Analysis Of Correlative Risk Factors For C5 Palsy After Anterior Cervical Decompression And Fusion For Cervical Degenerative Disease

Objective: To present the cases of 9 patients who developed C5 palsy after anterior decompression and explore the mechanism and correlative risk factors of C5 palsy development,especially with respect to radiographic changes.Methods: A retrospective medical record review was performed on 96 patients who underwent anterior decompression and fusion in our ward from Jan.2015 to Jun.2016.C5 paralysis was defined as deterioration in muscle power of deltoid or biceps brachii by at least 1 grade by manual muscle testing without aggravation of lower extremity function.The patients were divided into two groups one had experienced C5 paralysis(group A with C5 paralysis)and the other one had not(group B without C5 paralysis).Age,gender,duration of the disease,No.of surgical levels,cervical curvature correction,anterior-posterior diameter of the C4/5 foramen,intervertebral height variation and high signal intensity zone(HIZ)of spinal cord in T2-weighted MRI at C4/5 were measured and compared.The risk factors of C5 paralysis were detected by logistic regression analysis.Results: Both operations went well,9 patients suffered postoperative paralysis in the upper extremities(C5 radiculopathy).5 cases occurred from anterior cervical discectomy and fusion,2 in anterior cervical corpectomy and fusion and the rest came from hybrid(ACDF+ACCF).There were no statistic difference in age,gender,duration of the disease,intraoperative blood loss,preoperative of JOA score and HIZ of spinal cord in T2-weighted MRI at C4/5.However cervical curvature correction,anterior-posterior diameter of the C4/5 foramen,intervertebral height variation had significant differences between the two groups.Logistic regression analysis revealed that cervical curvature,diameter of the C4/5 foramen were the key risk factors for the incidence of C5 palsy.Conclusion: For patients who underwent anterior cervical decompression,cervical curvature and diameter of the C4/5 foramen were the key risk factors for the incidence of C5 palsy.Thus proper decompression plan should be made.A larger number of patients will be required to confirm our conclusions.However further more studies with a prospective design shall be required.