1. A defect in the posterosuperior area of the anatomical neck of the humerus was demonstrated roentgenographically in patients with acute anterior dislocation and both by roentgenograms and at surgery in patients with recurrent anterior dislocations.
2. This defect can rarely be seen on conventional, routine roentgenograms of the shoulder; at times it can be demonstrated in an uncertain degree of internal rotation. It can easily be seen in the simple roentgenographic projection described.
3. Since this defect, if large, may facilitate recurrent dislocation, it should be looked for in all acute injuries. If it can be accomplished by adequate immobilization, this defect should be allowed to meal and fill in.
4. In recurrent dislocation of the shoulder the defect should be evaluated when planning surgical repair. It is the author's opinion that the defect, if large, should be repaired just as the labral defect is repaired anteriorly.
5. The defect, usually traumatic in origin, should not be confused with normal anatomical variations.
Copyright 1959 by The Journal of Bone and Joint Surgery, Incorporated