Currently there is no "artificial cartilage" injection available, although injections of cortisone or hyaluronate (Synvisc) have been shown to be effective in relieving osteoarthritis pain and stiffness. A newer therapeutic approach involves removing articular cartilage cells (chondrocytes) from the patients joint, expanding them in the laboratory, and implanting them in the damaged areas; however, this requires at least two arthroscopic procedures and appears to work best in younger patients with small, isolated areas of cartilage damage. If your problems are primarily soreness and stiffness, adding some physical therapy modalities, such as heat, ultrasound, or aquatic therapy, may be beneficial. Topical preparations that are applied to the skin, such as those containing capsaicin or menthol, also may help relieve the soreness and stiffness. You might also consider wearing a neoprene knee brace during activities such as tennis.