Knee Bursitis
Knee bursitis is the inflammation of a bursa around the knee joint. Bursae are small sacs filled with synovial fluid that help reduce friction between tendons, ligaments, muscles, skin, and bones. When inflamed, they can cause pain, swelling, redness, warmth, and difficulty moving the knee.
What are bursae?
Bursae are small fluid-filled sacs found in different regions of the body. They act as natural shock absorbers, reducing friction between tendons, muscles, skin, and bones.
The term bursa itself comes from Latin and means pouch.
In the knee, there are several bursae, but the most frequently affected is the prepatellar bursa, located between the patella and the skin, at the front of the knee.
When the bursa becomes inflamed and fluid accumulates inside, bursitis occurs.
Main causes of bursitis in the knee
Bursitis can arise for various reasons. The most common causes include: direct trauma to the front of the knee, falls, prolonged kneeling, repetitive flexion and extension movements of the joint, sports activities, and some inflammatory diseases.
Professionals who frequently work kneeling, such as installers, gardeners, and construction workers, have a higher risk of developing prepatellar bursitis.
Main symptoms of knee bursitis
Symptoms can vary depending on the degree of inflammation. In the case of prepatellar bursitis, the most common symptoms are: localized swelling in the front of the knee, pain when touching the area, tenderness when kneeling, redness, a feeling of local heat, and functional limitation.
In many cases, the main symptom is increased volume in the front of the knee, and there may be little pain.
When might bursitis be a cause for concern?
Bursitis becomes a concern when there is a local infection. There is an important difference between simple inflammatory bursitis and infectious bursitis, also called septic bursitis.
In infectious bursitis, the following may occur: intense redness that progressively increases, stronger pain, significant increase in local temperature, fever, malaise, and limited mobility.
It is common to have a wound on the skin near the patella in cases of infected prepatellar bursitis.
These cases require prompt medical evaluation, as they may require antibiotics and drainage.
How is the diagnosis made?
Diagnosis is usually made through clinical evaluation by an orthopedist.
Depending on the case, additional tests may be requested, such as: ultrasound, X-rays, magnetic resonance imaging (MRI) and laboratory tests.
When infection is suspected, aspiration of fluid from the bursa may be necessary for analysis.
Treatment of knee bursitis
For most patients with prepatellar bursitis, initial treatment is conservative, i.e., non-surgical.
The main measures include: relative rest, ice application, local compression, anti-inflammatory medication, and avoiding putting direct weight on the knee.
It is always very important for the doctor to advise the patient about warning signs, which may indicate the transformation of inflammatory bursitis into infectious bursitis. These signs include: fever, local redness, and a significant increase in pain. If warning signs are present, the patient should always seek medical attention, as the treatment plan must be modified.
Chronic or recurrent cases and infectious bursitis may require specific surgical treatment.
How to prevent prepatellar bursitis?
Some measures help reduce the risk of bursitis in the knee, such as using knee protection (knee brace), avoiding repetitive trauma to the front of the knee, strengthening the muscles of the lower limbs, treating inflammation early, and adjusting sports and professional activities when necessary.
When should you see an orthopedist?
It is important to seek specialized evaluation when there is: persistent swelling in the knee, significant pain, intense redness, fever, functional limitation, or recurrence of the problem.
Correct diagnosis is essential to differentiate bursitis from other conditions that can also cause a swollen knee.
