Orthopaedic surgery for hemiplegia

Aidan Cosgrove is a Consultant Orthopaedic Surgeon at the Musgrave Park Hospital, Belfast. Here he discusses orthopaedic surgery for hemiplegia.

Hemiplegia is caused by damage to nerve tissue in the brain, leading to an loss of control especially in the limbs, where the effect of the damage appears. Unfortunately at present it is not possible to repair the damage within the brain. This is not to say that motor control cannot be improved by therapy and training. However, at present most of our surgical efforts are directed towards the physical effects of the neurological damage. Although we cannot take away the underlying abnormality, in situations where this leads to deformity interfering with the working of the body significant improvements can be made with surgery.

Treating children

In children with hemiplegia there is often a disturbance of growth in the affected limbs, particularly of muscle but also, to a lesser extent, of bone. This is most marked further along the limb. So, for example, in the leg we often see the calf muscle becoming tighter with growth and the child increasingly walks on the toes. This is often more marked in those children in whom the muscles at the front of the leg work poorly. These effects can be reduced with the use of physiotherapy and splints, but even despite the best care, in many cases one needs to think about surgical correction to ensure the best results.

The physical effects

The actual deformities that occur vary from child to child, depending on the neurology. In the leg, turning in of the foot (although in some children the foot turns out), bunions, deformities of the toes, tightness in the calf muscles and tightness in the hamstring muscles leading to bending of the knees are the most frequently seen problems. In the bones, most children generally have a slight decrease in length, generally about an inch shorter than the other leg. Occasionally children may also develop a twisting inwards of the thigh bone and a twist in the lower leg, either inwards or outwards. People with hemiplegia also tend to walk with the affected side of the pelvis a little bit behind.

The arm

In the arm, deformities mostly tend to be more marked further out. The thumb tends to become tight into the hand, the wrist can become bent downwards and the elbow flexed with the arm turned in at the shoulder. Posturing of the arm during walking and especially running often makes this appear worse. Unlike other children with cerebral palsy, children with hemiplegia very rarely develop more central deformities such as scoliosis or dislocation of the hip.

Goals of surgery

Before embarking on surgery it is important to establish the goals. In the lower limb these are often to normalise the movements in the affected leg, this can help stability, reduce abnormal pressure on the skin of the foot and (perhaps most importantly) improve the appearance of walking. Although cosmetic surgery may not sound terribly rewarding, it is the appearance of their leg which is often the most distressing to children, especially once they reach adolescence, particularly as most children with hemiplegia have very good use of their lower limb. The problems seen are very different from the upper limb. In the lower limb it is necessary to use both legs for walking and running. As these are repetitive patterns of movement, it is often possible to achieve a high level of function even with a lot of neurological impairment.

However, in the upper limb each limb can act independently and do very complex and varied tasks, which requires a lot of feedback and perception of the limb. So if impairment is present the good arm is preferred very strongly, with the affected arm either left redundant or relegated to very simple tasks such as clasping. Therefore even if deformities are corrected it is very unlikely that this will result in improved function. This means that the potential for upper limp surgery is very limited compared to lower limb surgery. Upper limb surgery is largely used to improve the appearance of the limb. In rare instances deformity in the upper limb can give problems such as a thumb digging into the palm, in these cases surgery can relieve the irritation.

Surgical procedures

The surgical procedures used in hemiplegia are generally quite straightforward and involve lengthening or transferring the tendons of muscles, stabilising of joints and on occasion the cutting and re-orientating of bone (osteotomy). The most difficult aspect of surgery is the decision making, in terms of what surgeries to perform and when is the best time to perform surgery. Nowadays most of this type of surgery is performed by orthopaedic surgeons who specialise in the management of children. In complex cases gait analysis can be useful to study walking to help decide on the appropriate surgery. Gait analysis involves attaching sticky markers to the skin and using cameras to measure the movements. It also uses instruments in the ground to measure the forces involved, and at times electrodes are used to measure the activity in the muscles. Using and interpreting gait analysis is quite complex and is available in only about ten centres in the UK. It is probably not essential for all children with hemiplegia prior to surgery but is very useful for quality control of surgery.

Timing of surgery

The timing of surgery is important. If done at an early age when there is a lot of growth left the deformities can come back. If the surgery is done at maturity the deformities can be quite difficult to correct and rehabilitation can be difficult. Generally the best time is between six and eleven years. However, if deformities are quite severe it may be necessary to perform surgery earlier than this. Saying this, there is a large window of opportunity, so the surgery can be timed to fit in best with other considerations such as schooling and availability of physiotherapy.

Surgery for hemiplegia generally requires an inpatient stay in hospital, the length depending on the extent of surgery. In recent years there have considerable advances in the management of pain, with the use of regional blocks, like epidurals, and the use of patient controlled analgesia pumps. So most of this surgery can be now performed without any significant pain. After surgery it is often necessary to immobilise the area in a plaster cast, generally for about six weeks. It may then be necessary to use splints to ensure that the correction achieved at surgery is maintained.

Rehabilitation

Rehabilitation after surgery is critical, since without good physio input deformities can readily come back. The rehabilitation period often takes quite a long time and it may be a year or longer before the full benefits are seen. This all means that before surgery is undertaken a plan should he made to identify the resources needed for rehabilitation. There is little point in doing surgery if it is going to take four or five months to get new splints and there is no physiotherapist available.

In summary

For many children with hemiplegia surgery will he very helpful at some stage, but it needs to he a part of a whole package of care to ensure that their full potential is achieved.