What is Arthrogryposis

TL;DR: Arthrogryposis, or Arthrogryposis Multiplex Congenita (AMC), is a condition characterized by multiple joint contractures present at birth that limit the range of motion in various parts of the body. It typically results from fetal akinesia (lack of movement) during development, which leads to muscle weakness and the development of fibrous tissue around the joints.

What is Arthrogryposis and how does it affect the body?

Arthrogryposis is an umbrella term rather than a single diagnosis, referring to a group of conditions involving congenital joint contractures. Because joint movement is essential for normal musculoskeletal development in the womb, a lack of movement—often caused by issues in the nervous or muscular systems—results in the stiffening of joints. While the primary presentation involves the skeletal system and muscular system, the condition can also involve the nervous system, respiratory system, digestive system, and urinary system depending on the specific underlying cause.

What are the primary symptoms and physical features?

The clinical presentation of Arthrogryposis varies significantly between individuals. At DiseaseMaps.org, 383 members have shared their experiences, highlighting the diverse nature of these symptoms. Common physical features and associated issues include:

• Joint contractures: Typically affecting the hands, wrists, elbows, shoulders, hips, and feet (e.g., clubfoot).


• Muscle weakness: Often generalized, contributing to the limitation of movement.


• Skeletal involvement: Scoliosis (curvature of the spine) is frequently observed, along with chronic back, shoulder, and arm pain.


• Distinctive facial features: Conditions like "whistling face" (Freeman-Sheldon syndrome) are sometimes associated.


• Hand abnormalities: Camptodactyly (bent fingers) and clasped thumbs.

How common is Arthrogryposis?

Arthrogryposis is considered a rare condition. The most common form, Amyoplasia, has an estimated incidence of approximately 1 in 3,000 to 1 in 5,000 live births. Because it is an umbrella term, the prevalence of the broader spectrum of Arthrogryposis can be difficult to quantify precisely, as it encompasses over 400 different genetic or environmental conditions that cause joint contractures.

What causes this condition?

The underlying mechanism of Arthrogryposis is fetal akinesia. During gestation, if a fetus does not move sufficiently due to neurological, muscular, or connective tissue deficits, the joints begin to lock in place. This can be triggered by genetic mutations, maternal illness, uterine crowding, or restricted space in the womb. Unlike some developmental conditions, Arthrogryposis is not always hereditary; in many cases, it occurs sporadically without a family history.

How is it differentiated from other conditions?

What differentiates Arthrogryposis from other musculoskeletal disorders is the timing and nature of the contractures. While other conditions might cause joint stiffness later in life, the hallmark of Arthrogryposis is that the joint limitations are present at birth (congenital). Clinicians distinguish it from similar conditions by evaluating whether the primary issue is neurological (e.g., nerve damage), muscular (e.g., myopathy), or connective tissue-based.

Next steps

• Consult with a pediatric orthopedic surgeon or a geneticist to determine the specific subtype of Arthrogryposis.


• Engage with physical and occupational therapists early to maximize joint range of motion and functional independence.


• Connect with the 383 members of the DiseaseMaps.org community to share experiences and learn about coping strategies.


• Maintain regular monitoring for secondary complications like scoliosis or respiratory health issues.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Arthrogryposis Multiplex Congenita.


• Orphanet: Portal for rare diseases and orphan drugs (Orpha.net).


• OMIM (Online Mendelian Inheritance in Man): Database of human genes and genetic disorders.


• Arthrogryposis Group: Support and information for patients and families.