In addition, studies by Ohio State scientists indicate the procedure may have distinct advantages for athletes by shortening the time it takes for them to return to play and restoring a competitive level of performance.
Overall, the procedure, called autologous chondrocyte implantation (ACI), is becoming a popular option among younger patients with damaged cartilage. Most of the 13,000 procedures performed nationwide having occurred in the past few years.
With ACI, the patient undergoes two surgical procedures, the first to remove a small sample of undamaged cartilage cells, and a subsequent procedure a few weeks later to implant regenerated cells that now number in the millions.
“We can harvest those cells, send them to the lab, where they actually grow and expand,” said Dr. David Flanigan, an orthopedic surgeon at Ohio State who specializes in the procedure.
The main component of the knee joint surface is a tissue called hyaline cartilage, which can become rough or damaged. When it is damaged, the joint surface may no longer be smooth and causes pain upon movement.
Flanigan likens a cartilage defect to that of a pothole. “After wear and tear, over time the pothole can get bigger,” he said. “The goal is to resurface – to give it a brand new “street,” in essence by filling the pothole.”
In a laboratory, the extracted cells, or chondrocytes, are multiplied in a culture, a process that can take approximately six weeks. The cells are then frozen to await implantation back into the patient. During surgery, the cells are injected back into the knee compartment under a piece of tissue taken from the covering of the bone.
The ACI procedures are performed using minimally invasive techniques, which result in less trauma to the body and can increase longevity of the knee and prevent or delay major surgical interventions later in life. The first procedure, to extract the cells, is performed using an arthroscope – a small device that requires only small puncture-like openings through the skin. The second procedure to implant the cells is performed using a small incision in the knee joint.
ACI is a treatment considered for young, healthy patients with medium to large sized damage to their cartilage. Older adults are less likely to benefit from the surgery. The procedure is not applicable to osteoarthritis patients, however, can be beneficial to repair injuries due to trauma, athletics and other conditions.