Stem Cell Bone Repair

The ankle is made of three bones, the tibia (shinbone), fibula (the small bone toward the outside of the leg) and the talus (anklebone). There are two joints: an ankle joint and a syndesmosis joint (which connects the tibia and fibula). The ankle is a very flexible joint. It can move up and down and side to side. The ankle also takes on a tremendous amount of pressure and strain during movement. Strong bands of tissue, called ligaments, hold the bones in place and give the ankle stability.

Annually, about 492,000 ankle fractures occur in the U.S. Signs of an ankle fracture can include: severe pain, swelling, bruising and tenderness at the site of the fracture, inability to put weight on the injured foot and a change in the way the ankle looks compared to the other ankle. Sometimes the bone isn’t broken, but the injury causes a severe sprain or torn ligaments around the ankle. In either case, a physician should be consulted for proper treatment.

Treatment for ankle fractures depends upon the location and extent of the damage. Initially, a leg cast or splint may be placed on the affected leg to hold the joint structures in position and give time for the area to heal. If the fracture is severe or the bones are unstable, surgery may be needed. Doctors use tiny screws, plates and rods to hold the bones together. Torn ligaments may be sutured or repaired. Normally, it takes about six weeks for a broken bone to heal. Most people can return to normal activities after three to four months. If ligaments, tendons or muscles are damaged, healing time can take much longer.

Stem Cells for Ankle Fractures

Some fractures heal very slowly after treatment, while others fail to heal or don’t heal properly. In these cases, patients may need more surgery to stabilize the joint. Researchers at Union Memorial Hospital in Baltimore, MD, are now studying the use of a patient’s own bone-marrow-derived stem cells to stimulate and speed healing. Stem cells reproduce and have the capability to mature into cells that produce bone, cartilage, tendons and muscle.

To obtain the stem cells, a large hollow needle is inserted into several locations in the hip bone to retrieve bone marrow. The fluid from the bone marrow is placed in a centrifuge and spun at a high speed to concentrate the stem cells. When the surgical repair is finished, the stem cell concentrate can be injected directly into the site of the injury. If surgeons need to fill in a gap, a matrix (a type of scaffolding) of soft tissue or bone substitute is soaked with the bone marrow concentrate. Then, the treated material is implanted into the site.

Inside the body, the concentrated stem cells start making new tissue cells to repair the damage. Orthopedic Surgeon and Researcher, Lew Schon, M.D., says the stem cells may turn into tendons, ligaments or bone, depending on what the body needs. The investigators have also found that the stem cells produce growth factors that reduce inflammation and swelling. Thus, patients have less pain and begin healing much faster. Schon first used the stem cell concentrate on high risk patients for whom other surgeries had failed. He says 80 to 90 percent of those patients have very little pain and swelling three to four days after the surgery.

Schon says the stem cell concentrate doesn’t help everyone, but, in his experience, it works for about 9 out of ten patients. He estimates about 200 to 300 physicians around the world are using similar techniques to enhance healing of fracture sites.

For general information on fractures:

American Academy of Orthopaedic Surgeons