Borderline Developmental Dysplasia of the Hip: A Risk Factor Predicting the Development and Poor Prognosis after Core Decompression for Idiopathic Osteonecrosis of the Femoral Head.

The incidence of BDDH was significantly higher in patients with idiopathic ONFH than matched controls, and idiopathic ONFH patients who underwent CD with BDDH had lower mean HHS as well as 5-year survival rate than those without BDDH. Therefore, BDDH should be considered a risk factor predicting the development of idiopathic ONFH as well as poor prognosis after CD.