Surgeon aiming to avoid hip replacements
Injecting stem cells repairs bone damage, according to Yale doc
Wiznia treats the condition by removing stem cells from the patient’s bone marrow and injecting them into the femoral head. While people assume hip replacements are required because of osteoarthritis, caused by damage to the cartilage that covers the head of the femur, “10 percent of hip replacements are actually done because of vascular necrosis of the femoral head,” Wiznia said.
NEW HAVEN — The hip requires a well-formed ball and socket to keep us walking, standing and bending without pain, but without good blood flow, the head of the femur — the ball in the joint — can crack and become deformed.
For a variety of reasons, including trauma to the hip, diabetes and excessive alcohol use, the problem can occur as early as 30 years old, according to Dr. Daniel Wiznia, an orthopedic surgeon with Yale Medicine who specializes in hips and knees.
Wiznia is using a simple operation to inject patients’ stem cells into the hip joint, restoring the blood flow necessary to repair the hip bone’s cells. He said it can reduce the need for hip replacements by up to 10 percent.
“The bone is alive, so it has blood vessels coursing through it, supplying nutrients,” Wiznia said. “When the blood supply is damaged, then the bone can’t rebuild,” a condition known as vascular necrosis or osteonecrosis
Wiznia compared the head of the femur, the ball that fits into the pelvic socket, to an old china teacup, which over time becomes covered with fine cracks. As we move about and put weight on our hip, “that load actually causes the bone to bend a little bit,” he said.
“The hip experiences
very high loads and it slowly crumbles and collapses,” said Wiznia, an assistant professor in both the Yale School of Medicine and the Yale School of Engineering and Applied Science. “Fractures can also occur with this condition,” he said.
Unlike china, though, bone “does have cells that can help replenish it,” called osteoblasts, Wiznia said. They can repair the damage, but they require a blood supply.
Wiznia treats the condition by removing stem cells from the patient’s bone marrow and injecting them into the femoral head. While people assume hip replacements are required because of osteoarthritis, caused by damage to the cartilage that covers the head of the femur, “10 percent of hip replacements are actually done because of vascular necrosis of the
femoral head,” Wiznia said.
He said there are about a dozen causes: high-dose steroids needed because of asthma, autoimmune conditions or rheumatologic conditions, trauma caused by a fall, a dislocated hip or other fracture and excessive alcohol use. “We have found that patients that have a high alcohol intake, this can weaken the blood supply to certain regions of the body,” Wiznia said. He said excessive drinking would be “someone who’s drinking every day, more than one drink a day.”
Additional causes include HIV, sickle cell disease, clotting disorders, diabetes and lupus, he said. Chemotherapy and radiation also are “toxic to the small vessels,” he said.
Hip replacements only last about 20 years, however, so younger people likely would have to get a second or even third one, at higher risk. If the need for a replacement is because of vascular necrosis, those surgeries may be avoidable, Wiznia said.
“If we can catch it early, we can treat it with this stem cell therapy that we’re using at Yale,” he said. Bone marrow is taken from the pelvis and progenitor cells, a type of stem cell that creates the particular cell tissue from which it’s taken, are injected into the hip.
“They send signals for the body to produce new blood vessels and to repair the bone damage,” Wiznia said. “We’ve seen with this treatment we can prevent collapse 75 percent of the time. Without the treatment, collapse is going to happen 50 percent of the time.”
He said the surgery is “very minimally invasive,” with “two incisions that are smaller than a centimeter.” The patient goes home afterward and can return to work in a few days, he said.
A person will know they have the condition if they feel “a toothachy pain in the groin or the buttock … a sharp pain or sort of an achy pain that keeps them up at night,” Wiznia said. He said it doesn’t feel like nerve pain. “It’s deep,” he said.
Another sign is increased stiffness in the joints, Wiznia said. “They’re having trouble putting on a sock, putting on a shoe, bending over from a seated position,” he said.
“A lot of times, patients will come in and say, ‘my right hip hurts,’” he said. “Eighty percent of patients that have a vascular necrosis in one hip will have it in the other,” even without noticing symptoms. “The most important thing is to catch it early.”
Wiznia said researchers are “developing new techniques to target the region of interest” — the exact location of the damage. “It’s a personalized, custom surgery for each patient,” he said.
He said the same problem can happen in the knees and shoulders, but the hip is the most common area because of the heavy weight it bears, which is why obesity is a problem. “Every pound that we have is an extra 10 pounds through the hip joint,” he said.
Excessive weight not only can damage the blood vessels but wear down the cartilage that helps the ball glide in the socket. He recommended Yale’s Metabolic Health and Weight Loss Program at 40 Temple St. “I’ve had patients lose over 120 pounds, 150 pounds, just working with that team,” he said.
The program “takes a while … many months, but it makes a big difference,” Wiznia said. The clinic can be contacted at 203-7854138. He also advocated that people take calcium and vitamin D for bone health.