Purpose: A prospective study was conducted in 160 children presenting varus trauma of the ankle. The purpose of the study was to validate the Ottawa ankle rules in children. Application of the Ottawa rules can reduce the number of x-rays by 25% but little work has been reported concerning their validation (Chande 1995).

Material and methods: One hundred sixty children, 71 boys and 89 girls, mean age eleven years three months (range 3 – 15 years) were included in this study conducted between February 2001 and December 2001. Clinical presentations with an obvious diagnosis of ankle fracture were excluded (six patients). Epidemiological and clinical data and the initial Ottawa criteria were recorded on a data sheet with a specific number of assigned items. A standard radiographic work-up with an anteroposterior, lateral and oblique view of the ankle was obtained in all cases. All patients were seen at a second consultation on day 8 by another physician to confirm diagnosis. The x-rays were read three times: by the emergency care physician, and by a second physician and a paediatric orthopaedic surgeon at the 8-day consultation.

Results: Diagnosis which were confirmed were: benign sprains (BS) (n=71), moderately severe sprains (MS) (n=47), severe sprains (SS) (n=2), type I epiphyseal detachment (ED) (n=21), fractures (n=13) (8 fifth metatarsal, 1 triple fracture line, 1 medial malleolus, 2 lateral malleolus, 1 tarsal scaphoid).

For the Ottawa criteria, ankles positive for pain and at least one other criterion were: 64/77 BS, 43/47 MS, 2/2 SS, 21/21 DE and 13/13 fractures. All fractures were diagnosed at the first exam or at the 8-day exam.

Discussion: Based on our findings, the clinical Ottawa rules cannot be considered to be validated for children. Using these rules, x-rays would have been performed in 143 patients to identify 13 fractures that were not clinically obvious. Because the Ottawa rules are insufficiently specific for children, we recommend, like Brooks (1981) to use more rigorous clinical criteria for the diagnosis of ankle trauma in children.

The diagnostic criteria used in this study enabled correct first intention diagnosis in 129 patients with trauma. We propose ordering x-rays only for children with signs of moderate or severe sprain or pain in zone C (base of the fifth metatarsal: 8/8) or E (medial border of the foot: tarsal scaphoid fracture). For other cases (98/160) physical examination is sufficient.

Conclusion: We do not consider the Ottawa clinical rules to be valid for varus ankle trauma in children. We propose clinical criteria which can limit the number of x-ray work-ups by 60% in children with this type of trauma.