The knee and in the narrower sense the knee joint is the largest joint in the human body. It is stressed the most and so knee pain can repeatedly occur in the knee region. There are different causes that can cause pain, one of which is inflammation of the knee. If this inflammation affects the joint, it is called arthritis. As a result of inflammation in the knee, both mobility and function may be restricted and treatment is necessary.
The reasons for inflammation in the knee can be of various origins such as rheumatic, infectious, degenerative or traumatic in nature. Rheumatoid inflammation in the knee has arisen from a chronic process. It is based on a misdirection of the own immune system and belongs to the autoimmune diseases. It is a systemic disease and usually affects the whole body. The immune system attacks the body's own structures such as cartilage or other parts of the joint, which leads to a painful reaction and can irreversibly damage the joint in the further course. Gradually, cartilage or other parts of the joint are destroyed, which leads to shape and axis deviations, which can result in restricted movement.
This contrasts with the infection-related inflammation in the knee. This can be caused by microorganisms such as bacteria, viruses or fungi. They can get into the knee either through the bloodstream or through surgery. In this case too, the inflammatory processes in the joint can lead to irreversible damage and thus to impaired function.
In addition, the cause of the joint inflammation can be an accident or an injury to the knee; this is referred to as post-traumatic inflammation if germs have been carried into the knee joint in this way and cause inflammation.
Furthermore, signs of wear can lead to constant inflammatory irritation of the joint, which can also lead to inflammation in the knee. The pathogenesis is due to a process in which pro-inflammatory (pro-inflammatory) cytokines and mediators are released. This is followed by increased blood flow to the tissue with the result of edema formation, which can explain the symptoms, because regardless of the cause of the inflammation in the knee, the symptoms are classic signs of inflammation, such as redness, swelling, overheating and pain with functional restrictions in the knee. These signs of inflammation are particularly pronounced in infection-related arthritis caused by bacteria. The joint can also have a stiffness. Other symptoms can be of a general nature, such as fatigue and fever.
Many things can help with diagnostics. First of all, a detailed medical history should be made, in which one discusses previous illnesses and operations. A joint mobility test and a history of pain should also follow.
A joint effusion may follow the exam, meaning there is too much fluid that should not normally be there. In this case a knee puncture can be done. The liquid obtained can then be examined for possible causes such as bacteria, and red and white blood cells can also be determined, which can also indicate the cause. A removal of the synovial fluid without previous effusion can thus provide clues to the genesis.
Furthermore, in the case of inflammation in the knee, blood values can also be changed in general, which is why blood sampling is part of the diagnosis, whereby different inflammation values can be determined.
Imaging methods such as X-rays can be used. Depending on the cause of the inflammation, x-rays of other joints, such as hands, feet or the spine, can also be taken to rule out various underlying diseases such as gout or rheumatism. In general, elevation or cooling helps with acute inflammation in the knee joint. Painkillers and anti-inflammatory agents such as ibuprofen or diclofenac can also be taken.
Anti-inflammatory drugs such as steroids can also be helpful. However, it is important that the correct treatment of joint inflammation can only take place with the correct diagnosis. In infectious arthritis, for example, you need a drug against the pathogen, such as antibiotics. Since rheumatoid arthritis is caused by another underlying disease, additional therapy for acute inflammation is necessary.
In terms of imaging, the inflammation can essentially be flanked by three examination methods:
The patella is a triangular, disc-shaped flat bone viewed from the front, which is part of our knee joint and plays an important role in the mobility and strength of our knee. The kneecap is connected to the large thigh muscle, the quadriceps femoris muscle, in the tendon of which it is firmly anchored and serves as a sesame leg. The function of a sesame leg is to gain an additional distance from the bone (in this case to the thigh) and thus to create a larger lever for the tendon of the muscle so that the muscle has to use less force to move the bone.
That is why you can build up so much strength with the thigh muscle via the knee joint. The back surface of the kneecap is covered with cartilage to allow the knee joint to move smoothly.
Like almost every other organ, the kneecap can also ignite. This can lead to considerable pain and restricted movement in the knee joint.
The main symptom of inflammation of the knee joint is knee pain, especially in the front area of the knee joint and directly above / below the kneecap.
In addition, there may also be typical signs of inflammation, such as overheating of the knee joint, more or less severe reddening of the skin around the kneecap, swelling of the entire knee joint. After sitting for a long time in a position with the knees bent, it is difficult for those affected to get up and the pain increases for a short time.
Permanent movement helps to relieve the pain.
The most common cause of inflammation of the kneecap is overload. Often the cartilage substance is also affected. Running, running or jumping off a lot causes strong mechanical shock and pressure forces on our knees, which can irritate or inflame the kneecaps. This can occur both acutely due to an excessive load, or gradually take a chronic course.
If the patella is hit unhappily by a hard impact, so that it cannot be dampened by the sliding movement in the knee, the cartilage can be damaged and the patella is literally crushed.
Cartilage degeneration or knee osteoarthritis can also be accompanied by inflammation of the kneecap. Due to the disturbed sliding friction on the underside of the kneecap due to the cartilage damage, a nerve irritation occurs, which is felt as pain. In addition, there are inflammatory processes in or on the kneecap, which produce metabolic products that have to be cleared by the body's own immune cells, causing fluid to collect in the knee.
The so-called patella tip syndrome is a very common morbid and inflammatory disease of the kneecap, which is also caused by unfavorable stress.
The diagnosis of inflammation of the patella is mainly made by the clinical examination of the knee. For this purpose, the knee is inspected for redness and malposition and then examined for restricted movement, tenderness and overheating.
Imaging methods such as X-rays or magnetic resonance imaging (MRI) of the knee can also be used to make a diagnosis.
Therapy for patella inflammation can be conservative. The most important measure is to relieve the knee and avoid strong impacts and compressive forces on the knee. In addition, non-steroidal anti-rheumatic patients, such as ibuprofen or diclofenac, can be used to treat the pain and the inflammation.
Another therapy option would be the use of cortisone injections in the affected joint to locally counteract the inflammation. In addition, physiotherapy can be useful, as can heat or cold therapy, depending on the stage of the inflammation.
If knee osteoarthritis or cartilage degeneration is present, more complex therapy and possibly surgery is required.
The prognosis depends on the cause of the patella inflammation. With a simple overload of the knee, the complaints with adequate therapy usually resolved within a few weeks and you can slowly start to put normal strain on the knee again.
However, if there is a chronic wear of the cartilage of the inflammation, complaints often remain, as cartilage does not grow back and pain that is exposed due to the cartilage damage can cause repeated pain.
The patellar tendon (patellar tendon) connects the large thigh muscle, the quadriceps femoris muscle, to the shin bone via the kneecap and thus plays an important role in the stabilization and mobility of the knee joint. Together with the kneecap, which reinforces the leverage of the thigh muscle, the patella tendon enables the lower leg to stretch.
An incorrect or excessive strain on the knee can easily lead to irritation and inflammation of the patella tendon, which is associated with severe knee pain and restricted movement.
The most common cause of inflammation of the patellar tendon is a failure or overload, which causes irritation of the tendon. In particular, sports in which there are frequent start and stop movements, landings after jumps and sudden changes of direction put a lot of strain on the patellar tendon. The patella tendon is permanently stressed while running.
In addition, permanent overload can lead to the so-called patella tip syndrome. This is a wear and tear disease that causes chronic irritation of the patellar tendon at the transition between the tendon and the bone.
Other causes that can lead to inflammation of the patella tendon: footwear, incorrect technique during sports, anatomical defect (bow legs, X legs, leg dysmetry), too hard running surface (e.g. asphalt) or muscular imbalance.
Pain at the lower end of the patella is typical for inflammation of the patella tendon. Most of the time the pain only occurs on one side, only about 20% of all cases affect both knees. Depending on the progress of the inflammation, the pain can only occur after a training session, during training or even in everyday life or at rest. Above all, the stretching movement hurts in the knee.
If the patella tendon is completely torn or damaged, the lower leg can no longer be stretched out.
The focus of the diagnosis is the clinical examination of the affected knee. The doctor will examine the knee for redness, swelling, restricted movement and pressure pain. The pressure pain below the kneecap and pain when stretching the leg against resistance is striking here.
Imaging procedures such as ultrasound or an MRI from the knee can confirm the diagnosis. MRI of the knee is particularly suitable for determining how far the inflammation and any damage to the tendon have progressed, since active inflammations can be identified in this procedure.
Accompanying tears, cracks or partial tears of the patellar tendon can also be seen on the MRI.
An X-ray examination can also be useful to rule out a possible bone fracture.
The exact assessment of the extent of the inflammation by the imaging methods is very important, as this influences the course of therapy.
Patellar tendinitis can be divided into three stages.
The most important measure in therapy for inflammation of the patellar tendon is to protect the affected knee joint. Sport should only be done in a pain-free area and ideally paused at the beginning and slowly increased again after a few weeks. In order to keep the load when running low, routes with lots of curves, climbs or uneven ground should be avoided.
In addition, exercise therapy in the form of physiotherapy can help relieve the tendon and get used to adequate stress. Cold treatments and special exercises can also relieve the pain.
In addition, non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or diclofenac, can be taken. These have anti-inflammatory and analgesic effects. However, the side effects of prolonged use of these drugs should be considered and prophylaxis may be taken, especially to prevent the common complications in the gastrointestinal tract.
A varied and well-structured training plan can avoid unnecessary overloading of the patellar tendon. It would be ideal to switch between different sports such as running, swimming, cycling and strength exercises in order to avoid one-sided stress.
Extensive stretching before running is also a good measure to prevent irritation. Before exercising, especially the hip, thigh and calf muscles should be stretched well.
The prognosis of patellar tendinitis depends on the stage. Most cases are mild to moderate inflammations (see stage I and II above), which give a good prognosis and no permanent damage.
Only the severe inflammation can lead to permanent, untreatable damage. It is therefore important to recognize the disease at an early stage and to take a break from training if necessary.
The quadriceps tendon is the muscle tendon of the strong quadriceps muscle, which lies on the front of the thigh and is responsible for the powerful extension of the knee.
While the different muscle parts arise from different structures, the quadriceps tendon attaches to the tibial tuberosity, which is prominently palpated on the shin.
The kneecap is embedded in the quadriceps tendon. From the kneecap, the quadriceps tendon continues as the patellar ligament. Inflammation in the quadriceps tendon usually occurs at the transitions to the bone, that is, where the tendon attaches to the upper kneecap, arises at the lower pole and ends at the shin.
It is a sign of chronic overload.
Inflammation of the quadriceps tendon arises in most cases from a chronic overload of the tendon and all structures connected to it. Chronic overload occurs especially when jumping, playing sports or running regularly, but also during professional activities that are mainly performed on the knees, such as tiling.
Due to the clustered and strong contraction of the quadriceps muscle, there is in principle a constant pull on the quadriceps tendon and the attached bone attachment.
In addition, an axis misalignment, such as X-legs, can have a negative impact on the tension of the quadriceps tendon, which places greater strain on it. The force effect is greatest at these tendon-bone boundaries, which is why the inflammation often occurs there.
In the course of chronic inflammation, calcifications can occur in the tendon due to metabolic processes, which in addition lead to pain and degeneration, i.e. wear and tear of the tendon apparatus.
If the quadriceps tendon is already attacked and damaged too much by the inflammatory process, it can no longer withstand the high forces during movement and cracks can occur. In the worst case, a partial or even complete rupture of the quadriceps tendon follows as part of the inflammation.
The diagnosis of inflammation of the quadriceps tendon is first made according to the clinical picture. This means that the patient visits a doctor because he has noticed pain or a restriction when moving the knee, and the patient then uses a physical examination and a medical history to characterize the symptoms.
The focus is on the attachment point of the quadriceps tendon to the kneecap and shin. There, the tenderness can typically be pinpointed precisely, in some cases even swelling, hardening due to limescale deposits or a dent after the tendon has torn.
Various tests can also be used to determine the strength and function of the quadriceps tendon when stretching the knee to define the extent of the inflammation.
It is important to distinguish that the knee joint itself is not impaired in its function. Carrying out a detailed medical history can provide additional information on the development of the inflammation, the course and symptoms.
Imaging measures can also be carried out, for example an ultrasound of the quadriceps vision. The tendon tissue can be assessed with the question of inflammation or rupture.
Typical signs that speak for inflammation are calcification, water accumulation, the loss of smooth borders of the tendon fibers or tears.
Alternatively, a lateral x-ray of the knee can be taken, again taking care of calcification in the quadriceps tendon. In order to clarify a rupture of the tendon, an MRI scan of the knee is made, since it is easier to differentiate the soft tissue of the quadriceps tendon and thus also determine the thickness, which should not be less than about 7 mm.
The affected person becomes aware of the inflammation of the quadriceps tendon primarily due to a punctiform tenderness over the corresponding tendon section. Inflammation and thus tenderness typically occurs at three points: either on the upper edge of the patella, on the lower edge or on the tibial tuberosity of the tibia.
This pressure pain, which is caused by the inflammation of the quadriceps tendon, can well lead to pain during movement, especially with the triggering overload, which leads to a restriction in the freedom of movement of the knee, while the knee itself is not functionally impaired.
To treat inflammation of the quadriceps tendon, conservative therapy can be considered initially. First, the strain on the quadriceps tendon, which is one of the main causes of inflammation, should be reduced to a minimum. Only when this stressor is removed can the inflammation of the quadriceps tendon recede and heal.
Local physiotherapy can on the one hand promote healing and, on the other hand, promote the durability of the tendon in order to avoid future inflammation due to overwork. In addition, you can also counteract incorrect loading of the quadriceps tendon by learning new, gentler movements.
Anti-inflammatory and analgesic medication should be part of conservative therapy. On the one hand, the remedies are said to reduce the patient's suffering under the painful inflammation of the quadriceps tendon and to enable painless movement again. On the other hand, they should promote recovery by suppressing the inflammatory reaction.
If conservative therapy fails and chronic complaints arise from the inflammation of the quadriceps tendon, a surgical intervention can be considered. However, this does not serve to treat inflammation, but is intended to alleviate the pain caused by removing any lime.
In addition, a torn or partially torn quadriceps tendon can be reconstructed as part of an operation. Cutting out the inflamed area does not make sense, as this would not give a better result and the function of the tendon would be lost.
As a rule, conservative therapy, especially the reduced stress, is very helpful.
To counteract inflammation of the quadriceps tendon, it is recommended to avoid overloading the quadriceps tendon in particular if there is sufficient physical activity. This does not automatically mean that sport can no longer be practiced, but that triggering movements are only carried out in moderation. It can also help to increase the resilience of the quadriceps tendon in advance by means of targeted stretching exercises.
The inflammation of the quadriceps tendon can sometimes be very persistent and lengthy in therapy. Nevertheless, one should try to positively influence the healing and regeneration process of the quadriceps tendon through the above-mentioned therapeutic options in order to enable painless mobility and stress again.