Collagen Meniscus Implant: The Future of Meniscal Injury Repair

The future of treatment for meniscal injuries lies in natural regeneration of the damaged meniscal cartilage. A pioneer of this potentially revolutionary technology is Regen Biologics, Inc. with its lead product, the Collagen Meniscus Implant (CMI). The CMI, which serves as a scaffold for the regeneration of meniscal tissue, is currently available to patients in clinical trials being conducted in the United States and Europe.

Each knee joint contains two menisci, lateral and medial, which essentially are fibrous cartilage cushions that alleviate pressure between the thigh bone (femur) and the shin bone (tibia). Meniscal injuries most commonly occur when the meniscus is damaged or torn due to twisting motion of the knee.

In most cases conventional surgical treatment for meniscal injuries is partial removal of the damaged area of the meniscus. However, in the long run, the direct bone on bone contact between the femur and tibia where the meniscus is missing can lead to degeneration of the articular cartilage and eventually osteoarthritis.

The CMI accounts for the lost meniscus by providing a collagen scaffold on which the body can regenerate the lost meniscal tissue. The scaffold is created from collagen fibers isolated from cow Achilles tendon. The fibers are then manipulated to create a pore structure appropriate to serve as a scaffold and to resemble the shape of a meniscus.

In an arthroscopic procedure, a portion of the CMI identical to the size of the missing meniscal tissue is sutured into the existing meniscus. Ideally, overtime the body will regenerate the missing meniscal tissue using the CMI graft as a scaffold. In the process the body will resorb the CMI, leaving a naturally repaired meniscus in place.

An initial clinical feasibility test with ten participants conducted in the United States showed promising results. The CMI was found to be implantable and to result in a significant decrease in pain after a three-year period. In addition, it was shown that meniscal cartilage regeneration through the CMI template is possible since new meniscal tissue was found to be replacing the scaffold as the CMI was resorbed.