Radiographic anatomy of the intertubercular groove of the humerus.

Disturbances of the gliding mechanism of the tendon of the long head of the biceps brachii in the intertubercular groove have been suggested as a cause of shoulder pain. The purpose of this paper was to find a standard radiographic view for measurements of the intertubercular groove of the human humeral head. The effect of the direction of the X-ray beam on the image of the groove was studied in cadaver specimens. A standardized optimal X-ray beam direction was subsequently used in a clinical study on 30 patients. In all the patients the groove could be delineated and the depth, width and slope of the medial wall measured. The width and depth of the groove was neither significantly correlated to the size of the humeral head nor the sex. The slope of the medial wall varied from 18 to 71 degrees (mean 48.1 +/- SD 10.7 degrees).