The successful treatment of focal full-thickness articular defects of the knee has continued to present a formidable challenge, and no traditional treatment method has provided consistent acceptable, long-term clinical results. Patients with significant chondral defects frequently have persistent joint line pain, swelling, and catching in the knee. In contrast to marrow stimulation and treatment techniques such as abrasion arthroplasty, drilling, or micro fracture — all of which populate the defect with pluripotential stem cells, the use of cultured autologous chondrocytes fills the defect with cells of a committed pathway to develop hyaline-like cartilage. This hyaline-like cartilage more closely recreates the wear characteristics and durability of normal hyaline cartilage than the fibrous or fibrocartilage repair tissue formed by pluripotential stem cells.
Articular cartilage is an extremely systematized avascular tissue composed of chondrocytes embedded within an extracellular matrix of collagens, proteoglycans and no collagenous proteins. Its main purpose is to permit the smooth articulation of joint surfaces, and to cushion compressive, tensile and shearing forces. Articular cartilage damage is caused by both acute and repetitive trauma resulting in knee pain, effusion or mechanical symptoms such as catching and locking, and swelling. Since articular cartilage is avascular it has little capacity to repair itself or regenerate. Articular cartilage lesions that are left untreated may progress to debilitating joint pain, dysfunction, and osteoarthritis. The prevalence rate for cartilage lesions in the knee has been reported to be 63% in patients undergoing investigational arthroscopies.