Determinants of non-union after standard plate fixation for combined radial and ulnar fractures in adults

Treatment of mid-shaft fractures of both forearm bones in adults typically consists of individual plate fixation of each bone according to AO principles. The primary objective of this multicentre retrospective study was to identify predictive and prognostic factors of failed bone union after internal fixation with a standard plate in adults. 130 mid-shaft fractures of both forearms occurred in 92 men and 38 women, who had a mean age of 35.1 years were reviewed; 42 were open: 31 were Gustilo type I, 10 were type II and 1 was type III. All patients underwent ORIF using a direct approach over the supinator crest for the ulnar fracture and using an anterior approach at the level of the radial fracture by dynamic compression plate in 90 cases and a limited-contact dynamic compression plate in 40 cases, all with 3.5 mm diameter screws. The radiographs from all patients were reviewed after a minimum follow-up of 12 months: primary union of both forearm bones occurred in 121 of the 130 cases after a mean of 4.6 months (+/- 2.6). 104 patients were reviewed clinically with a minimum follow-up of 12 months and a mean of 36 months (+/- 21.7). According to Tscherne-Oestern classification, 79 % of patients had a very good outcome, 6 % had a good outcome, 10 % had a fair outcome and 5 % had a poor outcome Non-union occurred in 9 patients (one septic): 4 times at both fracture sites, 4 times at the ulna only and once at the radius only. The mean age was higher in the patients with non-union: 46.4 years versus 34.2 (P = 0.08). Smoking, alcoholism, associated head trauma, presence of pre-operative nerve deficit and open fracture did not appear to be risk factors for non-union. The type of plate used and the number of screws placed on either side of the fracture site had no effect on union. This patient series had a similar non-union rate to the one reported in other published studies, likely because the technical rules were followed. A lack of statistical power probably prevented us from identifying prognostic factors for bone union.