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Year |
2001 |
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Question Number |
40. |
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Category |
Select |
Question
A 40 y/o woman who abuses alcohol and drugs reports increasing pain in the right sternoclavicular region for the past 3 weeks. She has no fever, and clinical examination of the region is normal except for pain. Plain X-rays are normal. Lab studies show that the ESR is moderately elevated and the CBC and WBC are normal. What is the most likely diagnosis?
1. Osteoarthritis of the sternoclavicular joint (SCJ)
2. Septic arthritis of the SCJ
3. Osteolysis of the medial clavicle
4. Instability of the sternoclavicular joint
5. Idiopathic hyperostosis of the SCJ
Figures
Answer (click for answer)
Answer: 2
Explanation: First the wrong answers. Hpyerostosis of the SCJ affects women and men in the age group of 30-50. However unlike our 40 y/o patient, the condition is often bilateral and has findings on plain films. The process begins at the junction of the medial clavicle, the first rib, and the sternum as an ossification of the ligaments and then the bones. Also there is limitation of shoulder motion. Number #4 is wrong because the patient does not complain of any instability and there is no mention of it in the question. Osteolysis occurs in women over the age of 40 and is due to chronic stress on the SCJ. Labs may be normal however there are findings on plain film of sclerosis and expansion of the medial third of the clavicle. The joint space is preserved. Osteoarthritis of the SCJ would show narrowing of the joint space on xray and other typical finding of OA. SC joint infections are not uncommon in IVDA patients, which our patient is just such a person. The ESR is up moderately and is the only indication of infection given. By process of elimination, answer #2 makes sense.
Reference: The Orthopaedic Bible, Rockwood and Green (4th edition) Chapter 21