More than 20000 American suffer from Osteonecrosis each year. As the condition progresses, bone cells cannot repair themselves and cannot sustain bone integrity, and in the end die. Thus, bone decay leads to reduce blood flow to that area, further weakening the entire upper leg skeletal structure. If not treated, ball portion of hip’s ball and socket joint will surrender and collapse. At the end a complete hip replacement surgery is required.
An orthopedic surgeon with Yale School of Medicine, Daniel Wiznia, is trying a surgical technique drafted to decrease the need of hip replacements to about 10%. Self-renewal ability of patient’s own stem cells plays key role for bone regrowth. Hence, restoring blood flow and avoiding further surgery.
Patients usually get this diagnosis in their 30s and 40s which present a certain challenge. Although hip implant lifespan has increased greatly in past years. However, patient who had a total hip replacement at that age, mostly needs a redo later in life. Doing the same treatment at an older age brings new complications and risks, making it harder to control down the road. The goal in patients with this state then becomes very clear: prevent the head of the femur (thighbone) from collapsing.
Technique
Wiznia, assistant professor of orthopedics and rehabilitation, draws from both of those areas of expertise to use 3D imaging technology as part of a new joint-protection procedure. In the last few years, he has worked closely with the Yale School of Engineering & Applied Sciences. Also with the Integrated 3D Surgical Team at the Yale School of Medicine to tailor this treatment to each patient. Imaging proved quite critical to the successful outcome of this technique.
“One of the challenges of orthopedic surgery in the human body is that surgeons are operating in a three-dimensional space and often rely on two-dimensional imagery such as X-rays,” Wiznia says. “Through computer modeling, we are able to customize those images and create models that are specific to each patient, which, in turn, increases outcomes and overall post-operative success rates.”
Wiznia collects the bone marrow form the patient’s pelvis. Then, by using centrifuge, he isolate and concentrate individual’s own stem cells. The dead bone area is then injected with materials containing stem cells. As study shows that stem cells has the ability to regrow, repair and regenerate damage bone and tissue. Hence, Wiznia believes that this treatment reduces the risk of head of femur from collapsing. Shortly after the procedure, patients experienced restored of blood supply to the area. Also new cells repopulate the bone. Therefore, this can be a plus point to ease the need for temporary hip replacement surgery.
Challenges
Recognizing, diagnosing and carrying out the surgical procedure before the collapse is the main challenge. “Because vascular injury usually is painless,” says Wiznia. “Patients generally are unaware of specific time when injury occur, due to which cases are rarely discovered on time.”
Avascular necrosis of the hip is normally present on both side. Patients who already knows are encourage. It can develop at different rates on the two sides. So, even though one side is diagnosed too late, there still is a chance to save the other one.
“We usually are able to catch that second asymptomatic side in those situations and run the core decompression with stem cell treatment before it collapses,” Wiznia says. “This stem cell therapy has shown improved pain and function. The stem cells decrease the risk of the femoral head from collapsing. That ultimately translates into fewer young patients requiring hip replacements along with future treatments in their later years.”