Paste a VALID AdSense code in Ads Elite Plugin options before activating it.
If you are not sure what is causing your knee pain then why not check out our symptom checker? Simply tick the symptoms which apply to narrow down the possible injuries.
We have categorised the injuries below into acute knee injuries which occur suddenly, often through an impact, twisting or trauma to the knee, anterior (at the front of the knee), lateral (outside of the knee), medial knee pain (inside of the knee) and posterior knee bain at the back of the knee.
Acute knee injuries
An acute knee injury is usually one that occurs suddenly through impact or trauma. They are often serious injuries and occur commonly in contact sports and those involving a lot of twisting, turning and changes of direction. Symtoms often incllude sudden pain and rapid swelling. Immediate first aid for knee injuries of RICE (rest, ice, compression and elevation) is important and should be applied as soon as possible.
The most common acute knee injuries are:
ACL sprain - a tear to the anterior cruciate ligament usually from twisting the knee or an impact or trauma.
MCL sprain - a tear of the medial ligament on the inside of the knee, usually caused by an impact to the outside of the knee which stretches the ligament.
Patellar dislocation - dislocation of the kneecap mostly round the outside of the knee. It may dislocate and then quickly go back to its normal position.
Medial meniscus tear - injury to the cartilage meniscus on the inside of the knee joint.
PCL sprain - a tear to the posterior cruciate ligament which crosses over in the middle of the knee with the anterior cruciate ligament. The PCL prevents the shin bone moving backwards and the knee bending the wrong way. It can be injured by twisting the knee or when the knee is forced to bend back the wrong way.
See more on acute knee injuries.
Pain on the front of the knee
Pain at the front of the knee is known as anterior knee pain. Symptoms often come on gradually without a specific cause which can be identified. The precise location of the pain may also be difficult for the patient to identify. The most common injuries at the front of the knee are:
Patellofemoral pain syndrome comes on gradually with symptoms of aching pain in the knee joint and specifically around the knee cap. The knee will usually be swollen. It is caused by the patella rubbing on the bone underneath.
Patella tendinopathy or patella tendonitis which is inflammation or degeneration of the patella tendon which attaches the kneecap to the front of the shin bone (tibia).
Quadriceps tendinopathy is inflammation or degeneration of the tendon of the quadriceps muscles at the front of the thigh. Pain is felt along the top of the kneecap which comes on gradually.
Fat pad impingement is where the fat pad (known as Hoffa's pad) becomes pinched. Symptoms include tenderness around the bottom and under the kneecap. Patients may have a history of being able to over straighten the knee.
See more on anterior knee pain.
Pain on the outside of the knee
This is pain on the outside of the knee which comes on gradually. They are often overuse injuries. The two most common causes are:
Iliotibial band friction syndrome - this is inflammation of the iliotibial band through friction as it rubs on the bone. The band is a long tendon of the tensor fascia latae muscle in the hip and runs along the outside of the thigh.
Lateral meniscus tear - this can be from an acute tear which has failed to heal or can be through degeneration of the cartilage meniscus which are semi circular shaped pads in the knee. Their function is to cushion the joint and provide support.
See more on lateral knee pain.
Pain on the inside of the knee
Medial knee pain refers to pain on the inside of the knee. It usually comes on gradually over time and is less common than pain felt at the front or outside of the knee. The most common causes are:
Patellofremoral pain - this is mainly an injury felt at the front of the knee but can also cause symtoms on the inside of the knee.
Medial meniscus tear - is a tear or degeneration of the semi cicular cartilage discs found in the knee joint.
Medial ligament sprain - this is a tear to the medial ligament on the inside of the knee and although it is more commonly and acute knee injury it can also occur gradually over time.
Osteoarthritis - is wear and tear in the joint over time. Symptoms include pain and swelling and can often have similar symptoms to a medial ligament sprain in the early days.
See more on medial knee pain.
Pain at the back of the knee
Posterior knee pain as it is known can often be referrred pain from an injury elsewhere. The most common causes are:
Referred pain - which can come from an injury or problem in the lower back, front of the knee or other nerve problem in the hip of buttocks.
Biceps femoris tendinopathy - which is inflammation or degeneration of the tendon of one of the hamstring muscles as it inserts into the back of the knee.
Baker's cyst - is a large golf ball sized swelling at the back of the knee which is caused by another injury within the joint itself.
The knee joint consists of the femur bone (thigh bone), the tibia bone which is the thick load bearing bone in the lower leg or shin and the fibula bone on the outside of the lower leg. The fibula is thinner and its function is more for muscle attachment rather than load bearing. Finally the patella or kneecap sits on the front of the knee and acts as a level system with the thigh muscles and aids smooth movement of the knee joint.
The bones of the knee joint are connected by four ligaments the medial and lateral ligaments attach on the inside and outside of the knee respectively and prevent sideways movement of the bones. The anterior cruciate ligament and the posterior cruciate ligament cross over front to back in the middle of the knee joint and prevent forwards and backwards movement of the bones.
Hard articular or hyaline cartilage covers the ends of bones and underneath of the patella and proves a smooth protective layer. Cartilage meniscus sit on top the the tibia and fibula bones to provide a support for the ends of the thigh bone and to cushion the joint from impact.
The knee joint is surrounded by a joint capsule which is a thick ligamentous structure. Inside this capsule is the synovial membrane which provides nourishment and synovial fluid to all the surrounding structures and act as a lubricant during movement. A number of muscles attach to varous points in the joint to provide movment. The quadriceps at the front of the thigh attach to the top of the patella and then to the tibia bone through the patella tendon (or ligament as it is often called). The hamstring muscles at the back the thigh attach to the top of the tibia and fibula bones and bend the knee.
See more on knee anatomy.