Periarticular Calcification
Periarticular means “around a joint.” The term describes the tissues and structures surrounding a joint, including tendons, ligaments, muscles, connective tissue, and other soft tissues. In people affected by Generalized Arterial Calcification of Infancy (GACI) and related disorders, periarticular tissues can sometimes be affected by abnormal calcification.
What Is Periarticular Calcification?
Periarticular calcification occurs when calcium-containing mineral deposits develop in the soft tissues surrounding a joint. This is different from calcium that is normally stored in bones and teeth. When abnormal calcification in joints or surrounding tissues occurs, it can contribute to stiffness, discomfort, and reduced range of motion.
These calcium deposits on joints and surrounding tissues may interfere with how freely a joint moves. The location, severity, and effects of calcification can vary from person to person.
How Is Periarticular Calcification Related to GACI?
GACI is a rare genetic disorder associated with abnormal calcification in the body. GACI Type 1 is part of the ENPP1 Deficiency disease spectrum, while GACI Type 2 is associated with ABCC6 Deficiency. Although GACI is best known for calcium deposits in the arteries, calcification can also affect other areas of the body, including the joints and soft tissues.
Both ENPP1 Deficiency and ABCC6 Deficiency are associated with low levels of inorganic pyrophosphate (PPi), a substance that normally helps prevent inappropriate mineralization of soft tissues. When PPi levels are too low, calcium and phosphate can accumulate where they normally would not, contributing to abnormal soft-tissue and joint calcification.
For example, joint calcification has been reported in infants with GACI Type 2 associated with ABCC6 Deficiency. In people with ENPP1 Deficiency, musculoskeletal complications can also occur alongside vascular and skeletal manifestations.
How Can Periarticular Calcification Affect Movement?
The effects depend on where the calcification develops and how extensive it becomes. Calcium deposits on joints or in surrounding tissues may contribute to:
- Joint stiffness
- Pain or discomfort
- Reduced flexibility
- Limited range of motion
- Difficulty with certain movements or activities
Brighter Hope Foundation notes that surgery has been used in at least one reported case to remove periarticular calcification in a person with GACI with the goal of improving joint range of motion and function.
Because GACI, ENPP1 Deficiency, and ABCC6 Deficiency can affect individuals differently, concerns about calcification in joints should be evaluated by the appropriate medical specialists as part of an individualized care plan.
Learn More About GACI and Related Conditions
Brighter Hope Foundation provides trusted information and resources for families, caregivers, and healthcare professionals seeking to better understand these rare calcification disorders.
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