Arthrogryposis: Understanding Congenital Joint Contractures
Arthrogryposis refers to a broad group of disorders characterized by multiple congenital joint contractures, where two or more joints are fixed or stiffened from birth. This condition can affect one or more limbs and varies in severity, with some children experiencing only mild joint stiffness, while others may have more extensive deformities that significantly affect mobility and function.
How Common It Is and Who Gets It? (Epidemiology)
Arthrogryposis affects approximately 1 in 3,000 live births and is associated with over 300 different underlying conditions. It is often seen in both boys and girls, with a slight predominance in males. The condition is present at birth and may be diagnosed early in infancy, although its severity and the number of affected joints can vary widely.
Why It Happens – Causes (Etiology and Pathophysiology)
Arthrogryposis is primarily caused by the lack of normal fetal movement, which can result from a variety of factors:
- Neurogenic causes (90% of cases): Issues such as abnormal nerve function or muscle development during fetal growth.
- Myopathic causes (10% of cases): Conditions that affect the muscles directly, impairing their ability to move the joints.
- Autoimmune-related causes: In some cases, antibodies produced by the mother, such as in myasthenia gravis, can block the fetal acetylcholine receptors, leading to temporary muscle weakness and joint contractures.
The exact cause may vary, and in many cases, a genetic mutation or abnormality can be identified, though the specific cause remains unknown for many individuals.
How the Body Part Normally Works? (Relevant Anatomy)
The body’s joints are held together by ligaments, tendons, and muscles that allow for movement and flexibility. In arthrogryposis, several joints become stiff or fixed in place due to abnormal fetal development. Key affected areas are the shoulders, elbows, wrists, hips, knees, and feet. The contractures restrict normal joint motion, and the muscles around these joints may be underdeveloped or weak, further impairing movement.
What You Might Feel – Symptoms (Clinical Presentation)
Symptoms of arthrogryposis vary based on the severity and joints involved. Common symptoms include:
- Joint stiffness and limited movement in multiple limbs.
- Contractures in the shoulders, elbows, wrists, hips, knees, and feet.
- Clubfoot, which causes the feet to turn inward.
- Difficulty performing routine tasks due to reduced range of motion, such as walking, reaching, or using the hands.
- Facial abnormalities in some cases, such as micrognathia (small jaw) or a limited mouth opening.
How Doctors Find the Problem? (Diagnosis and Imaging)
Diagnosis is typically made based on physical examination:
- Inspection and palpation: The doctor will examine the limbs for signs of joint contractures, stiffness, and deformity.
- Imaging: X-rays and MRIs may be used to assess the extent of joint contractures and any associated bone deformities.
- Genetic testing: Used to identify specific mutations or conditions associated with arthrogryposis, which can help guide treatment.
- Muscle biopsy: In some cases, a biopsy may be performed to assess muscle tissue.
Classification
Arthrogryposis can be classified based on the type and severity of the joint involvement:
- Type I: Single localized deformity (e.g., forearm pronation).
- Type II: Full expression of the condition, with multiple joint contractures and muscle involvement.
- Type III: Full expression with additional involvement of non-musculoskeletal systems and possible polydactyly (extra fingers or toes).
Other Problems That Can Feel Similar (Differential Diagnosis)
Conditions that can mimic arthrogryposis include:
- Cerebral palsy: While cerebral palsy also involves motor dysfunction and joint stiffness, it is caused by brain injury rather than a congenital genetic defect.
- Neurological disorders: Certain neurological conditions can cause joint stiffness and muscle weakness that may resemble arthrogryposis.
Treatment Options
Non-Surgical Care
Early intervention is key to managing symptoms and improving function. Common non-surgical treatments include:
- Physical and occupational therapy: Focuses on improving mobility, strength, and joint function.
- Splinting and casting: Helps position joints correctly to prevent further contractures and to improve movement.
- Orthotics: Braces or foot supports may be used to assist with mobility and maintain joint alignment.
- Massage therapy: May help reduce stiffness and improve joint flexibility.
Surgical Care
Surgical intervention is considered for more severe cases where non-surgical measures are insufficient. Surgical procedures may include:
- Soft tissue releases: To relieve joint contractures and improve mobility.
- Osteotomies: To correct bone deformities and improve joint function.
- Tendon transfers: In cases where muscle weakness is a significant issue, tendons from other parts of the body may be relocated to improve function.
- Joint releases: To correct severe joint deformities and improve function.
Recovery and What to Expect After Treatment
- Non-surgical recovery: The goal of therapy is to improve range of motion and strength. This process can take time, with many children requiring consistent therapy throughout childhood.
- Surgical recovery: Post-surgical recovery often involves physical therapy and rehabilitation to regain movement. Full recovery depends on the extent of the surgery and the severity of the condition.
Possible Risks or Side Effects (Complications)
- Nonunion: If bones do not heal properly after surgery.
- Infection: A risk with any surgery.
- Joint stiffness: Even after treatment, some patients may continue to experience limited range of motion.
- Muscle weakness: Following surgery or casting, some patients may need extensive therapy to rebuild strength.
Long-Term Outlook (Prognosis)
The prognosis varies depending on the severity of arthrogryposis and the specific joints affected. With early treatment, many individuals can achieve functional independence, although some may require long-term therapy or assistance with daily activities. In severe cases, individuals may experience persistent disability or require surgical intervention throughout their life.
Out-of-Pocket Costs
Medicare
CPT Code 27360 – Lengthening or Shortening of Single Tendon, Leg, Open: $213.96
Medicare Part B covers 80% of the approved cost for this procedure once your annual deductible has been met, leaving you responsible for the remaining 20%. Supplemental Insurance plans such as Medigap, AARP, or Blue Cross Blue Shield typically cover the remaining 20%, reducing or eliminating out-of-pocket expenses for Medicare-approved procedures. These plans work in coordination with Medicare to fill the coverage gap.
If you have Secondary Insurance such as TRICARE, an Employer-Based Plan, or Veterans Health Administration coverage, it will act as a secondary payer. These plans usually cover any remaining balance, including coinsurance or small deductibles, which typically range from $100 to $300 depending on your plan and provider network.
Workers’ Compensation
If your tendon lengthening or shortening is required due to a work-related injury, Workers’ Compensation will cover all medical expenses, including surgery and rehabilitation. You will not have any out-of-pocket expenses, as the employer’s insurance carrier directly pays for all approved treatments.
No-Fault Insurance
If your tendon surgery is related to an automobile accident, No-Fault Insurance will typically cover the full cost of your treatment, including surgery and postoperative care. The only possible out-of-pocket cost may be a small deductible or co-payment depending on your policy.
Example
Jack Robinson required tendon lengthening (CPT 27360) after a leg injury to improve function. His estimated Medicare out-of-pocket cost was $213.96. Since Jack had supplemental insurance through AARP Medigap, his remaining balance was fully covered, leaving him with no out-of-pocket expenses for the procedure.
Frequently Asked Questions (FAQ)
Q. What is arthrogryposis?
A. Arthrogryposis is a condition where a child is born with multiple joint contractures, meaning some joints do not move as much as normal and may be stuck in one position.
Q. What causes arthrogryposis?
A. Arthrogryposis can result from a variety of factors including decreased fetal movement, abnormalities of muscles, connective tissues, nerves, or the central nervous system.
Q. Is arthrogryposis genetic?
A. Arthrogryposis can sometimes be genetic, but most cases are sporadic with no clear inheritance pattern.
Q. How common is arthrogryposis?
A. Arthrogryposis occurs in approximately 1 in 3,000 live births.
Q. What joints are most commonly affected by arthrogryposis?
A. The joints most commonly affected are the shoulders, elbows, wrists, hips, knees, and feet.
Q. Are there different types of arthrogryposis?
A. Yes, there are different types, with amyoplasia being the most common form.
Q. What is amyoplasia?
A. Amyoplasia is the most common type of arthrogryposis characterized by severe joint contractures and muscle weakness.
Q. How is arthrogryposis diagnosed?
A. Arthrogryposis is diagnosed through clinical evaluation and imaging studies such as X-rays, and sometimes genetic testing is performed.
Q. What treatments are available for arthrogryposis?
A. Treatments include physical therapy, occupational therapy, splinting, serial casting, and surgical interventions when necessary.
Q. What are the goals of treating arthrogryposis?
A. The goals are to improve joint mobility and strength, enhance function, and enable the child to perform daily activities independently.
Q. Can surgery help in arthrogryposis?
A. Yes, surgery can help by releasing joint contractures, repositioning bones, and improving overall function.
Q. What types of surgeries might be performed for arthrogryposis?
A. Surgeries may include tendon releases, tendon transfers, joint releases, osteotomies, or other corrective procedures.
Q. Is early treatment important in arthrogryposis?
A. Yes, early treatment is important to maximize joint mobility and function as the child grows.
Q. Can children with arthrogryposis lead independent lives?
A. Many children with arthrogryposis can lead independent lives with appropriate treatment and therapy.
Q. Is physical therapy important for children with arthrogryposis?
A. Physical therapy is critical to improve joint motion, muscle strength, and functional ability.
Q. Can orthotics be used in arthrogryposis treatment?
A. Yes, orthotics such as braces or splints are often used to maintain joint positions and assist in mobility.
Q. Is recurrence of joint contractures possible after treatment?
A. Yes, recurrence of joint contractures is possible, especially during periods of rapid growth.
Summary and Takeaway
Arthrogryposis is a congenital condition marked by joint contractures, which can affect multiple joints in the body. While early treatment with therapy and splinting can greatly improve mobility and function, surgical intervention may be required in more severe cases. The prognosis is generally good with appropriate management, although some patients may require long-term support.
Clinical Insight & Recent Findings
A 2025 study published in The American Journal of Medical Genetics introduced a new international framework to better describe and classify the features of Arthrogryposis Multiplex Congenita (AMC).
Led by McGill University and Shriners Hospitals for Children, the team created standardized terminology within the Human Phenotype Ontology (HPO)—a universal language for medical data—to accurately capture joint contractures, the hallmark of AMC. The project added 37 new terms and restructured existing ones to represent specific types of joint involvement, such as shoulder, hip, knee, and wrist contractures.
This refinement improved the ability to identify, compare, and research AMC cases worldwide. By promoting consistent clinical descriptions and supporting genetic data integration, the study provides a foundation for improved diagnosis, data sharing, and research collaboration across countries. (“Study creating a standardized system for describing arthrogryposis features – see PubMed.”)
Who Performs This Treatment? (Specialists and Team Involved)
Arthrogryposis treatment often involves a multidisciplinary team, including orthopedic surgeons, physical therapists, occupational therapists, and genetic counselors.
When to See a Specialist?
Consult a specialist if your child experiences difficulty moving joints or has abnormal posture or limb positioning from birth.
When to Go to the Emergency Room?
Go to the emergency room if there is severe pain, swelling, or if an injury occurs that worsens joint mobility.
What Recovery Really Looks Like?
Recovery involves regular physical therapy to improve joint mobility and muscle strength. In severe cases, surgery may be required, and recovery time may vary depending on the procedure.
What Happens If You Ignore It?
If left untreated, arthrogryposis can lead to permanent joint deformities and functional limitations. Early intervention is key to improving long-term outcomes.
How to Prevent It?
Prevention is not possible for congenital forms of arthrogryposis, but early diagnosis and intervention can help improve function and mobility.
Nutrition and Bone or Joint Health
A diet rich in calcium, vitamin D, and protein supports bone and joint health, which is crucial for individuals with arthrogryposis.
Activity and Lifestyle Modifications
Encourage low-impact activities that promote flexibility and strength. Avoid high-stress activities that could exacerbate joint stiffness or deformity.
Dr. Mo Athar
