Lifewatch: Knee Meniscus Tears

MISSOURI -- Torn cartilage in the knee can be painful and often times difficult to repair.

A new device is helping those hard-to-treat tears heal themselves.

Playing college football is hard on the body.  Starting right guard for the University of Missouri, Kurtis Gregory, knows that all too well.

"My rear end hit the floor and I just kinda felt something that didn't seem right," said Gregory.

Gregory tore his meniscus, the cushion of cartilage in the knee that provides padding and stability to the joint.

"I couldn't even walk to practice," said Gregory.

Torn menisci are often difficult to repair, or they are irreparable and are removed.  The latter option results in joint pain that can lead to arthritis.

But now, researchers have found a way to help torn menisci heal themselves.  Dr. Jimi Cook, a veterinarian, has been testing a new device called a bio-duct in some animal knees.

"Dogs knees and human knees are really comparable both in the problem that occurs and the way that we treat them," said Dr. Cook.

Together, Dr. Cook and Dr. Kane conducted research that led to the FDA approval of bio-duct in humans.

Bio-duct works by acting as a tunnel to transport cells and blood from the vascular outer part of a meniscus to the site of the tear, which doesn't receive blood flow.

"We're actually kind of plumbing the meniscus. The cells and the blood supply to allow them to heal is just not there in that tissue, so this device actually brings that in a directed manner," said Dr. Cook.

The device is implanted arthroscopically and is bio-absorbable, so it doesn't need to be removed.

With adequate blood supply, a meniscus tear can heal itself completely in less than 12 weeks.

Dr. Kane said the bio-duct is ready to be used to treat human meniscus tears, and will be widely available within the next few months.


Schwartz Biomedical

Dr. Jimi Cook


BACKGROUND: The knee is a complex joint, consisting of bones, ligaments and cartilage. Two C-shaped pieces of cartilage called menisci (plural for meniscus) sit in the middle of the knee and curve around the inside and outside of the joint to provide cushion and stability. A meniscus tear is a common injury that occurs when excess strain in places on the knee during a pivoting or cutting movement. Meniscus tears are particularly common in athletes and often accompany tears of the anterior cruciate ligament (ACL), one of the main ligaments holding the knee joint together.

TRADITIONAL TREATMENTS: The first symptoms of a meniscus tear often include a popping sound coming from the knee joint, swelling and pain. If a lateral tear occurs, meaning the meniscus has torn lengthwise, it's possible for the loose cartilage to flip into the joint itself causing the knee to lock. In some cases, rest, ice and medication are enough to relieve the pain of a torn meniscus. In other cases, surgery is required to repair or remove a torn meniscus. The surgery is often done arthroscopically, meaning a tiny incision is made and a small device called an arthroscope, which contains a light and a small camera, is inserted into the knee. Once the arthroscope is inserted the surgeon can either use small instruments to repair or trim the meniscus through the arthroscope itself or through other tiny incisions.

If the torn meniscus isn't surgically repairable and a portion must be removed, it can leave the patient with altered knee function and stability that can in turn lead to arthritis. If a meniscus has totally degenerated, a total knee replacement may be recommended.

SELF-HEALING: When meniscus function is deficient, bone rubs on bone and arthritis is likely to develop and progress. Because two-thirds of the meniscus is avascular (lacks a blood supply), a tear in that region will not repair itself. A new device called a BioDuct will transport blood and cells from the vascular portion of the knee to the avascular portion of the meniscus. Supplied with blood and cells for healing, the previously untreatable meniscal tear now has the potential for allowing the knee joint to be saved.

Veterinarian Jimi Cook, DVM, Ph.D. and orthopedic surgeon Steve Kane, M.D. teamed up at the University of Missouri to test BioDuct in both dogs and humans. "Dogs knees and human knees are really comparable both in the problem that occurs and the way that we treat them," said Dr. Cook. A research team, lead by Dr. Cook, performed the BioDuct surgery on 25 dogs that had worst-case scenario meniscal tears. With the BioDuct, the meniscus in the dogs' knees had complete or partial repair after a few weeks in all cases. "With the BioDuct, surgeons will be able to repair torn menisci and induce healing. People with meniscus injuries now have a better future ahead," said Dr. Cook. BioDuct has received FDA approval for humans based on the trails performed at the University of Missouri. Dr. Cook and Dr. Kane say they expect to see BioDuct be put into practice by orthopedic surgeons across the United States in upcoming months.

Reported by Kristy Ondo