Leave it Alone: Ulnar Nerve Management in Distal Humerus Fracture Fixation – A Large Database Study

Abstract

ABSTRACT Objectives: To determine the impact of intra-operative ulnar nerve manipulation during distal humerus open reduction internal fixation (ORIF) on post-operative ulnar neuritis. Methods: This study was a retrospective cohort analysis using the PearlDiver Mariner Database. Patients undergoing ORIF of distal humerus fractures were identified using Current Procedure Terminology (CPT) codes. Concurrent ulnar nerve transposition, neuroplasty, or neurolysis was defined using CPT-64718, occurring on the same day as the index procedure. Patients with pre-existing ulnar neuropathy within one year prior to the index procedure were excluded. The incidence of delayed ulnar neuropathy, occurring at least 2 weeks post-operatively, was compared at 3, 6, 9, and 12 months. Multivariable logistic regression models were employed to evaluate the association between ulnar nerve transposition, neuroplasty, or neurolysis and the development of delayed ulnar neuropathy, adjusting for the effects of age, sex, insurance type, and Elixhauser comorbidity index. Results: 16,881 patients who underwent distal humerus ORIF were identified, of which 2,016 (11.9%) received concurrent ulnar nerve transposition, neuroplasty, or neurolysis. The cohorts differed by age and insurance type (p<0.001). Ulnar neuropathy between 2 weeks and 1 year occurred in 191/2,016 (9.5%) patients who received ulnar nerve transposition, neuroplasty, or neurolysis and 742/14,865 (5.0%) patients who did not (p < 0.001). Ulnar nerve transposition, neuroplasty, or neurolysis was associated with increased odds of delayed ulnar neuropathy at all time points (p<0.001). Conclusion: Ulnar nerve transposition, neuroplasty, or neurolysis at the time of distal humerus ORIF was associated with an increased incidence of delayed post-operative ulnar neuritis.