[Ankylosing hyperostosis of the sternoclavicular joint]

The rarely occurring ankylosing hyperostosis of the sternoclavicular joints can be taken as a paradigm of chronic seronegative inflammation of tendinous insertion involving the capsular apparatus of the sternoclavicular joints. Etiologically uncertain erosions of the insertion lead to reparative ossifications. There are few symptoms but the course is protracted. If the condition cannot be arrested by anti-inflammatory drugs in its initial stages, there develops a progressive loss of sternoclavicular joint function. The case is described of a 66-year-old woman who has had the condition for 33 years. At wide intervals she has had severe pain. Electromyography a few years after biopsy gave an indication of mild irritation of the roots C 7 and C 8. Resulting from loss of function of the sternoclavicular joint the acromioclavicular joint was dislocated. No specific drug or surgical treatment has so far been necessary.