Authors: Abdolhamid Meimandi-Parizi, Ahmad Oryan and Ali Moshiri
Tendon injuries are commonly encountered in the orthopaedic clinics. The major limitations to manage these injuries are poor healing response and development of peritendinous adhesions in the injured area. This study was designed for application of a novel collagen implant on tendon healing in animal model. Seventy five White New-Zealand rabbits were divided into treated (n=20) and control (n=20) groups and 35 rabbits for pilot study in 5 groups. A 2cm defect was created in the left Achilles tendon of all rabbits. The defects of the treated animals were filled with collagen implants but in control rabbits the gap was left untreated. Clinical examination was done and scored. Study was continued for 120 days. The samples of all animals were examined at macroscopic and microscopic level and the dry matter content, water delivery and water uptake characteristics Compared to the controls, the treated lesions showed improved tissue alignment and less peritendinous adhesion, muscle atrophy and fibrosis. They also showed significantly better clinical scoring, indices for water uptake and water absorption than the controls. The collagen implant was invaded by the inflammatory cells at the inflammatory phase, followed by fibroplasia phase in which remnant of the collagen implant were still present while no inflammatory reaction could be seen in the lesions. However, the collagen implant was completely absorbed in the remodeling phase and the newly regenerated tendinous tissue filled the gap. Collagen implant used in this study was biodegradable, biocompatible and possibly could be considered as a substitute for auto and allografts in clinical practice in future.
Keywords: Tendon, Collagen, Bioimplant, Healing, Rabbits