Predictivity of International Hip Dysplasia Institute classification in Pavlik harness treatment and correlation with Graf ultrasonographic classification

Hip ultrasonography applied according to Graf's criteria is frequently used in early diagnosis and monitoring of developmental dysplasia of the hip (DDH). Recently, the International Hip Dysplasia Institute (IHDI) classification has been proposed to be a prognostic indicator for patients with walking-age DDH. The purpose of this study is to evaluate the reliability of IHDI classification in the follow-up of patients with DDH diagnosed by ultrasonography scanning. A total of 69 hips of 38 patients (10 men, 28 women; mean age 59.9 ± 19.8 days, range 29-90 days) were diagnosed with DDH younger than 90 days of age. The AP pelvis radiographs of the patients who were diagnosed with DDH by ultrasound and classified according to the Graf method were evaluated and classified according to IHDI classification. A total of 52 hips were treated successfully with Pavlik harness treatment, 15 hips underwent closed reduction and pelvipedal casting (PPC) and 2 hips underwent open reduction and PPC after failed Pavlik harness treatment. Increasing IHDI grades correlated with the failure of Pavlik harness treatment (P = 0.001). Graf classification was not found to be predictive of successful Pavlik harness treatment (P = 0.482). There was no significant correlation between the IHDI classification and the Graf classification (Kappa = 0.079 ± 0.102, P = 0.402). The IHDI method is reliable in predicting the success of Pavlik harness treatment in patients diagnosed with DDH using the Graf method.