Transforaminal lumbar interbody fusion: comparison between open and mini-open approaches with two years follow-up.

ABSTRACT

BACKGROUND: Transforaminal lumbar interbody fusion (TLIF) is an efficient technique which can achieve a fusion rate of up to 90%. Minimally invasive approaches have become increasingly popular because they appear to minimize iatrogenic soft tissue and muscle injury. As minimally invasive TLIF gains popularity, its effectiveness compared with open TLIF has yet to be established. OBJECTIVE: A retrospective study was performed with the aim to compare long-term outcomes of patients who underwent mini-open TLIF with those who underwent open TLIF. METHODS: This is a retrospective review of prospectively collected data. Between 2005 and 2008, 100 patients underwent TLIF for low-grade spondylolisthesis or degenerative disc disease; 60 underwent open TLIF and 40 underwent mini-open TLIF. The mean age in each group was 48 years, and there were no statistically significant differences between the groups. Data were collected perioperatively. Pain and functional disability were measured using visual analogue scale (VAS) and Oswestry disability index (ODI) at 3 months, 6 months, 1 year, and 2 years. In addition, the fusion was evaluated at 1 year on a computerized tomography (CT) scan. RESULTS: The mean VAS improved from 7.3 to 3.8 for back pain and from 7 to 2.7 for leg pain and the ODI decreased from 60 to 30% at 2 years postoperatively. The fusion rate at 1 year was 98%. There were no statistical differences for the clinical and radiological outcomes between the groups. The mean operative time was 186 minutes in the open group and 170 minutes in the mini-open group (p < 0.05) and the mean blood loss was 486 mL in the open group and 148 mL in the mini-open group (p < 0.01). CONCLUSION: The mini-open TLIF for symptomatic low-grade spondylolisthesis and degenerative disc disease is an effective option that achieves the same clinical and radiological outcomes at a minimum 2-year follow-up and reduces perioperative morbidity.