However, like most upper extremity anomalies, not all patients with a congenital radial head dislocation present alike. Consider first that most of these dislocate so that the radial head moves in the posterior and lateral (outside) direction. A smaller number dislocate in the anterior direction. And anterior dislocations are most likely to block elbow flexion. These dislocations may be accompanied but limited forearm rotation (i.e., palm up and palm down) and, less commonly, pain. But, each child presents differently.
In the recent Oberg Manske Tonkin classification scheme for upper extremity anomalies, congenital radial head dislocation is categorized as a malformation (i.e., problem with limb formation while the baby is in the womb) involving the entire limb but in the radial- ulnar (inside, outside) direction (technically a I.A.2.v). And while our future understanding of these anomalies will undoubtably grow, I believe this grouping is the right place for this condition. I believe the following child shows why.
|Congenital radial head dislocation with a lack of elbow straightening.|
|Congenital radial head dislocation with good but not perfect elbow bending.|
|Congenital radial head dislocation with a very limited ability to supinate (turn palms up).|
|Congenital radial head dislocation with near perfect pronation (turning palm down).|
|Congenital radial head dislocation x-rays. Both the right and left side look the same. Notice that the radial head is dislocated in the anterior direction.|
Charles A. Goldfarb, MD
My Bio at Washington University