C5 Nerve Palsy After Posterior Instrumentation and Decompression in Cervical Spine Surgery: A Review of the Literature.

C5 nerve palsy is a well-documented postoperative complication of cervical spine surgery, particularly following posterior decompression and fixation procedures. With incidence rates reported between 4% and 30%, it poses significant clinical challenges due to its impact on upper limb function and patient quality of life. Typically emerging within one to four weeks post-surgery, C5 palsy is marked by deltoid and biceps muscle weakness and sensory deficits in the C5 distribution. The pathogenesis is multifactorial, involving spinal cord shift, reperfusion injury, and foraminal stenosis, with surgical factors such as decompression extent and alignment correction also contributing. While most cases respond favorably to conservative management, including physical rehabilitation, some patients experience prolonged recovery or residual deficits. Recovery rates range from 71% to 96%, emphasizing the importance of individualized rehabilitation protocols. Anatomical predispositions, preoperative conditions, and surgical techniques are critical in both the development and management of this complication. Continued research is needed to refine predictive models and tailor treatment strategies based on patient-specific and procedural variables. This review study aims to collect available data and summarize the information available in the medical community according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.