Short and long terms healing of the experimentally transverse sectioned tendon in rabbits

Forty white New Zealand mature female rabbits were randomly divided into two equal groups of 28 and 84？DPI After tenotomy and surgical repair of the left SDFT, the injured legs were casted for 14？days. The weight of the animals, tendon diameter, and clinical, radiographic and ultrasonographic evaluations were conducted at weekly intervals. The animals were euthanized on 28 and 84？DPI and the tendons were evaluated for histopathological, ultrastructural, biomechanical and percentage dry weight parameters.Although the clinical, ultrastructural, morphological and biomechanical properties of the injured tendons on day 84 showed a significant improvement compared to those of the 28 DPI, these parameters were still significantly inferior to their normal contra-lateral tendons.This study showed that tendon healing is very slow and at 84？days post-injury the morphological and biomechanical parameters were still inferior to the normal tendons and many collagen fibrils still had the same diameter as those seen at 28 DPI.