Background: Cervical spondylotic myelopathy increases with age, but not all cases are symptomatic. It is usually diagnosed clinically and radiologically (X-ray and magnetic resonance imaging). Surgical treatment is indicated in severe symptomatic cases, while treatment controversy exists in the presence of less severe cases. Anterior and posterior approaches are generally used for decompression with no significant differences in the results of both. Methods: A total of 287 patients of cervical spondylotic myelopathy were treated at our hospital between January 2004 and December 2015. Only 140 patients were eligible for our study. They had at least 5 years of follow-up using full clinical scores and radiological evaluation. They were divided into two groups: group I with 73 patients (aged 23–79 years) underwent posterior decompression, lateral mass instrumentation, and fusion, while group II with 67 patients (aged 33–70 years) underwent anterior decompression, instrumentation, and fusion. Neck Disability Index, local score, and X-ray were used in the evaluation of the patients. Results: Preoperative mean ± standard deviation of Neck Disability Index of both the groups was 32.06 ± 6.33 and 29.88 ± 5.48, which improved in the last visit (>5 years) to 5.81 ± 7.39 and 2.94 ± 5.48 for groups I and II, respectively (p value <0.05). The local score of groups I and II was (P = 1, F = 21, G = 31, E = 19) and (P = 1, F = 12, G = 36, E = 18), which on discharge day improved to (P = 1, F = 4, G = 12, E = 55) and (P = 0, F = 3, G = 6, E = 58) at last follow-up, respectively. Fusion rate was nearly equal for both the groups during all the follow-up intervals and it was 91.1% and 91.7% in the last follow-up. Conclusion: There were no significant differences in the clinical and radiological results between the anterior and posterior approaches used in the surgical treatment of spondylotic cervical myelopathy. However, statistically significant results of Neck Disability Index of anterior approach were not clinically important and may be due to changes in the size and shape of the neck in group II.
Duality Between the Local Score of One Sequence and Constrained Hidden Markov Model