Tendon-to-Bone Tunnel Healing in a Rabbit Model: The Effect of Periosteum Augmentation at the Tendon-to-Bone Interface

Purpose : This study evaluated the effect of the periosteum-wrapped tendon on tendon-to-bone healing using a rabbit model. Materials and Methods : Twenty New Zealand white rabbits were used. The animals were divided into two groups, a group with periosteum-wrapped tendon and a control group without a periosteal wrap. Both legs were operated upon in the same manner. The long digital extensor tendon was harvested and transplanted into the proximal tibial tunnel. One limb was transplanted with the tendon wrapped with periosteum facing the cambium layer to the tendon, while the other was without periosteum. The healed tendon-bone attachment was evaluated at 3-weeks and 6-weeks histologically and by biomechanical testing. Results : At 3 and 6 weeks, histologic examination demonstrated more extensive bone formation around the tendon with closer pposition of new bone to the tendon in the limb with the periosteum-wrapped tendon graft than in the control limb. Biomechanical testing demonstrated the higher pullout strength of tendon in the limb with the periosteum-wrapped tendon graft at 3 and 6 weeks with statistically significant differences between the limb with the periosteum-wrapped tendon graft and the control limb at 3 and 6 weeks. Conclusion : Histological and biomechanical data suggest superior healing in the periosteum-wrapped group. This study demonstrates that periosteum can enhance the healing process when a tendon graft is transplanted into a bone tunnel.