麻豆视频

Research

Scientists Discover Way to Jumpstart Bone's Healing Process

Apr. 22, 2009
In-Body Stem Cell Therapy Has Enormous Potential for Bone Injuries

麻豆视频


Rarely will physicians use the word 鈥渕iraculous鈥 when discussing patient recoveries. But that鈥檚 the very phrase orthopaedic physicians and scientists are using in upstate New York to describe their emerging stem cell research that could have a profound impact on the treatment of bone injuries. Results from preliminary work being released today, patients confined to wheelchairs were able to walk or live independently again because their broken bones finally healed.

At the heart of the research is the drug teriparatide, or Forteo, which was approved by the FDA in 2002 for the treatment of osteoporosis. Astute observations led a team of clinicians and researchers to uncover how this drug can also boost our bodies鈥 bone stem cell production to the point that adults鈥 bones appear to have the ability to heal at a rate typically seen when they were young kids.

presented in February at the meeting revealed that of 145 patients who had an unhealed bone fracture 鈥 half of them for six months or longer 鈥 93 percent showed significant healing and pain control after being on teriparatide for only eight to 12 weeks. These findings were enough to convince the to fund a , and if the preliminary data are any indication, researchers may have discovered a new, in-the-body stem cell therapy that can jumpstart the body鈥檚 natural healing process in bones.听

A 61-year-old male fractured his tibia while skiing, and three months later, still had not healed (left). Patient did not want surgery, and opted to take teriparatide. After three months on the drug, the fracture (right) began to heal, and today, the patient is back to his active lifestyle.

The clinical implication is significant, as orthopaedists can soon have a new tool at their disposable to deal with many common, painful bone ailments including the tens of thousands of painful fractures for which there is no treatment (pelvic fractures, vertebral compression fractures, clavicle fractures), fractures that won鈥檛 heal, fractures in patients that are either too sick to have surgery or chose not to have surgery, and even reduce the size of a incision in some surgeries.

Aging Bones Heal Slower

Of the estimated six million fractures in the United States each year, approximately five percent will have slow or incomplete healing.听According to , who heads up orthopaedic bone research at the 麻豆视频 and is the principal investigator of the clinical trial, a large portion of non-healing fractures tend to occur in older adults.

鈥淚n many people, as they get older, their skeleton loses the ability to heal fractures and repair itself,鈥 Puzas said.听鈥淲ith careful application of teriparatide, we believe we鈥檝e found a way to turn back the clock on fracture healing through a simple, in-body stem cell therapy.鈥

Those especially hard hit are the nearly 60,000 Americans suffering from pelvic fractures, where bracing and immobilization are not an option for an injury that leaves people immobile and in pain before the bone fuses.

鈥淚t takes three to four months for a typical pelvic fracture to heal. But during those three months, patients can be in excruciating pain, because there are no medical devices or other treatments that can provide relief to the patient,鈥 said medical director of the at the 麻豆视频.听鈥淚magine if we can give patients a way to cut the time of their pain and immobility in half?听That鈥檚 what teriparatide did in our initial research.鈥

Bukata said much more was at stake then just comfort and pain relief. Patients who would ordinarily be confined to nursing homes or require additional medical attention because of non-healing fractures might be able to live an independent life. Bukata and Puzas estimate that if this drug saved just one week in a nursing home, it would pay for itself 鈥 and beyond.

鈥淢any people don鈥檛 realize that pelvic fracture carries with them the same mortality as hip fractures 鈥 in one year, approximately one-quarter of all older women with pelvic fractures will die from complications,鈥 Bukata said. 鈥淎nd during that year of recovery, a patient typically puts a greater strain on our health care system, not to mention their pain and suffering.鈥

Translational Research at Work

The impetus for the research began in Bukata鈥檚 clinic, where she saw painful bone fractures in osteoporotic patients quickly heal within a few months of taking teriparatide. At the time, Bukata also served on a research team at the University鈥檚 , and she began to advocate that the team direct its efforts in an entirely new direction based on the results she was seeing with patients who were taking teriparatide.

鈥淚 had patients with severe osteoporosis, in tremendous pain from multiple fractures throughout their spine and pelvis, who I would put on teriparatide,鈥 said Bukata. 鈥淲hen they would come back for their follow-up visits three months later, it was amazing to see not just the significant healing in their fractures, but to realize they were pain-free 鈥 a new and welcome experience for many of these patients.鈥

Puzas and Bukata developed a plan to focus attention in both the lab and clinic to understand if her observations were a fluke or if there was an underlying scientific process producing such life-changing results for patients.

鈥淲hile we had come to understand how teriparatide builds bone more robustly than the body can on its own, up to that point, we had no clue how the drug would or could help with fracture healing,鈥 Puzas said.听

Bukata began prescribing teriparatide to patients with non-healing fractures, and was amazed at her findings:听93 percent showed significant healing and pain control after being on teriparatide for only eight to 12 weeks. And in the lab, Puzas began to understand how teriparatide stimulates bone stem cells into action.听

Closing the Gap

When a fracture occurs, a bone becomes unstable and can move back and forth creating a painful phenomenon known as micromotion. As the bone begins healing it must progress through specific, well-defined stages. First, osteoclasts 鈥 cells that can break down bone 鈥 clean up any fragments or debris produced during the break.听Next, a layer of cartilage 鈥 called a callus 鈥 forms around the fracture that ultimately calcifies, preventing the bony ends from moving, providing relief from the significant pain brought on by micromotion.

Only after the callus is calcified do the bone forming cells 鈥 osteoblasts 鈥 begin their work.听They replace the cartilage with true bone, and eventually reform the fracture to match the shape and structure of the bone into what it was before the break.

According to Puzas, teriparatide significantly speeds up fracture healing by changing the behavior and number of the cartilage and the bone stem cells involved in the process.

鈥淭eriparatide dramatically stimulates the bone鈥檚 stem cells into action,鈥 Puzas said. 鈥淎s a result, the callus forms quicker and stronger. Osteoblasts form more bone and the micromotion associated with the fracture is more rapidly eliminated. All of this activity explains why people with non-healing fractures can now return to normal function sooner.鈥

鈥淭he decreased healing time is significant, especially when fractures are in hard-to-heal areas like the pelvis and the spine, where you can鈥檛 easily immobilize the bone 鈥 and stop the pain,鈥 Bukata added. 鈥淭ypically, a pelvic fracture will take months to heal, and people are in extreme pain for the first eight to 12 weeks.听This time was more than cut in half; we saw complete pain relief, callus formation, and stability of the fracture in people who had fractures that up to that point had not healed.鈥

The new clinical research will study post-menopausal women and men over 50 who come to the Emergency Department at Strong Memorial Hospital with a low-energy pelvic fracture. Patients will be divided into two groups -- one offered teriparatide, the other a placebo -- and followed for 16 weeks to measure the fracture healing process in a variety of ways:听pain levels, microscopic bone growth determined through CT scans and functional testing of bone strength, among others.听

Editor鈥檚 Note:听, manufacturers of Forteo, are providing the medication for the clinical trial.听Both Drs. Puzas and Bukata are members of Eli Lily's speaker bureau.听