Every physician who treats fractures wants a therapeutic means of accelerating fracture healing. The prospect of such therapy deserves having special attention called to it.
Benfer and Struck (see p 838) provide evidence that locally applied soluble pig collagen benefits fracture healing. In controlled experiments on rats, collagen-treated fractures showed more rapid healing by x-ray and histologic criteria as well as greater breaking strength than control fractures at comparable healing periods. Realizing that rat bones differ from adult human bones in having open epiphyses and not osteons, the authors extended their experiments to dogs. Dogs have human-type osteotic bone and the average age of 2½ years for these dogs is beyond the age (1½ years) of epiphyseal closure. This is of some importance, since significant differences have been demonstrated between growing and mature bones in regard to healing fractures, and the greatest clinical value of a healing accelerator would be