The wrist is almost always flexed. The position of wrist flexion is different for each child and the effect of the flexion is also different for each child. However, anyone who flexes their own wrist realizes how much that affects the ability to move the fingers. When the wrist is flexed, it is impossible to make a tight fist. Other factors compound this difficulty. First, obviously, the muscles are limited in arthrogryposis- this also affects finger motion. And second, the functional limitations of arthrogryposis make two- handed activities important. The flexed wrist position makes it difficult to use both hands together.
Therefore, the concept of straightening the wrists makes sense for a number of reasons. First, the straighter wrist position allows the best finger function. A change in wrist position cannot overcome the limitations of the muscles in arthrogryposis- but it can help the child function as best as possible.
Second, a straighter wrist allows the hands to work together. Because of the overall limitations in function, using both hands together is vital, made even more important in kids severely affected.
Technically, the surgery of closing wedge osteotomy (osteotomy= cutting the bone) of the wrist removes a wedge of bone from the top of the wrist bones (the dorsal carpus). By removing a triangular wedge of bone, the wrist is brought into a straighter position. Additionally, the radiocarpal joint (one of the places which allows wrist motion) is preserved, thus allowing wrist motion. So this is NOT a wrist fusion. Other parts of the procedure may include tendon release (if tight on the palm side of the wrist) and also tightening or centralization of the tendons on top of the wrist. Patients and families have been very happy with this surgery. It improves function and also improves the appearance of the wrist.
|Arthrogrypotic wrist before surgery|
|Arthrogrypotic wrist after osteotomy|
|Arthrogrypotic wrist after surgery. Note small incision. Pins are visible and can be removed at approximately 6 weeks.|