With the growing number of justifications for and popularity of minimally invasive surgery (MIS) for lumbar spinal fusion, a large-scale outcomes study comparing MIS, and conventional procedures is necessary. The researchers queried about the Quality Outcomes Database for patients with degenerative spine illness and who underwent elective lumbar fusion. They used ideal matching to construct two extremely homogeneous groups in terms of 33 baseline factors, with a 1:2 ratio between patients who underwent MIS and those who received open lumbar fusion (including demographic characteristics, comorbidities, symptoms, patient-reported scores, indications, and operative details). Overall satisfaction, reduction in the Oswestry Disability Index (ODI), and reduction in back and leg discomfort, as well as hospital length of stay (LOS), operating time, reoperations, and inadvertent durotomy rate, were all studied. On the North American Spine Society measure, satisfaction was characterized as a score of 1 or 2. The MCID (minimal clinically relevant difference) in ODI was defined as a drop of ≥ 30% from baseline. 

The MIS and open groups had 1,483 and 2,966 patients. At 3 months, patients who had MIS fusion had a higher chance of being satisfied (OR 1.4, p = 0.004); at 12 months, there was no difference (OR 1.04, p = 0.67). Lumbar stenosis, single-level fusion, a higher American Society of Anesthesiologists Physical Status Classification System grade, and the lack of spondylolisthesis were linked to a higher likelihood of MIS satisfaction than open surgery. At 3 months (mean difference 1.61, p = 0.006; MCID OR 1.14, p = 0.0495) and 12 months (mean difference 2.35, p < 0.001; MCID OR 1.29, p < 0.001), patients in the MIS group had slightly lower ODI scores. MIS was also linked to reducing leg and back pain at both follow-up time points.

MIS was linked to a higher likelihood of satisfaction three months after lumbar fusion in patients with degenerative spinal conditions. At the 12-month follow-up, there was no discernible difference. MIS had a slight but persistent advantage in lowering the ODI and back and leg pain, linked to a lower reoperation rate. The surgical time and incidental durotomy rate were not different between the two groups; however, the MIS group had a shorter LOS. Patients who received MIS were less likely to require revision surgery at 12 months (4.1% vs 5.6%, p = 0.032).