||Fig. 7. Boxer's fracture. When the metacarpal head impacts a
hard surface, the resulting fracture allows it to displace palmarly (1.).
If the displacement is greater than can be compensated by normal joint
motion, extensor tendon imbalance will result in a proximal interphalangeal
joint extensor lag and eventually flexion contracture of this joint (2.).
Open injuries sustained in this fashion such as the clenched fist
bite wound may be difficult to assess because soft tissues shift after