Arthrogryposis

WHAT IS ARTHROGRYPOSIS? Arthrogryposis Multiplex Congenita is a term used to describe a baby born with multiple joint contractures and covers a wide range of conditions. It is not a medical diagnosis but a description of the condition. A contracture is a limitation in the range of movement of a joint; the joint may be fixed in either a flexed or extended position.

'Classic' Arthrogryposis, as referred to by some doctors, is characterised by the internal rotation of the hands, sloping shoulders, thin legs and long tapering fingers. However the positions of the feet, knees and hips are very variable. In some cases only two or three joints may be affected but in others all joints, including spine and jaw are affected.

The majority of children with Arthrogryposis fall within the normal range of intelligence, a few however, may have a learning disability. There are more than 200 conditions in which multiple congenital contractures may be present. These can roughly be divided into three groups;

Children in the last category tend to do very poorly and may not survive. This is usually obvious in the new-born period and is not something that develops at a later stage

WHY DOES IT HAPPEN?
There are a number of things that can go wrong and affect normal development of the joint and cause the fixation.

Muscle Defects - the muscles fail to form or function normally or undergo a degenerative process in the womb.

Neurological Deficit - absent, abnormal or malfunctioning nerves.

Abnormal connective tissue or joints - which limit movement.

Decreased space in which the foetus can move - insufficient fluid in the womb, an abnormal shape to the womb, twins or more.

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A characteristic feature of the condition is dimples near the affected joints and these suggest contact between the skin and bone during the early stages of pregnancy. As many joint spaces have formed by the seventh week and folds appear in the skin by the eleventh week, this gives an indication as to when the disability is caused.

Research using animal models has also shown that stopping a foetus moving at 10 - 12 weeks gestation, induces fixed joints. Normally a foetus moves almost continuously. The movement seems to be necessary for normal growth of the limbs and joints. If the foetus stops moving the joints, for one of the reasons already mentioned, they become stiff and it is then difficult for them to stretch and resume normal movement in the womb.

Occasionally mothers mention that there was less foetal movement than they expected or had previously experienced, although this is often said in retrospect. Mothers sometimes ask - 'Was it something I did?' Research, however, has shown that rarely is there a history of the mother having been ill, taken medication or any other maternal problem.

WILL IT HAPPEN AGAIN? Because there are so many conditions that can come under the heading of Arthrogryposis, it is important at some stage to establish the type your child has as this will have a bearing on whether the condition is hereditary. Amyoplasia, the most common form of Arthrogryposis, is not inherited and there is no significant risk of further children or your child's offspring being affected.

However, Distal Arthrogryposis, which primarily affects just the hands and feet, does have a genetic basis. It is advisable to seek genetic counselling at one of the Regional Genetic Centres throughout the country, where the risks can be quantified. Your GP or paediatrician will be able to refer you to a geneticist.

For some years the incidence figure for Arthrogryposis in the UK was given as one in 56,000 births, but more recent data from the registrars of congenital birth defects suggested a higher incidence of 1 in 3000 to 5000 births.

However, Arthrogryposis was the primary diagnosis in only one third of these births. About thirty babies will be born every year in the UK where Arthrogryposis is the cause of their problems. These children have the prospect of a normal, healthy life despite their varying physical limitations. Arthrogryposis also occurs frequently in conjunction with other serious congenital abnormalities where, sadly, the babies die in the neonatal period.

WHAT CAN BE DONE? Early diagnosis is essential so that treatment can start as quickly as possible. To assist in that diagnosis a series of tests may be carried out to eliminate other distinct conditions. These tests may include, for example, investigations on the central nervous system; a head scan; a muscle biopsy; x-rays of spine, pelvis and the limbs involved.

Physiotherapy is the immediate concern and plays a leading role in the treatment of Arthrogryposis. A programme of passive stretching while the baby's tissues are still supple, needs to be introduced as soon as possible to try and increase the range of movement in the stiff joints. This is coupled with the use of splints to maintain a good position in the limb. The success of repositioning joints and limbs that can be achieved by persistent physiotherapy cannot be over-emphasised.

The physiotherapist should teach the parents the correct techniques so that they can continue the daily programme at home in between hospital visits. Later the use of serial plasters and corrective surgery complements the work of the physiotherapist. To help the child to stand and maybe later to walk, lightweight orthoses (splints or callipers) might be introduced at an appropriate stage.

Difficulties that children encounter with function of the upper limbs are often overcome by trick movements they learn for themselves. If the aid of personalised equipment is needed an occupational therapist will be able to give help and advice. Surgery of the upper limbs needs to be approached with some caution, although there are many well-tried operations that are of benefit.
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Improvement of hand deformities has been difficult and often there is little positive response to surgery, because there is often so little muscle to deal with and the anatomy so abnormal. With improving surgical techniques the future for these operations is looking brighter.

It is essential to stimulate the baby to use whatever amount of movement may be present in order to gain normal everyday experiences. Toys and play have an important role by encouraging and developing every movement the child has; toys put just out of reach encourage the baby to move or stretch to get them.

Positioning too can be helpful; if a baby has difficulty bringing its hands together, laying him or her on their side helps; a corner seat can provide support for a child who has poor sitting balance allowing them to play more easily and later a standing frame will support a child whilst playing at a low table and also encourage weightbearing through the legs and feet.
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The majority of children with Arthrogryposis achieve some degree of walking either with the help of calipers, splints and crutches, or completely independently. Others may become wheelchair users, but this should not be seen as a negative aspect as it allows the child to explore their environment and move about independently. Mobility is important for learning, socialising and gaining independence. Children can learn at a surprisingly young age (2 years) to drive a powered mobility aid.

"Children with Arthrogryposis are very rewarding to treat because they have the characteristic of being highly motivated and great achievers" John Fixsen. MChir., FRCS

MEDICAL PROBLEMS RELATED TO ARTHROGRYPOSIS A study by Prof. Richard Robinson of the members of TAG in 1987 and 1988 highlighted some of the medical problems experienced in childhood. A number of parents reported that their children had had recurrent or frequent chest infection or that they had difficulty throwing off coughs and colds. The feeling was though that this became less of a problem as the child got older.
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A significant proportion of the children had feeding and subsequent speech problems. This could be caused by the baby not swallowing and moving it's facial muscles whilst in the womb which would mean that the facial structures did not develop properly. In the early days the baby may be a 'slow' feeder because the muscles in the jaw are affected and later this could have some effect on the development of speech. The support from a speech therapist experienced in developing the oral skills of handicapped children can help with both problems.

Many of the children were reported to have poor weight gain or to be small generally. This is possibly linked to the difficulty in getting the baby to take enough nourishment in the first year or so of life.

From the children Prof.Robinson had already met, he expected that body temperature might be a problem. Several parents said their children became more hot and sweaty than would be expected. Most though said that the child's arms and legs became very cold, this is possibly because the child is immobile.

Control of body temperature is governed by the involuntary nervous system and so it was interesting to look at other functions controlled in this way. Bowel movement is one of these functions and a significant number of parents also reported that their children had problems with constipation.
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This study dealt with the problems some children may encounter. Almost nothing is known about medical problems of adults and the elderly. Whether arthritis later becomes a significant problem for example, might be another area for future research.

THE FUTURE The majority of children in TAG attend mainstream schools, some with extra support if needed, others may first have had a few years at a nursery or primary school for children with special needs. For a few children though, because they may have severe or additional problems, a special school will be a more suitable choice and an equally satisfactory environment for the child.

Arthrogryposis is described as being a very heterogeneous condition, meaning, one that is diverse in character. Therefore the way in which each child is affected can vary greatly although there can be striking similarities between groups of children.
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Doctors understandably find it difficult to give an accurate picture of the future of each child. But it can be said that through physiotherapy, selective use of surgery and orthoses the majority of children born with Arthrogryposis go on to lead full and active independent lives.