General Information Arthrogryposis is a nonprogressive conditions characterized by multiple joint contractures found throughout the body at birth. A contracture is the limitation of movement of a specific joint, in other words, a joint that does not have a full range of movement.
Causes The causes of arthrogryposis are varied and not entirely understood but are presumed to be multifactorial. In most cases, arthrogryposis multiplex congenita (AMC) is not a genetic condition. However, in approximately 30% of cases, a genetic cause can be identified. The major cause of arthrogryposis is fetal akinesia (ie, decreased fetal movements) due to fetal abnormalities (eg, neurogenic, muscle, or connective tissue abnormalities; mechanical limitations to movement) or maternal disorders (eg, infection, drugs, trauma, other maternal illnesses). Arthrogryposis occurs in about 1 in every 3,000 live births.
Clinical Manifestations Although joint contractures and associated clinical manifestations vary from case to case, several characteristics are common, including the following: Involved extremities are fusiform (cylindrical) in shape, with thin subcutaneous tissue and absent skin creases. Deformities are usually symmetric, and severity increases distally, with the hands and feet typically the most deformed. Joint rigidity may be present. The patient may have joint dislocation, especially the hips and, occasionally, the knees. Atrophy may be present, and muscles or muscle groups may be absent. Sensation is usually intact, although deep tendon reflexes may be diminished or absent. Distal joints are affected more frequently than proximal joints. Observe flexion versus extension, limitation of movement (fixed vs passive vs active), and characteristic position at rest; note the severity of all limitations. Range of motion in the jaw is frequently limited.
Treatment Early in life, patients with joint abnormalities are typically treated with stretching exercises and splinting to improve motion. Splinting and occupational/hand therapy are the treatment of choice for patients with mild to moderate deformity.
Some patients may have persistent functional difficulties despite a rigorous physical therapy regimen. In certain situations, surgery is recommended to improve limb position and function. These procedures may include muscle releases, tendon transfers, or bony fusions. Posterior elbow release and triceps lengthenings, for example, may be performed after two years of age in improve elbow flexion. Tendon transfers to restore active elbow flexion may be considered in some children after five to seven years of age. Wrist flexion deformities may be treated with tendon transfers and/or bony procedures to change the alignment of the wrist. Finally, surgical procedures to rearrange the skin between the thumb and index finger may benefit selected patients with tightness between the thumb and palm. While improvements can be made, most patients will have persistent muscular and/or joint limitations due to the underlying condition.
Helpful Websites Arthrogryposis Multiplex Congenita Support, Inc
Research Hall, J. (1997). Arthrogryposis multiplex congenita: etiology, genetics, classification, diagnostic approach, and general aspects. Journal of Pediatric Orthopaedics , 159-166.