OVERVIEW: What every practitioner needs to know

Are you sure your patient has arthrogryposis multiplex congenita? What are the typical findings for this disease?

The diagnosis of arthrogryposis multiplex congenita or amyoplasia usually is made at birth. It may be suspected in utero, as it can be associated with diminished fetal movement during pregnancy, low amniotic fluid levels, or potential joint contractures seen on ultrasonography. The most common findings related to this disease are multiple joint contractures of both upper and lower limbs that occur in a relatively symmetrical nature.

Secondary findings are joint dislocations, particularly the hip, and feet in a position similar to clubfoot. Approximately 20% of individuals have abdominal abnormalities, including bowel atresia. Most patients have normal intelligence.

To be sure that one has the correct diagnosis of arthrogryposis multiplex congenita, considering the wide number of abnormalities that may be associated with joint contractures, after birth it is important to have an evaluation by a pediatric neurologist and a geneticist. It is estimated that up to 50% of children with clinical signs of joint contractures may have an alternative specific diagnosis.

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What other disease/condition shares some of these symptoms?

The term arthrogryposis is a descriptive term for congenital contractures, that is, joint contractures that are present at birth. Multiple processes can cause joint contractures in infants. Some joint contractures are isolated to one joint or extremity. An example is an isolated congenital clubfoot.

When joint contractures affect two or more extremities, the term arthrogryposis is frequently used to describe the findings; however, this clinical finding is characteristic of multiple disorders.

One major distinguishing feature of these disorders is normal neurologic function. A normal neurologic examination is suggestive of arthrogryposis multiplex congenita or amyoplasia. If the neurologic examination is abnormal, the central or peripheral nervous system and the muscles need to be examined to determine a primary diagnosis for the joint contractures that is distinct from amyoplasia.

What caused this disease to develop at this time?

Arthrogryposis congenita multiplex or amyoplasia occurs in approximately 1 in 3000 live births for unknown reasons. There has been an increased prevalence in twins and in situations that lead to decreased limb movement in utero, such as intrauterine crowding, a decreased amniotic fluid level (oligohydramnios), and uterine shape abnormalities.

It is important to distinguish amyoplasia from arthrogryposis or joint contractures secondary to other issues (connective tissue disoder, central nervous system abnormality, muscle disorders) and to distinguish amyoplasia from diseases of joint contracture that are confined to one limb or to one area of an extremity (distal arthrogryposis).

Multiple diseases with isolated joint contractures have been associated with specific genes and have a known inheritance pattern. Therefore, it is important to make a specific diagnosis in each child if possible.

What laboratory studies should you request to help confirm the diagnosis? How should you interpret the results?

There are no laboratory tests that are diagnostic for arthrogryposis multiplex congenita or amyoplasia. Laboratory tests may be performed to rule out other causes of joint contracture and to ensure the true diagnosis of amyoplasia.

Would imaging studies be helpful? If so, which ones?

Radiographic imaging studies are important to distinguish joint dislocations, in particular dislocation of the hips.

Confirming the diagnosis

During pregnancy, ultrasonographic abnormalities and decreased fetal movements can suggest the possibility of a fetus who has some form of arthrogryposis or joint contracture. This usually occurs in the second or third trimester. Consultations with pediatricians, obstetricians/gynecologists, and high-risk pregnancy physicians may aid in targeting specific genetic testing during pregnancy if it is desired. Prenatal counseling may be suggested; however, it is of limited use if a specific diagnosis is not known.

After birth, consultation with pediatricians, neurologists, and geneticists is essential for a specific diagnosis. If the diagnosis proves to be other than amyoplasia, the inheritance, natural history, treatment guidelines, and prognosis may vary.

If you are able to confirm that the patient has arthrogryposis multiplex congenita, what treatment should be initiated?

When a child has classic arthrogryposis mutliplex congenita or amyoplasia, initial treatment should include the assembly of a multidisciplinary team including a pediatrician, a physical therapist, an occupational therapist, a pediatric physiatrist, and an orthopedic surgeon.

Treatment should be initiated within the first few months of life with the specific goals of joint mobilization, splinting for improved position and enhanced function, and physical and occupational therapy to maintain joint mobility and to enhance muscular strength.

Longer term treatment goals include increased joint mobility, increased muscular strength, and adaptive bracing/aids for maximizing independence, for example, walking and daily tasks of eating and performing a toilet.

Conservative management includes bracing and adaptive devices to maximize independence and activities of daily living. More aggressive management includes surgical intervention to releasejoint contractures and soft tissue and bone surgery for functional positioning of extremities (hand, foot) for improvement in walking and functional independence.

What are the adverse effects associated with each treatment option?

There are few adverse effects in regard to conservative management of arthrogryposis multiplex congenita joint contractures. Surgical intervention to maximize independence needs to be accompanied with a clear understanding of the purpose of the intervention, since surgery in itself can produce some scar tissue and stiffness over and above the disease itself.

Surgical intervention applied appropriately has proved to be remarkably successful in the functional independence of affected individuals. Surgical intervention does maintain the usual complication risk of nerve and artery injury, failure of bone to heal appropriately, and the limited gains or expectations of the patient.

What are the possible outcomes of arthrogryposis multiplex congenita?

The combined treatment options of conservative and surgical management have maximized the ambulatory and functional potential of affected individuals with arthrogryposis multiplex congenita. Although blinded randomized studies have not been done, case study populations have provided significant evidence that the life of someone with amyoplasia is significantly enhanced through surgical managment. Without such management, functional and ambulatory skills are not maximized and overall outcome of the disease is poor.

What causes this disease and how frequent is it?

Arthrogryposis multiplex congenita is a sporadic disorder occurring in approximately 1 in 3000 births. There is no known genetic transmission, no known infectious properties, and no known predisposing elements related to the disorder.

How do these pathogens/genes/exposures cause the disease?

There are no pathogens/genes/exposures that cause arthrogryposis multiplex congenita. Screening for alternative specific diseases with joint contractures with the aid of an experienced geneticist and neurologist may involve specific genes or pathogens.

What complications might you expect from the disease or treatment of the disease?

Complications of conservative management can include skin issues with forced bracing and/or manipulation in physical therapy. With aggressive therapy, individuals may suffer from stress fractures of the involved extremities. Surgical intervention, although seemingly necessary to maximize independence, may be complicated by nerve or artery injury, failure of bony union, and unrealistic expectations regarding surgical outcomes.

How can arthrogryposis multiplex congenita be prevented?

At the current time, there is no known way to prevent arthrogryposis multiplex congenita. It occurs in approximately 1in 3000 births and is associated with interuterine crowding and low amniotic fluid volume, but there are no preventive measures. Genetic characteristics are unknown.

What is the evidence?

Bamshad, M, Van Heest, AE, Pleasure, D. “Arthrogryposis: a review and update”. J Bone Joint Surg. vol. 91. 2009. pp. 40-6. (An excellent summary of amyoplasia and the distal arthrogryposes.)

Beavan, WP, Hall, JG, Bamshad, M. “Arthrogryposis multiplex congenita (amyoplasia): an orthopaedic perspective”. J Pediatr Orthop. vol. 27. 2007. pp. 594-600. (Excellent summary of joint contracture issues from an orthopedic perspective.)

Fassier, A, Wicart, P, Dubousset, J. “Arthrogryposis multiplex congenita. Long-term follow-up from birth to skeletal maturity”. J Child Orthop. vol. 3. 2009. pp. 383-90. (Excellent retrospective work on 11 children followed extensively.)

Navti, OB, Kinning, E, Vasudevan, P. “Review of perinatal management of arthrogryposis at a large UK teaching hospital service in a multiethnic population”. Prenat Diagn. vol. 30. 2010. pp. 49-56. (Good review of perinatal issues.)

Ongoing controversies regarding etiology, diagnosis, treatment

Ongoing research relates to seeking an underlying cause for amyoplasia and future replacement of muscle tissue through stem cell work for the production of more muscle mass as a treatment option.