The Change of Range of Motion at Anterior Compression of the Cervical Cord after Laminoplasty in Patients with Cervical Spondylotic Myelopathy

Objective Degenerative diseases of the spine, such as cervical spondylotic myelopathy (CSM), are increasing among the old age population, and surgical treatment of CSM is becoming more and more common. The aim of this study was to investigate how functional recovery can be influenced by anterior compression of the spinal cord (ACS) after laminoplasty for treatment of patients with CSM. Methods We retrospectively analyzed 32 patients admitted to Ewha Womans Mok-Dong Hospital with CSM who underwent open-door laminoplasty from January 2012 to December 2014. We divided patients into 2 groups according to whether ACS was or not preoperatively. Each group was analyzed clinical and radiological parameters which were Japanese Orthopedic Association (JOA) scores and its recovery rate, sagittal alignment and range of motion (ROM). Results The mean duration of symptom was 11.2 months (range, 6-22 months). A significant difference in recovery rate of the total JOA score was shown between the 2 groups, especially upper extremity motor function. No difference in preoperative JOA score between the 2 groups, but recovery rate of each group was 20.05%±18.1%, 32.21%±25.4%, statistically significant (p<0.005). Upper motor and sensory function was not significantly different in the 2 groups. Preoperative, postoperative and preservation of ROM was 44.3°±10.1°, 41.8°±15.7°, 87.9%±35.4% each at ACS (-) group. A significant difference in postoperative ROM was identified between ACS (-) and ACS (+) group. Postoperative anterior compression of the spinal cord was recognized 14 cases which were classified from its causes. Conclusion Cervical ROM decreased significantly after laminoplasty, but 85.3% of the preoperative ROM was preserved. The postoperative reduction of ROM in group with anterior compression of spinal cord was identified.