gms | German Medical Science

Objective: In Germany and the US, most patients with cervical spinal canal stenosis are treated by mono- or multisegmental anterior cervical decompression and fusion (ACDF) or corpectomy. Major disadvantages are adjacent segment disease (ASD) and, especially in corpectomy, hardware failure. Laminectomy and laminoplasty are easier to perform and rarely result in ASD. However, the risk of kyphotic deformation is higher, possibly due to bilateral detachment of the paraspinal muscles and destabilization of both facet joints. To overcome these disadvantages, we evaluated the usefulness of unilateral laminotomy and bilateral decompression in undercutting technique.

Method: A prospective non-randomized trial was initiated and 25 patients with symptomatic cervical spinal canal stenosis were included up to now. In all patients, preoperative magnetic resonance (MR) imaging and pre- and postoperative computerized tomography (CT) were obtained. CTs in sagittal and axial plane were used to measure the width and the area of the spinal canal at the stenotic segment(s). Neck disability index (NDI), modified Japanese Orthopedic Association (JOA) score, motor and somatosensory evoked potentials (MEP, SEP) were measured before and 5 days after surgery.

Results: A total of 25 patients were included till now. 11 patients suffered from mono segmental and 14 of bi-segmental stenosis. During the follow-up period of 6 weeks we did not observe any complication. SEP and MEP remained stable or improved in all patients. In general patients received less pain medication. Directly after surgery the JOA score improved from 10 to 11 and after 6 weeks to 15. The NDI improved from 13 to 11 and after 6 weeks to 7. The width and the area of the spinal canal improved from 0.8-1.2 (mean 1.1) and 0.65-0.95 (mean 0.85) cm² before surgery to 1.32-1.6 (mean 1.45) and 1.35-1.61 (mean 1.46) cm² after surgery.

Conclusions: Unilateral laminotomy and bilateral decompression with undercutting to the opposite side shows equal results for decompression of the cervical spine compared to previous publications using laminectomy and laminoplasty. This is an alternative approach to reduce muscle trauma by a dorsal approach to the spine. This ongoing study will compare these findings with standard decompression techniques like laminectomy and laminoplasty using JOA (Japanese orthopedic association) score and neck disability index (NDI).