Comparison of 0-degree and 30-degree endoscopes in unilateral biportal endoscopic decompression for lumbar spinal stenosis: Which preserves the facet joint better?

Abstract

PurposeThis study aimed to compare the radiological and clinical outcomes of unilateral biportal endoscopic lumbar decompression (UBELD) performed with 0-degree and 30-degree endoscopes.MethodsPatients with single-level lumbar spinal stenosis without instability were included in this single-center retrospective study. The patients were categorized into two groups on the basis of the angle of the endoscope used by the surgeon. Clinical outcome measures included JOA scores, Oswestry Disability Index (ODI), and VAS scores for low back and leg pain, assessed preoperatively and at 12 months postoperatively. Ipsilateral and contralateral osteotomy angles, overhang distance, and ipsilateral inferior articular process (IAP) area were measured.ResultsAmong the 81 patients who met the inclusion criteria, a 30-degree endoscope was used in 51 patients, while a 0-degree endoscope was used in 30 patients. The JOA score, VAS-leg score, VAS-low back pain score, and ODI significantly improved in both groups at the final follow-up period (p < 0.001). Postoperative VAS-low back pain score in the 30-degree endoscope group was significantly lower than that in the 0-degree endoscope group (1.4 vs 2.9, p < 0.001). Significant differences were also observed in the ipsilateral osteotomy angle (77.8° vs 87.8°, p < 0.001), overhang distance (-1.16 mm vs -4.39 mm, p < 0.001), and the postop/preop ratio of ipsilateral IAP area (0.74 vs 0.69, p = 0.006). Radiological parameters for facet preservation were better in the 30-degree endoscope group.ConclusionSuccessful clinical improvements were achieved with both endoscope angles. However, facet preservation parameters were more favorable in the 30-degree endoscope group compared to the 0-degree endoscope group.