Flatt and Wood reported on symphalangism and divided it into 3 types (a long time ago- 1975, in the journal Hand)
- Symphalangism with normal length fingers (i.e. True Symphalangism)
- Symphalangism with short fingers (symbrachydactyly)
- Symphalangism with another syndrome like Aperts
The clinical examination is notable for the lack of motion of one or more of the interphalangeal joints- typically the proximal interphalangeal joint. It can be one finger or it can be many fingers. Importantly, the normal creases of the fingers are not there in symphalangism.
|The arrow is pointing to the top of the PIP joint of the pointer (index) finger. Note the normal creases which demonstrate that the finger has been moving.|
|Symphalangism. This is the child attempting to make a full fist. The PIP joints do not flex (bend) much.|
|The other hand in Symphalangism. This is the child attempting to make a full fist. The PIP joints do not flex (bend) much.|
Also note the lack of creases on the tops of the fingers.
|Careful review of the x- rays show that the PIP joints have not developed in symphalangism.|
|Lateral view (side view) of the hand and fingers. The PIP joints have not developed in symphalangism. The arrow marks the PIP joint of the long finger (middle finger).|
My Bio at Washington University