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What is Arthrogryposis Multiplex Congenita (AMC)?

Arthrogryposis Multiplex Congenita (AMC) is a descriptive term used to describe over 300 conditions that cause multiple curved joints in areas of the body at birth.

AMC is not a specific diagnosis but rather a clinical finding of permanent shortening of joints also referred to as non-progressive congenital contractures.

In the UK alone over 260 babies are born with AMC each year, that's one in every 3,000*

Symptoms of Arthrogryposis Multiplex Congenita (AMC) vary drastically from person to person particularly as there are over 300 types of conditions that are covered by the descriptive term Arthrogryposis however the commonality being stiff joints and muscle weakness.

The areas that are most likely to have lack of movement are the shoulders, elbows, wrists, hands, hips, knees and feet. AMC is non-progressive meaning that the lack of movement, does not get worse as time goes by however, it is recommended that people affected seek advice to potentially prevent further impediments of the joints.

Occasionally AMC can also affect the central nervous system of which the survival rate can be low.

* Source: Arthrogryposis A Text Atlas Edited by Lynn T. Staheli MD, Judith G Hall MD, Kenneth M Jaffe MD

Treatment of Arthrogryposis Multiplex Congenita (AMC)

Arthrogryposis is a diverse condition and no two people affected are alike but there can be striking similarities between groups of children. Doctors and Paediatricians find it difficult to give an accurate picture of the future of each child.  However, through physiotherapy, selective use of surgery and orthoses (splints or callipers), the majority of children go on to lead full and active lives.

With every baby born with Arthrogryposis, it is important that an accurate diagnosis is sought as soon as possible.  A specific diagnosis will provide information about the prognosis, risk of recurrence as well as to guide health practitioners to the best therapies.  To help distinguish between the different types of Arthrogryposis, the doctors are likely to use all the diagnostic tools available and are likely to ask you about:

Family history

This is essential especially if there are other affected children in the family.  The doctor will look at paternal and maternal ages and ask about close marriages, known as consanguinity, in the family.

Prenatal history

Were there any maternal illness or fever, trauma or injury, any exposure to drugs, alcohol, medications that can cause birth defects?  Doctors will also specially ask about baby’s movement before the birth.

Birth history

This will include the length of the pregnancy and labour, time and length of delivery, position of the baby at birth and prenatal outcome.

The baby will undergo a series of tests to eliminate other distinct conditions and may include x-rays of spine, pelvis and the limbs; a muscle biopsy; MRI scans; a head scan as well as investigations on the central nervous system.

The success of repositioning joints and limbs through physiotherapy cannot be over emphasised.  During the first 3 to 4 months of life when the contractures tend to loosen significantly – known as the ‘Grace Period’ – some of the muscles that appear to be unusually weak may significantly increase in strength and bones tend to increase in mineralization and growth.  During this time the lungs continue to develop and the gut tends to improve in function.

Physiotherapy can usually be started even before a specific diagnosis has been determined.  By introducing an early programme of passive stretching while the baby’s tissues are still supple, it will help increase the range of movement in the stiff joints. This is often coupled with the use of splints to maintain a good position in the limb.  Parents should be taught the correct techniques so that they can continue therapy at home between hospital visits.  Often the use of serial plasters and corrective surgery later on in life complements this work and may help a child to stand and walk.  Lightweight splints or callipers might be introduced at the appropriate age

Improvement of hand function can be difficult as there may be little muscle to deal with and the anatomy is badly affected. Trick movements that they learn for themselves can often help children overcome difficulties they may have with their upper limbs.  If the aid of personalised equipment is needed an Occupational Therapist will be able to give help and advice.  There are some well-tried operations which have proved to benefit some children but surgery of the upper limbs needs to be approached with some caution although new surgical techniques are constantly being introduced.

It is essential to stimulate the baby to use whatever movement they already have.  ‘Play’ can encourage this, and by putting toys just out of reach it can persuade them to move or stretch.  Positioning too can be helpful:

  • if a baby has difficulty bringing his or her hands together, laying them on their side helps.
  • a corner seat can provide support for a child who has poor sitting balance, allowing them to play more easily.
  • a standing frame will support a child whilst playing at a low table encouraging weight-bearing. through legs and feet.

The majority of children with Arthrogryposis achieve some degree of mobility; either with the help of callipers, splints and crutches or completely independently.

Download more detailed advice on Physiotherapy for Children with Arthrogryposis from Mia Dunkley, Senior Paediatric Physiotherapist at Great Ormond Street Hospital, London.