Inter-observer reliability of the ankle-brachial index in a pediatric setting.

Objective: The aim of our study was to determine the inter-observer reliability of the ankle-brachial index (ABI) in the pediatric population. This was done to determine if this simple diagnostic test could be utilized in lieu of CT angiograms to reduce radiation exposure to children sustaining trauma, particularly physeal fractures about the knee.

Design: Diagnostic study of consecutive patients with no applied "gold-standard" test.

Setting: Level I pediatric hospital.

Patients/participants: Thirty consecutive patients from a busy fracture clinic were recruited. Patients ranged in age from 7-17 years.

Intervention: Manual systolic blood pressure measurements from uninjured limbs were taken by two independent attending orthopaedic surgeons from the ipsilateral brachial, dorsalis pedis, and posterior tibial arteries of each patient.

Main outcome measurements: The intraclass correlation coefficients from each anatomic area were calculated.

Results: Intraclass correlation of measurements from all three anatomic locations showed good inter-observer reliability. The intraclass correlation coefficients from the brachial, dorsalis pedis, and posterior tibial arteries were 0.699, 0.815, and 0.740, respectively. Therefore, the calculation of the ABI was consistent between the two observers despite any variability in individual pressure measurements.

Conclusions: The ABI is a fast, non-invasive test that can be applied to the pediatric population in the evaluation of lower extremity arterial injury associated with orthopaedic trauma. It can obviate the need for tests such as CT angiograms that have inherent risks, particularly those associated with radiation exposure that are of concern in a young child.