A 25-year-old female patient came to the Nutrition Clinic for monitoring of her nutritional status; seven months earlier she had been diagnosed with Ulcerative Colitis (UC), and during this period she had received treatment with corticosteroids: methylprednisolone 1.5 mg/kg/24 h IV during two months of admission and 30 mg/24 h of prednisone orally in a descending dosage for the remaining five months. He reported arthralgia in both knees, and on examination showed pain on posterior rotation in both femoral heads, more evident in the right hip, which also showed limited internal rotation; the left knee had reduced flexion movement, and on gait examination there was claudication to the right side.
No markers of autoimmunity were detected, and plasma concentrations of calcium, phosphorus and vitamin D were within the normal range. Bone densitometry (BMD) showed osteoporosis at the lumbar spine (T score - 3, 1) and osteopenia at the femoral neck (T score - 1.5). Plain radiographs showed data suggestive of grade II NA in both femoral heads, more evident on the right side; in the knees an osteochondral lesion was observed in the internal femoral condyle of the left knee with irregularities in its articular surface. MRI confirmed necrotic lesions in both femoral heads and in both knees, both on the tibial and femoral side. The next MRI, performed only 3 months later, showed evidence of subsidence in the right hip.

The patient was treated with alendronate and calcium and vitamin D supplementation for osteoporosis, corticosteroids were discontinued and weight bearing of the affected joints was advised.