DEVELOPMENT OF APPROACHES TO IMPROVE THE HEALING FOLLOWING MUSCLE CONTUSION

Muscle injuries are a challenging problem in traumatology, and the mos t frequent occurrence in sports medicine. Muscle contusions are among the most common muscle injuries. Although this injury is capable of he aling, an incomplete functional recovery often occurs, depending on th e severity of the blunt trauma. We have developed an animal model of m uscle contusion in mice thigh energy blunt trauma) and characterized t he muscle's ability to heal following this injury using histology and immunohistochemistry to determine the level of muscle regeneration and the development of scar tissue, We have observed a massive muscle reg eneration occurring in the first 2 wk postinjury that is subsequently followed by the development of muscle fibrosis. Based on these observa tions, we propose that the enhancement of muscle growth and regenerati on, as well as the prevention of fibrotic development, could be used a s approach(es) to improve the healing of muscle injuries. In fact, we have identified three growth factors (bFGF, IGF-1, and NGF) capable of enhancing myoblast proliferation and differentiation in vitro and imp roving the healing of the injured muscle in vivo, Furthermore, the abi lity of adenovirus to mediate direct and ex vivo gene transfer of beta -galactosidase into the injured site opens possibilities of delivering an efficient and persistent expression of these growth factors in the injured muscle. These studies should help in the development of strat egies to promote efficient muscle healing with complete functional rec overy following muscle contusion. (C) 1998 Elsevier Science Inc.