SIS and Ligament Repair.
By Margaret Wan, Body1 Staff
Ligament repair is also making progress. One of the most common injuries, known as
ACL tear, can now be reconstructed through surgery. A piece of ligament is taken from
elsewhere in the patient’s leg, or synthetic ligament is used. It is grafted into the knee and
held in place with a button on the top and a pin on the bottom. This kind of repair allows
most patients to return to normal activity and participate in their favorite sports.
Right now, a material called SIS is under development that would allow the patient to
grow back a damaged ligament or tendon. A very thin piece of pig intestines, about as
thick as a piece of paper, forms a scaffold where the patient’s own cells could grow.
"The SIS implants generally start out weaker than synthetic ligaments but become heavier
and stronger with use, just like natural tissue," according to the inventor of SIS, Dr.
Stephen Badylak. Studies in animals show the implant also helps increase the flow of
blood to the injured area to aid in healing. Clinical trials in humans are underway. When
available, this technology would complement the newest methods of ligament repair.