Gonalgia, or knee pain, it is a common problem, responsible of several medical examinations.

It is a symptom that can be provoked by many different causes: it can occur in a young person hurting after a distortive trauma (with related joints or menisci lesions), in an elderly person suffering of knee arthrosis, in an athlete with an inflamed rotular tendon (jumper knee), in a teenager  feeling pain at the tibial apophysis (Osgood - Schlatter disease).

And the list could go on: there can be arthritic conditions (rheumatoid arthritis, gout), pathologies of the patella cartilage (rotular chondropathy, also known as runner knee) or a bursitis (laundress knee).

Obviously symptoms can be more or less acute depending on their gravity and on the type of pathology which caused gonalgia, so depending on which structure of the knee has been affected. In general it is possible to distinguish between acute pain, usually as a consequence of a trauma, and chronic pain.

In case of knee sprain it may occur a damage (up to breaking)  to one or more ligaments, short bands of  fibrous tissue that connect tibia to femur and which ensure stability to the joint (collateral ligament and cruciate ligament).

In these cases the knee looks swollen, pain is acute and it is increased by stressing or moving the joint that, in the event a ligament is broken, will experience an unusual mobility.

trauma can also cause a lesion of one of the two menisci, pads of cartilaginous tissue between the tibia and the femur. In case of lesion, besides pain and swelling, there can be other symptoms.

Sometimes it can happen that an edge of the meniscus while moving in the joint gets stuck in it, blocking it; another symptom of a meniscus lesion is a sudden collapse of the knee, i.e. while going down the stairs.

Sometimes what causes knee pain are not acute traumas. This is the case of patella tendinitis (see) where inflammation is usually provoked by a functional overload. It is common between athletes who frequently jump (basketball or volleyball players, runners) and it is characterized by pain and swelling in the anterior part of the knee, right under the patella. Pain increases when jumping, running and in general when stressing the tendon.

Sometimes repetitive traumas can lead to a bursitis, the inflammation of the small sac of synovial fluid that helps reducing the friction between bones, muscles and tendons. When experiencing a bursitis (laundress knee) the area looks swollen, warm and aching, rigidity sensation can be felt when bending the knee and obviously ache increases when kneeling.

A common cause of pain in teenagers is the Osgood-Schlatter’s syndrome, characterized by ache and swelling of the osseous prominence located right under the patella and it is caused by an inflammation of the extremities of the tibia that are not completely ossified. Pain degenerates when the kid (more often in case of boys) does some kind of sport, especially when this involves running and jumping, and it gets better with some rest. It usually lasts weeks or months and can come back during the growth period.

What is more frequent in young girls and runners is the rotulian chondropathy instead, also known as “anterior ache of the knee”, being the latter the specific symptom; ache typically degenerates when sitting with legs bended with an angle of 90 degrees (also known as the cinema sign) or when walking downhill.

Knee arthrosis shows up with different ache intensity, sometimes together with tumefaction and that increases when standing or walking. Especially in the morning, when waking up, there can be rigidity of the joint, that usually gets better within a couple of minutes.

The symptoms of rheumatoid arthritis are more serious: the damaged joint (usually both knees are affected) is warm, painful, swollen; rheumatoid arthritis affects also other joints (usually of the hands) and not only the knee. Morning rigidity is a typical symptom and it usually lasts for a period longer than 30 minutes. With time joints incur in deformity.