Clinical outcomes of unilateral biportal endoscopic lumbar interbody fusion (ULIF) compared with conventional posterior lumbar interbody fusion (PLIF).

Background Context: In recent years, unilateral biportal endoscopic lumbar interbody fusion (ULIF) has been more and more favored by spinal surgeons because of its advantages of low trauma, rapid recovery, high fusion rate and fewer complications.

Purpose: To compare the clinical effects of ULIF with those of conventional open posterior lumbar interbody fusion (PLIF).

Study Design: Prospective case control study.

Patient Sample: Twenty-seven patients treated by ULIF and thirty-three patients treated by PLIF.

Outcome Measures: The preoperative baseline and surgical technique-related outcomes (mean operation time, blood loss during operation, postoperative drainage, and postoperative hospital stay) were compared between the two groups. The clinical status of the two groups before and after surgery were also compared: visual analogue scale (VAS) score of the legs and back, Japanese Orthopedic Association (JOA) score and Oswestry Disability Index (ODI). The clinical laboratory indexes of the two groups before and after the operation were compared: C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), creatine phosphokinase (CPK), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), as well as the incidence of complications, such as dural tear, nerve root injury and infection.

Methods: Adult patients who underwent L3-S1 single level lumbar interbody fusion were included in the study. They were divided into a PLIF group and a ULIF group according to the type of surgery. This study comprised 60 cases: 27 cases in the ULIF group and thirty-three cases in the PLIF group.

Results: There was no significant difference in preoperative baseline between the two groups. The ULIF group experienced less blood loss, postoperative drainage and a shorter postoperative hospital stay than the PLIF group; however the ULIF group required a longer operation time than the PLIF group (p<.05). CRP, ESR, CPK, IL-6, and TNF-α levels of the PLIF group were all significantly higher than those of the ULIF group 5 days after surgery (p<.05). The improvements in the VAS scores for back pain, VAS scores for leg pain and JOA score in the ULIF group were all significantly better than those in the PLIF group at 5 days after surgery (p<.05). There was no significant difference in fusion rate at 6 months between the 2 groups (p>.05).

Conclusions: This study showed that ULIF and PLIF were both effective surgical techniques for lumbar interbody fusion. However, ULIF caused less bleeding, reduced inflammatory reaction, less tissue damage and faster postoperative recovery compared with PLIF. Both long-term follow-up and larger clinical studies are needed to validate the clinical and radiological results of this surgery.