Predictors of Nonunion in Humerus Shaft Fractures in Adults in Lomé (Togo)

Abstract

Background: To identify predictors of humerus shaft fractures nonunion in adults whatever the type of treatment performed. Patients and Methods: We conducted a retrospective study among patients who had a fracture of the humeral shaft moving towards healing or nonunion. Patients were treated in the orthopedic trauma unit of Sylvanus Olympio Teaching Hospital and two other private clinics in Lome between January 2008 and June 2012. On the X-ray of each patient, we measured the angulation, the diastasis, and inter fragmentary contact. For each included patient, we looked for: age, sex, medical history, body mass index (BMI), according to the third location of the shaft fracture, the type of fracture according to AO classification and the type of opening according Tscherne classification. Results: During the study period, 184 patients with humeral shaft fracture were identified. Of these 108 were men. The mean age of patients was 37.3 years. The fractures were treated conservatively in 100 patients (54.3%), 78 treated surgically and six (3.3%) have discharged from hospital against medical advice for traditional treatment. The factors that were associated with nonunion of humerus shaft fractures in these patients were: the opening of the fracture (RR = 4.5; 95% CI = [2.9; 7.1]), the presence of immediately radial paralysis (RR = 5.6; 95% CI = [3.7; 8.5]), the existence of other associated lesions or fracture (RR = 1.8; 95% CI = [1.1; 3.1]), energy of the trauma (RR = 2.3; 95% CI = [1.3; 4.4]) and type III classification of Tscherne (RR = 0.3; 95% CI = [0.2; 0.6]). After multivariate analysis, factors that remained significantly associated with the failure of consolidation were: the existence of diastasis > 2 mm (OR = 7.6; 95% CI = [2.2; 25.6)), the Body Mass Index (BMI) > 25 (OR = 1.3; 95% CI = [1.1 - 1.6]) and the existence of other bone lesion (OR = 4.3; 95% CI = [1.4 - 18.9]). Conclusion: BMI greater than 25, the existence of an interfragmentary gap of more than 2 mm and existence of other bone lesions are significant risk factors for nonunion in humerus shaft fractures. The traditional treatment, common singular factor to the African environment, should not be ignored. Control of these predictors is necessary in carrying out the treatment of humerus shaft fractures.