Clinical outcomes of unpowered osteotome-assisted unilateral biportal endoscopy (UBE) for the treatment of lumbar spinal stenosis: a retrospective cohort study

Retrospective cohort study. To compare the clinical and radiographic outcomes of unpowered osteotome-assisted versus powered drill-assisted unilateral biportal endoscopy (UBE) for the treatment of single-level lumbar spinal stenosis. We retrospectively reviewed 127 consecutive patients who underwent UBE using either an unpowered osteotome or a powered drill. Perioperative variables, blood loss-related parameters, complications, and serial clinical outcomes were collected. Postoperative CT and MRI were used to compare the adequacy of decompression and facet preservation between the two techniques. Clinical outcomes were comparable between the two groups. At the final follow-up, the JOA score was 21.07 ± 2.76 in the unpowered osteotome group and 21.74 ± 2.06 in the powered drill group (p = 0.151), whereas the corresponding VAS score for leg pain was 2.31 ± 0.46 versus 2.47 ± 0.47 (p = 0.451). Total blood loss did not differ significantly between groups (257.42 ± 101.76 vs 247.78 ± 117.89 mL, p = 0.165). Operative time was significantly shorter in the unpowered osteotome group (101.64 ± 34.76 vs 124.76 ± 46.73 min, p = 0.041). At 12 months, radiographic parameters, including the lateral recess angle, lateral recess height, superior articular distance, spinal canal area, and facet joint preservation rate, were comparable between groups. In this retrospective cohort, unpowered osteotome-assisted UBE achieved clinical and radiographic outcomes comparable to those of powered drill-assisted UBE, without increasing blood loss or complications, while shortening operative time.