Collagen scaffolds: A new method to preserve and restore the severely injured meniscus

The meniscus cartilage has been shown clearly to be an extremely important structure of the knee joint. The meniscus serves several functions, including load distribution, force transmission across the joint, lubrication, and joint stability. Consequently, it has been shown that loss of the meniscus cartilage of the knee increases the concentration of stresses on the articular surfaces of both the femur and the tibia, causes knee joint instability, and frequently leads to osteoarthritis, which may produce irreversible damage to the joint surfaces. Although new and improved surgical techniques to repair torn meniscus cartilage have been described in recent years, little progress has been made in efforts to replace the meniscus with various types of prostheses. Prosthetic replacement of the meniscus has been difficult, if not impossible, because of the necessity of exact matching of the size and the shape of the lost meniscus, as well as the unique and extremely complex biomechanical and biochemical properties of the normal meniscus. Consequently, since 1984, the authors have used tissue engineering techniques to develop a resorbable collagen scaffold that would support ingrowth of new tissue and eventual regeneration of the lost meniscus tissue. This collagen-based implant has been shown in numerous animal studies to support ingrowth and maturation of the meniscus fibrochondrocytes and the development of a mature and functional new tissue matrix. This article summarizes some of the authors' laboratory findings as well as the initial clinical results obtained in two human feasibility studies.