Introduction: Several minimally invasive fusion strategies have been described, like anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF) and two lateral approaches, extreme and direct lateral interbody fusion (XLIF and DLIF), all with pros and cons compared to open surgery and each other. The benefits of MIS techniques are less blood loss, faster postoperative ambulation, lower opioids use, and shorter hospital stays, which are nearly always significantly better than an open procedure (1). However, there is limited date on how MIS techniques compare with each other, especially in the treatment of a specific spine diagnosis such as degenerative spondylolisthesis.

Methods: Review of our clinical database and patient medical records for sex, direct surgical cost, age at surgery, pre-op BMI, EBL, hospital LOS, duration of surgery, post-operative complications, and patient reported functional outcomes (Oswestry Disability Index-ODI and Visual Analog Scales-VAS). These outcomes are reported at pre-op, 6 weeks, 6 months, and 1 year+ post-operative terms. We used paired t-test and a two-sample t-test with equal variances to determine means, standard errors, and p-values for statistical significance.

Results: There were 32 patients in the LIF group and 39 in the TLIF group. There was no significant difference in age, BMI, direct cost, hospital LOS, or duration of surgery between the 2 groups. EBL was significantly less for LIF patients (p value 0.0007.) Both LIF and TLIF patients had significantly improved clinical outcomes at each time points post op with a tendency for improved outcome in TLIF patients (p values .0029 and .0039.)

Conclusions: Both MIS-LIF and MIS-TLIF demonstrate significant and sustained improvement outcomes in patient pain and quality of life. When compared against each other, MIS-TLIF seems to offer better functional outcomes. We plan to carry out a RCT of TLIF versus LIF in the treatment of degenerative spondylolisthesis.

Patient Care: The results demonstrate that MIS-TLIF and LIF are effective treatment of degenerative spondylolisthesis and will further educate patients about their treatment options.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) understand MIS treatment options for patients with degenerative spondylolisthesis and their clinical effectiveness. 2) Cost effectiveness of MIS TLIS and LIF for treatment of spondylolisthesis.

References: Spoor AB1, Öner FC. Minimally invasive spine surgery in chronic low back pain patients (2013) J Neurosurg Sci. 57(3):203-18.