En Bloc Cervical Laminoplasty While Preserving the Posterior Structure with Arcocristectomy in Cervical Spondylotic Myelopathy.

Aim: To evaluate the clinical success of the en bloc laminoplasty and impact of the arcocristectomy on postoperative axial pain of the patients with cervical spondylotic myelopathy (CSM).

Material And Methods: A retrospective review of 81 patients with CSM who underwent en bloc cervical laminoplasty while preserving posterior structure of the cervical spine during the period from 2007 to 2014 was performed. Arcocristectomy was performed if the C6-7 level was included in the surgery. The posterior spinal elements and muscles attached to the spinous process of C2 and C7 were preserved. Thus, postoperative deformity of the cervical spine could be avoided. The neurological status of the patients was assessed using the modified Japanese Orthopedic Association (JOA) scale. The neurological recovery rate was calculated according to the Hirabayashi method.

Results: The mean modified JOA scale score was 11.4±2.4 preoperatively and 15.0±3.9 postoperatively. The neurological recovery rate was 68.6%. C7 arcocristectomy was performed in 19 patients. No axial pain was noted in the first 2 postoperative months. Keyhole foraminotomies were performed in 11 patients and radicular pain completely resolved after surgery. Temporary C5 nerve root palsy was observed in 3 patients. Mean cervical spine lordosis was 10.6o±10.5o preoperatively and 8.6o±9.5o postoperatively. No postoperative spinal instability or kyphotic deformity was noted.

Conclusion: En bloc cervical laminoplasty while preserving posterior structure is useful in preventing postoperative spinal malalignment and axial pain. Arcocristectomy is an effective technique for the prevention of postoperative axial pain in patients with C6-7 spinal stenosis.