[Clinical study on lumbar spondylolisthesis treated by minimally invasive transforaminal lumbar interbody fusion]

To retrospectively analyze the treatment of lumbar spondylolisthesis using minimally invasive and open transforaminal lumbar interbody fusion (TLIF), and compare the clinical results of two techniques.

From June 2006 to May 2010, 371 patients with lumbar spondylolisthesis grade 1 and 2 were treated with TLIF, pedicle screw fixation and followed up. The mean age was 50.4 years (range, 37 - 85 years). There were 172 patients who underwent minimally invasive TLIF and percutaneous pedicle screw fixation were set as the MIS-TLIF group, 199 patients who underwent open TLIF and pedicle screw fixation were set as the OTLIF group. The operative time, blood loss, X-ray exposure time and complications were compared between the two groups. Clinical outcome was assessed using the visual analog scale (VAS) and the Oswestry disability index (ODI). Fusion rates were determined by using CT scan reconstruction and dynamic lumbar radiography in last fellow-up.

The average follow-up duration was 32.7 months with a range of 12-58 months. The gender, age, classification of spondylolisthesis and level of fusion showed a identical pattern in both groups. The mean intra-operative blood loss (310 ± 75) ml and postoperative blood loss (38 ± 13) ml in MIS-TLIF group were significantly superior to the intra-operative blood loss (623 ± 156) ml and postoperative blood loss (184 ± 72) ml in OTLIF group (t = 2.836 and 3.274, P < 0.01). Comparing with the OTLIF group (20 ± 10) s, the MIS-TLIF group had a significantly longer radiation time (51 ± 19) s (t = 2.738, P < 0.01). There was no statistical difference in operating time, lower back pain VAS scores, ODI scores and incidence of complication between the two groups.

Comparing with open TLIF, minimally invasive TLIF is a safe and reliable procedure for treatment of lumbar spondylolisthesis grade 1 and 2 with potential advantages.