Comparison Between Anterior And Posterior Decompression With Instrumentation For Cervical Spondylotic Myelopathy

Object. A variety of anterior, posterior, and combined approaches exist todecompress the spinal cord, restore sagittal alignment, and avoid kyphosis, butthe optimal surgical strategy remains controversial. The authors compared theanterior and posterior approach used to treat multilevel cervical spondyloticmyelopathy (CSM), focusing on sagittal alignment and clinical outcome.Methods. The authors studied48patients with CSM who underwentmultilevel decompressive surgery using an anterior or posterior approach withinstrumentation (24patients in each group), depending on preoperativesagittal alignment and direction of spinal cord compression. In the anteriorgroup, a1–2-level corpectomy was followed by placement of an expandabletitanium cage. In the posterior group, a multilevel laminectomy and posteriorinstrument tation using lateral mass screws was performed. Postoperativeradiography and clinical examinations were performed after1week,12months, and at last follow-up (range3–33months, mean16months). Theradiological outcome was evaluated using measurement of the cervical andsegmental lordosis. Results. Both the posterior multilevel laminectomy (with instrumentation)and the anterior cervical corpectomy (with instrumentation) improved clinicaloutcome. The anterior group had a significantly lower preoperative cervicaland segmental lordosis than the posterior group. The cervical and segmentallordosis improved in the anterior group by8.8and6.2°, respectively, anddeclined in the posterior group by6.5and3.8°, respectively. The loss ofcorrection was higher in the anterior than in the posterior group (2.0vs0.7°,respectively) at last follow-up.Conclusions. These results demonstrate that both anterior and posteriordecompression (with instrumentation) are effective procedures to improve theneurological outcome of patients with CSM. However, sagittal alignment maybe better restored using the anterior approach, but harbors a higher rate of lossof correction. In cases involving a preexisting cervical kyphosis, an anterior orcombined approach might be necessary to restore the lordotic cervicalalignment.