The effect of local hematoma blocks on early fracture healing.

To test the effects of lidocaine and bupivacaine on early fracture healing, the tensile strength of five groups of femora from normal rats 14 and 35 days after production of a closed diaphyseal fracture were compared. Data indicate that, in experimental animals injected with local anesthetics at the fracture site, no measurable difference is noted in callus composition, tensile strength, or histological appearance during the early phases of fracture repair prior to callus remodeling.