Clinical Features and Surgical Results of Cervical Myelopathy Caused by Soft Disc Herniation

OBJECTIVE There are many causes of cervical myelopathy including trauma, degenerative conditions, tumors and demyelinating disorders. However, myelopathy caused by soft disc herniation might be seen rarely than the spondylosis caused by hard disc. Here, authors retrospectively analyzed the clinical features and results of cervical myelopathy caused by soft disc herniation. METHODS From March 2010 to December 2010, 134 patients with degenerative cervical spinal disease were treated with anterior cervical discectomy and interbody fusion. Among them, 21 patients with cervical myelopathy secondary to cervical soft disc herniation were analyzed. Their clinical features, preoperative and, postoperative clinical results were evaluated by Nurick Grade and Japanese Orthopaedic Association scale (JOA) retrospectively. Preoperative clinical features including duration of myelopathy, pain intensity and postoperative clinical results including improvement rate of myelopathy and radiculopathy were retrospectively analyzed by Nurick Grade and JOA scale. We also evaluated correlation between the duration of symptom, type of the disc herniation, pain intensity and clinical outcome. RESULTS Mean age was 49.7 and male was predominant. Gait disturbance with mild to moderate pain was most common symptom in clinical features. Severe pain was shown in only 9 cases, and the other 12 cases experienced mild to moderate pain. Mean duration of myelopathy was 1.18 month. The mean JOA scores were 11.22 before surgery and 14.2 after surgery. The mean Nurick grades were 2.78 before treatment and 1.67 after treatment. Neurologic status of mild or moderate pain group on preoperative state is worse than that of severe pain group. The patients with duration of myelopathy symptom (<1 month) showed lower clinical improvement rate than the patients with myelopathy over 1 month. Patients with median type of disc herniation showed poorer neurological status than those with paramedian type of herniation in preoperative state. CONCLUSION Authors reviewed the clinical features and surgical outcome of the cervical myelopathy secondary to cervical soft disc herniation. We presumed that patients of more than one month of symptom duration, mild to moderate initial symptom would be related with better postoperative improvement rate.