Unilateral versus bilateral pedicle screw fixation with transforaminal lumbar interbody fusion for treatment of lumbar foraminal stenosis

Transforaminal lumbar interbody fusion (TLIF) with bilateral pedicle screw fixation (BPSF) is an effective treatment for lumbar foraminal stenosis (LFS). However, the effects of TLIF with unilateral pedicle screw fixation (UPSF) on LFS treatment have not been clearly elucidated.We conducted this study to compare clinical outcomes and radiographic results of TLIF with UPSF and BPSF 2 years after the surgical treatment.Prospective randomized study.This study included 23 patients undergoing TLIF with UPSF and 25 patients undergoing TLIF with BPSF.Clinical outcomes were evaluated by visual analog scale (VAS) for low back pain and leg pain and Oswestry Disability Index (ODI) score. Radiographic outcomes included foraminal height, disc space height, segmental lordosis, and final fusion rates.The clinical and radiographic outcomes were compared between the UPSF and BPSF group. The postoperative improvements were evaluated in either group. Intraoperative data such as duration of operation and estimated blood loss were collected. This study was registered at clinicaltrials.gov.Analysis of the VAS and ODI scores showed significant improvements in clinical outcomes within each group. No significant differences between the 2 groups were noted in the improvements of the VAS and ODI scores. The mean operative duration and blood loss were significantly greater in the BPSF group than in the UPSF group. There were significant improvements in the height of the foramen and intervertebral space and segmental lordosis in both groups, while there was no significant difference between the groups in amount of the improvements. No significant difference was found in the final fusion rates.TLIF is an appropriate procedure for LFS treatment. With balanced intervertebral support using a cage, UPSF could achieve similar and satisfactory effects on lumbar segmental stability and fusion compared to BPSF. The unilateral approach appears to be associated with slightly shorter operative time and less blood loss.