Abstract
OBJECTIVE: To assess the feasibility and clinical results of microscopic minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using a novel tapered tubular retractor that preserves the multifidus. METHOD: A total of 122 patients underwent MIS-TLIF using a tapered tubular retractor system from March 2016 to August 2017. Perioperative parameters and follow-up outcomes were reviewed. RESULTS: The follow-up period was 23.95 ± 1.43 months. The operative time averaged 130.48 ± 34.44 minutes. The estimated blood loss was 114.10 ± 96.70 mL. The mean time until ambulation was 16.33 ± 6.29 hours. The average visual analogue scale (leg/waist) and Oswestry Disability Index scores (preoperative to last follow-up) improved from 4.93 ± 2.68/3.74 ± 2.28 to 0.34 ± 0.77/0.64 ± 0.74 and from 59.09% ± 22.34 to 17.04% ± 8.49, respectively. At the last follow-up, 98.36% of the patients achieved solid fusion. Cerebrospinal fluid leakage occurred in two cases. The asymptote of the surgeon's learning curve occurred at the 25th case. There were no significant differences between the preoperative qualitative and quantitative analyses of multifidus muscle fatty infiltration and those at the final follow-up. CONCLUSION: MIS-TLIF can be performed safely and effectively using this tapered tubular retractor system, which helps preserve the multifidus.