Minimally Invasive Transforaminal Lumbar Interbody Fusion: An Attractive Option for Select Failed Backs

Study Design: Retrospective case series. Purpose: To compare minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) outcomes in primary and revision surgeries. Overview of Literature: Revision spinal fusion is often associated with an increased risk of approach-related complications. Patients can potentially benefit from the decreased approach-related morbidity associated with MI-TLIF. Methods: Sixty consecutive MI-TLIF patients (20 failed back [Fa group], 40 primary [Pr group]) who underwent surgery between January 2011 and May 2012 were reviewed after Institutional Review Board approval to compare operative times, blood loss, complications, Oswestry Disability Index (ODI) scores, and Visual Analog Scale (VAS) scores for back and leg pain before surgery and at the last follow-up. Results: Nineteen revision surgeries were compared with 36 primary surgeries. One failed back and four primary patients were excluded because of inadequate data. The mean follow-up times were 28 months and 24 months in the Pr and Fa groups, respectively. The mean pre-and postoperative ODI scores were 53.18 and 20.23 in the Pr group and 52.01 and 25.72 in the Fa group, respectively (ODI percentage change: Pr group, 60.36%+/-29.73%; Fa group, 69.32%+/-13.72%; p=0.304, not significant). The mean pre-and postoperative VAS scores for back pain were 4.77 and 1.75 in the Pr group and 4.1 and 2.0 in the Fa group, respectively, and the percentage changes were statistically significant (VAS back pain percentage change: Pr group, 48.78+/-30.91; Fa group, 69.32+/-13.72; p=0.027). The mean pre-and postoperative VAS scores for leg pain were 6.52 and 1.27 in the Pr group and 9.5 and 1.375 in the Fa group, respectively (VAS leg pain percentage change: Pr group, 81.07+/-29.39; Fa group, 75.72+/-15.26; p=0.538, not significant). There were no statistically significant differences in operative time and estimated blood loss and no complications. Conclusions: MI-TLIF outcomes were comparable between primary and revision surgeries. The inherent technique of MI-TLIF is particularly suitable for select failed backs because it exploits the intact paramedian corridor.