In a fracture healing experiment using rabbit tibiae, apparatus was used to produce a constant measured compression at the site of surgically produced fractures. The apparatus did not hold the fracture rigidly immobilized, but permitted a degree of motion. Under these conditions, compression itself was not a uniformly beneficial factor in fracture healing. In excess, compression acted adversely on the healing process, resulting in slower healing and a bulkier, less mature callus. Excess compression was also related to an adverse response in the diaphysis manifested by resorption of bone along Haversian canals with resultant diminution of structural substance of the cortex.
Laros GS. Fracture HealingCompression vs Fixation. Arch Surg. 1974;108(5):698-702. doi:10.1001/archsurg.1974.01350290062010