Modeling the tendon suture with its isolation to demonstrate primary regeneration of the junction area

Introduction Functional recovery of the finger flexor tendon after surgical treatment is a problem due to formation of unavoidable blocking adhesions. For prevention of the adhesions, the mechanical separation of the sliding surfaces of the tendon and the wall of the fibro-osseous canal with a polymer tube was proposed. However, despite good clinical results, it is not possible to morphologically confirm the healing of the suture zone after such an intervention. Objective To present an experimental model and technique of surgical intervention on the calcaneal tendon of laboratory animals for isolation and blocking with a polymeric tube, longitudinally cut, for obtaining and studying the regenerate in the suture site. Materials and methods In an experiment under inhalation anesthesia with Isoflurane on both hind paws of 10 laboratory Wistar rats, the tendon suture was simulated with blocking and isolation of the tendon suture (n = 14) and the control operation without isolation (n = 6). The tendons were excised three weeks post-surgery, and the appearance and histological picture of the regenerates in the suture zone were examined. Results The surgery model with isolation of the suture site on the calcaneal tendons of rats reproduces well and adequately simulates the operation on the human hand tendons. The morphology of the obtained regenerates demonstrates the restoration of continuity with the formation of tendon-like tissue at the junction. In the experiment, subtotal isolation did not lead to tendon necrosis, but slowed down the healing of the suture zone. The tube prevented the formation of adhesions and maintained tendon nutrition through the fissure space. Conclusion Modeling of the operation of tendon suture on the rat calcaneal tendon with its isolation provides material for demonstration the primary tendon regeneration in vivo. Regeneration of the suture site during subtotal isolation slows down and occurs due to the cells of the tendon itself.