Aseptic femur head necrosis revealing Cushing's disease: a rare presentation

Abstract

Background: Cushing's disease is an endocrine disorder and may be associated with non-traumatic osteonecrosis of the hip. We report the case of avascular necrosis of the femoral heads (AVNFH) as the presenting manifestation of Cushing's disease. Case presentation: A 29-year-old male patient was referred to our department because of non-traumatic bilateral hip pain evolving for two years. The pain was associated with lameness when walking. He noticed a drop in libido since one year with erectile dysfunction. Physical examination revealed facio-truncal obesity, abdominal violaceous striae, dorsal hyper-kyphosis, a pain and limitation of internal rotation of the left hip with a Lequesne index of 16. The standard radiography showed a loss of sphericity of the left femoral head with an aspect of eggshell. The MRI confirmed the diagnosis of a bilateral AVNFH. The baseline cortisol level was 287 ng/ml. AVNFH as the presenting manifestation of Cushing's disease was suspected and confirmed by a pituitary MRI which revealed a pituitary adenoma. A discharge of the hips was indicated. The patient underwent surgical resection of the adenoma and was referred to the endocrinology department. The histopathological examination confirmed the diagnosis of pituitary adenoma (corticotrope adenoma). The patient has also received an intravenous perfusion of 5 mg of Zoledronic acid. The follow up was marked by the regression of the symptoms of Cushing's disease and the hip pain. Conclusion: AVNFH as the presenting manifestation of Cushing's disease is rarely described. Hence, it’s needed to exclude endogenous hypercorticism in any patient with idiopathic osteonecrosis.