Ganglion cyst knee

Ganglion Cyst of the Knee: A Retrospective Review of a Consecutive Case Series The aim of this study was to describe relevant medical history, clinical symptoms and outcomes in 12 patients having undergone surgical treatment of intra-articular ganglion cysts of the knee at our Department from January 2010 to June 2016 Ganglion Knee Cyst Information Knee Cyst is a fluid-filled synovial fluid swelling that causes a lump around the knee area. The Ganglion Knee Cyst can cause tightness and restricted movement hence it can be painful when you bend or extend your knee. Knee Cysts are difficult to treat because they are mostly connected to the knee joint A ganglion cyst diagnosis may be confirmed by aspiration, a process in which your doctor uses a needle and syringe to draw out (aspirate) the fluid in the cyst. Fluid from a ganglion cyst will be thick and clear or translucent. Care at Mayo Clini Objective: To explore the diagnosis and treatment of ganglion cysts of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) of the knees. Methods: Retrospective analysis of clinical data of patients with ganglion cysts of ACL and PCL as confirmed by arthroscopy and pathology. Results: All patients were followed up at the clinic in a mean period of 2 years, and their.

Ganglion Cyst of the Knee: A Retrospective Review of a

Knee Cyst - Ganglion Cyst Home Treatmen

There is broad differential for cyst-like lesions around the knee.. Differential diagnosis Cysts. synovial cyst. popliteal synovial cyst - Baker cyst; ganglion cyst. intra-articular ganglion cyst A meniscal cyst is a collection of joint fluid caused by a tear within the meniscus cartilage, the joint pad over the knee. It may have no symptoms, or it may cause pain, swelling, or mechanical issues with the knee What Is a Ganglion Cyst? A ganglion cyst is a small sac of fluid that forms over a joint or tendon (tissue that connects muscle to bone). Inside the cyst is a thick, sticky, clear, colorless,.. Dr. Ebraheim's educational animated video describes ganglion cysts - Ganglion Cysts around the knee.Follow me on twitter:https://twitter.com/#!/DrEbraheim_UT.. A knee cyst that is causing symptoms and cannot be treated with medication may require surgical removal. Most cysts that arise in the knee develop from what are known as bursae. Bursae are sacs located in the parts of joints where friction occurs. If joint overuse leads to injury, these bursae may fill with fluid, forming cysts


Ganglion cyst - Diagnosis and treatment - Mayo Clini

  1. Ganglion Cysts A ganglion cyst is a fluid-filled lump below the surface of the skin that appear on near joints and tendons. They usually do not cause any symptoms and often disappear on their own. Treatment ranges from observation to an outpatient surgery called a ganglionectomy
  2. A ganglion cyst is a tumor or swelling (benign, not cancerous) usually on top of a joint or the covering of a tendon (tissue that connects muscle to bone). It looks like a sac of liquid (cyst) located just under the skin. Inside the cyst is a thick, sticky, clear, colorless, jellylike material
  3. Ganglion cysts are common findings around the knee and other joints but association with either the anterior cruciate (ACL) or posterior cruciate ligament (PCL) is considered rare. These cysts are often symptomatic. A ganglion is a cystic lesion containing mucin-rich fluid associated with a joint or tendon sheath

Magnetic resonance imaging of the left knee was ordered, which revealed a septated ganglion cyst within the femoral notch that caused moderate displacement of the cruciate ligaments, which were otherwise intact . Following arthroscopic excision of the cyst and subsequent physical therapist intervention, the patient's symptoms fully resolved. Anterior cruciate ligament (ACL) ganglion cysts, commonly referred to simply as ACL cysts, along with ganglion cysts arising from the alar folds that cover the infrapatellar fat pad, make up the vast majority of intra-articular ganglion cysts of the knee Question: I have ganglion cyst on my knee what should I do?Can you suggest some alternative treatment and remedies for ganglion cyst? Answer: A ganglion is a swelling of the tendon sheath filled with fluid and benign in nature.It is usually painless, movable, swelling seen behind the joints of the knee, wrist and ankle. It is not clear what causes ganglion in the knee joint, but presumed to be.

A ganglion cyst is a fluid-filled noncancerous lump that usually develops in the wrist or hand. But some occur in the ankles or feet. When a ganglion cyst presses on a nerve it can be painful. And.. These cysts usually develop on the wrist, but they can appear on the hand, ankle, foot, or knee. They look like small lumps under the skin. Ganglion cysts are not cancerous, and they are usually. Purpose: To increase awareness of the presence of ganglion cysts of the anterior cruciate ligament and to consider this diagnosis in any knee that has lost range of motion (ROM) in the absence of osteoarthritis. Type of study: Case series. Methods: We present a series of 15 cases recorded over a period of 5 years illustrating the clinical presentation and additional pathology seen at arthroscopy The ganglion cyst is most frequently located around the dorsum of the wrist and on the fingers. 80% of ganglion cysts are found in the wrist, although they may occur in the foot. popliteal cyst, on the other hand, are generally located behind the knee area. Ganglion cysts are commonly observed in association with the joints and tendons

What is ganglion cyst? Definition and Etymology. In Greek, ganglion means a ball-shaped swelling or knot under the skin [1].A cyst is a closed fluid-filled sac that is formed in the tissues [2].A ganglion cyst is a noncancerous fluid-filled sac that arises from the muscle tendon, tendon sheath, joint capsule or ligament, most commonly on the wrist or foot [3] knee, e.g. ACL ganglion cyst; spinoglenoid notch: spinoglenoid notch ganglion cyst; ankle: foot; Classification. There are many ways of classifying ganglion cysts. In relation to structure, e.g. bone. within bone: intraosseous ganglion cyst; adjacent to the bone: periosteal ganglion cyst - rare and may occur more frequently in males Ganglion cyst in knee Because the knee is one of the most abused joints of the body, it is also a common site for the appearance of ganglion cysts. Repeated injuries like sprains and strains may injure the delicate membranes covering the knee. Cysts forming on the back of the knee are also called popliteal ganglion cysts or baker cysts

ACL cyst | Image | Radiopaedia

Diagnosis and treatment of ganglion cysts of the cruciate

Baker's cysts are fluid-filled lumps or sacs that form behind your knee. This condition can be caused by a knee injury or a condition like arthritis. If you have a Baker's cyst, you may not experience any symptoms, have mild pain and discomfort, or feel severe pain. In severe cases, surgery may be an option On the other hand, a ganglion cyst is mobile and pliable to the touch. It will move around under the skin. The cancer I saw was around the ankle, says Dr. Anderson. Typically, that's not where ganglion cysts occur. I find ganglion cysts around the joints of the big toe, the cuboid lateral foot, and the dorsal foot Introduction. Intra-articular ganglion cysts of the knee are uncommon. During an autopsy in 1924, Caan first reported a ganglion cyst on the anterior cruciate ligament (ACL). 1 Intra-articular cysts are predominantly incidental findings on MRI and arthroscopy with the reported prevalence of 0.2% to 1.3% and 0.6% respectively. 2, 3 Ganglion cysts are found to be more often associated with the. Intraarticular ganglia of the knee are uncommon; however, these ganglion cysts may produce knee discomfort without a clear etiology. We present the cases of 10 patients with ganglion cysts arising from cruciate ligaments of the knee joint who underwent arthroscopic excision after MR examination

Dr. Michael Schwartz answered. 33 years experience Vascular Surgery. Depends: Ganglion cysts (also known as Baker's Cysts) are synovial cysts of the knee joint. In most cases they are treated conservatively Scroll Stack. Longitudinal. Lobulated anechoic cyst with few thin septa is noted on the lateral aspect of the knee. Size - 26 x 26 x 17 mm. It is superficial to lateral collateral ligament which is intact. Biceps femoris tendon is deep to the posterior part of the cyst. The common peroneal nerve is about 1 cm posterior to the cyst Knee Cysts is difficult to treat because of they are mostly connected to the knee joint. Although it's 90% synovial fluid like all ganglia the location makes it hard to diagnosis and remove. Ganglion Knee Cyst symptoms are swelling, discomfort and very painful around the knee Baker's Cysts (ganglion cysts) usually develop as the result of an underlying knee injury or condition. Addressing the Baker's Cyst alone won't get rid of it. Aspiration may bring down your Baker's Cyst, but this won't prevent it from coming back. Many common treatments for Baker's Cysts, such as cortisone injections, only address the symptoms 1.Open excision of extraarticular portion of ganglion cyst, left knee. 2.Left knee arthroscopy with partial synovectomy and debridement of intraarticular ganglion cyst. I have 27347 for #1. I have 29874 for the arthro of the intraarticular ganglion cyst. Can I code 29875 for the partial synovectomy as well? Anyone have any thoughts on this.

Experts say ganglion cysts may go away on their own, but you may need medical treatment if your cyst is painful or interferes with your wrist movements. Ganglion cysts are round or oval fluid-filled lumps that develop on your tendons or in your joints in your wrists or hands, though they may also form on your ankles or feet Notes: A ganglion cyst is formed when fluid leaks into the sheath around the tendon/joint. Hitting it with a heavy object will rupture the cyst and let the fluid drain into the surrounding tissue. My method was more gentle and allowed a more natural reversal of the problem, forcing the fluid back out of the cyst gradually without damaging the. Intra-articular ganglion cysts are well known to occur in the dorsal wrist, palm, and shoulder but rarely to originate in the knee joint [1, 2].Ganglion cysts of the knee arise from both the cruciate ligaments and menisci as well as from the popliteal tendon, alar folds, and subchondral bone [2-4].Here we report a case of an arthroscopically confirmed ganglion cyst arising from the posterior. Purpose: Ganglion cysts of the knee associated with anterior cruciate ligament (ACL) are a very rare entity and commonly a missed clinical diagnosis. High clinical suspicion and magnetic resonance imaging (MRI) scan aids in the diagnosis. Materials and Methods: We present three cases (2 men and a woman) of ganglion cysts associated with ACL. All of them had knee pain for more than a year. Ganglion cysts associated with the PCL can cause knee pain and limitation of knee flexion. MRI evaluation is a noninvasive method of diagnosing PCL ganglion cysts

Ganglion cyst - Symptoms and causes - Mayo Clini

ganglion cysts in knee - Orthopedics - MedHel

Ganglion cyst removal — sometimes called ganglionectomy — involves the surgical removal of a ganglion cyst. These cysts appear as balloon-shaped capsules with slender stalks that attach to herniated joint capsules, tendon sheaths, and other muscle and bone connectors. Commonly, these cysts appear on your hands, foot, wrists, ankles, or. In most cases, consideration of the clinical history, careful evaluation of the MR appearance, including the lack of ancillary findings of an ACL tear, and physical examination allow confident differentiation of a ganglion cyst from a cruciate ligament tear. References. 1 Brown MF, Dandy DJ: Intra-articular ganglia in the knee. J Arthosc 6:322. A ganglion cyst or synovial cyst, bible cyst or bible bump that is also known as a fluid-filled bump under the skin near a joint in some areas such as the wrist, knee, foot, shoulder, ankle, elbow, etc The ganglion cyst is most frequently located around the dorsum of the wrist and on the fingers. 80% of ganglion cysts are found in the wrist, although they may occur in the foot. popliteal cyst, on the other hand, are generally located behind the knee area. Ganglion cysts are commonly observed in association with the joints and tendons Meniscal cysts are relatively rare, but may be present in patients with complaints of knee pain. The majority of cysts are associated with meniscal tears and are often identified incidentally during MRI examination for a suspected internal derangement. 1-3. Accurate diagnosis facilitates timely and appropriate intervention

Bursae, Cysts and Cyst-like Lesions About the Kne

Baker's cyst - Symptoms and causes - Mayo Clini

Cysts are abnormal sacs or bulges, often containing fluid, that can form in the skin or in the body. Although there are many different types, most are not cancerous. Most frequently, cysts can be found in the skin, ovaries, breasts, and kidneys. Forms of Cysts Ganglion. Ganglion cysts occur along with the tendons or joints of the wrists or. A ganglion is a sac-like swelling or cyst formed from the tissue that lines a joint or tendon. The tissue, called synovium, normally functions to produce lubricating fluid for these areas. A ganglion is a cyst formed by the synovium that is filled with a thick jelly-like fluid. While ganglia can follow local trauma to the tendon or joint, they usually form for unknown reasons Sometimes a Baker's cyst will disappear on its own. However, if the cyst is large and causes pain, your doctor may recommend the following treatments: Medication. Your doctor may inject a corticosteroid medication, such as cortisone, into your knee to reduce inflammation. This may relieve pain, but it doesn't always prevent recurrence of the cyst

Cyst-like lesions around the knee Radiology Reference

51 year old woman with a recurrent right foot ganglion cyst (J Am Podiatr Med Assoc 2020;110:Article9) 54 year old man with posttraumatic extensive ganglion cyst to the knee (Clin Pract 2011;1:e61) 88 year old woman with a large multilocular ganglion cyst of the right temporomandibular joint (J Oral Maxillofac Surg 2016;74:1783 Ganglion Cyst | Complete Aspiration | Ganglion Treatment | #drtusarofficial#GanglionCyst #GanglionAspiration #GanglionTreatmentHello every body - hope you ar.. Knee pathologies that have been linked to Baker's cysts include the presence of meniscus tears, size of effusion, osteoarthritis, chondral lesions, inflammatory arthritis, and anterior cruciate ligament tears. Of these disorders, meniscus tears are most frequently associated with popliteal cysts Ganglion cyst of the cruciate ligament is rare and the first case of ACL cyst was reported by Caan [] during an autopsy.The reported ganglion cysts were more common with ACL than that with PCL, usually localized at the tibial attachments [2-5].Incidence of this disorder was the highest for 20-40 years of age group [].The reported prevalence of this disorder was 0.2-1.3% by MRI imaging.

Meniscal Cysts: Symptoms, Causes, Diagnosis, and Treatmen

4 Self Treatments For Baker's Cysts In The Knee. Have you been told that you have a baker cyst, you're getting swelling behind the knee, you probably have had a history of knee arthritis and meniscus problems as well. If this is the case, most of the time, people are left hanging with what to do about their Baker's cyst.. Ganglion cyst at the front of the wrist. Draining this ganglion may be useful, but it can be dangerous as the cyst is often close to the artery at the wrist (where you can feel the pulse). Problems after surgery include: persistent pain. loss of wrist movement. trapping of nerve branches in the scar A sports-related injury or other blow to the knee can cause A Baker's cyst. Gout . This type of arthritis, which results from the buildup of uric acid in the blood , can lead to a Baker's cyst

Ganglion Cyst: Symptoms, Causes, Diagnosis, and Treatmen

  1. A ganglion cyst is a fluid-filled lump under the skin, often over a joint or in a tendon in the hand or wrist. If the cyst appears on top of the wrist, it is called a dorsal wrist ganglion cyst. A cyst on the palm side of the wrist is a volar wrist ganglion cyst. These cysts are usually harmless
  2. Ganglion Cyst Symptoms, Pain Relief, Treatment, and Removal: A ganglion cyst is a swelling or tumor on a joint or tendon sheath.Ganglionic cysts form on the elbow, knee, foot, shoulder, wrist, toe or finger. Symptoms and signs include a mass that changes in size, is somewhat painful, and the pain is made worse by joint motion
  3. Intra-articular ganglion cysts of the knee joint are rare occurrences. They are usually encountered as incidental findings in MRI, or in arthroscopy. Arthroscopic resection and debridement is regarded as the gold standard treatment in ganglion cyst of the knee. However, very rarely, these masses may extend subcutaneously across the retinaculum
  4. Ganglion cysts are characterized by small (1-3 cm) raised bumps that appear on the joints or tendons of the ankle, as well as toes, wrists, fingers, knees and other joints. These small, noncancerous tumors are filled with a thick, clear, sticky material, which can be seen by shining light through the growth
  5. A Baker's cyst, or popliteal cyst, is a fluid filled swelling that develops on the back of a person's knee. Baker's cysts can sometimes rupture, potentially leading to pain and swelling
  6. The most common clinical finding was knee pain. There were swelling at the medial side of the knee in two patients, swelling at the lateral side of the knee in one patient and swelling in the popliteal region in one patient. CONCLUSION: MR appearance of ganglion cysts arising from the tendons and ligaments of the knee is characteristic

Ganglion Cysts Around The Knee - Everything You Need To

Normally ganglion cysts are round or oval and are filled with a jelly-like fluid. Small ganglion cysts can be pea-sized, while larger ones can be around an inch (2.5 cm) in diameter. Ganglion cysts can be painful if they press on a nearby nerve and their location can sometimes interfere with joint movement. Normally a ganglion cyst is treated. I have had Ganglion cyst before, actually quite a few over a 20 year period. Knee, elbow, wrist and finger. I found the best thing to do for me was to tightly wrap over the cyst with an elastic bandage or band and take aleve. I used to use advill 600's but being a type II diabetic now the doctor will only allow me to use aleve

What Is the Treatment for a Knee Cyst? (with pictures

Popliteal (Baker) cysts, meniscal cysts, proximal tibiofibular joint cysts, and cruciate ligament ganglion cysts are cystic masses commonly found about the knee. Popliteal cysts form when a bursa swells with synovial fluid, with or without a clear inciting etiology. Presentation ranges from asymptomatic to painful, limited knee motion Volar ganglion cyst: A ganglion cyst on the underside of the wrist is a volar wrist ganglion cyst. Less commonly, a ganglion cyst may form on a foot or ankle or near other joints in the body. The cysts may increase and decrease in size, becoming larger if you engage in repetitive motions with the affected joint and smaller with less joint use What is inside a ganglion cyst? There is a fluid inside the ganglion cyst called synovial fluid. This is a pocket that pours out of the joint. This is clear jellylike fluid. Watch the video above to see what it looks like. Symptoms of the ganglion cyst: A ganglion cyst generally does not hurt. But it does look like a hard bump. It can be soft. A lump on the side of knee - either inside or outside- is most likely a meniscal cyst. A meniscal cyst is a collection of thick fluid arising from a tear of the meniscal cartilage, which is the cushioning of the knee. However, not all lumps in the knee are meniscal cysts

Ganglion Cyst Home Treatment. Medically reviewed by Gerhard Whitworth, R.N. A ganglion cyst is a common, noncancerous, fluid-filled lump found on joints or tendons. The majority of ganglion cysts. Ganglion cysts associated with knee cruciate ligaments are uncommon and usually occur in the ACL, with a prevalence of 1.3% in a group of 1767 consecutive patients referred for MRI examinations of the knee and 0.6% after arthroscopy. 8,11,12 The etiology of these ganglion cysts is unknown Intraosseous ganglion cyst knee Download Here Free HealthCareMagic App to Ask a Doctor All the information, content and live chat provided on the site is intended to be for informational purposes only, and not a substitute for professional or medical advice Ganglion cysts within the knee joint are unusual lesions and may produce clinical manifestations mimicking internal derangement of the knee. Intra-articular ganglion cyst of the knee was first reported by Caan (2) in 1924, who incidentally found a ganglion cyst of the anterior cruciate ligament (ACL) at autopsy

A Baker's cyst is a fluid-filled swelling that can develop behind the knee. It is one cause of knee pain. It is named after a doctor called William Baker who first described this condition in 1877. It is also sometimes called a popliteal cyst, as the medical term for the area behind your knee is the popliteal fossa Cystic lesion around knee usually presents as painless swelling and diagnosed incidentally by imaging for any internal derangement of the knee. Few cases presented with pain. Intra-tendinous patellar ganglion is very rare in location for the disease. Ganglionic cyst usually treated by aspiration followed by steroid and surgical excision in some cases

Ganglion Cysts: Causes, Symptoms, Diagnosis & Treatmen

  1. ed. In total, 85 intra-articular soft tissue masses were found within the knee cavity. Of these, 76 were incidental and asymptomatic findings in arthroscopy performed for treatment of osteoarthritic.
  2. A ganglion cyst may be seen in all joints with varying frequency depending on the location, but it is rare in the knee joint. , The reported prevalence of ganglia in the knee joint are from 0.2 to 1% on knee MRI and 0.6% on knee arthroscopy. Many cases of ganglia, ranging in size from 1.8 to 4.5 cm, have been reported, and occasionally they are bilateral
  3. Anterior cruciate ligament (ACL) ganglion cyst and ACL mucoid degeneration are two non-traumatic pathologies that have been increasingly found be associated with insidious onset chronic knee pain. They may also present as a limited range of motion of the knee due to either pain or mechanical block [1-4]
  4. The ganglion cyst often develops in the top part of the wrist, in the middle or near the middle. The result is that bending (extending, that is) the wrist produces discomfort. It may also feel like something's in there blocking the full range of extension
  5. The physician listed 27339 (Excision, tumor, soft tissue of thigh or knee area, subfascial (eg, itramuscular); 5 cm or greater. The pathology report come back showing this to be a ganglion cyst with hematoma. My thoughts are that we should change the 27339 to a 27347 (Excision of lesion of meniscus or capsule (eg, cyst, ganglion), knee
  6. Ganglion, right knee. M67.461 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2021 edition of ICD-10-CM M67.461 became effective on October 1, 2020. This is the American ICD-10-CM version of M67.461 - other international versions of ICD-10 M67.461 may differ
  7. http://thekneepainguru.com/ - Bakers Cysts and Knee Pain - Medical and Holistic Approach: Ask The Knee Pain GuruTreatment for a Baker's Cyst depends on the c..

About Knee Baker's Cyst Removal What is a Baker's Cyst? A Baker's cyst, also called a popliteal cyst, is a small collection of fluid in a cyst behind the knee joint. It's usually the result of a problem inside the knee joint, such as arthritis or a cartilage tear. When the knee produces too much fluid, it can pooch out the back o Watch Dr. Knight as he carefully removes a volar wrist ganglion cyst. He mobilizes and protects the radial artery and removed the large cyst down to the wris.. Tumors and cysts are two distinct entities. Cyst. A cyst is a sac that may be filled with air, fluid or other material. A cyst can form in any part of the body, including bones, organs and soft tissues. Most cysts are noncancerous (benign), but sometimes cancer can cause a cyst. Tumor. A tumor is any abnormal mass of tissue or swelling A case series for ganglion cyst of the cruciate ligament with MRI findings, clinical presentation, and management options along with review of literature is presented. Of 8663 consecutive patients referred for knee MR imaging, 31 were diagnosed with ganglion cysts of the cruciate ligaments, including 21 men and 10 women of ages 12 to 73 years (mean: 37) A Patient's Guide to Popliteal Cysts and Treatment Midlothian, VA . Introduction. A popliteal cyst, also called a Baker's cyst, is a soft, often painless bump that develops on the back of the knee.A cyst is usually nothing more than a bag of fluid. These cysts occur most often when the knee is damaged due to arthritis, gout, injury, or inflammation in the lining of the knee joint

Anterior cruciate ligament mucoid degeneration | ImageBaker's cyst on the leg - Stock Image - C011/0411

Ganglion Cyst Pain Relief, Treatment, Removal & Cur

• Cystic lesions are common in knee MRI and the commonest, the Baker's cyst, has an incidence of 38 %. • Synovial cysts, meniscal cysts, normal knee bursae and recesses have characteristic MR appearances. • Miscellaneous cyst-like lesions may require a more dedicated MR protocol for a correct diagnosis A ganglion cyst or a Bible cyst is a benign swelling or bulge that often appears around or on joints and tendons in the hand or foot. A ganglion manifests as a subcutaneous limp or nodule. The size can change in time and it can also disappear completely. [1 Our ganglion cyst treatment is 100% Natural, FDA Doctor Endorsed. It Relieves PAIN and Heals Quickly by Dissolving and Removing your ganglion cyst right from the comfort of your home. A Lot of people just like you have been cured with the G-Relief Capsules. Stops Pain, Heals Quickly. Take Action Now

Drainage of Huge Ganglion Cyst - YouTubeTumors, Ganglions & Cysts | Spartanburg Hand SurgeryFiguring Out a Complex Patient with an SI Joint CystCommon Intraosseous Cysts - Radsource

Ganglion cyst surgery is an outpatient procedure that removes both the balloon and the stalk of the cyst. This reduces the chance of the cyst recurring. However, there is still a small chance the cyst will return even after surgery Baker's cysts are fluid-filled sacs that form behind the knee. Baker's cysts are often harmless, but you should see a doctor if it is painful because it may indicate a more serious problem like an infection or a blood clot. Cysts are small, fluid-filled sacs that can appear anywhere on your body. These growths are called a Baker's cyst when. Baker's Cyst (Popliteal Cyst) Baker's cysts, also known as popliteal cysts, are one of the most common disorders in the knee. These fluid-filled cysts form a lump at the back of the knee that often causes stiffness and discomfort. The condition is named after the 19 th century surgeon who first described it, Dr. William Morrant Baker Subchondral bone cysts (SBCs) are sacs filled with fluid that form inside of joints such as knees, hips, and shoulders. The sac is usually primarily filled with hyaluronic acid. Hyaluronic acid is.