Complications

Back pain

Occasionally people with certain forms of short stature, such as achondroplasia, may suffer from back pain. If this is associated with pain in the legs or numbness and the collapsing of the legs then medical advice may be necessary. These symptoms may indicate pressure on the spinal cord and nerve roots associated with the curvature of the spine in the lower back region and the narrow diameter of the spinal canal.

The abnormal diameter of the spinal canal (called spinal stenosis) affects the spine from the base of the skull to the tail bone. This usually causes back and leg pain but occasionally the bladder or bowel may be affected. If symptoms are progressive and become disabling, then investigations and possibly operations may be required. To evaluate the condition the specialist may use an x-ray, myelograms (where a fluid dye is injected into the spinal fluid to show any blockage), or computer tomography and magnetic resonance imaging.

In some disorders there are growth abnormalities in the spinal bones causing curvature of the spine e.g. scoliosis. Treatment of this may require bracing with a spinal jacket and occasionally surgery.

Surgical procedures used for spinal problems include:

(1) Laminectomy – the removal of the laminae i.e. the back of the spinal canal, in order to give the nerve tissue more room. This operation is used particularly where there is narrowing or spinal stenosis.

(2) Spinal fusion is an operation to join two or more neighbouring vertebrae together with bone from another part of the body. The purpose of this is to prevent instability and abnormal movement, and to correct and hold a deformity such as sconosis.

(3) Spinal curvature – a number of segments may be fused and usually a metal rod or heavy duty wires are used to hold the bones in place.

Skull Abnormalities and Hydrocephalus

In children without growth disorders the skull is made up of large bone plates loosely joined with cartilage allowing for expansion due to rapid brain growth in early childhood but in children with growth disorders there is sometimes a problem with the bone plates fusing together too quickly or constricting the brain in one area so that the skull bulges out elsewhere to compensate. This leads to the prominent forehead in achondroplasia. This need not cause concern. Skull abnormalities can be associated with a build up in pressure in the fluid which surrounds the brain and psinal cord. If this pressure becomes too much it can cause headaches. Mild hydrocephalus is almost considered “normal” for achondroplasia and has no untoward effects but a regular check of head circumference is advisable and scans can reveal if the skull is expanding more rapidly than is necessary for brain growth.

A consequence of abnormal skull growth is a problem with the jaws and teeth. Small jaws can result in overcrowded teeth. If the jaws grow disproportionately, as happens in achondroplasia, there are problems with the upper and lower teeth not meeting together properly to chew. The removal of selective teeth can help.

Joint pain

In later life, pain, swelling and giving way of joints is often experienced but can respond well to physical treatment. For people with growth disorders, abnormalities in the size and shape of joints together with looseness of tissues may aggravate the natural wear and tear process leading to increased pain and disability. Loose joints is a problem which may result in pain especially in the legs. A bow leg deformity may not cause pain but can adversely affect the joints and in extreme cases should be treated surgically to straighten the legs. Joint problems in the legs are made worse when the body is heavy, so it is sensible for all people of short stature not to become overweight.

Surgery and the risks involved

Many corrective operations are possible to alleviate problems associated with growth disorders. Surgery for anyone carries certain risks but for people of short stature these may be increased.

Anaesthesia

People of short stature should be carefully monitored during surgery. Some people may have an adverse reaction to a specific anaesthetic, so care should be taken when administering them. The dosage should be carefully calculated to take into account the individual’s weight and height.

Intubation

Maintaining an airway while unconscious involves inserting a tube down the throat, and this may cause some difficulties. If the patient has a narrow throat a child’s-size tube should be used.

Position and structure of body organs

Body organs may not follow the normal pattern of the average individual in persons of short stature. The success of some orthopaedic procedures, e.g. hip replacement, relies on joining artificial materials to existing bones, or grafting bone from one area to another. It must be remembered that the bone strength and structure in some growth disorders is often abnormal, and therefore cannot be relied upon to be as resilient or respond in the same way as normal bone.

Ear problems

Many people suffering a growth disorder may have a hearing loss. This may be caused by structural abnormalities inside the ear and the bones which transmit the sound waves (conductive hearing loss), this is usually called “glue ear”. Fluid fails to drain from inside the ear and instead builds up and becomes infected. It is the eustachian tube which drains this fluid and allows air pressure either side of the ear drum to be equalised. Achondroplasia children tend to have narrow eustachian tubes, and “glue ear” is a common cause of deafness. A child suffering repeated infections may need to be prescribed antibiotics. It is necessary sometimes to have a grommet inserted which maintains a small perforation in the ear drum to assist in the equalisation of pressure and the draining of fluid.

Respiratory complaints

Some conditions of short stature are prone to respiratory problems such as nasal discharge and a wheezing chest.

Sleep Apnoea

While sleeping and breathing seem like fairly straightforward tasks, there are a great number of people who have trouble doing both simultaneously. These individuals have sleep apnoea, a disorder characterised by periodic stoppage of breathing during sleep. The medical profession is now becoming aware of the fact that people with certain types of short stature, especially achondroplasia, may be more likely to develop sleep apnoea.

Obstructive sleep apnoea is by far the most common type of apnoea. It is caused by a blockage in the upper air way that is only present during sleep. A partial blockage of the upper air way is also what causes snoring, so many individuals with obstructive sleep apnoea started out as snorers.

When a person with obstructive sleep apnoea drifts off to sleep, the muscles in his/her air way relax, allowing the soft tissues in the throat to obstruct the air way. Despite the blockage, the person will still go through the motions of breathing, yet no air passes in or out. After a period of time, which can last up to a minute or two, the person’s body realises that it is not receiving oxygen. The person wakes up enough to regain muscle ton ein the upper airway, removing the blockage and allowing air to come in. A person with severe sleep apnoea remains aroused only long enough to gasp some air, then drifts off to sleep, allowing the blockage to form again. This cycle can repeat itself hundreds of times a night. In the morning, the person with sleep apnoea will be sleepy, because although he/she is in bed for eight or more hours, he/she is actually waking up to breath every minute or so.

An additional complication of sleep apnoea relates to oxygen loss. Each time a person stops breathing for more than a few seconds, the oxygen level in his/her blood decreases. When he/she wakes up to breath, the oxygen level goes back up to normal. This lack of oxygen during the night can severely affect the organs in the body, e.g. the heart may develop irregular beats, and lack of oxygen in the brain may produce a gradual memory loss.

Children with sleep apnoea, especially those with short stature, face an additional risk. According to Dr. German Nino-Murciam of Stanford Sleep Disorders Clinic in Stanford, California, short-statured children who have untreated sleep apnoea may not develop to their full potential height because of lack of oxygen during crucial growing periods.

(Source: Information Guide to Persons of Short Stature, edited by Stephen Pinnell, pp. 20-22)

© 2014 SSPA.