About 6 million people in North America suffer bone fractures each year and 5 to 10 percent of these patients are resistant to healing, according to the American Academy of Orthopaedic Surgeons. This means that about half a million Americans annually have fractures that don’t heal. UC Davis researchers are developing an improved surgical therapy for such fractures, using stem cells and innovative technology.
After a broken bone is treated, new bone tissue usually begins to form and connect the broken pieces. However, some bone fractures don’t heal due to a lack of adequate stability, blood flow, or large bone loss. For instance, severe bone fractures that are caused by a high-energy car wreck are more likely not to heal. Several other factors increase the risk of non-healing bones, including older age, diabetes, poor nutrition, use of tobacco, and severe anemia. Traditional treatments to address this problem, such as bone grafts taken from another part of the body, often lead to pain, dysfunctional limbs, and disabilities.
In the last several years, the application of stem cells directly to the wound site has emerged as an improved way to treat non-healing fractures. However, acquiring the necessary stem cells from the patient, a matched donor, or embryo is problematic. Ideally the stem cells come directly from the patient, but this requires a painful surgical procedure with general anesthesia during which a large needle is used to retrieve the stem cells from the hip. In addition, the retrieved stem cells need to be isolated before they can be transplanted back into a patient, so a second surgery is required with a long combined recovery period.
“People come to me after suffering for six months or more with a non-healing bone fracture, often after multiple surgeries, infections and hospitalizations,” said Mark Lee, UC Davis associate professor of orthopaedic surgery, in a press release. “Stem cell therapy for these patients can be miraculous, and it is exciting to explore an important new way to improve on its delivery.”
In their new clinical trial, Lee’s team is testing a new SynGen Inc. device that processes the irrigation fluid obtained during an orthopedic procedure. This irrigation fluid contains abundant mesenchymal stem cells and other factors that can be used to help make new blood vessels and improve wound healing.
During the surgery, the irrigation fluid is aspirated and captured. The fluid is then centrifuged and processed using the new SynGen device, which rapidly isolates a concentration of mesenchymal stem cells in less then 30 minutes. These concentrated stem cells are then delivered to the patient’s fracture during the same surgery. The device is about the size of a food processor, so it can be easily used in an operating room.
“The device’s small size and rapid capabilities allow autologous stem cell transplantation to take place during a single operation in the operating room rather than requiring two procedures over a period of weeks,” said Lee in the press release. “This is a dramatic difference that promises to make a real impact on wound healing and patient recovery.”
The UC Davis researchers are already testing this new surgical treatment on patients. However, it is unclear when this treatment could move into general clinical practice.
A modified version of this story is posted on my KQED Science blog.