Minimally-invasive transforaminal lumbar interbody fusion (MITLIF) is commonly performed, but long-term prospective quality of life outcomes are lacking.

     318 patients (63 years, 19-94) who underwent MITLIF with percutaneous pedicle screw instrumentation were followed long-term (range, 2-7 years). Patients presented with spondylolisthesis (n=236, 74%), and degenerative disc disease (n=82, 26%). 196 women and 122 men were treated.

     Oswestry Disability Index (ODI), Short Form-36 (SF36) Physical Component Scores (PCS) and Mental Component Scores (MCS) were recorded prospectively . Blood loss, length of stay, and adjacent segment disease requiring reoperation were noted.

     Levels fused included L1-2 (n=3, 1%), L2-3 (n=19, 6%), L3-4 (n=34, 11%), L4-5 (n=163, 51%), L5-S1 (n=89, 28%), or multiple levels (n=10, 3%). Mean blood loss was 128.4 mL. Mean hospital stay was 4.37 days. ODI scores declined from 44.1 preoperatively to 28.1 (p<0.05) at one year, and 30.4 (p<0.05) during long-term follow-up. SF36 physical component scores (PCS) increased from 30.3 preoperatively to 39.6 (p<0.05) at one year and 38.7 (p<0.05) during long-term follow-up. SF36 mental component scores increased from 43.7 preoperatively to 48.5 (p<0.05) at one year and 49.1 (p<0.05) during long-term follow-up. Re-operation rate for adjacent level disease was less than 2% for the long-term follow-up period.

     This is a retrospective study.

     This prospective study shows statistically significant health care outcome improvements after MITLIF.

     These improvements are durable and remain statistically significant over the long-term, up to seven years. In addition to minimal blood loss and short hospital stay, there was a very low rate of adjacent segment disease requiring re-operation.