This report describes the result of shoulder motion measurements in a patient with sternocostoclavicular hyperostosis in whom all the ligamentous structures around the clavicle became ossified during a clinical course of over 20 years.
A 59-year-old man visited us in 1995 complaining of pain and limitation of motion in his right shoulder that had been lasting for a couple of years. He first noticed pain and swelling of the right clavicular region at the age of 32.Staphylococcus aureuswas cultured from the right clavicle in 1975. He also had been experiencing repeated low back pain. The laboratory tests in 1995 were positive for CRP and negative for the rheumatoid factor and HLA-B27.
The x-rays showed bilateral sternocostoclavicular hyperostosis, ossification of the right coracoclavicular ligament and ankylosis of the right acromioclavicular joint.
The motion of the right shoulder was 80°in flextion,15°in extension,30°in abduction,30°in adduction, -5°in external rotation and the right buttock in internal rotation posteriorly. When the arm was elevated in the scapular plane, the rotational arc was 80-90°below 60°of elevation, whereas it decreased to 20°in 70°elevation and 5°in 80°, i. e., maximal elevation. This was most probably because the complete ossification around the clavicle held the scapula unrotated during the arm movement so that, at the arm-trunk angle of 80°, the humerus reached a position equivalent to the 'pivotal position'in a normal shoulder.
