gms | German Medical Science

Objective: Laminectomy and laminoplasty are common methods for posterior decompression of the spinal cord in patients with cervical spondylotic myelopathy (CSM), but imply potential disadvantages (e.g. bilateral paraspinal muscle atrophy as a risk factor for instability or chronic pain). We evaluated if an unilateral posterior approach followed by bilateral decompression of the spinal canal could be a less invasive alternative.

Methods: All patients undergoing posterior decompression due to CSM between 2012 and 2018 in our university neurosurgical clinic were included and divided into two groups by surgical procedure: unilateral approach via laminotomy/hemilaminectomy combined with an "undercutting procedure" (group I) and laminectomy/laminoplasty (group II). We investigated the patients’ characteristics, imaging and surgical parameters as well as outcomes and quality-of-life (QOL) after long-term follow-up (ltFU).

Results: From altogether 616 CSM patients with decompressive surgery, 96 patients underwent posterior procedures, accounting within 7yrs for 23% of patients in this population. Mean age was 72.7yrs, with a predominance of the female sex (m:f=1:1:3). The most frequent symptoms were ataxia (74%) and sensory changes (57%) with a mean duration of 14.7mos. The most often location of stenosis was C3-5 (81%) with 1-level stenosis in 85% and 2-level stenosis in 9%, 3- or more level stenosis in 6% of the cases. None of the patients showed signs of spinal instability or required secondary stabilization. 45 patients with lateralized cord compression underwent an unilateral approach with bilateral decompression and 51 patients with circular pathology underwent laminectomy/laminoplasty (both groups: median Naganawa grade 3, i.e. severe cord impingement/deformity). There were no sign. differences of patients’ characteristics, intraop. blood loss, operation time and length of in-patient stay between both groups. Independed from the mode of surgical decompression, the spinal canal was sign. (p<0.001) widened (both groups: median postop. Naganawa grade 0, i.e. no stenosis) and both pain (p=0.026), myelopathic symptoms (mJOA-Score: p=0.003) and QOL (SF-36-PCS/-MCS: p=0.03/p=0.046) were sign. improved at ltFU (mean 28.3mos).

Conclusion: For posterior decompression of CSM, unilateral approach followed by bilateral decompression of the spinal canal via "undercutting" procedure could be an equally effective alternative to laminectomy in case of lateralized compression.