Anatomical Study About the Vascularization of the Ulna: Vascular and Mechanical Risk Factors Associated With Forearm Nonunion

In the anatomical study we investigated the extraosseous and intraosseous blood supply in fourteen specimens from the Department of Human Anatomy. We correlated the areas with a low vascularity with the usual areas that patients have ulnar nonunion.

In the clinical study we retrospectively reviewed a cohort of ulnar fractures treated surgically with open reduction and internal fixation (ORIF), during a period of 10 years (2007-2016). We identified 211 ulnar fractures. All patients had a minimum follow-up of 1 year. We defined non-union if there was no radiological consolidation of the fracture after this period, and we classified them according to Weber classification. We assessed risk factors like: fracture site vascularity, surgical treatment technique, biological factors of the patient, and the fracture's mechanism. We correlated data and associated risk factors from the anatomical and the clinical studies.

Data were analysed using SPSS software system version 21. Multivariate regression analysis was performed to assess independent risk factors of ulnar non-union. Chi square test or Fisher exact test was used to compare categorical measurements. Statistical significance was considered as p less than 0.05.