Is it safe for extended-role radiographers to measure migration percentage in children with cerebral palsy?

Abstract

Introduction: In the surveillance of children with cerebral palsy, the measurement of migration percentage is used to identify children at risk of hip dislocation. Early identification of children at risk facilitates early intervention with less invasive surgical procedures to prevent further deterioration. The aim of this study is to evaluate the safety of the measurements of migration percentage for surveillance in cerebral palsy by extended-role radiographers by evaluating the reliability and validity of measurements performed by these professionals.

Methods: A sample of thirty pelvic x-rays were selected from the local cerebral palsy database. A range of hip displacement was selected including some challenging borderline x-rays. All ten extended-role radiographers completed measurements using TraumaCAD which were repeated at a minimum of 4 weeks. Inter-rater and intra-rater reliability was calculated using intraclass correlation coefficients. The accuracy and safety of the system was evaluated by converting measurements into referral categories (red, amber or green) and cohen's kappa was calculated when categories were compared to measurements to orthopaedic surgeon RESULTS: The inter-rater reliability between radiographers was 0.938 (95% CI 0.914-0.991). The intra-rater reliability was 0.941 (95% CI 0.931-0.949). The percentage agreement was 94.8% for green, 93.8% for amber and 98.2% for red hips. The weighted kappa value was 0.923 (95% CI 0.889-0.957).

Conclusion: The reliability and accuracy of radiographer measurement of migration percentage is excellent. It is safe for radiographers to calculate the migration percentage using semi-automated software for the surveillance of children with cerebral palsy.

Implications for practice: We recommend the measurement of migration percentage may be performed by extended-role radiographers to deliver accurate and reliable measurements for use in cerebral palsy surveillance.

Keywords: Cerebral palsy; Measurements; Radiographer; Reliability.