Abstract
Introduction
The traditional treatment for lumbar stenosis with instability is laminectomy and posterolateral arthrodesis, ± interbody fusion. However, laminectomies remove the posterior elements and decrease available surface area for spinal fusion. A sublaminar decompression can achieve adequate decompression while preserving bone surface area to enhance spinal fusion.
Material and Methods
A retrospective review of 72 patients with degenerative pathology who underwent sublaminar decompression by a single surgeon at a single institution was performed. Data collected included baseline demographics, preoperative symptoms, operative data, symptoms at last follow-up (LFU), time to fusion, fusion rate, and radiographical measurements, consisting of thecal sac cross-sectional area, bilateral lateral recess height, and bilateral foraminal diameter on preoperative and postoperative scans. Paired t-tests were used to test significance of these changes.
Results
31 males and 41 females with median age 60 (range: 19-78) years underwent sublaminar decompression with fusion. A mean of 1.9 levels were fused. The mean VAS pain score improved from 6.8 preoperatively to 3.0 at last follow-up. Fusion imaging was available for 44 patients, with a fusion rate of 91%, and median time to fusion of 10.7 (range: 3.2-17.4) months. Preoperative and postoperative mean thecal sac cross-sectional area, right lateral recess height, left lateral recess height, right foraminal diameter, and left foraminal diameter were 153 and 209 mm2 (p = 0.000012), 5.9 and 5.9 mm (p = 0.5), 5.7 and 6.3 mm (p = 0.014), 4.6 and 5.2 mm (p = 0.0084), and 4.2 and 5.2 mm (p = 0.00012), respectively.
Conclusion
This study demonstrates that patients had sufficient decompression, as evidenced by improvement in clinical symptoms and statistically significant increases in thecal sac cross-sectional area and bilateral foraminal diameter. Therefore, sublaminar decompression may be an effective alternative to laminectomy in treating central and foraminal stenosis. Fusion rates in this study also compare favorably to traditional posterolateral technique with radiographic pseudoarthrosis occurring in only four patients.