Knee Pain

Cartilage is the connective tissue that coats the bones inside your joints and provides structure to ears and noses. A tough but flexible substance, cartilage is mostly water and gel. It has no nerves or blood vessels.

It has different jobs, but the one you’re probably most familiar with is cushioning joints. When cartilage starts to break down, your joints hurt — especially the knees. Shoulders and ankles can have problems too. Cartilage wears and gets weaker as you get older. An injury, like a ligament tear, also can cause cartilage damage. Joints without enough cartilage can develop arthritis.

Justin Arner, MD is an orthopaedic surgeon and sports medicine specialist with Burke and Bradley Orthopedics–UPMC. We asked him to weigh in on cartilage restoration and transplantation in young athletes and active people.

“With cartilage restoration, people can avoid the metal and plastic knee replacement options and ultimately preserve the joint,” says Dr. Arner. “This procedure is most common in the knee, but cartilage restoration can be used in other regions.”

Cartilage Restoration: An Emerging Science

Your body doesn’t make new cartilage without some kind of medical intervention. This is why cartilage repair is considered to be regenerative medicine. Regenerative medicine uses tissue engineering to repair problems the body can’t repair itself. Researchers have been investigating how to grow new cartilage, and studies show potential. But the expectations for regenerative medicine have sometimes gotten ahead of what doctors can actually do.

The good news is that the science is promising. Plus, surgeons have come up with proven techniques to help reduce pain from loss of cartilage. It’s important to keep in mind that cartilage restoration isn’t right for everyone. Many cartilage treatments are covered by insurance when physical therapy and other nonoperative approaches like injections aren’t successful. Some treatments are offered only as an out-of-pocket cost. Talk to your doctor and check with your insurance provider about coverage for your specific treatment.

“It’s important to note that, while cartilage restoration techniques continue to emerge, they’re certainly not experimental. This is an established science, and there is good research showing these are effective procedures on the right candidate,” says Dr. Arner. “It is a hot topic right now that continues to emerge and research suggests it can be made even less invasive and even more effective in the future.”

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Cartilage Restoration Techniques

Surgeons have options to restore cartilage, which are selected based on the patient’s specific needs (severity of injury, cartilage condition, active lifestyle, etc.). The most common techniques are:

  • Microfracture or drilling: Using an awl or drill, the surgeon makes small holes in the joint surface, which releases bone marrow elements and prompts healing. Your body creates a new blood supply, which can stimulate the growth of new cartilage.
  • Implantation: The surgeon removes the damaged cartilage, as well as a small bit of healthy cartilage. They use the healthy cartilage to grow new cartilage in the lab. When the cartilage is ready, the surgeon measures and cuts it to fit, then implants it where your cartilage is worn.
  • Transplantation: The surgeon takes healthy cartilage tissue from an area of bone that isn’t weightbearing (where you don’t need it as much). Then they transplant it to where you do need it. Surgeons also use donor cartilage from cadavers if a larger area of tissue is needed.

“Historically, orthopaedic surgeons have used plugs of cartilage with bone from other parts of the knee to promote healing. The surface technique with a biopsy of cartilage grown in the lab and transplanting donated cartilage are newer approaches. Microfracture is very effective short-term, but the newer approaches are often longer lasting,” says Dr. Arner.

Who Can Benefit from Cartilage Restoration?

The best candidates for any of these techniques are young athletes or active people. They have only a single acute injury or a condition like osteochondritis dissecans — not widespread cartilage damage. For example, someone who has an ACL injury with an irreparable piece of cartilage could be a good candidate. Someone with cartilage wear and tear that occurred over time likely is not.

Older adults with osteoarthritis in several joints — or severe cartilage damage in one joint — probably won’t benefit from these techniques. “Knee replacement is great for certain patients,” says Dr. Arner. “But in those patients that we can maintain the anatomy of their joint and keep it as close to what they were born with as possible, that’s what we want to do.”

Does Cartilage Restoration Work?

The goal of cartilage restoration is to reduce swelling and pain. Drilling and microfracture can help relieve pain, especially if the rest of the knee is in good shape. But the cartilage that grows isn’t as strong as the cartilage you were born with. “While the cartilage won’t be as strong as it was, the data for returning to high-level sports is strong about 6 to 9 months post-op,” says Dr. Arner.

Research shows that about 85% of implants integrate with the existing cartilage and survive, according to the Arthritis Foundation (AF). Cartilage transplants are equally successful, with about 88% of people returning to their sport, the AF says.

If you have cartilage surgery on your knee, you will be off that leg for some time after surgery. Dr. Arner says, “There is research showing that continual soft pressure on the knee is helpful in allowing the cartilage to heal. You’ll typically have 6 weeks of physical therapy for range of motion after surgery, followed by many more months of strengthening. It can be quite the process, but it has proven well worth it for some athletes hoping to get back to their sport.”

In any case of cartilage surgery, your doctor will let you know how long to keep the joint immobilized and nonweight-bearing. Your doctor should speak with you about your return to activity goals and tailor your treatment and recovery to that timeline if possible. Cartilage restoration isn’t for everyone. For athletes who are good candidates, it can certainly be a game-changer.

Cartilage Care at UPMC

Dr. Arner is an orthopaedic surgeon and sports medicine specialist focused on the surgical and nonsurgical management of knee, shoulder, elbow, and hip injuries — including those of the cartilage. He has specialized training and technical expertise in complex shoulder and knee arthroscopy, shoulder instability surgery, cartilage and meniscus surgery, elbow surgery, and sports hip injuries.

His clinical practice focuses on:

  • Sports medicine and arthroscopy
  • Shoulder instability and dislocation
  • Rotator cuff care
  • Shoulder arthritis and replacement
  • Knee ligament tears, including ACL
  • Cartilage injury and joint preservation
  • Elbow surgery
  • The athletic hip
  • Platelet rich plasma (PRP)

Dr. Arner sees patients at UPMC St. Margaret, the UPMC St. Margaret Harmar Outpatient Center, and UPMC Children’s Hospital of Pittsburgh.

For more information on cartilage restoration or to schedule an appointment with Dr. Arner, please call 412-784-5770.

The American Academy of Orthopaedic Surgeons, Articular Cartilage Restoration. Link.

About UPMC Orthopaedic Care

When you are dealing with bone, muscle, or joint pain, it can affect your daily life. UPMC Orthopaedic Care can help. As a national leader in advanced orthopaedic care, we diagnose and treat a full range of musculoskeletal disorders, from the acute and chronic to the common and complex. We provide access to UPMC’s vast network of support services for both surgical and nonsurgical treatments and a full continuum of care. Our multidisciplinary team of experts will work with you to develop the treatment plan that works best for you. Our care team uses the most innovative tools and techniques to provide better outcomes. We also are leaders in research and clinical trials, striving to find better ways to provide our patients care. With locations throughout our communities, you can find a provider near you.