Long-Term Evaluation of Ulnar Nerve Function in Patients with Distal Humerus Fractures Treated with Open Reduction and Internal Fixation: A Nerve Conduction Study.

Abstract

To investigate the long-term evaluation with electromyography of ulnar nerve function in patients with distal humerus fractures (DHFs) treated with open reduction and internal fixation. Retrospective cohort study. Level 1 trauma center. Fifty-two patients (20 men and 32 women) with DHFs. All patients underwent open reduction and internal fixation between 2002 and 2017 with a minimum five years' follow-up. The nerve conduction test was done for evaluation ulnar nerve function. Secondary outcomes were modified McGowan grading system for symptoms of ulnar neuropathy. The mean follow-up time was 112.7 ± 39 months after surgery. 28.8% (15) of the patients scored in Grade I, 30 (57.6%) in Grade II, and 7 (13.6%) in Grade III on the affected side according to McGowan grading scale. According to EMG results, 40.1% (21/52) of patients had abnormal results. There was significant difference between fracture and unaffected side regarding ulnar nerve motor wrist CMAP amplitude, motor below elbow CMAP amplitude, above elbow CMAP amplitude, above elbow MNCV, and sensory wrist amplitude. Ulnar nerve motor wrist-ADM latency (p = 0.01; r = 0.446) and ulnar nerve sensory conduction velocity (p < 0.001, r = -0.504) were significant correlation with McGowan grading scale. There were significant difference ulnar nerve motor amplitude and sensory wrist amplitude between fracture and unaffected side. A mean decrease in sensory amplitude of fracture elbow was found 25% compared to the unaffected side in our result. Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.