Arthrogryposis Multiplex Congenita (AMC) – Flashcards

"curved or hooked joints" Musculoskeletal disorder involving multiple joint contractures present at birth Description vs diagnosis Often accompanied by fibrous ankylosis

Classic AMC: hands, wrists, elbows, shoulders, hips, feet, knees affected Severe AMC: nearly every body joint involved including jaw and back Frequently contractures are accompanied by muscle weakness

hands, wrists, elbows, shoulders, hips, feet, knees affected

nearly every body joint involved including jaw and back

Wide spectrum of congenital deformities Basic classification: Only limb involvement Limb and trunk involvement Craniofacial or visceral involvement Severe central nervous system dysfunction At least 21 recognized forms of AMC Distal arthrogryposes- Syndromes that include AMC as set of symptoms Amyoplasia = primary form of AMC

Rare condition, affects 1-3 of every 10,000 births Affects races equally Males and females affected equally

Not entirely understood, many factors contribute It can be a component of conditions caused by environmental agents, single gene defects, chromosomal abnormalities, etc Abnormal nerve, muscle, and connective tissue development Possible neuropathic cause Lack of intrauterine movement Genetic factors Environmental factors

Born with multiple joint contractures in all limbs In most common form, amyoplasia, typical deformities are severe and symmetrical: Knee & elbow joints may appear thickened Muscles may be absent or incompletely formed If anterior horn cells in spinal cord are absent, may experience paralysis Skin- absent or diminished creases Intelligence normal Sensation intact UE & LE involved

Contractures Distal joints affected more than proximal Limitation of movement Limited jaw ROM Deformities/Malformations Craniofacial Spine Respiratory Limb Skin Cardiac Nervous system Muscle Connective tissue

Dx in utero via ultrasound Dx after birth when two or more joints in more than one limb are fixed from birth Thorough medical history and physical exam X-rays Additional tests blood test muscle biopsies imaging studies CT, MRI Differential Diagnosis

Physical activity limited due to orthopedic problems FM/GM skills Oral and speech development Dependence on others Social participation Walking ADLs

Tx team: pediatrician, neurologist, orthopedic surgeon, geneticist, speech therapist, physical therapist, occupational therapist.... Goal of tx: Improve function, not cosmesis Lower limb alignment and establishment of stability for ambulation Upper limb function for ADLs Therapy and bracing attempted first over surgical correction

Early AROM & PROM is key Focus on maintaining and increasing functional ROM and strength Splinting Serial casting Daily stretching/ PROM Adapted equipment Training for ADLs, school, play, and work performance Family education/Home programs Psychological adjustment support for child and family Alternative therapies: Aquatic therapy Hippotherapy

OT/PT and stretching may be harmful in some patients depending on dx Recurrence of deformities post stretching is common and surgery is often indicated Splinting combined with OT/PT preferable to continuous casting splints/casts may restrict movement Pre/Post- op precautions Airway management Anesthesia can be difficult secondary to vascular access restriction Intubation

Goal: Improve limb position and function Improvement can be made, however most patients will still have persistent muscular &/or joint limitation due to underlying condition Bony procedures/bony fusions Tendon transfers Muscle releases

No cure Prognosis varies -Depends on natural history -Depends on response to therapies Life span usually normal, however: -Lethal forms of AMC often cause miscarriage, stillbirth, or neonatal death secondary to malformation so severe, its impossible for child to live -Scoliosis may compromise respiratory function -50% pts with limb involvement and CNS dysfunction die within 1st year AMC disorders are non-progressive -With therapy and surgery, contractures frequently improve -Regression of gains made is common Independence in ambulation and function can be achieved in some cases