A new surgical technique for repairing damaged knee cartilage was performed recently on two patients at Munson Army Health Center.
They are the only procedures of this type performed in the Kansas City Metro area by Dr. (Maj.) Dimitri M. Thomas, chief of surgery at MAHC. This new technique was approved for use in December 2016 and the first procedure was performed in the United States Jan. 30.
Matrix autologous chondrocyte implantation is a third-generation autologous chondrocyte implantation that uses the patient’s own cartilage cells to fill a defect in his or her native cartilage.
“There are procedures that can restore cartilage to defects in the knee,” Thomas said. “Some involve transplanting mature bone and cartilage from a cadaver into the patient. The advantage of the MACI is that it is the patient’s own tissue.”
The procedure involves several steps. A preliminary arthroscopic surgery is done to confirm the suitability of the damage for repair. If the patient is a good candidate, a small sample of cartilage is taken from the non-load bearing area of the knee. The cells are sent to a lab in Boston, where they are grown out. The cells are then returned two to four weeks later, after they have been inserted on a porcine collagen membrane patch.
A second surgery is then performed by opening the knee, and the patch is cut to fit the defect. The knee is closed up and rehabilitation begins.
“The patch is what makes this surgery different than the previous ACI surgeries,” Thomas said. “The patch replaces the internal stitches, which makes the surgery time shorter.”
It takes at least a year for the cells to fully mature. Some studies have shown that it may take two years or longer for the cells to mature fully.
“My knee has been hurting for a very long time. There is a lot of wear and tear on my knees because of years of jumping out of airplanes and running,” said Maj. Steven C. Davies, a Command and General Staff College student. “I am very thankful for this procedure because I am too young for a knee replacement.”
Patient compliance is key to a successful outcome, Thomas said. There is an extensive recovery and not everyone may be a candidate for this procedure.
“Patients need to understand that even with a successful implantation and outcome, the knee is not 100 percent normal,” Thomas said.
“The best course of treatment for young people with knee pain is to be cognizant of their activities and body weight,” he added. “Knee strengthening exercises are essential for prevention, and mixing up activities such as rowing, elliptical training, biking and swimming may help to avoid knee injury.”