Observations on a series of thirty-six animals are submitted to show the comparative stimulating effect of selected substances on the repair of fresh fractures when injected into the site of injury.
Leg-against-leg control in the same animal tends to eliminate discrepancies due to individual variability where animal is compared with animal.
Of the selected substances employed as stimulants to bone repair, amniotic-fluid concentrate gave the only definite results.
Injection may be done at the time of fracture or it may be delayed for from one to four days.
The results obtained in this experimental series suggest the clinical application of this treatment to fresh fractures in sites notorious for delayed union or non-union of bone.