What is Arthrogryposis (AMC)?

Arthrogryposis multiplex congenital (AMC) is the congenital joint contracture in two or more areas of the body. “Arthrogryposis” comes from Greek, meaning “curving of joints.” Children born with joint contractures have abnormal muscle tissue fibrosis, causing muscle shortening, and cannot perform active extension and flexion in the affected joint or joints.

Arthrogryposis is divided into amyoplasia, distal arthrogryposis, and syndromic. Amyoplasia is characterized by severe joint contractures and muscle weakness. Distal arthrogryposis mainly involves the hands and feet. Neurological or muscle disease forms of arthrogryposis are in the syndromic group. Those with arthrogryposis often have every joint affected. 84% of all limbs are involved; in 11%, only the legs are involved; in 4%, only the arms are involved. When affected, joints display typical symptoms.

The range of motion can differ between joints because of the different deviations. Contractures in the joints can result in delayed walking development in the first 5 years, but the severity of contractures does not necessarily predict eventual walking ability or inability. There are a few slightly more common diagnoses, such as pulmonary hypoplasia, cryptorchidism, congenital heart defects, tracheoesophageal fistulas, inguinal hernias, cleft palate, and eye abnormalities.

What Causes Arthrogryposis (AMC)

Any factor that curtails fetal movement may result in congenital contractures and arthrogryposis. However, its exact causes are unknown.

• Extrinsic factors: The malformations of arthrogryposis can be secondary to environmental factors such as decreased intrauterine movement, oligohydramnios (low volume or abnormal distribution of intrauterine fluid), and defects in the fetal blood supply.
• Intrinsic factors: Molecular, muscle- and connective tissue development disorders or neurological abnormalities.
• Molecular basis: More than 35 specific genetic disorders are associated with arthrogryposis. Most of those mutations are missense, which means the mutation results in different amino acids.
• Muscle and connective tissue development disorders: A loss of muscle mass with an imbalance of muscle power at the joint can lead to connective tissue abnormality, causing joint fixation and reduced fetal movement.
• Neurological abnormalities: Up to 80 per cent of the most severe forms of arthrogryposis cases are caused by neurological abnormalities, which can be either genetic or environmental.

Arthrogryposis (AMC) Diagnosis

Diagnosis can be made prenatally in approximately 50% of fetuses with arthrogryposis. Routine ultrasounds can display a lack of mobility and abnormal positions of the fetus. A child can be diagnosed with arthrogryposis via physical examination, confirmed by ultrasound, MRI, or muscle biopsy.

Arthrogryposis (AMC) Prognosis

Arthrogryposis is non-progressive, so with proper medical treatment, health can be stable or improved. Arthrogryposis cannot be cured, but with proper treatment, most children significantly improve their range of motion and ability to move their limbs, enabling full lives. Surgical intervention may also improve joint mobility and function.

Arthrogryposis (AMC)Treatment

Arthrogryposis treatment includes occupational therapy, physical therapy, splinting, and surgery. The goals of these treatments are increasing joint mobility, and muscle strength and the development of adaptive use patterns that allow for walking and independence with activities of daily living. Since arthrogryposis includes many different types, the treatment varies between patients depending on the symptoms. Surgical techniques may also be used.

Mobility for Arthrogryposis

Some with arthrogryposis have difficulty walking, requiring a power wheelchair. Quantum Rehab manufactures technologically-advanced power wheelchairs that meet the needs of those living with arthrogryposis. Quantum’s TRU-Balance 3 seating is adaptable to address individual seating needs, including contractures. Its drive controls can be mounted wherever needed for access by the user. These features and more allow Quantum to custom tailor a power chair to an individual’s arthrogryposis mobility needs.

Solution

Quantum Rehab power bases consist of a wide array of models, each incorporating various components to accommodate the comprehensive needs of individuals requiring a complex rehab product. The Quantum Edge 3, with industry-first 4.5 mph at iLevel, offers the most advanced power chair experience ever. Q6 Power Chair Series, which includes the Edge 3 and Q6 Edge 2.0, provide highly adjustable mid-wheel drive power bases.

The Q6 Edge 2.0 all accept our optional iLevel technology, which offers up to 12 inches of lift at 4.5 mph. The 4Front® is a quiet, more responsive front-wheel drive power chair that features automotive-grade suspension with unprecedented comfort and rides quality.