Biportal endoscopic multisegment decompression laminectomy for cervical spondylotic myelopathy

OBJECTIVE: This case series introduces a modified biportal endoscopic technique for treating multilevel cervical spondylotic myelopathy (CSM) and evaluates midterm clinical and radiological outcomes. METHODS: Biportal endoscopic decompression laminectomy using the spinous process floating technique was performed on patients with multilevel CSM. Radiographic measurements, including the C2-7 Cobb angle, range of motion, and cross-sectional area (CSA) of the dural sac and extensor muscles, were assessed preoperatively and 1-year postoperatively. Clinical outcomes were analyzed using the visual analog scale (VAS) and Japanese Orthopaedic Association (JOA) scale scores, with detailed complications documented. RESULTS: Ten patients with 26 spinal segments underwent this surgery. The mean VAS and JOA scale scores showed significant improvement at the final follow-up: VAS neck score 6.0 ± 1.0 to 3.2 ± 0.4, VAS arm pain score 7.7 ± 0.6 to 2.4 ± 0.7, and JOA score 12.3 ± 0.6 to 15.5 ± 0.5 (all p < 0.05). The mean C2-7 Cobb angle gradually decreased after surgery but this increase was not statistically significant (9.9° ± 7.7° preoperatively, 7.4° ± 8.7° at 1 year, and 7.0° ± 8.6° at final follow-up). The reduction in the CSA of neck extensor muscles was minimal (12.9% ± 9.9% reduction at 1 year). The dural sac CSA expansion was sustained at 1 year (54.6% ± 36.6% increase). Delayed stress fractures of the spinous process occurred in 3-segment operations. CONCLUSIONS: Biportal endoscopic posterior cervical laminectomy for multilevel CSM was performed successfully without serious complications. Biportal endoscopic cervical laminoplasty significantly expanded the central canal in patients with CSM and provided favorable clinical outcomes after surgery. This technique offers a minimally invasive alternative to traditional surgery.