Purpose

To determine the impact of sonographic information on surgeons' diagnostic thinking and decision-making in the management of infants with clinically suspicious hip dysplasia.

Four experienced consultant surgeons examined 66 hips referred for possible hip dysplasia and reported for each hip (i) the confidence level (visual analogue scale 0-100) about the diagnosis of this hip, and (ii) how they would manage the hip. Each infant was referred to ultrasound and the same surgeon repeated the rating with the sonographic information available. We determined the efficiency in diagnostic thinking and calculated the mean gain in diagnostic confidence that was provided by the sonographic information. We also determined the therapeutic efficacy, ie the impact of ultrasound information on surgeons’ management plans.

The ultrasound led to a change in diagnosis in 34/66 (52%) hips. However, the management plan only changed in 21/66 (32%) hips. The mean gain in reported diagnostic confidence was 19.37 (95% CI = 17.27, 21.47). If the treatment plan did not change, there still was a gain in diagnostic confidence but this gain was small with a mean value of 8 (95% CI = 5.29, 10.70). However, if the ultrasound led to a change of the treatment plan, the mean gain in diagnostic confidence was much higher with 46 (95% CI = 30.53, 60.79). The difference was -37.67 (P < 0.0001). Ultrasound was most useful (mean gain >30) in hips demonstrating limited abduction or a positive Galeazzi sign.