Intercostal nerve injury after rib fractures: A case series correlating electrodiagnostic testing with imaging, ultrasound, and surgical findings

BACKGROUND: Intercostal nerve injury can occur after rib fractures, resulting in denervation of the abdominal musculature. Loss of innervation to the rectus abdominis and intercostal muscles can cause atrophy and subsequent eventration, pain, and cosmetic issues. Intercostal electrodiagnostic testing can diagnose and localize intercostal nerve damage after rib fractures at levels T7 and below. OBJECTIVE: To characterize rib fracture patterns associated with intercostal nerve injury and evaluate the diagnostic and surgical utility of preoperative nerve conduction study/electromyography (NCS/EMG) findings. METHODS: Eight patients with NCS/EMG-diagnosed intercostal nerve injury following rib fractures were included in the study. A total of 17 levels with intercostal nerve damage were identified on electrodiagnostic testing. Descriptive rib fracture characteristics were obtained from preoperative chest computed tomography by a single chest wall surgeon and analyzed for displacement, degree of rib separation, fracture location, and presence of intercostal muscle, lung, and retroperitoneal hernias. Preoperative electrodiagnostic testing results were correlated with computed tomography rib fracture characteristics, ultrasound measurements of rectus abdominis cross sectional thickness, and direct intraoperative intercostal nerve evaluation using an intraoperative nerve stimulator. RESULTS: = 0.432). CONCLUSIONS: The present case series describes the rib fracture characteristics, ultrasound assessment, and interoperative intercostal nerve stimulation findings of patients with preoperative NCS/EMG-diagnosed intercostal nerve injury after rib fractures. Intercostal nerve damage resulting in rectus abdominis atrophy after rib fractures may be an underrecognized and thus undertreated complication of rib fractures. Preoperative electrodiagnostic testing demonstrates high diagnostic accuracy and can guide surgical planning. Awareness of high-risk fracture patterns may improve clinical decision-making and outcomes in rib fracture management.