Weighted diagnostic criteria for developmental dysplasia of the hip

To establish clinical diagnostic criteria for developmental dysplasia of the hip (DDH) that model the practices of expert clinicians.

Of 23 clinical criteria for the diagnosis of DDH, ranked in order of diagnostic importance by international consensus, the 7 most highly ranked were placed in all possible combinations to create unique case vignettes. Twenty-six experts rated 52 vignettes for the presence of DDH. We modeled the data to determine which of the 7 criteria were associated with a clinician's opinion that the vignette represented DDH. From the resulting regression coefficients, for each vignette we calculated a probability of DDH. An independent panel rated the same vignettes using a visual analog scale response. We correlated the visual analog scale ratings with probabilities derived from the model.

Our model identified 4 of 7 criteria as predictive of DDH (P < .001): Ortolani/Barlow test (β = 3.26), limited abduction (β = 1.48), leg length discrepancy (β = 0.74), and first-degree family history of DDH (β = 1.39). There was substantial correlation between the probability of DDH predicted by the model and that derived from an independent expert panel (r = 0.73; P < .001).

Weighted clinical criteria for inferring the likelihood of DDH produced consistent results in the judgment of 2 separate groups of experts. Using these weights, nonexperts could establish the probability of DDH in a manner approaching the practice of clinical experts.