How many bursa sacs in the knee

They facilitate movement and reduce friction where tendons or muscles pass over bony prominences. The knee bursae can be either communicating or non-communicating with the knee joint itself. Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys.

Updating… Please wait. Unable to process the form. Check for errors and try again. Thank you for updating your details. Log In. Sign Up. Superficial infrapatellar bursitis, also called clergyman's knee, is due to inflammation and fluid accumulation resulting from chronic stress. Clinically, there is a palpable swelling inferior to the patella. On imaging, it should be differentiated from subcutaneous edema: edema is seen as a diffuse fluid collection seen all over the anterior aspect of the knee, whereas bursitis appears as a localized collection with well-defined borders.

Superficial infrapatellar bursitis. A year-old female presented with an anterior knee swelling. Sagittal proton-density fat saturated A and sagittal gradient-echo T2W B images show a distended superficial infrapatellar bursa arrows.

On MRI, deep infrapatellar bursitis appears as a triangular fluid collection posterior to the patellar tendon [ Figure 3 ].

When found in adolescents, it should be differentiated from Osgood—Schlatter disease [ Figure 4 ]. In addition, cases of Osgood—Schlatter disease, on clinical examination, display pain and tenderness at the insertion of the patellar tendon.

Deep infra patellar bursitis. A year-old male presented with anterior knee pain: sagittal T2W image shows a distended deep infra patellar bursa arrow.

Osgood—Schlatter disease. An year-old male presented with anterior knee pain: sagittal proton density A and sagittal true inversion recovery magnitude TIRM B images show thickening of the patellar tendon at the tibial tuberosity arrow and a distended deep infrapatellar bursa arrowhead. The suprapatellar bursa is located between the quadriceps tendon and the femur. Failure of regression of the transverse septum formed in embryonic life between the suprapatellar plica and the knee joint fluid leads to the formation of this bursa.

It may be found incidentally [ Figure 5 ] or, when large and loculated, it may present as a mass above the knee joint. Suprapatellar bursitis. A year-old male presented with internal derangement of the knee: sagittal proton density fat saturated A and axial T2W gradient-echo B images show a distended suprapatellar bursa arrows and in addition, a partial tear of the anterior cruciate ligament thick arrow in A.

The pes anserine bursa separates the pes anserine tendons, consisting of the distal sartorius, gracilis, and semitendinosus tendons, from the subjacent distal portion of the tibial collateral ligament and the bony surface of the medial tibial condyle.

On MRI, pes anserine bursitis appears as an oblong multiloculated fluid collection seen along the anserine tendons on the posteromedial aspect of the knee [ Figure 6 ]. This is best appreciated on T2W axial images. It is commonly confused with a popliteal cyst; the pes anserine bursa is located posteriorly and medially along the semitendinosus, whereas the popliteal cyst is located more often in the midline posteriorly.

Pes anserine bursitis. A year-old female presented with pain along the posteromedial aspect of the knee: Coronal proton density A and axial T2W B images show a distended pes anserine bursa arrows.

The pes anserinus tendons arrowhead in B are seen inferior to the bursa. The medial collateral ligament bursa is located between the superficial and deep layers of the medial collateral ligament. On MRI, medial collateral ligament bursitis appears as a T2 hyperintensity between the superficial and deep fibers of the medial collateral ligament [ Figure 7 ]. It must be differentiated from meniscocapsular separation. In meniscocapsular separation, in addition to fluid collection between the superficial and deep fibers of the medial collateral ligament, there is a tear of the peripheral corner of the medial meniscus and meniscal displacement from the outer cortical margin of the tibia.

Medial collateral ligament bursitis. A year-old female presented with knee swelling: sagittal true inversion recovery magnitude TIRM A and axial T2W B images show a distended medial collateral ligament burse arrows. The iliotibial bursa is located between the distal part of the iliotibial band near its insertion on Gerdy tubercle and the adjacent tibial surface. Iliotibial bursitis and tendinitis are usually due to overuse and varus stress of the knee. An adult body contains about bursae.

It is one of the bursae most likely to develop bursitis. To understand what causes knee bursitis, it is helpful to know more about the prepatellar bursa and bursae in general:. There are many reasons a prepatellar bursa may become inflamed, such as repeated irritation, an injury, or an underlying inflammatory condition. Repeated irritation from kneeling is the most common reason.

These nicknames arose because people whose jobs require frequent kneeling are prone to knee bursitis. Men aged 40 to 60 years are most likely to be affected.

With rest and home treatment, the swelling and other symptoms caused by knee bursitis may go away in a couple of weeks. Medical treatment may be necessary if symptoms persist longer than 2 or 3 weeks after beginning rest and home treatment. Knee bursitis that does not go away or comes and goes repeatedly is considered chronic bursitis. When knee bursitis is chronic it is more challenging to treat. When pressed, the lump at the front of the knee may feel like a water balloon. The knee may also feel tender, stiff, and painful.

Interestingly, prepatellar bursitis is not always painful. See Prepatellar Bursitis Symptoms. Knee pain, along with skin that is warm to the touch, may be a sign of infection. An infected bursa septic bursitis is a serious condition and requires immediate medical attention. This condition is called septic bursitis , and requires urgent treatment. Septic bursitis is common in the prepatellar bursa because it lies just below the skin.

Call your doctor if you have a fever in addition to pain and swelling in your knee. Knee bursitis is a common complaint, but your risk of developing this painful disorder can increase from:. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.

This content does not have an English version. This content does not have an Arabic version. Overview Knee bursae Open pop-up dialog box Close. Knee bursae Bursae are small fluid-filled sacs shown in blue that reduce friction between moving parts in your body's joints.