Preserving Paraspinal Integrity: Functional and Radiological Results of Spinous Process–Splitting Lumbar Decompression

Background: Lumbar canal stenosis is a leading cause of neurogenic claudication and disability. Conventional laminectomy decompresses neural elements but often results in paraspinal muscle atrophy, ligament disruption, and instability. Spinous process–splitting laminectomy (SPSL) preserves musculoligamentous integrity while achieving adequate decompression. Objective: To evaluate clinical, functional, and radiological outcomes of SPSL in single- and two-level lumbar canal stenosis. Methods: Twenty patients underwent SPSL and were assessed preoperatively and at 6 months postoperatively using VAS, ODI, MMT, 6MWD, and lumbar lordosis (LL). Operative time, blood loss, complications, and hospital stay were recorded. Correlation analyses identified predictors of functional recovery. Results: SPSL significantly improved outcomes: VAS decreased from 6.65 ± 1.34 to 0.45 ± 1.05 (p<0.0001), ODI from 30.95 ± 7.7 to 7.55 ± 3.99 (p<0.005), MMT from 3.3 ± 0.73 to 4.7 ± 0.4 (p<0.0001), and 6MWD from 250.85 ± 103.1 m to 651.15 ± 131.3 m (p<0.0001). LL improved from 34.5 ± 6.6° to 39.75 ± 3.79° (p<0.008). One patient developed a superficial wound infection managed conservatively. Lower preoperative 6MWD correlated with greater functional gains (r = -0.48, p = 0.016). Conclusion: SPSL is a safe, reproducible technique for lumbar decompression, providing effective pain relief, functional improvement, and restoration of spinal alignment while minimizing muscle and ligament injury.