Introduction: C5 nerve root palsy after cervical spinal surgery is a serious complication leading to motor decline of the deltoid. However, the incidence and perioperative risk factors are not fully understood.

Methods: A retrospective review was conducted over 2 years at a single institution involving patients receiving posterior cervical decompression. We included all patients undergoing cervical laminectomy with or without fusion from September 2014 to September 2016. Exclusion criteria included surgery not involving the C4-C5 level, anterior surgery at the C4-C5 level within the last 6 months and lack of follow-up data. Incidence of C5 palsy was the primary outcome. Secondary outcomes include characterizing C5 palsy among patient age, sex, comorbid conditions, procedure type, preoperative and postoperative spinal cord width, operative neurological monitoring, and kyphosis correction.

Results: 238 patients were identified and 19 were removed by the exclusion criteria. Of the 219 patients (68.0% male) included for analysis, the overall incidence rate of C5 nerve root palsy was 5.02% (N = 11). All 11 diagnoses of C5 palsy were in males (P = 0.02). There was a trend towards significance for increased preoperative width of spinal canal with lower C5 palsy incidence (P = 0.073). The incidence rate of C5 palsy was not significantly different in the laminectomy alone and laminectomy with fusion groups (6.7% vs 4.2%, respectively; P = 0.42). The laminectomy only group was younger (61.09) compared to the laminectomy with fusion (65.55) group (P = 0.02).

Conclusions: The incidence of C5 nerve root palsy was 5.02% and is consistent with previously published studies. There was a trend towards decreased incidence of C5 in patients with larger preoperative spinal cord widths. There was no significant difference in incidence of C5 palsy in laminectomy alone or laminectomy with fusion. The results of this study suggest that male gender is associated with increased risk of C5 palsy.

Patient Care: Characterization of the incidence rate of C5 and its perioperative risk factors will guide patient couseling and best surgical practice.

Learning Objectives: By the conclusion of the session, participants should be able to: 1) Describe the importance of characterizing risk factors associated with C5 palsy after posterior cervical surgery. 2) Discuss, in small groups, the current understanding of C5 Palsy incidence. 3) Identify effective prognostic factors increasing the risk for C5 Palsy

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