Knee bursitis (ICD M70.5) is an inflammation of a bursa in the knee or knee joint. This can occur in various locations:
- in the area in front of the kneecap, or
- on the inner and back sides of the knee joint.
Knee pain? Bursitis is often the underlying cause. © westfotos.de / Fotolia
In prepatellar bursitis, the bursa in front of the kneecap is affected by inflammation. Infrapatellar bursitis, on the other hand, is limited to the bursa located below the kneecap. There are also bursae in the back of the knee that can become inflamed. Medically, a distinction is made between prepatellar bursitis and infrapatellar bursitis.
A bursa, known in medical terminology as a “bursa synovialis,” is a sac of tissue filled with fluid. Bursae are always found in areas where joints are subjected to particularly high stress. This structure acts as a cushion, reducing pressure and friction on the skin, muscles, bones, and tendons. While most of the approximately 160 bursae are fairly resilient, other joints are prone to bursitis. The knee joint is one of these susceptible joints.
Inflamed bursa below the kneecap (pictured: side view) © Henrie / Fotolia
If the knee is exposed to pressure and/or excessive (improper) stress over an extended period, the bursa can become inflamed. Thus, bursitis is one of the typical overuse reactions of the knee joint. A bursa irritated by constant kneeling, sports, or pressure may initially become painful and then, later, become inflamed.
However, bursitis in the knee can also occur after a fall onto the knee or the kneecap. In such cases, bacteria can enter through an open wound, leading to an infection of the bursa. In this scenario, bursitis may also be caused by bacteria. Such inflammation of the bursa should be evaluated by a doctor to rule out serious complications and other causes of bursitis.
There are various risk factors for inflammation of the bursa in the knee. These include:
- one-sided physical work, such as tiling or gardening;
- acute injuries from sports accidents or falls;
- chronic joint conditions such as osteoarthritis or arthritis;
- sports activities that put strain on the knee, such as surfing, tennis, or soccer.
Bursitis causes swelling at the affected site on the knee. The overlying skin is reddened, and the entire inflamed area feels warm to the touch. Those affected experience pain, particularly during movements that put strain on the inflamed structure. Knee mobility is often restricted.
Typical symptoms include pain, swelling, warmth, and a visible bulge. Another symptom may be increased tenderness.
Depending on the location of the inflammation, specific symptoms may occur:
- In prepatellar bursitis, bending the knee is particularly painful. The inflammation manifests as redness and swelling directly in front of the kneecap.
- In infrapatellar bursitis, on the other hand, the area below the knee swells. In addition to bending, hyperextension of the knee often causes pain in this form of bursitis.
Symptoms of bursitis in the knee can begin acutely or become chronic due to prolonged strain.
The patient’s description of their symptoms and a visual examination of the knee usually provide sufficient evidence for a preliminary diagnosis of “bursitis in the knee.” Since the inflammation is often caused by overuse, the doctor will also ask the patient about physically demanding activities during the consultation. The patient’s occupation, sports history, as well as any falls, injuries, or pre-existing conditions are also of interest when taking the medical history (anamnesis).
To confirm the diagnosis, the doctor performs a physical examination following the medical history. During this examination, the doctor pays particular attention to swelling, redness, or warmth in the knee area.
An ultrasound can reveal whether excess fluid has accumulated in the bursa. If an infection is suspected or if there is significant swelling, a aspiration may be recommended. During this procedure, fluid is extracted and examined in the laboratory.
If a patient frequently suffers from bursitis in the knee, further diagnostic testing may be necessary. For example, an X-ray can provide evidence of changes in the knee joint area and thus help identify possible underlying conditions. If metabolic disorders such as gout or rheumatic diseases are suspected, a blood test may be advisable.
Bursitis in the knee is usually treated conservatively. The RICE principle outlines the first steps in first aid:
- P - Rest. The knee joint needs time and rest until the inflammation subsides and it can bear weight again.
- E – Ice: Pain relief through cooling the knee joint, for example with an ice pack (wrapped in a towel to make the cold more comfortable).
- C – Compression: Light pressure reduces swelling.
- H – Elevating the knee joint promotes blood flow and reduces swelling.
The affected knee joint should be rested and cooled. Depending on the location of the inflammation, a special knee tape wrap may also help relieve symptoms; a doctor or physical therapist can advise you on this. Anti-inflammatory medications can be taken to manage the pain.
Physical therapy can help reduce improper weight-bearing and maintain mobility. Exercises and treatment may include, for example, gentle mobilization without applying pressure to the affected area.
If necessary, you can place a rolled-up towel under the back of the knee to position it more comfortably. The appropriate treatment depends on the cause and severity of the condition. It takes time for the inflammation to subside. Cool the knee with an ice pack wrapped in a cloth and elevate it. A light compression bandage can help reduce swelling.
If there are no open wounds, a specialist can, in cases of severe swelling accompanied by an uncomfortable feeling of pressure, puncture the bursa to drain the fluid using a syringe. Afterward, if necessary, the specialist may also inject anti-inflammatory cortisone directly into the inflamed bursa to combat the inflammatory reaction within the bursa itself.
A puncture can relieve pressure on the knee in cases of chronic bursitis. © ursule / Fotolia
However, it is important to note that an injection into the knee joint always carries risks. For example, bacteria can enter the bursa or the knee joint and worsen the inflammation there. Maintaining sterile conditions is therefore particularly important.
If the symptoms of inflammation persist for several weeks or if inflammation recurs repeatedly, this indicates chronic bursitis. If conservative treatment is ineffective, the doctor may surgically remove the affected bursa, either partially or completely.
If the symptoms of inflammation persist for several weeks or if inflammation recurs repeatedly, this indicates chronic bursitis. Chronic bursitis can also cause severe pain and recurring symptoms. If conservative treatment for bursitis is ineffective, the doctor may perform surgery to partially or completely remove the affected bursa. This procedure is called a bursectomy.
Surgery is primarily considered when bursitis is persistent, recurrent, complicated by a bacterial infection, or significantly impairs knee function.
The course and duration of bursitis depend, on the one hand, on the cause and severity, and, on the other hand, on the treatment. As a rule, however, bursitis responds well to treatment and heals relatively quickly. In cases of mild inflammation, sick leave is generally not required, or if needed, only for a few days up to a maximum of two to four weeks. Severe inflammation requiring surgery, on the other hand, can result in several weeks of absence from work.
Bursitis of the knee occurs primarily in people who have to kneel frequently as part of their job. Sports activities that put strain on the knee can also lead to bursitis. However, with adequate rest, you can counteract the inflammation, so that the unpleasant pain usually subsides quickly.
Knee braces help prevent bursitis. © Picture-Factory / Fotolia
Bursae protect the knee joint from excessive strain. As long as they are not inflamed, they perform their shock-absorbing function almost unnoticed. To protect the bursae—and thus the knee joint—special knee pads or braces can be worn during strenuous activities or sports that put strain on the knees. Regular breaks and gentle mobilization through balanced knee movements keep the knee joint strong and healthy.
Bursitis in the knee and its treatment primarily affect people who have to kneel frequently for work-related reasons. Similarly, sports activities that put strain on the knees can lead to inflammation in the knee. With adequate rest, you can counteract the inflammation, so that the unpleasant pain usually subsides quickly.
Appropriate healthcare providers include specialists in orthopedics and trauma surgery, sports medicine physicians, and—if rheumatic causes are suspected—rheumatologists.
What is bursitis of the knee?
Bursitis of the knee is an inflammation of the bursa surrounding the knee joint. This often causes excess fluid to accumulate in the tissue. The area becomes painful and may be swollen.
How do you recognize bursitis in the knee?
Common signs include pain, swelling, warmth, and tenderness. The symptoms often worsen when bending, straightening, or kneeling. Depending on its location, bursitis can occur in front of, below, or behind the kneecap.
How is bursitis in the knee treated?
Treatment for bursitis usually involves rest, cooling, elevation, compression bandages, and anti-inflammatory medications. Sometimes the knee is immobilized. If there is significant fluid buildup, surgery may be helpful.
When is surgery necessary for knee bursitis?
Surgery is rarely necessary; it may be considered if the bursitis persists despite treatment, recurs frequently, is severely infected, or if there is chronic inflammation of the bursa.
How can knee bursitis be prevented?
Knee braces, bandages, rest, and avoiding prolonged pressure on the knee can help prevent it. Especially in occupations or sports that involve frequent kneeling, you should regularly relieve pressure on the knee and pad it well.
