Annotation: parathyroid hormone and fracture healing.

This annotation describes some early rat studies which conclude that parathyroid hormone (PTH) has more dramatic stimulatory effects on bone repair than on untraumatized bone. It also suggests, based on the effects of PTH on osteoblasts, that it is more likely to accelerate normal fracture healing than to prevent non-union. The only 2 controlled clinical trials that have been published are critically discussed. Although both are encouraging and appear to show acceleration of normal fracture healing, they have methodological shortcomings that preclude definitive conclusions.