Bone Growth After Pediatric Hand Transplant Is Major Milestone in Reconstructive Surgery

In 2015, reconstructive plastic surgeons at Children's Hospital of Philadelphia faced a daunting challenge. Their patient was a young boy who suffered the amputation of both hands as a result of life-threatening sepsis. There was also another complicating factor: the same infection had led to the loss of both kidneys, necessitating a kidney transplant.

With that challenge came a unique opportunity. The patient was already taking immunosuppressive drugs to prevent rejection of his kidney transplant – opening the possibility of double hand transplantation to restore form and function. It would be the first procedure of its kind, and it raised a critical question: Would the transplanted hands grow along with the recipient?

According to a four-year follow-up study by Benjamin Chang, MD, and colleagues at Children's Hospital of Philadelphia and the University of Pennsylvania, the transplanted hands grew at essentially the same rate as expected in a healthy child. "The results show that hand transplantation can be an option for reconstruction and rehabilitation in growing children," Dr. Chang commented. The study appears in the December issue of Plastic and Reconstructive Surgery®, the official medical journal of the American Society of Plastic Surgeons (ASPS).

The procedure was the first bilateral (both sides) pediatric hand/forearm transplant procedure performed in a young child. The groundbreaking procedure was successful: one year later, with intensive follow-up and therapy, the patient's new hands were functioning well.

In the new study, Dr. Chang and colleagues took an in-depth look at how the transplanted tissues grew in the years after surgery. Using follow-up x-rays, they performed detailed calculations to assess bone growth and skeletal maturation, compared to "normative" growth rates in healthy children.

The results showed steady growth of the forearm bones (radius and ulna): between nine and ten millimeters (mm) per year. Bone age – a standard assessment of skeletal maturation – increased by one year at each follow-up visit, just as expected in a healthy child. Growth rates were similar for both transplanted hands.

The patterns were consistent with data on normal growth. Total growth of the transplanted bones was 37.7 mm – not significantly different from the expected bone growth of 35.5 mm in healthy children.

An inch and a half of bone growth over four years may not seem like a big deal. However, it's a meaningful step forward in the potential use of hand transplantation in children. The study provides the first long-term follow-up after hand transplantation during a period of rapid bone growth, in a child who lost his hands during "a critical window of fine motor development."

While bone growth is a significant achievement, Dr. Chang also notes that the patient "is now able to use his hands for playing video games, writing, scaling a rock-climbing wall and, most importantly, using the bathroom by himself."

Hand transplantation is a type of procedure called vascularized composite allotransplantation (VCA). That term refers to transplants combining different types of tissues, such as skin, muscle, blood vessels, nerves and bone. Facial transplantation is another type of VCA.

In addition to successful restoration of hand function for the young transplant recipient, the study "celebrates another major milestone in reconstructive surgery," Dr. Chang and colleagues conclude. "Although pediatric upper extremity VCA has not yet been widely adopted, our follow-up suggests that it may offer the advantage of growth rates similar to established non-transplant norms."

Plastic and Reconstructive Surgery® is published by Wolters Kluwer.

Click here to read "Four-Year Follow-Up of the World’s First Pediatric Bilateral Hand-Forearm Transplants: Do They Grow as Expected?"

Article: "Four-Year Follow-Up of the World’s First Pediatric Bilateral Hand-Forearm Transplants: Do They Grow as Expected?" (doi: 10.1097/PRS.0000000000007338)