Validity and Reliability of a Measuring Device Based on Sound Transmission for Diagnosis of Hip Dysplasia in Newborns

Sound transmission has been used for diagnosis of hip dysplasia in newborns and infants with tunning fork and sthetoscope. The study aims to identify the validity of a device based on sound transmission. Male and female newborns from Celaya, Gto, ranging from 4 to 28-day-old were selected for the study. The sound transmission device was used both, in bilateral assessment (compared sound transmission) and on each hip separately (sound transmission with extension/flexion). In the first application if the sound is lower by a digit, there is a hip unhealthy. In the second application if the sound is increased by a digit, there is also an alteration of the hip. A hip ultrasound was applied using the Graf technique as a gold standard. Sensitivity, specificity and predictive values were calculated to identify validity. The intra-observer and inter-observer Kappa Test was applied to identify reliability. The hips of 103 newborns were assessed, obtaining a sensitivity of 60.9%, and a specificity of 92%; it should be a positive predictive value of 51.9% and a negative predictive value of 95% for the compared sound transmission test. In the sound transmission test with extension/flexion, the values were 82.6%, 96.2%, 73.1% and 97.8% for sensitivity, specificity, positive predictive value and negative predictive value, respectively. The result of the intra-observer kappa was 0.80 and the inter-observer was 0.70 for the compared sound transmission. The intra-observer Kappa was 0.88 and the inter-observer was 0.78 for the compared sound transmission test with extension/flexion. The device for sound transmission is valid and reliable for the diagnosis of dysplastic development hip disease in newborns.