Arthrogryposis: Definition, Symptoms, Causes, Diagnosis and Treatment

It is the development of non-progressive contractures that affect one or more areas of the body before birth (bad congenital formation).

In general, it is a condition in which a joint is permanently fixed in a bent (bent) or straightened (extended) position, totally or partially restricting the movement of that bodily extremity.

When Arthrogryposis affects two or more different areas of the body, it is called Multiple Congenital Arthrogryposis .

The symptoms of this condition are present from the gestation period of the fetus because it is a congenital anomaly. However, specific symptoms and physical findings can differ greatly in the range and severity of one person to another.

In most cases, affected babies have contractures of several joints, usually the legs and arms are most affected.

The joints of the shoulders, elbows, knees, wrists, ankles, fingers, toes, and hips are also commonly affected.

The jaw and back may also be affected in people with multiple congenital arthrogryposis.

In most cases, this genetic disorder affects more than 400 different joints of the body causing isolated or multiple contractures and the severity of these disorders varies drastically.

Signs and symptoms

The most common universal symptom is limited or absent movement around small and large joints (contractures).

The muscles of the affected limbs may be underdeveloped ( hypoplastic ), which results in a tubular limb with a soft, pasty feel. Soft tissue bands can form on the affected joints.

In addition to joint abnormalities, they may also have abnormally thin and fragile long bones in the arms and legs, as well as cleft palate.

In men, the testicles may not descend to the scrotum ( cryptorchidism ). Intelligence may or may not be affected. Approximately one third of people with Arthrogryposis may have structural or functional abnormalities of the central nervous system.

The additional symptoms associated with this anomaly are related to the underlying disorder that causes the condition in each individual.

Two of the most common forms of arthrogryposis are amypialasia and a group of genetic disorders called distal arthrogryposis.

Amioplasia is the most common form of arthrogryposis and is a disorder characterized by multiple contractures of the joints.

The shoulders can be turned internally and stretched inward (adducted), the elbows generally extend and the wrists generally flex.

In most affected people, the fingers are flexed and rigid.

Although in most reports, the distal joints (that is, joints farther from the center of the body) are often more affected, the shoulders and hips (which are proximal joints) often have significant contractures.

Affected people usually have severe clubfoot and some affected people may have dislocated hips.

In some cases, you can find a birthmark on the face known as “stork mark”.

Individuals with amioplasia usually have normal intelligence, however, approximately 10% of people with this type of condition have abdominal abnormalities such as gastroschisis or intestinal atresia.

Another 10% have distended, squashed or missing toes. Amioplasia seems to be sporadic and non-recurrent in families.

In contrast, distal arthrogryposis is a specific subgroup and is characterized by multiple congenital contractures.

Common symptoms include contractures of two or more areas of the body, less involvement of the proximal joints (those closer to the center of the body) and highly variable expressivity, which means that specific symptoms vary widely even among individuals with the same disorder

At least 10 different forms of distal arthrogryposis have been identified, including Freeman-Sheldon syndrome, Gordon syndrome, trismus-pseudocamptodactyly syndrome, multiple pterygium syndrome, and Sheldon-Hall syndrome.

Causes of Arthrogryposis

It can occur as part of certain disorders in a single gene that can be inherited as autosomal recessive, autosomal dominant or X-linked traits.

It can also appear as part of chromosomal disorders (for example, trisomy 18, many microdeletions and micro-duplications).

In addition there are some cases where abnormalities or disorders are associated with inadequate development of the central nervous system or the peripheral nervous system or as part of intrinsic muscle disorders.

These disorders can be genetic or they can occur due to environmental factors.

It is believed that the primary underlying mechanism that causes congenital contractures is the decrease in fetal movement during development.

Joints begin to develop in a fetus around five or six weeks of pregnancy. Movement is essential for the proper progress of the fetal joints.

The lack of movement causes excessive tissue connected around the joints, which can cause it to be fixed and / or limit its movement.

In theory, any factor that decreases or restricts fetal movement can cause congenital contractures. Such factors would include fetal overcrowding (where there is not enough room for the fetus to move) as when there are multiple births or uterine structural abnormalities.

Restricted fetal movement can also occur secondarily to maternal disorders, which include viral infections, drug use, trauma or other maternal diseases.

Low levels of amniotic fluid around the fetus ( oligohydramnios ) have also been linked to decreased fetal movement.

Central and peripheral nervous system disorders associated with Arthrogryposis include a condition in which the brain and spinal cord do not allow them to close before birth (meningomyelocele).

Spinal muscular atrophies and disorders in which there is incomplete development of certain portions of the brain (for example, anencephaly, hydranencephaly or holoprosencephaly   develop due to multiple factors, including genetic and environmental factors (multifactorial inheritance).

Diagnosis

The diagnosis of Arthrogryposis is based on the identification of characteristic symptoms (for example, multiple congenital contractures), a detailed history of the patient and a thorough clinical evaluation.

Certain tests may be necessary to determine the underlying cause, including nerve conduction, electromyography, and muscle biopsy, which can help diagnose neuropathic or myopathic disorders.

Treatment for Arthrogryposis

Standard physical therapy, which can improve joint movement and prevent muscle atrophy in the neonatal period, is beneficial.

Gentle manipulation of the joints and stretching exercises can also be beneficial. Removable splints for knees and feet that allow regular muscle movement and exercise are also recommended.

In some cases, surgery may be necessary to achieve better positioning and increase the range of motion in certain joints, especially in the ankles, knees, hips, elbows or wrists.

In rare cases, tendon transfers have been made to improve muscle function. Tendons are the tissue through which the muscle joins the bone.

Genetic counseling can be beneficial for the people affected and their families. Another treatment is symptomatic and supportive.