Health-related quality of life outcomes with minimally invasive transforaminal lumbar interbody fusion

Long-term prospective outcomes in patients undergoing minimally-invasive spinal fusion for debilitating back pain have not been well studied.

Methods. 318 patients (mean age 63 years, range 19-94) who underwent MITLIF were followed over 7 years. Patients presented with spondylolisthesis (n = 236, 74%), and degenerative disc disease (n = 82, 26%). Health care quality of life measures studied were Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF36) for 7 years. Other outcomes analyzed included pre- operative co-morbidities, age, bone quality, and complications.

Results. 196 females and 122 males were treated. 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 multi-level instrumentation(n = 10, 3%). Estimated blood loss and hospital stay were 128.4 mL and 4.37 days. VAS scores declined from 7.02 preoperatively to 4.3 (p <.01)at one year follow-up. ODI scores declined from 44.1 preoperatively to 28.1 (p <.01) at one year. SF-36 physical component scores(PCS) increased from 30.3 preoperatively to 39.6 (p <.01) at one year. SF-36 mental component scores(MCS) increased from 43.7 preoperatively to 48.5 (p <.01) at one year. Re-operation rate for adjacent level disease was less then 2% over the 7 year period. Approximately 25% of patients comprising mostly elderly, caucasian women had moderate to severe osteoporosis. No device failures were seen in this group of patients. Approximately 60% of patients had at least two of the co-morbidities: high blood pressure, cardiac disease,obesity, diabetes, h/o stroke.