Knee Cartilage Repair

Playing sports like football, basketball and soccer puts extra pressure on the knees and can result in torn ligaments because of the starting, stopping, pivoting and twisting required. Often when ligaments tear, there is also cartilage damage.

For years, the standard treatment for cartilage damage has been a scraping technique called arthroscopic debridement and lavage. Now new treatments are regenerating and repairing knee cartilage to help athletes return to their previous level of play.

David Crumbie, MD, a sports medicine fellowship-trained orthopedic surgeon and assistant professor at The University of Texas Medical School at Houston, is affiliated with the Memorial Hermann | Rockets Sports Medicine Institute. He compares cartilage damage to a bad door hinge.

“When you tear knee ligaments, it’s like having a loose door hinge,” he says. “The hinge may work for a bit, but the more you open and close the door, the looser the hinge becomes. Similarly, the more you use the knee, the more disruptive the cartilage damage becomes.”

Left untreated, defective cartilage can further deteriorate and lead to the onset of arthritis.

While the scraping procedure is usually effective for the casual athlete with small areas of articular cartilage damage, Dr. Crumbie may consider a number of other knee cartilage repair procedures, based on a patient’s age, activity level and future athletic goals. “As a sports medicine surgeon, you need to be prepared and comfortable with all techniques and not rely solely on one,” he says.

Other techniques, by increasing invasiveness, include microfracture surgery, osteochondral autograft transfer or transplantation surgery (OATS) and autologous chondrocyte implantation (ACI). Insurance typically covers these procedures.

In microfracture, the surgeon removes the damaged cartilage and taps tiny holes into the bone to allow blood to seep into the injured area. When the blood clots, it forms a scar-like cartilage. Dr. Crumbie said this surgery is particularly effective for patients who are still growing. In fact, he has had high school football players return to their pre-injury levels of play after microfracture, but he also points out there is a longer rehabilitation than with the scraping procedure.

“Patients can’t put weight on the knee for six to eight weeks but will work on range of motion and strengthening exercises. By the time they return to play, it’s usually more than six months,” he says.

In the OATS procedure, small plugs or grafts of healthy cartilage and bone are harvested from a non-weight bearing area of the knee and transplanted into the injured area. Like microfracture, it takes six months or more before an athlete returns to play. A variation of OATS uses cartilage from a cadaver, but study results vary on its effectiveness.

ACI, the most invasive technique, requires two surgeries. First, healthy cartilage cells are arthroscopically extracted from a non-weight bearing area of the knee, then grown in a laboratory. In the second surgery, the new cells are implanted into the damaged area. Because this requires an incision in the front of the knee, rehabilitation is longer.

Although there is disagreement about returning to athletic play, Dr. Crumbie says “You probably want to avoid high impact sports after this procedure.”

Ready for Backup – Storing Cells for Additional Knee Cartilage Repair

Cartilage damage is sometimes hidden by bone bruises and often is found to be more extensive during surgery than it appears on an MRI.

“If I see a bone bruise, I let the patient know it can take one or even two years to completely heal and that we don’t know what effect that might have for the cartilage in that area,” says Dr. Crumbie.

If the damaged area is larger than expected, Dr. Crumbie can extract healthy cartilage cells for a future ACI. “There’s no cost to grow the cells and the lab holds them for five years, so if the patient become symptomatic one or two years after the initial procedure, this provides another option.”

While these advanced knee cartilage repair procedures bring the promise of renewed mobility for patients with cartilage damage, they are not progressive solutions. Dr. Crumbie likes to present all options to patients, saying, “Once you get to microfracture, you can still perform the other procedures but generally the success rate is not as good as if they were performed as the primary procedure.”

The team of physicians, orthopedic surgeons, therapists, and trainers at Memorial Hermann | Rockets Sports Medicine Institute treat a variety of sports injuries, allowing the active patient to return to their desired activity level in a safe, effective, and timely manner.