Arthogryposis Multiplex Congenita

Question 1

definition of AMC

Answer 1

A nonprogressive neuromuscular disorder present at birth and characterized by multiple joint contractures and muscle weakness

Mild cases involve only 2 joints while more severe cases may involve major joints in the extremities, as well as the spine and TMJ. The joints involved present with severe ROM limitations with very few degrees of movement to no available movement.

Question 2

etiology

Answer 2

Unknown; although the principal cause of AMC is believed to be decreased fetal movements (akinesia) caused by maternal or fetal abnormalities

theories:

• musculoskeletal/neuromuscular
• neurological: degeneration of anterior horn cells?
• connective tissue
• genetic link

Question 3

links to AMC

Answer 3

• maternal fever, maternal viral infections
• vascular compromise between mom and fetus
• septum in uterus
• decreased amnionic fluid

Question 4

diagnosis

Answer 4

NO prenatal diagnostic test

abnormal positioning may be detected by ultrasound

Question 5

classical presentations

Answer 5

1. extended UE and flexed LE

2. flexed UE and extended LE

Question 6

clinical features

Answer 6

• Joint deformity of the extremities
• no creases on joints
• Joints are usually affected in a symmetrical pattern in the extremities with greater distal than proximal involvement; rigid joints
• deep tendon reflexes are absent or reduced

***sensation is INTACT
normal intelligence and speech

Question 7

surgeries

Answer 7

LE

• early (first 2 yrs)
• for knee contractors, club floot

UE

• later, possibly grade school
• for optimizing function
• tendon transfers

Question 8

OT goals

Answer 8

• Early PROM to support active movement and prevent further muscle atrophy
• Promote independence in self-care, play, and fine motor skills through use of adaptive equipment
• Maximize participation at home and in school and community environments

Question 9

Treatment

Answer 9

• PROM exercises – best if started in the first year of life and before 3 years of age
• Positioning to decrease deformity and increase function
 Splinting and serial casting as needed to increase joint ROM to improve hand function
• Assist in determining the need for orthotics and assistive devices (Equipment needs to be as lightweight as possible to facilitate use and increase compliance)
• Facilitate normal movement against gravity and postural reactions in trunk
• Promote functional hand use and innovative ways to hold utensils and writing implements
• Adapt clothing to increase independence (ie. velcro versus buttons)
• Promote weightbearing in to bilateral LE to reduce possible hip dislocation and promote strengthening needed for ambulation
• Maximize opportunities for cognitive and social development

Question 10

Precautions and Contraindications:

Answer 10

• Progress is slow and requires patience and persistence
• PROM – stretch only to the end range and then maintain stretch with cast or splint
• Forceful aggressive stretching of a rigid joint can result in damage to the joint capsule and surrounding soft tissue
• Monitor PROM and stretching activities due to fragile bone structure

Question 11

Concerns for Older Children with AMC:

Answer 11

• May develop secondary problems related to overuse of functional muscles or joints.
 Arthritis
 Carpal tunnel
 Tendonitis