1. A 17 year old girl presents with pain in the distal forearm which has worsened over the last six to eight weeks. Plain films show an eccentric lytic radiolucency in the distal radius with a soap-bubble appearance. The most likely pathology is:

1. a. Enchondroma

2. b. Aneurysmal bone cyst

3. c. Simple bone cyst

4. d. Fibrous dysplasia

5. e. Chondroblastoma

2. A 35 year old man presents with increasing stiffness in his knee and soft-tissue swelling around the joint. Plain films show multiple areas of irregular cyst-like radiolucencies in the distal femur. There are no areas of abnormal calcification and there is no evidence of periarticular osteoporosis. MR shows a low signal joint effusion on both T1 and T2 sequences. The most likely diagnosis is:

1. a. Synovial osteochondromatosis

2. b. Pigmented villonodular synovitis

3. c. Osteoarthritis

4. d. Reiter's syndrome

5. e. Osteomyelitis

3. A 56 year old motorcyclist has a trauma series of plain films following a road traffic accident. On evaluation of the lateral cervical spine film, which of the following soft-tissue parameters would be a concerning feature?

1. a. Predental space of 3 mm

2. b. Nasopharyngeal space of 7 mm

3. c. Retropharyngeal space of 10 mm

4. d. Retrotracheal space of 20 mm

5. e. Decreased disc space at the C5/6 level

4. A 20 year old man presents with an increasingly painful right thigh which is worse at night. Plain films of the area show a lucent area measuring approximately 8–9 mm in the distal femur surrounded by extensive sclerosis.