Cervical Spondylotic Myelopathy:Postoperative Results and Prognostic Factors

Kim, Hyun Jib; Chung, Chun Kee

Abstract

There are many factors affecting surgical results of cervical spondylotic myelopathy. Age, duration of symptom, neurologic status, and direction of surgical approach are side to have prognostic implications. Also a high signal intensity on T2 weighted magnetic resonance imaging(HSI on T2WI) is insisted as a poor prognostic factor. We analyzed these factors in 56 patients treated over a 10-year period retrospectively. Statistical analysis was done using chi square, Mantel-Haenszel. Cochran-Mantel-Haenszel, Wilcoxon, and logistic procedure. We preferred anterior decompression when compressive lesions existed ventrally. However posterior decompression was performed in a 4 or more level stenosis. Age ranged from 22 to 74 year(mean : 50.8). 25 patients underwent the anterior procedure, 33 patients the posterior procedure, and 2 both procedures. Neurologic status was graded both preoperatively and at follow-up using the Nurick grading system from 1 to 5. The preoperative Nurick grade was 2.75+/-0.16(mean+/-SE). Mean follow-up period was 13.8 months(SE 0.14). The follow-up Nurick grade was 2.125+/-0.14, and these was noted an improvement of 0.63+/-0.12. The amount of improvement was equivalent between the anterior and the posterior approaches(0.52 vs. 0.73 respectively, p=0.67). There was no mortality. Uni- and multivariant analysis demonstrated that age, duration of symtom and HSI on T2WI had no significant effect on either follow-up Nurick grade or amount of improvement, but the preoperative Nurick grade had a significant effect(p<0.000). Comparable results can be obtained with either approaches if chosen properly. Only the preoperative Nurick grade has the prognostic value.