Background: Rupture of tendons is a common injury. The outcome of surgical repair of injured tendon is often unsatisfactory.  At best, the restored tendon is about half of its initial mechanical properties. In this study the effect of zenologous and autologous platelet gel were compared in rabbit model.

Methods: 45 rabbits in the age range of 7 months to 1 year old were divided into autologous, zenologous and control groups. Superficial digital flexor tendon was cut transversely and then sutured with Mayer stitch pattern. Then 5cc of either aotologous or zenologous platelet gel was injected to the incision area. The control group had no material injection. On 7th, 14th, and 28th post-operative days, five rabbits of each group were euthanized and tendons were harvested for histopathological and biomechanical evaluations. The results were analyzed statistically.

Results: Biomechanical factors were significantly superior in the autologous and zenologous groups than the control group. In histopathological examination the autologous groups showed a significant difference in fibroblast maturation in all the tested weeks. The collagen fiber alignment at 7th postoperative day and collagen accumulation on 7th and 28th postoperative days were superior in autologous compared with zenologous and control groups.

Conclusions: Utilization of zenologous platelet gel has a positive effect on tendon healing, but not as good as autologous platelet gel.