Delayed Post-Operative C5 Palsy After Reduction of Unilateral Cervical Facet Dislocation: A Case Report

A 60-year-old female sustained a left unilateral C3-4 facet dislocation and underwent urgent open reduction and posterior instrumentation. The patient subsequently developed delayed onset right upper extremity weakness affecting the C5 myotome, prompting a diagnosis of post-operative right C5 palsy (C5P). With conservative management, the patient had a complete neurologic recovery in eight months. Surgeons must be aware of the development of post-operative C5P whenever operating on the cervical spine, regardless of the operative level or procedure performed. This is the first documented case of C5P after the reduction of a facet dislocation, which occurred after a procedure not involving the C4-5 level.