Health Matters 8/21: Cartilage Restoration Restores Joint Function and Prevents Future Arthritis


By William Rossy, M.D.

In the past, if you suffered a knee injury, chances were that you would eventually develop osteoarthritis, leading to severe pain that would likely require knee replacement surgery.

Today, however, cartilage restoration techniques can help younger adults prevent arthritis before it starts and avoid pain and surgery later in life.

The Orthopaedics Program at Penn Medicine Princeton Medical Center provides comprehensive care and minimally invasive techniques, including cartilage restoration, to treat a wide range of orthopaedic conditions.

Knee Injuries Increase Arthritis Risk

For people who play sports that involve a lot of pivoting, like soccer and basketball, the risk for knee injuries is high.

One of the most common knee injuries among athletes is an anterior cruciate ligament (ACL) tear or sprain. The ACL runs diagonally in the middle of the knee and prevents the tibia from sliding out in front of the femur. It also provides rotational stability of the knee.

Injuries to the ACL are typically caused by:

• Changing direction rapidly
• Stopping suddenly
• Slowing down while running
• Landing from a jump incorrectly
• Direct impact, such as from a football tackle

Another common knee injury is a kneecap dislocation, which occurs when the kneecap slips out of the grove where it normally sits, causing your knee to buckle and leading to pain.

Kneecap dislocations can happen if your bones are out of alignment or your thigh muscles are weak. This can also be caused by a sharp blow to the knee.

Both ACL tears and kneecap dislocations can also cause damage to the protective cartilage in the knee and lead to osteoarthritis, a degenerative joint disease that, according to the Centers for Disease Control and Prevention, affects more than 32.5 million American adults.

Osteoarthritis occurs when the cartilage in the joint breaks down and wears away, causing the bones in the joint to rub against each other.

When this happens it can lead to pain, swelling and decreased range of motion.

In addition to injury, other risk factors for osteoarthritis include age, gender (women are more likely to develop osteoarthritis than men, especially after age 50), obesity and genetics.

Regrowing Cells

Traditionally performed on knees and sometimes on ankles, cartilage restoration surgery is designed to help restore natural function to the joint before osteoarthritis sets in.

To be a candidate for cartilage restoration, the remainder of the joint must be healthy and free of any signs of arthritis. As a result, these outpatient procedures are especially effective for patients under age 50, who are physically active.

Options for surgery can include the use of the patient’s own cartilage cells to promote healing and cartilage regrowth, or if the damaged area is large, cartilage tissues from an organ donor can be transplanted into the area.

When a patient’s own cartilage cells are going to be used, physicians first evaluate the structure and size of the damaged joint area with a standard knee arthroscopy procedure.

Then, a biopsy of healthy cartilage from a non-weight-bearing area of the joint is performed, and the cartilage cells that are removed are grown in a lab, increasing the number of cells exponentially.

Several weeks later, once the patient’s cartilage cells have reached the appropriate number, they are replaced back into the damaged area of the knee.

When donor cartilage is used, a precisely-sized piece of bone and cartilage is transplanted from the donor into the damaged area of the patient’s joint, replacing it with normal bone and cartilage. This technique requires one surgery and is typically done through a minimally invasive incision.

Full recovery from these procedures can take anywhere from four to nine months, depending on whether the cartilage used came from the patient or from a donor, and involves a period of non-weight-bearing restriction and physical therapy.

While the rehabilitation process is strict, following the recommended course of treatment results in a very high success rate for patients.

Penn Medicine Princeton Medical Center Princeton Rehabilitation offers comprehensive rehabilitation services for cartilage restoration and other conditions.

Penn Medicine Princeton Medical Center is rated by U.S. News and World Report as high performing in orthopaedics, knee replacement, and hip replacement. To find an orthopaedist with Penn Medicine Princeton Health, call 1-888-742-7496 or visit

William Rossy, M.D., is an orthopaedic surgeon specializing in sports medicine. He is a member of the medical staff at Penn Medicine Princeton Health.