Cartilage Injuries
Articular cartilage is the smooth surface attached to the end of your bones making up the joint. It allows your knee to move and glide easily and without pain. Cartilage can slowly wear out leading to arthritis, or it may be injured leading to an acute cartilage problem. Over time, acute cartilage injuries may lead to ongoing damage and slowly wear out leading to arthritis. Unfortunately cartilage injury does not repair by itself and surgery may be required to either fix an acute cartilage injury or deal with longer term cartilage wear.
Acute cartilage injuries may be sustained from a twisting sporting injury, often in combination with ligament injuries or with a patella dislocation. The injury to the cartilage is on a spectrum from small cartilage fragments coming loose to more severe injuries where large bone-cartilage fragments come away from the underlying bone leaving a defect. The short-term symptoms of these injuries are similar to most knee injuries. These include pain at the time of the incident, followed by swelling, stiffness and difficulty moving the joint. Over time the swelling may reduce, however pain may persist depending on the severity of the injury and there may be mechanical symptoms such as the knee “locking” when loose fragments jam up in the knee joint.
Osteochondritis Dissecans (OCD) is a particular cartilage condition which starts in childhood and adolescence. An OCD lesion is usually softer than the surrounding cartilage/bone interface and often involves the medial femoral condyle. The exact cause of this condition is uncertain, and symptoms include pain in the region associated with weight-bearing or activity as well as knee joint swelling. These symptoms may fluctuate for a long time and abate with resolution of the OCD, or may continue and sometimes lead to the OCD coming loose and floating in the knee joint. If the latter occurs, then symptoms may once again become mechanical with locking or jamming up of the knee.