Illustration 1 • Normal cartilage. Overview of the lateral joint compartment of medial femoral condyle
Illustration 2 • Small new cartilage damage at medial femoral condyle
Illustration 3 • Traumatic cartilage burst at back of patella
Illustration 4 • New cartilage damage: breakage of large portion of cartilage lining at lateral femoral condyle down to subchondral layer
With its unique qualities, joint cartilage serves as a shock absorber, and its smooth surface guarantees easy gliding, thus joint mobility. For normal joint function, joint cartilage as glide surface is indispensable.Various diseases lead to a breakup of cartilage. Most frequently, this is caused by
Contrary to most other tissues of the human body, cartilage tissue is hardly able to regenerate after injury. Cartilag damage usually does not heal immediately and progresses towards degeneration of articular surfaces (osteoarthritis). Conventional surgical procedures such as e.g. cartilage smoothing or drilling, either treat symptoms only or generate inferior fibrous scar tissue. This fibrous tissue has a diminished stress capacity and is quickly dissolved. Articular damage progresses and osteoarthritis develops. Success of conventional treatment lasts therefore for a short term only. New treatment methods aim at generating superior cartilage tissue with a high stress capacity. This new cartilage is to be as identical as possible with the original tissue and is to have the same qualities as the latter (elasticity, tear strength, glide capacity). Nowadays, there are essentially two methods to reach this aim:
These techniques have been successfully employed for a number of years, and clinical long-term results are very promising. The treatments mentioned above are extensive surgical procedures that require the opening of the knee joint. The following is an overview of the classic arthroscopic procedures:
Micro-fracturing can be performed when the cartilage damage is small and reaches deep to the bone. Small holes are drilled into the bone with pointed, circumflex instruments so that connective tissue (fibrous tissue) from the inside of the bone can grow into the cartilage defect.
Small, rotating and cutting instruments abrade superficial cartilage defects.