Sudden knee pain is usually caused by overstressing or injury. Very often these are minor injuries that do not require the intervention of the family doctor. The knee joint is particularly prone to damage and pain as it supports all the weight of the body and additional loads, when running or running. jump. People who are overweight or those who play a lot of sports, especially if it requires a lot of knee twists (e.g. football, skiing, or basketball), have a higher risk of suffering knee injuries.
Knee pain is very likely to occur during growth, but this is a normal process and generally does not require medical attention.
Knee pain can be caused by a number of factors, some minor, some more severe.
The most common are:
- sprains and strains
- pain in the front of the knee (around the kneecap)
- injury to the meniscus or cartilage
- bursitis ("Washerwoman's knee" in the case of work that weighs heavily on the knees)
- rupture of ligaments or tendons
- joint bleeding
- Osgood-Schlatter syndrome
- septic arthritis (inflammatory knee changes)
Sprains and strains
If the pain appears after engaging in excessive physical activity than usual, it could be caused by a sprain or strain. This means that the tissues of the knee have been injured but are not permanently damaged.
In most cases, sprains and strains can be treated at home with the so-called PRICE therapy (protection, rest, ice, compression and elevation; from the English protection, rest, ice, compression and elevation) which provides for the use of protection to avoid further injury; rest, that is, the reduction of physical activity; the application of ice packs; the application of elastic bands that compress to prevent swelling from developing; the lifting of the knee above the level of the heart. In addition to these indications, where necessary and advised by your doctor, you can take pain relieving medicines.
You can prevent sprains and strains from occurring by practicing a few simple steps:
- Always warm up your muscles before exercising and stretch them after you finish the activity
- increase the pace and intensity of physical activity gradually over time
- replace regular sports with other forms of physical exercise, if necessary
You may also choose to engage in low-impact physical activity, such as cycling and swimming, to improve fitness without risking knee injuries.
Pain in the front of the knee
If the pain occurs in the front of the knee, around the patella, it is called patellofemoral syndrome. It is not always easy to explain the causes of this type of pain; it is a pain linked to previous injuries, joint strain, muscle weakness and slight displacement of the patella.The pain can be subtle or intense and often affects both knees. It usually gets worse when sitting for prolonged periods, when squatting or bent over on your knees, or when climbing stairs.
The pain, in most cases, can be relieved with pain relievers, ice packs, and rest. Exercises to strengthen the muscles surrounding the kneecap can also help. Your physical therapist can recommend specific exercises to do to achieve this.
Damage to the meniscus or cartilage
The menisci are elastic pads of tissue located between the bones of the upper and lower leg, at the "height of the" knee joint. They have the function of absorbing the stresses which the bones encounter during movement by acting as structures that absorb blows.
When the knee is rotated sharply, the meniscus can tear, causing pain, swelling and sometimes blocking of movement. In addition to the meniscus, the cartilage that lines the joint can also be damaged.
Disorders caused by meniscus tears can be alleviated by resting or undergoing specific physiotherapy; in some cases it may be necessary to have surgery to remove or restore the part of the torn tissue.
In older people, repeated pain and stiffness in both knees can be signs of osteoarthritis, a disease that causes damage to the cartilage (protective layer of bone) of the knee joint and slight swelling of the tissues in and around the knee. "articulation. The pain can be made worse by putting weight on your knees, and stiffness can occur if you stand without moving them. The knees can also freeze completely or feel like they are sagging under the weight of the body.
In some cases, osteoarthritis can produce a swelling containing fluid that causes pain behind the knee. This phenomenon is known as a Baker's cyst or popliteal cyst.
Osteoarthritis does not usually affect young people, when it does most often it is people who are overweight or who have suffered from severe knee injuries in the past.
If you suspect that knee pain may result from osteoarthritis, you should contact your family doctor for proper evaluation and treatment. However, it is advisable to wear suitable footwear to decrease the tension on the joints, reduce weight, take painkillers or do physiotherapy, if recommended by the doctor; It is also useful to use supports such as, for example, walking sticks to avoid falls.
Overloading or injury to the tendon that connects the kneecap to the shin can cause patellar tendonitis (inflammation of the tendon). This condition is sometimes called "jumper's knee" as it can be caused by sports such as basketball or volleyball where jumps are performed. In addition to pain and tension, the knee may become swollen, red, and warm. Pain can be relieved by resting, applying ice packs, and taking pain relievers if advised by your doctor.
Repeated movement of the knee, or prolonged kneeling, can cause an excessive influx of fluid into the bursa located inside the joint. Normally, it contains a liquid called synovial fluid necessary to allow the bones to slide without friction that could damage them. The inflammation of the bursa, known as bursitis or, in this specific case, also as "washerwoman's knee", mostly concerns types of work that engage the knees (for example, carpet and carpet fitters) and some sportsmen (eg.the football players). The pain caused by bursitis worsens if the joint is completely bent. In these cases, the knee may swell, become tender, red and warm.
Bursitis can be treated at home in most cases. Resting the affected area and applying ice packs can reduce swelling. in addition, common pain relievers can provide pain relief until recovery. Before taking any medicines, however, it is recommended that you consult your doctor.
If the swelling extends, fever occurs or if the pain becomes persistent, you need to urgently consult your family doctor or go to the nearest emergency room because a bursa infection may have occurred (bursae) which requires the doctor's evaluation and the prescription of a suitable therapy.
Rupture of ligaments or tendons
Knee pain can also result from a tear in the ligament or tendon. Ligaments are thick bands of tissue that connect bones to joints, while tendons connect muscles to bones. The fabric can tear during sports involving running, such as rugby and soccer.
Injured tendons or ligaments on the side of the knee can produce pain even when the joint is at rest. The situation becomes worse when you bend the knee or put weight on it. In these cases, the surrounding area can become warm and swell. .
If you feel instability or a feeling of sagging, the anterior cruciate ligament (one of the most important ligaments in the knee) may have been torn. This can happen as a result of a sudden change of direction or a rotation of the leg that can cause a creak (pop). In these cases it is advisable to immediately contact your family doctor who may also request a visit to an orthopedic specialist.Surgery may sometimes be required to regain knee function.
In the case of severe damage to the knee joint, bleeding, known as haemarthrosis, can occur in the spaces of the knee joint. This happens when a cruciate ligament tears or fractures one of the bones in the knee. Signs of hemarthrosis are swelling of the knee, warming of the part, stiffness of movement and the appearance of bruises.
If your knee appears very swollen, you should go to a hospital right away as surgery may be required.
In people who are being treated with anticoagulant drugs, such as warfarin, bleeding in the joint could occur without causing obvious damage. In this case, when the damage becomes apparent, it is advisable to contact the family doctor to counteract the adverse effects therapy with anticoagulants.
In young people, usually between the ages of 10 and 15, the presence of pain, swelling and tenderness in the bony protuberance (called the tibial tuberosity), located on the upper part of the leg bone (tibia), just below the knee, may be Symptoms of Osgood-Schlatter Syndrome This disease, caused by tibial tuberosity lesions, is common in children who play sports based on running, jumping and requiring constant bending on the knees.
Pain relief can be achieved by reducing the pace of activity, taking pain relieving medicines if the doctor deems it appropriate, and applying ice to the painful area. Osgood-Schlatter disease almost always heals spontaneously as soon as the child has completed his growth, although, in some cases, it can continue into adulthood.
Gout is caused by an excessive presence of uric acid (a molecule derived from the metabolism of proteins) in the blood. When this substance reaches high values, crystals are formed which precipitate in the joints, inflaming them and causing pain. Knee gout can manifest itself with sudden attacks of pain and with redness of the skin that tends to become hot. Sometimes the pain is present even at rest and at night and limits the movement of the joint.
Gout can affect any joint and, sometimes, even before the knee, it can manifest itself in the big toe.
If you suspect that your knee pain may be due to gout, you should contact your family doctor who can recommend ice application or prescribe non-steroidal anti-inflammatory drugs (NSAIDs). To prevent repeated attacks, it may be useful to introduce changes in the diet. and / or undergo drug treatments aimed at decreasing the level of uric acid in the blood.
Septic arthritis (knee infection)
Septic arthritis is inflammation of the joint caused by a bacterial infection which, if not treated properly, could spread throughout the body and become potentially fatal. It causes severe pain, warming and swelling of the knee and can be associated with general malaise and fever.
It can be mistaken for gout. In case of suspicion, you should urgently consult your family doctor or go to the nearest emergency room. The treatment of septic arthritis involves the drainage of the fluid formed in the knee and its analysis before administering antibiotic drugs. Sometimes, arthroscopic (also called minimally invasive) surgery may be necessary to remove the infection.
It is advisable to contact your family doctor if:
- one cannot put the weight of the body on the knee because of the pain
- intense pain is felt even in weightlessness, for example at night
- the knee freezes or creaks causing pain (if it creaks without pain, you do not need to consult a doctor)
- the knee seems to sag under the weight of the body
- you are unable to fully bend or straighten the knee
- the knee appears to be deformed
- fever, redness, warmth around the knee or severe swelling appear
- you feel pain, swelling, numbness or tingling in the calf below the affected knee
- the pain does not improve within a few weeks or severe pain persists after a few days of home treatment
The family doctor will perform a thorough examination of the knee and ask about the person's health before the onset of the disorder (medical history). You may order further tests such as blood tests, x-rays or MRIs to diagnose the problem. In some cases it might prescribe a visit to an orthopedic doctor.