Knee surgery replaces cartilage

Melanie Evans

The pain in 19-year-old Morgan Montgomery’s knee hurt the most after a hard workout. His 7-year-old hockey injury continued to agitate him; the joint was often tender from walking or sitting too long.
Montgomery’s six prior surgeries failed to relieve the chronic pain caused by a quarter-sized lesion on his knee cartridge. But on Dec. 30 the St. Paul native underwent a surgery that finally provided a solution to his problem.
Montgomery is one of only two patients in Minnesota to have an operation that replaces damaged knee cartilage with healthy tissue cultivated in a lab from the patient’s own cells.
Performed by University assistant professor Robert LaPrade, the surgeries are another first for Minnesota’s medical community.
Although the procedure has been performed in the United States since 1995, LaPrade’s December operations were the state’s first.
For individuals who suffer from similar injuries to Montgomery’s, the operation — called autologous chondrocyte implants — offers the first long-term solution for the chronic pain of articular arthritis.
Because the body does not repair cartilage tissue, in the past doctors could do little more than provide short-term solutions, LaPrade said. Providing the body with actual replacement tissue creates a permanent answer.
“The surgery is an opportunity to return a patient to a normal lifestyle,” LaPrade said.
The doctor studied the process pioneered and patented by the Cambridge, Mass.-based company, Genzyme Tissue Repair, for a year before training for the procedure.
The surgery relies on healthy cells grown in a laboratory from a sample taken from the patient.
A small patch of the shin bone is removed and sewn over a tiny crater in the cartilage. The new cells are then injected under the flap and the area is sutured shut.
Attaching the bark-like film of bone to the cartilage is “like sewing tissue paper on a hard-boiled egg,” LaPrade said.
The process has been slow to take off in the United States because the company’s cell cloning process had no classification under Food and Drug Administration guidelines.
However, the process received FDA approval in August after the regulatory body found 70 percent of the surgery’s patients demonstrated improvement after an 18-month period. Following the approval, the number of health plans covering the new surgery doubled, said Glenn Booma, the company’s orthopedic project manager.
Rehabilitation takes more than six months, LaPrade said. Montgomery, a student at Montana State, will take winter quarter off to recover. Patients who undergo the surgery must keep off the knee for the first two months, LaPrade added.
Montgomery figures that lots of sleep is in his future. “I’m going to have to lie in bed for a month,” he said.