Is congenital thrombotic thrombocytopenic purpura a risk factor for ischemic osteonecrosis of the hip joint (Legg-Calvé-Perthes disease)?

Weise et al. reported on a 41-year-old patient previously diagnosed with congenital thrombotic thrombocytopenic purpura undergoing total hip replacement surgery for Perthes disease. This case raises the question whether ischemic osteonecrosis of the femoral head is another so far underrecognized comorbidity causally linked to congenital thrombotic thrombocytopenic purpura.