A randomized controlled trial with ≥5 years of follow-up comparing minimally invasive and open transforaminal lumbar interbody fusion in disc herniation at single level.

Minimally invasive transforaminal lumbar interbody fusion (m-TLIF) using transpedicular screws has various advantages over classical open (c-) TLIF. Up to date, comparative analyses of the TLIF procedures were following patients for <5 years. The objective of the present study was to compare the clinical effectiveness and complications of m- and c-TLIF in patients with single-level disc herniation with ≥5 years follow-up. Between June 2008 to July 2010, 91 patients with single-level lumbar degeneration were recruited and were randomly divided into two groups: m-TLIF and c-TLIF. The analyzed outcome measurements included: Surgery duration, intraoperative blood loss, X-ray exposure time, T2 relaxation time in magnetic resonance imaging (MRI), visual analogue scale (VAS) scores, Japanese orthopedic association (JOA) scores, fusion rate and complications during follow-up. No significant differences between m- and c-TLIF were observed with respect to surgery duration (P=0.077), volume of blood loss (P=0.115), complications and the need for an additional surgery (P=0.632). Significant differences between the groups were observed for X-ray exposure time (P<0.001) and MRI T2 relaxation times at 3 months post-surgery (P<0.001). At day 7 post surgery, recorded VAS and JOA scores were significantly improved in the m-TLIF compared with the c-TLIF group and non-significant differences between the groups were observed at >1 month follow-up. m-TLIF was a safe and effective tool in treating single-level lumbar disc herniation. However, careful attention to the surgical technique and precise anatomical knowledge were required. Further studies and refinement of the surgical techniques are necessary prior to treating multiple or more extensive lesions using the m-TLIF method.