Formation of a bone and joint following blunt injury to the pelvis.

The formation of a new bone from the lateral wall of the pelvis following blunt injury occurred in a 55-year-old woman. The bone articulated with the top of the trochanter by means of a synovial-lined joint. The case is an example of the remarkable ability of external forces to remodel newly formed bone into a functional architectural unit and to produce an accessory pseudojoint.