Osteoid osteomas are painful benign bone tumours usually less than 1.5cm in diameter which occur mostly in adolescents and young adults, and are rare in patients over the age of 40 years. The pain is well localised and may be more severe at night and it is often relieved by NSAIDs. Osteoid osteomas are vascular tumours and anything that promotes vasodilatation, such as alcohol, can cause an increase in pain. They occur most commonly in the proximal femur (upper part of the thigh bone) and the shafts of other long bones. They also occur less often in the bones of the foot and ankle and in the spine.
The NICE approved treatment of choice for the management of osteoid osteomas is radiofrequency ablation (RFA). In this technique a radiofrequency probe is directed into the osteoid osteoma under image guidance, usually by CT, and after checking its position the tumour is destroyed by thermal energy from the radiofrequency probe. Using RFA, around three out of four patients get a good response after one treatment session, and more than nine out of ten get a good response after one or two sessions. The risk of complications from RFA for osteoid osteoma is low.