intervertebral space (UIS) in each group or between groups before and after operation did not differ significantly. Both DR and TLIF are effective for adult patients with LGIS. As compared with TLIF, DR is more effective in preserving the ROM of the operative segment yet with less impact on adjacent segments.