Clinical and Radiographic Outcomes of Modified Unilateral Open-door Laminoplasty with Posterior Muscle-Ligament Complex Preservation for Cervical Spondylotic Myelopathy

Mini The surgical results of modified and traditional open-door laminoplasties were retrospectively compared. There were no differences in neurological outcomes and postoperative complications. However, compared with traditional laminoplasty, modified laminoplasty was associated with better maintenance of cervical curvature and ROM, as well as a lower incidence of postoperative axial symptoms. Study Design. A retrospective comparative study. Objective. The aim of this study was to evaluate the efficacy of modified unilateral open-door laminoplasty with posterior muscle-ligament complex preservation in treating cervical spondylotic myelopathy (CSM). Summary of Background Data. The prevalence of axial symptoms after open-door laminoplasty ranges from 5% to 86%. Current modified laminoplasty techniques cannot satisfactorily reduce postoperative axial symptoms. Methods. From June 2014 to July 2016, 36 patients with CSM underwent modified laminoplasty with posterior muscle-ligament complex preservation (modified group) and 27 patients underwent traditional laminoplasty (control group). The demographics, operation duration, blood loss volume, cervical curvature, cervical curvature index (CCI), range of motion (ROM), cervical posterior muscle volume on magnetic resonance imaging (MRI), axial symptoms, visual analog scale (VAS) score, Japanese Orthopedic Association (JOA) score, neck disability index (NDI), and complications were recorded and analyzed before operation, after operation, and at the final follow-up. Results. Cervical flexion curvature, cervical curvature, ROM, and CCI were better in the modified group than in controls at the final follow-up ( P < 0.01). Postoperative VAS and NDI scores were significantly reduced in the modified group compared with controls (1.15 ± 0.76 vs . 2.63 ± 1.06, 5.67 ± 2.57 vs . 8.89 ± 5.37, respectively) ( P < 0.01). Posterior muscle volume at the hinge side in the modified group was not different at final follow-up relative to that before the operation, whereas it was reduced in controls ( P < 0.01). Finally, the incidence of axial symptoms was significantly lower in the modified group than in controls (6% vs . 22%) ( P = 0.03). Conclusion. Modified unilateral open-door laminoplasty with posterior muscle-ligament complex preservation is effective for treating CSM with good recovery of neurological functions and satisfactory maintenance of cervical curvature and ROM. Furthermore, it reduces the incidence of postoperative axial symptoms compared with conventional open-door laminoplasty. Level of Evidence: 3