Knee tendon injuries range from tendinitis, the inflammation of a tendon, to a ruptured or torn tendon. Overuse of a tendon during activities like dancing, cycling or running stretches the tendon like a worn out rubber band causing it to become inflamed. Movements such as trying to break a fall can cause excessive contraction of the quadricep muscles and tear the quadriceps tendon above the patella or the patellar tendon itself. Highest incidence of injury occurs most commonly in older people whose tendons are weaker.
Tendonitis of the patellar tendon is known as jumper’s knee. This is derived from sports requiring jumping, like basketball, where the muscle contraction and the force of hitting the ground after a jump strains the tendon which causes inflammation or a tear after repetitive stress. Tendonitis will cause tenderness at the point where the patellar tendon meets the bone. Pain during faster movements such as jumping, running and speed walking can also be experienced. A complete rupture of the quadriceps or patellar tendon is not only painful but also creates difficulty bending, extending and lift the leg. If swelling is minimal a defect in the tendon near the tear may be present and can be identified during a physical examination. The patella will be lower in position than normal in a quadriceps tendon tear and higher than normal in a patellar tendon tear.
Initial treatment of tendonitis consists of rest, ice and elevation. Non-steroidal anti-inflammatory medication such as aspirin or ibuprofen will help relieve pain and decrease inflammation and swelling. If the quadriceps or patellar tendon is completely ruptured it will require surgical reattachment at the ends and casting and crutches will be necessary for up to 6 weeks post-surgery. If the tear is only partial a cast may be applied without performing surgery. Whether the tendon tear is partial or complete an exercise rehabilitation program is recommended to accelerate the healing process, although less intense than that prescribed for ligament injuries. The goals of exercise therapy is to restore the ability to bend and straighten the knee and to straighten the leg to prevent a repeat injury.
Osgood-Schlatter disease is caused by repetitive stress or tension on a part of the growth area of the upper tibia or apophysis. It is characterized by inflammation of the patellar tendon and surrounding soft tissue at the point where the tendon attaches to the tibia. The disease may also be associated with an avulsion injury, in which the tendon is stretched so much that it tears away from the tibia and takes a fragment of bone with it.
This disease most commonly affects active young people, particularly boys between 10 and 15, who play games or sports that include frequent running and jumping. Symptoms include pain just below the knee joint that worsens with activity and is relieved by rest. A bony bump may appear on the upper edge of the tibia, below the kneecap, that is particularly painful when pressed. While motion of the knee may go unaffected pain will likely last several months and may recur until a child’s growth is completed. Osgood-Schlatter disease disappears without treatment. Cold therapy or repeated applications of ice to the knee when pain first begins will relieve inflammation and is sometimes used in conjunction with stretching and strengthening exercises.
Iliotibial band syndrome is an overuse inflammatory condition from friction of a band of a tendon over the lateral condyle or outer bone of the knee. Although iliotibial band syndrome may be caused by direct injury to the knee, it is most often caused by the stress of longterm overuse, such as in exercise and sports training.
An aching or burning sensation during activity and pain localized at the side of the knee that radiates up the thigh are typical symptoms. A snap when the knee is bent and then straightened may also be experienced. Swelling is usually absent and knee motion normal. Treatment includes a reduction in activity and stretching and strengthening exercises. In rare cases when the syndrome doesn’t disappear, surgery may be necessary to split the tendon so it is not stretched too tightly over the bone.
Osteochondritis dissecans results from a loss of the blood supply to the area of bone underneath the knee joint. The affected bone and its covering of cartilage gradually loosen and cause pain. This disruption may eventually develop into osteoarthritis and can occur spontaneously in an active adolescent or a young adult. It is typically caused by a slight blockage of a small artery, an unrecognized injury or tiny fracture that damages the overlying cartilage. The bone undergoes avascular necrosis, degeneration, from lack of blood supply. If spontaneous healing doesn’t occur cartilage eventually separates from the diseased bone and a fragment breaks loose into the knee joint, causing weakness and sharp pain, leading the joint to lock. Surgical intervention will be required to fix the injured joint.
Plica syndrome is bands of remnant synovial tissue that have been irritated by overuse or injury. Synovial plicae are remnants of tissue pouches found in the early stages of fetal development. As the fetus develops these pouches normally combine to form one large synovial cavity. If this process is incomplete, plicae remains as four folds or bands of synovial tissue within the knee. Injury, chronic overuse and inflammatory conditions are associated with the development of this condition.
Pain, swelling a clicking sensation, locking and weakness of the knee are symptoms. Treatment reduces inflammation of the synovium and thickening of the plicae and includes ibuprofen and cold therapy or ice. A compression wrap or knee brace and strengthening exercises will help stabilize and reinforce the joint. If this treatment program fails to relieve symptoms within 3 months, surgery may be required to remove plicae. A cortisone injection into the region of the plica folds helps about 50% of the patients treated.