Could cartilage transplant cure your knee pain?
Courtesy of Metro Creative
Cartilage restoration surgery, which involves transplanting new cartilage into an injured knee, can be helpful to some who have been dealing with chronic pain issues.
Dr. Brian Moser
A technique that was once reserved only for high profile professional athletes is now offering more patients relief from chronic knee pain. It’s called cartilage restoration surgery and it involves transplanting new cartilage into an injured knee.
Treatment options for cartilage restoration have been available for several decades and became popular when surgeons started using microfracture techniques to treat knee cartilage defects in professional athletes in the 1990s and early 2000s, saidDr. Brian Mosier, co-director of the Center for Cartilage Restoration, Orthopaedic Surgery and Sports Medicine at Allegheny Health Network’s (AHN) Orthopaedic Institute.
“Since that time, significant innovation has occurred and we can treat a wide variety of cartilage problems in the knee using many exciting new techniques,” Mosier said. “This type of surgery is usually appropriate for younger patients (typically less than 55 years old) with focal cartilage defects, not osteoarthritis.”
That means most people with aches and pains because of arthritic knees wouldn’t be candidates, but there are still many patients who will want to investigate the procedure to find lasting pain relief.
What is cartilage?
Articular cartilage is the smooth surface that covers the end of the bones to help create a gliding surface and cushion. Cartilage defects may happen when the substance breaks down because of age, repetitive wear and tear or a traumatic injury such as twisting or falling on the knee.
The result is swelling, stiffness, aching and mechanical symptoms such as locking and catching. Articular cartilage has no blood supply, so it can’t heal itself or grow back. That leaves many people looking for other solutions such as injections to cushion the joint or surgery to repair it.
If the body can’t grow new cartilage inside the knee, then why not bring some in from a different area?
That’s the idea behind cartilage transplants and there are two options using a patient’s own cartilage cells and structure. The first is called osteochondral autografting.
“A wafer of bone and cartilage is taken from a less important, non-weight-bearing surface in the knee and transferred into the defect,” Mosier said. “This is typically used for smaller defects less than 1 to 1.5 cm in diameter.”
The second option is called autologous chondrocyte implantation (MACI) which involves two surgeries.
“In the first surgery, an arthroscopic evaluation is performed of the knee where the dimensions and location of the defect are assessed,” Mosier said. “At that time a cartilage biopsy is taken. The cartilage biopsy is then sent to a company named Vericel who can extract the cartilage cells from the piece of tissue and grow them in their lab.”
That’s right: Vericel grows new cartilage from the patient’s own cells – it just happens in a lab rather than inside their knee.
“The cells are impregnated onto a collagen membrane and sent back to the surgeon for implantation into the cartilage defect in the patient’s knee during a second surgery,” Mosier said. “This process usually entails a six- to eight-week time frame between the first and second surgeries.”
It’s not an easy or fast process, but it can be a solution for some patients and way to delay or avoid total knee replacement.
“The recovery process is long given the fact that we are relying on the cartilage cells to grow and create new cartilage-like tissue to fill the defect,” Mosier said. “Typically patients start therapy a week after surgery and are on crutches for six weeks. At approximately nine to 12 months they are allowed to return to work/play without restrictions.”
Mosier said this surgery and recovery are more comparable to that of an ACL reconstruction rather than a knee replacement.
The procedures are FDA approved and covered by most insurance plans. As for whom is the best candidate, Mosier said most of these techniques are only approved for patients under age 55.
“I like to believe in physiologic age rather than chronological age as I have many patients in their 60s and 70s who are extremely active and not great candidates for knee replacements,” he said. “The best candidates for cartilage restoration surgery are active individuals with focal full-thickness cartilage defects, not osteoarthritis. My goal is to get patients back to all of their desired activities.”
Another option for treating cartilage defects called osteochondral allografts uses outside tissue from a donor rather than the patient’s own cartilage.
“In this treatment, a core of bone and cartilage from someone who has passed away two weeks prior is harvested and processed for sterilization then implanted into a socket created by the surgeon in the recipient’s knee cartilage defect,” Mosier said. “There is no rejection medication needed as the bony portion of the donor graft does not contain cells. The rehab is similar to the autograft options.”
For more information on these procedures, visit MACI.com.