Donors and Doctors Save Lives with Skin and Bone Transplants

The delicate art of transplanting body tissues such as bone and skin is fast becoming a commonplace procedure, says a leading orthopaedic oncologist.

"We are doing tissue transplants daily at the Medical College," notes Donald A. Hackbarth Jr., MD, Medical College of Wisconsin Associate Professor of Orthopaedic Surgery. "We are constantly doing bone grafts."

Dr. Hackbarth, who practices at the Froedtert & The Medical College of Wisconsin Orthopaedic Surgery Clinic, also serves on the advisory board of the Musculoskeletal Transplant Foundation.

Making a Difference for Others
The tissue gifts of 6,100 people helped to provide grafts to 231,000 people in 2005. In almost all cases, tissue donors are recently-deceased adults who have signed consent forms such as the one located on the back of Wisconsin driver's licenses. Even in death, donors can sustain or save the life of someone who has been traumatized by illness or injury.

"Yes, I have signed my donor card, and suggest that everyone does," says Dr. Hackbarth. "There are hundreds of thousands of people who need tissue transplants, so this is vitally important."

Since Wisconsin law requires that surviving family members also consent to the donation of tissue, the doctor also advises people to discuss their wishes with their families in case they come to an untimely death. A family donating a member's body can be assured that it will be treated with dignity, that the process will not interfere with the funeral, and that no cost will be incurred by the family.

Unlike organ transplants, the problem of the recipient's body rejecting tissue is only rarely an issue. "Generally, there is not much of a reaction from the body's immune system with tissue transplants," says Dr. Hackbarth.

Another key difference is that tissues can be used for up to five years, in contrast to organ transplants, where the transplantation typically must be conducted soon after organ procurement. "The exception is cartilage, where we have about 21 days to use it," Dr. Hackbarth notes. Cartilage cells are preserved in a special culture medium while cultures and viral tests are performed so the cartilage can be used as soon as possible, before it loses its living characteristics.

Bone Grafting Merges New, Existing Bone
Bone transplantation serves as a demonstration of how science has progressed through the years. One of the most remarkable aspects of bone transplants is that the donor bone will begin to, in effect, merge with the recipient's bone. The donor bone is composed of a kind of latticework, and live bone cells from the recipient will begin to grow into it like plants into a trellis, substituting new bone for the donor bone.

"Eventually, the body removes the donor tissue and replaces it," explains Dr. Hackbarth. This process can take anywhere from three months to years.

Since the first successful bone graft was conducted in 1880 in Scotland, the art of bone grafting has become infinitely more sophisticated. There are several types:

Autografting is the process of replacing bone affected by trauma or tumors with bone from another part of the ill or injured person's own body. "There are some bones that can be borrowed," Dr. Hackbarth says. "We often see a graft from the pelvis to the spine or to correct a defect in a long bone. Another frequent procedure is to take some of the fibula (the smaller lower-leg bone) to graft on to a forearm or hip."

By far the most common approach to bone grafting is allografting, a transplant from a deceased donor to a recipient. "Obviously, this is easier on the patient because autografting involves the possibility of pain in two places, the site from where the graft was taken as well as the site where it is inserted," he notes.

Science has also provided for the development of substitute grafts, in which strong but inanimate elements such as coral, porcelain, and other manufactured products can be used when other options are not available.

Normally, the age range of donors is restricted from 18 to 60 because the body's bones have matured and have not yet begun to weaken.

Wide Range of Tissues Can Be Donated
A remarkable range of body parts can be harvested from deceased donors to help the living, Dr. Hackbarth says. These include bones, bone filler, joints, ligaments, tendons, and heart valves, among others. The increasing expertise of tissue banks even allows them to store excess skin from people who have undergone gastric bypass surgery, and thus aid burn victims whose skin has been seared.

Successful use of donated tissue requires careful handling throughout a complex process. "The tissue is procured using sterile technique in an operating room within four hours of the donor's death. We perform blood tests to ensure that we will not be transmitting a disease such as HIV or Hepatitis B or C," Dr. Hackbarth explains. "We need to examine the donor's medical history and social history - for drug use, certain diseases, and existing viruses."

The tissue is then sent to a main tissue bank and quarantined until all tests are completed. The tissue banks are operated under strict codes set by the American Association of Tissue Banks.

Donated tissue is stored until use after freezing, freeze-drying, or irradiation procedures. Some of these processes help to diminish some of the immune response to the transplanted tissue by the recipient.

One of the larger controversies emerging in the tissue donation field is the emergence of for-profit tissue banks over the last decade. Dr. Hackbarth sees no place for profit-making in this area.

"Tissue is a precious gift, not something to be sold," he states firmly. "I happen to believe that not-for-profit is the purest way to operate." The Musculoskeletal Transplant Foundation follows that philosophy, he notes.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.