C3-6 Laminoplasty for Cervical Spondylotic Myelopathy Maintains Satisfactory Long-Term Surgical Outcomes

Study Design Prospective cohort study. Objective To clarify long-term surgical outcomes of C3-6 laminoplasty preserving muscles attached to the C2 and C7 spinous processes in patients with cervical spondylotic myelopathy (CSM). Methods Twenty patients who underwent C3-6 open-door laminoplasty for CSM and who were followed for 8 to 10 years were included in this study. Myelopathic symptoms were assessed using Japanese Orthopaedic Association (JOA) score. Axial neck pain was graded as severe, moderate, or mild. C2-7 angle was measured using lateral radiographs of the cervical spine before surgery and at final follow-up. Results Mean JOA score before surgery (11.7) was significantly improved to 15.2 at the time of maximumrecovery (1 year after surgery), declining slightly to 14.9 by the latest follow-up. Late deterioration of JOA score developed in eight patients, but was unrelated to the cervical spine lesions in each case. No patient suffered from prolonged postoperative axial neck pain at final follow-up. The mean C2-7 angle before surgery (13.8 degrees) significantly increased to 19.2 degrees at final follow-up. Conclusions C3-6 laminoplasty preserving muscles attached to the C2 and C7 spinous processes in patients with CSM maintained satisfactory long-term neurologic improvement with significantly reduced frequencies of prolonged postoperative axial neck pain and loss of C2-7 angle after surgery.