Endocrine Abstracts

We present the case of a 32 year old woman presenting to her GP with right lower leg pain. This pain was worse at night, but responded to simple analgesia. She was initially diagnosed with arthritis but the leg pain worsened and became bilateral. She had no other significant past medical history with no history of fevers, trauma, fractures or dental problems. She had no relevant family, social or medication history.

On examination, there was no tenderness on bone palpation or active and passive adjacent joint movements. There were no overlying skin changes or joint swellings. Investigations confirmed normal biochemistry including alkaline phosphatase (51iu/L (NR 30-130) and inflammatory markers. Plain radiographs revealed bilateral focal segmental cortical sclerosis involving the mid-diaphyseal region of the tibiae and femora, with resultant narrowing of the medullary cavity. MRI of the lower legs demonstrated associated marrow oedema and bone scanning showed increased tracer uptake in these mid-diaphyseal areas. Bone densitometry however was entirely normal. Based on the clinical and radiological features she was diagnosed with Ribbing Disease.

Ribbing Disease is a rare form of sclerosing dysplasia characterised by benign endosteal and periosteal bone growth confined to the diaphysis of long bones. Most commonly the disease presents with leg pain in young women classically involving the femora and tibiae. It is important to exclude other causes of bone pain including osteomyelitis, fractures, osteosarcoma and Camurati-Engelmann Disease. Treatment is mainly supportive with analgesia but can include bisphosphonates and orthopaedic intervention.

This case demonstrates a rare cause of a common symptom presenting to metabolic bone clinics and highlights the important history, examination and investigation pathway of bone pain.