Search

Background: Lumbar spinal stenosis is a prevalent and increasingly important cause of low back pain, leg pain, and walking impairment. Minimally invasive decompressive techniques such as spinous process (SP) osteotomy have become more common in recent years. The main aim of this study was to investigate the proportion of complete SP union and whether complete radiological healing after the osteotomy is associated with superior clinical outcome after 2 years., Methods: In this retrospective cohort study, 149 patients were included from the Spinal Stenosis Trial, a part of the NORwegian Degenerative spondylolisthesis and spinal STENosis study. Computed tomography imaging was performed 2 years postoperatively. The number of osteotomies and the number of SP unions were recorded. Patients were divided into groups based on the degree of union: nonunion, partial union, and complete union. Rate of success (>30% improvement in Oswestry Disability Index [ODI]) and mean change in ODI were the primary outcome measures. We compared the differences between baseline and follow-up between the Degree of Union groups., Results: The study included 102 of 149 eligible patients. Ten patients (9.8%) were classified as having nonunion, 15 (14.7%) as having partial union, and 77 (75.5%) as having complete union. Of the 155 osteotomies, there were 122 classified as union (77%). The success rate was 74%, with no influence of SP union. The mean change in the ODI was -20.1 (95% CI -37.0, 14.2) with no influence of SP union., Conclusions: We found no influence of SP union, classified by computed tomography, on clinical outcome 2 years after SP osteotomy in patients with lumbar spinal stenosis., Clinical Relevance: Supplying useful information about SPO to assist surgeons in the choice of decompressive technique., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2024 ISASS. To see more or order reprints or permissions, see http://ijssurgery.com.)

Background: Currently, there are different routines in Norwegian hospitals regarding how recent magnetic resonance imaging (MRI) of the lumbar spine should be performed before surgery. Patients with lumbar spinal stenosis from the Norwegian degenerative spondylolisthesis and spinal stenosis study, who had 2 preoperative MRIs performed within the year before surgery, were included. The aim of the present study was to evaluate the utility of repeated preoperative MRI for patients undergoing decompressive spine surgery for degenerative spinal stenosis., Methods: For all included patients, the changes between the 2 preoperative MRIs were investigated for disc degeneration (Pfirrmann's classification), foraminal stenosis (Lee's classification), spondylolisthesis, and central canal stenosis (Schizas score and dural sac cross-sectional area)., Results: A total of 65 patients (78 levels) were included. Thirty-seven patients were women, and the mean age was 67 (range 48-79) years. Schizas score showed a clinically meaningful change of ±2 or 3 grades in 5 levels, and dural sac cross- sectional area was reduced in 47 levels with a mean change of -2.3 mm 2 . Three levels had a clinically relevant change in grade of foraminal stenosis of ±2. For disc degeneration, 53 of the levels had no change, and the rest of the levels had a change of ±1 grade. Increased spondylolisthesis was measured at 21 levels, and the mean slip was <2 mm. Also, 4 levels had >2 mm slip., Conclusion: For patients undergoing surgery for lumbar spinal stenosis, repeated MRI within the year before planned surgery showed few significant changes in common radiological parameters. The benefit for the surgeon of repeat MRI is therefore limited., Competing Interests: Declaration of Conflicting Interests : The authors report no conflicts of interest in this work., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2023 ISASS. To see more or order reprints or permissions, see http://ijssurgery.com.)