Conditions associated with pain at the front of the knee
There are several medical conditions linked to pain at the front of the knee. Generally, they are caused by:
- damage from a fall or a sports injury
- overusing the knee
Patellofemoral pain syndrome (PFPS) is one of the most common knee conditions related to sports injuries. It means pain related to the kneecap (the patella) and the thigh bone (the femur). Doctors sometimes refer this as ‘patella maltracking’ or ‘runner’s knee’.
When you bend and straighten your leg, your kneecap slides up and down a groove at the end of your thigh bone. Damage or swelling in the knee joint stops the kneecap from sliding smoothly and causes pain.
Patella tendinopathy means wear and tear of the tendons around the kneecap, which can be due to overuse. Small tears in the tendon can cause inflammation (tendinitis). These tears are usually cause by sudden injury. These conditions are sometimes called ‘jumper’s knee’. Quadriceps tendinitis is a similar condition.
Infrapatellar fat pad syndrome is a condition where the fat pad below the kneecap gets pinched between the kneecap and the thigh bone. It’s most often caused by over-straightening the leg repeatedly or standing for long periods. It is sometimes called Hoffa’s syndrome.
Anterior cruciate ligament injury is an overstretching or tearing of this ligament, which runs across the knee from the thigh to the shin bone. A tear may be either complete or partial. This is a sudden injury, usually caused by a twisting of the knee. It can happen if you suddenly slow down, stop or change direction.
Osteoarthritis of the knee is a common cause of knee pain. The smooth, shiny cartilage that lines the knee joint becomes worn. This causes pain and increasing damage to the knee over time. It mostly affects people over 50. The older you are, the more likely you are to get it.
Less common conditions causing pain at the front of the knee
Bursitis is inflammation of the fluid sacs that act as cushions around the kneecap. It can be caused by kneeling a lot and is sometimes called housemaid’s knee. More commonly these days, it’s caused by overuse, a sudden increase in sports training, by being overweight, or by other conditions such as rheumatoid arthritis or gout.
Chondromalacia of the patella is a condition where the smooth tissue under the kneecap (the cartilage) can soften and break down.
Recurrent partial dislocation (subluxation) of the patella is an uncommon condition that can run in families. There is sudden pain in the knee, as it gives way. It can be seen in people with ‘knock-knees’. This affects the tracking of the kneecap (the movement of the knee cap as it glides across the thigh bone).
Osgood-Schlatter disease is a condition seen mostly in teenagers who take part in a lot of sports. This condition causes pain and tenderness just below the kneecap, at the top of the shin bone (the tibia).