Functional and Radiological Outcomes in Minimally Invasive Surgery-Assisted Transforaminal Lumbar Interbody Fusion in...

Minimally invasive surgery-assisted transforaminal lumbar interbody fusion (MIS-TLIF) is increasingly used for the surgical management of selected patients with degenerative lumbar spine disease. By utilizing a muscle-sparing approach, MIS-TLIF aims to achieve neural decompression and spinal stabilization while reducing approach-related morbidity. This study evaluated the functional and radiological outcomes of MIS-TLIF in patients with degenerative lumbar disease.

A prospective observational study was conducted at Institute of Medical Sciences and SUM Hospital, Bhubaneswar, India, on 30 consecutive patients with lumbar degenerative disease who had failed at least six months of conservative treatment. Patients included in the study had unilateral lower-limb radiculopathy associated with radiologically confirmed degenerative lumbar pathology. All patients underwent single-level unilateral MIS-TLIF using a tubular retractor system, local autologous bone graft, PEEK (polyetheretherketone) or titanium interbody cage, and pedicle screw fixation. Intraoperative localization and implant positioning were performed using fluoroscopy; navigation and routine neuromonitoring were not used. Clinical outcomes were assessed using the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). Radiological assessment included intervertebral disc height, foraminal height, segmental stability, and fusion status. Patients were followed for six months postoperatively.

Thirty patients were included, with a mean age of 51.7 ± 2.3 years (range, 40-62 years). Seventeen procedures were performed at L4-L5 and 13 at L5-S1. Significant postoperative improvement was observed in VAS and ODI scores at all follow-up intervals compared with baseline (p < 0.001). The mean VAS decreased from 7.67 ± 1.09 preoperatively to 1.03 ± 0.72 at six months, while the mean ODI decreased from 63.8 ± 7.51 to 11.5 ± 2.79. Intervertebral disc height increased from 6.88 ± 1.36 mm to 12.1 ± 1.28 mm at two weeks and remained stable at six months. Foraminal height increased from 13.7 ± 1.88 mm to 18.8 ± 1.42 mm at two weeks and remained 18.6 ± 1.42 mm at six months. Fusion was demonstrated in nine of 30 patients (30%) at six months according to the Modified Bridwell criteria on plain radiographs. The mean operative time was 178 ± 38.9 minutes, estimated blood loss was 139 ± 18.2 mL, and mean hospital stay was 3.33 ± 0.99 days. Recorded complications included dural tear, pedicle screw malposition, and postoperative hematoma.

MIS-TLIF demonstrated favorable short-term clinical and radiological outcomes in this prospective cohort. However, the small sample size, six-month follow-up, absence of a comparator group, lack of blinded outcome assessment, and plain-radiograph-based fusion assessment limit conclusions regarding definitive long-term fusion and comparative efficacy. Larger studies with longer follow-up and appropriate comparator groups are required.