The Effects of Synovium Transplants on Tendon Healing In Vitro

INTRODUCTION: Injuries to the finger flexor tendons are common, and sometimes result in considerable disability. Although flexor tendon healing follows similar stages of wound healing as other tissues, tendinous tissues require a longer time to heal than other connective tissues, which may be due to their hypocellular and hypovascular nature. The nutrition of flexor tendon comes from intratendinous blood flow from vincula and from diffusion of the synovial fluid in the flexor synovial sheath. After flexor tendon injury, these nutritional sources could be jeopardized, further affecting tendon healing as well. Intrinsic tendon healing is important, since the adhesions of extrinsic healing hinder hand function. Almost 30 years ago Lundborg described an in vivo model in which tendons could heal without adhesions. Although others questioned the model’s validity, many subsequent studies have shown that flexor tendons do have the capacity for intrinsic healing, and more recent studies have shown that synovial cells can accelerate connective tissue healing. The purpose of this study was to investigate whether synovium implantation between repaired tendon ends could stimulate and accelerate tendon healing in a canine in vitro model.