Is ulnar nerve transposition beneficial during open reduction internal fixation of distal humerus fractures?

OBJECTIVES: The purpose of this study was to compare the incidence of ulnar neuritis with and without ulnar nerve transposition during open reduction and internal fixation (ORIF) of distal humerus fractures.
DESIGN: Multicenter retrospective cohort series.
SETTING: : Two Level I trauma centers. PATIENTS: Two cohorts were identified: 89 patients (mean age, 48.6 years) who had not undergone an ulnar nerve transposition and 48 patients (mean age, 43.2 years) who had undergone a transposition during ORIF of a distal humerus fracture (Orthopaedic Trauma Association 13A or 13C). INTERVENTION: All patients underwent ORIF of a distal humerus fracture with or without anterior subcutaneous ulnar nerve transposition based on surgeon preference. MAIN OUTCOME MEASURE: Presence or absence of ulnar neuritis (ulnar-sided paresthesias, numbness, or intrinsic weakness) or reoperation related to ulnar nerve symptoms.
RESULTS: : Average follow up was 9.6 months in the transposition group and 16.0 months in the nontransposition group. Transposition of the ulnar nerve was found to be an independent variable associated with ulnar neuritis (P < 0.001). The incidence of ulnar neuritis was 33% (16 of 48) with transposition and 9% (eight of 89) without transposition (P = 0.0003). Of the patients with ulnar neuritis, one patient in the nontransposition group (1%) and two patients in the transposition group (4%) required additional surgery specifically related to the ulnar nerve. One patient who had undergone transposition developed chronic motor and sensory denervation.
CONCLUSION: Patients who underwent ulnar nerve transposition at the time of ORIF of distal humerus fractures had almost four times the incidence of ulnar neuritis than those without transposition. We do not recommend routine transposition of the ulnar nerve at the time of ORIF of distal humerus fractures.