Single Versus Double Intramedullary Fixation of Paediatric Both Bone Forearm Fractures: Radiological Outcomes

Introduction Both bone diaphyseal forearm fractures are common in children. If the reduction is unstable, intramedullary fixation using elastic intramedullary nails (EIN) is an option. Intramedullary fixation may be either of single (S-EIN) or both (double) bones (D-EIN). Some reports have shown poorer outcomes with S-EIN. Our aim was to critically analyse the radiological features of EIN cases, comparing results for single and both bone fixation. Method Retrospective review (two years: November 2014-November 2016) of EIN forearm procedures. Radiological reduction of the radius/ ulna (AP/lateral) was measured on theatre fluoroscopy and six week radiographs. The results were categorised by angulation: (i) <10°, (ii) 10-20°, and (iii) >20°. Results Of 36 patients (19 boys, 17 girls), 13 had S-EIN (mean age 9.6 years, range 7-14) and 23 had D-EIN (mean age 10 years, range 7-14). In the S-EIN group, two and 11 had the ulna and radius fixed, respectively. Intraoperatively, of the 13 S-EIN patients, nine had <10° angulation of the radius or ulna, two had 10-20°and two had >20°. All 23 D-EIN patients had intraoperative radiology showing <10° angulation of both bones and maintenance of reduction of <10° angulation at six weeks post surgery. However, some S-EIN patients had increased deformation: at six weeks, four patients had 10-20° and three patients >20°. No patient in either group had revisional treatment. Time in cast postoperatively was similar in both groups: S-EIN, 6.15 weeks (4-12) and D-EIN, 5.5 weeks (3-8). Operative time was 64 mins (43-82) and 76 mins (45-86) in S-EIN and D-EIN groups, respectively. No other complications were recorded. Conclusion Though there may be particular reasons for selecting single bone fixation, this series shows a propensity to increased angulation of fractures fixed by S-EIN (7/13 in this group). We advise caution in the use of single bone fixation for both bone forearm fractures.