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Disease Profile

Synovial Chondromatosis

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Synovial osteochondromatosis


Musculoskeletal Diseases


Synovial chondromatosis is a type of non-cancerous tumor that arises in the lining of a joint. The knee is most commonly affected, however it can affect any joint. The tumors begin as small nodules of cartilage. These nodules can separate and become loose within the joint.[1] Some tumors may be no larger than a grain of rice.[2] Synovial chondromatosis most commonly occurs in adults ages 20 to 50. Signs and symptoms may include pain, swelling, a decreased range of motion, and locking of the joint.[1][2] The exact underlying cause of the condition is unknown.[1] Treatment may involve surgery to remove the tumor. Recurrence of the condition is common.[1]


The exact underlying cause of synovial chondromatosis is unknown.[3][4] Some research suggests that trauma may play a role in its development because the condition primarily occurs in weight-bearing joints. Infection has also been considered as a contributing factor.[4] The condition is not inherited.[3]

Synovial chondromatosis can reportedly occur as either a primary or secondary form. Primary synovial chondromatosis, which is more rare, occurs spontaneously and does not appear to relate to any pre-existing conditions. Secondary synovial chondromatosis is the more common form and often occurs when there is pre-existent osteoarthritis, rheumatoid arthritis, osteonecrosis, osteochondritis dissecans, neuropathic osteoarthropathy (which often occurs in diabetic individuals), tuberculosis, or osteochondral fractures (torn cartilage covering the end of a bone in a joint) in the affected individual.[5]


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

      In-Depth Information

      • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
      • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Synovial Chondromatosis. Click on the link to view a sample search on this topic.


        1. Synovial chondromatosis. Children's Hospital Boston. https://www.childrenshospital.org/az/Site1034/mainpageS1034P1.html. Accessed 5/18/2011.
        2. Joint tumors. Merck Manual. https://www.merckmanuals.com/home/sec05/ch063/ch063c.html?qt=synovial%20chondromatosis&alt=sh. Accessed 5/18/2011.
        3. Synovial Chondromatosis. American Academy of Orthopaedic Surgeons. May 2011; https://orthoinfo.aaos.org/topic.cfm?topic=A00602. Accessed 6/24/2013.
        4. Synovial chondromatosis. Boston Children's Hospital. 2011; https://www.childrenshospital.org/az/Site1034/mainpageS1034P0.html. Accessed 6/24/2013.
        5. Nicolai B Baecher. Synovial Chondromatosis. Medscape Reference. August 8, 2012; https://emedicine.medscape.com/article/1254671-overview. Accessed 6/24/2013.

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