Diseases & injuries of the knee

In the healthy knee joint, a firm, rubbery material called cartilage covers the end of each bone. Cartilage provides a smooth, gliding surface for joint motion.

In osteoarthritis, a degenerative joint disease, the cartilage breaks down, causing pain, swelling and problems moving the knee.

Treatment in early levels of this chronic disease, consists of anti-inflammatory drugs, physical therapy and corticosteroid injections to manage the symptoms. Also, intra-articular injections with hyaluronic acid can be helpful.

In cases of small areas of cartilage damage a small surgical arthroscopic procedure can improve the situation.  Tiny holes (micro-fractures) are drilled into the areas of damaged cartilage. This exposes the blood vessels that lie inside the bone and triggers the bone to produce new cartilage. The new cartilage that grows is less supple than the original hyaline cartilage type, but can help to keep the knee stable.

In severe stages of osteoarthritis, a total knee replacement might be the best solution

One of the most common sports knee injuries is a sprain or tear of the anterior cruciate ligament (ACL).

The anterior (ACL) and posterior (PCL) cruciate ligaments are important to stabilize the knee joint. They control the back and forth motion of the knee.

A tear of the anterior cruciate ligament leads to instability of the knee.

The ligament will not heal without surgery. But non-operative  treatment can be effective for patients who have only minimal symptoms of instability or a  very low activity level.

In case of severe instability and in sport active patients surgery (operative orthopaedics) is recommended to restore full function and stability of the knee.

In most cases the torn ligament is replaced by a tendon graft, that is taken from the patient’s patella or hamstrings tendon, and imitates the original anterior cruciate ligament (anterior cruciate ligament reconstruction).

Further information: http://orthoinfo.aaos.org/topic.cfm?topic=A00549

Meniscus tears are among the most common knee injuries.

Two wedge-shaped pieces of cartilage (medial and lateral meniscus) lie between the thighbone and shinbone. The menisci act as “shock absorbers” in the knee. They are tough and rubbery to help cushion the joint and keep it stable.

Injuries to the meniscus lead to pain at the inner (medial) or outer (lateral) part of the knee. Sometimes the knee is catching or locking. Diagnosis of a meniscal tear is made by clinical examination and a concomitant MRI scan.

Arthroscopic surgery with removal of torn parts of the meniscus (partial meniscectomy) might be a possible solution. Some meniscus tears can be repaired by suturing (stitching) the torn pieces together.

Further information: http://orthoinfo.aaos.org/topic.cfm?topic=a00358

The kneecap (lat.: patella) is a triangular shaped bone that sits in front of the knee joint. The tendon of the quadriceps femoris muscle attaches to the base of the patella and it plays an important role in straightening the knee.

Sometimes injuries can lead to dislocation of the kneecap and damage the ligaments that hold the kneecap in place.

Non-surgical treatment with stabilization and strengthening of the knee muscles might be successful.

Because a dislocation damages knee tissue, the patella often remains looser, or more unstable, than it was before the injury. As a result, the patella may dislocate again. In these cases surgery is recommended with reconstruction of the damaged ligaments.

Further information: http://www.orthoinfo.org/topic.cfm?topic=A00707