An experimental study on the significance of muscle tissue interposition on fracture healing

Ten ulnae of mongrel dogs were osteotomized and a 3 to 5 mm cylindrical segment of bone removed from each shaft. In 10 ulnae of the opposite forelimb, living muscle tissue was placed in the resection site. The control ulnae (Set 1, Set 2) revealed 60 per cent unions, while the experimental ulnae revealed 100 per cent non-unions as determined by radiological and histological examination. Although necrotic muscle will be invaded by primitive bone, healing is certainly delayed or does not occur. A large muscle mass contributes a barrier too large to be successfully incorporated into the healing process of a fracture of the shaft of a long bone. On the basis of this experiment fractures should be opened and obstructing tissue removed whenever conservative measures fail to remove muscle interposition.