Neurologic Recovery after Anterior Cervical Discectomy and Fusion

Abstract

BACKGROUND CONTEXT: Recovery of neurological function is an expected outcome in patients undergoing ACDF. The rate of neurologic recovery, however, is not well described in the literature. Furthermore, the etiology of neurologic deficits that arise after ACDF is unclear. PURPOSE: The purpose of this study is to describe the natural history of neurological recovery after ACDF. STUDY DESIGN/SETTING: Retrospective review of neurological outcomes in patients from a prospectively collected database. PATIENT SAMPLE: Patients who were 18-80 years of age, diagnosed with cervical radiculopathy, underwent single-level ACDF between 1/98 and 9/09, and followed for a minimum of 1 year, were included. Patients with a history of spine infection, cervical spine fracture, spinal tumor, traumatic spinal cord injury or cervical myelopathy were excluded. OUTCOME MEASURES: Recovery of preoperative motor and sensory deficits and development of new onset post-operative motor and sensory deficits. METHODS: Sensory and motor deficits were documented, graded based on physical exam findings at preop and postop visits. The rate of recovery was calculated based on the number of patients that saw normalization of neurologic function. New postop neurologic deficits were calculated and determined to occur at one or more of the following: the surgical level, an adjacent level, or a different level. Fisher's exact test was used to compare the rate of neurologic deficits occurring in patients with preop neurological deficits versus those without. RESULTS: Of 142 included patients, 28% were smokers, there was a 1.25:1 male to female ratio, and the mean age was 45.8(plus or minus)9.2 years. At the time of surgery, 60% had a sensory deficit. Recovery of sensory function was seen in 86% of patients by 1 year. By final follow-up, new sensory deficits developed in 22% of patients of whom 69% had adjacent level sensory deficits. Interestingly, 25% of the patients with a sensory deficit preop developed new adjacent level sensory deficits, while only 5% of patients without a sensory deficit preop developed new adjacent level sensory symptoms (p