[Research progress of etiologies for C 5 palsy after cervical decompression].

Objective: To review the definition and possible etiologies for C ₅ palsy.
Methods: The literature on C ₅ palsy at home and abroad in recent years was extensively reviewed, and the possible etiologies were analyzed based on clinical practice experience.
Results: There are two main theories (nerve root tether and spinal cord injury) accounting for the occurrence of C ₅ palsy, but both have certain limitations. The former can not explain the occurrence of C ₅ palsy after anterior cervical spine surgery, and the latter can not explain that the clinical symptoms of C ₅ palsy is often the motor dysfunction of the upper limb muscles. Based on the previous reports, combining our clinical experience and research, we propose that the occurrence of C ₅ palsy is mainly due to the instrumental injury of anterior horn of cervical spinal cord during anterior cervical decompression. In addition, the C ₅ palsy following surgery via posterior approach may be related to the nerve root tether caused by the spinal cord drift after decompression.
Conclusion: In view of the main cause of C ₅ palsy after cervical decompression, it is recommended to reduce the compression of the spinal cord by surgical instruments to reduce the risk of this complication.