Comparative observation of C5 nerve root palsy after posterior surgical treatment of multilevel cervical spondylotic myelopathy / 中国医师进修杂志

ABSTRACT

Objective To compare the incidence of C5 nerve root palsy after laminoplasty and laminectomy with internal fixation for treating multilevel cervical spondylotic myelopathy (MCSM).Methods From January 2008 to August 2012,98 patients with MCSM were treated with laminoplasty (47 patients,group A) or laminectomy (51 patients,group B) with internal fixation.All the patients were followed up for 13-56(26.5 ± 7.9) months.In both groups,Cobb's method was applied to measure cervical lordotic angle,and Ishihara's method was conducted to measure cervical curvature index (CCI) before and after operation.The incidence of C5 nerveroot palsy was recorded and compared.Results The incidence of C5 nerve root palsy in group A was 2.1％ (1/47),while 21.6 ％ (11/51) in group B (x2 =5.430,P ＜ 0.05).The JOA scores in group A and group B before and after operation and improvement rate of JOA scores had no significant difference (P＞ 0.05).The cervical lordotic angle and CCI in group A and group B before and after operation had no significant difference (P ＞ 0.05).The improvement rate of CCI between two groups had no significant difference (P ＞ 0.05).All of 11 patients with C5 nerve root palsy were group B 1,and other 40 patients were group B2.The improvement rate of CCI in group B1 was significantly higher than that in group B2 [(38.7 ± 18.3)％ vs.(22.1 ± 12.1)％](t =1.772,P＜ 0.05).Conclusions Compared with laminoplasty,laminectomy with internal fixation has a higher incidence of C5 nerve root palsy.The C5 nerve root palsy may be associated with postoperative increase of cervical lordosis angle.Moreover,tethering of the C5 root may he one of its important pathomechanisms.