Comparative study of two spinous process (SP) osteotomy techniques for posterior decompression surgery in lumbar spinal stenosis: SP base versus splitting osteotomy

Gun Woo Lee, Myun-Whan Ahn

To compare the postoperative clinical and radiological outcomes of the SP base osteotomy versus SP splitting techniques for PD for treating LSS. Of 139 patients who underwent PD surgery for LSS, 97 who met the study criteria were enrolled in the study. Group A comprised 53 patients who underwent SP base osteotomy, and group B included 44 patients who underwent SP splitting osteotomy. The primary study endpoint was intensity of lower back pain (LBP) and pain radiation to the lower extremities measured with the visual analogue scale (VAS). Secondary endpoints included (1) clinical outcomes assessed using Oswestry disability index and 12-short health form questionnaire; (2) surgical outcomes; and (3) procedure-related complications. LBP was more or less greater in SP base osteotomy group than in SP splitting osteotomy group at postoperative 1 week and 1 year (P = 0.04 and 0.03), but radiating pain was no significant difference between the groups throughout the 1-year follow-up period. One year after the surgery, the fusion rate at the osteotomized site was significantly greater in SP splitting osteotomy group (77%) than in SP base osteotomy group (55%) (P = 0.03). Clinical outcomes, surgical outcomes, and complications did not differ significantly between groups during follow-up times. The two SP osteotomy techniques offer excellent clinical and radiological outcomes at least for the first year after the surgery. In fusion rate at the osteotomized SP site, the SP splitting technique was superior to the SP base osteotomy technique. These slides can be retrieved under Electronic Supplementary Material.