Cord-lamina angle and foraminal diameter as key predictors of C5 palsy after anterior cervical decompression and fusion surgery.

Background: C5 nerve root palsy (C5P) is a rare but documented complication after cervical decompression surgery. Despite multiple proposed mechanisms, research on risk factors for C5P after anterior cervical discectomy and fusion (ACDF) remains insufficient.

Objective: The aim of this study was to identify specific risk factors associated with C5 nerve root palsy after ACDF.

Methods: A total of 108 patients who underwent ACDF surgery were divided into C5P and non-C5P groups. The basic data, preoperative Japanese Orthopaedic Association score, cervical curvature correction at C2-7 and C4-5, anterior-posterior diameter (APD) at C4/5, spinal-cord-lumbar angle (CLA) at C4/5, foramen magnum occipitalis at C4/5, and the presence of preoperative high-signal areas in the C4/5 spinal cord on T2-weighted magnetic resonance imaging, were present. Risk factors associated with C5P were identified using logistic regression analysis.

Results: There were no significant differences between the two groups in terms of age, gender, disease duration, diagnosis, preoperative Japanese Orthopaedic Association score, number of operated segments, APD, or high-intensity zone. LRA showed that a larger CLA and narrower FD at C4/5 were the main risk factors for the development of C5P (P < 0.05).

Conclusion: A larger cord-lamina angle and a narrower foraminal diameter at C4/5 are significant risk factors associated with the development of C5 palsy following ACDF.