Scoliosis

What is Scoliosis?

Scoliosis is a sideways curvature of the spine accompanied by a twisting of the spine. This can cause the shoulders, hips or waist to appear uneven.

The twist is best seen by others when you bend forwards at the hips.

Why do I have scoliosis?

Scoliosis in NOT a diagnosis on its only: it describes the shape of the spine (bending to the side and rotated).

There are multiple causes of scoliosis- it is essential to determine the cause of the scoliosis to determine what the natural history will be be and what the appropriate management is.

Idiopathic

By far the most common “cause” of scoliosis. The exact underlying reason for the curve is not known. There are genetic influences but oftentimes there is no reason found

(a) adolescent idiopathic scoliosis

This occurs as the child approaches maturity and is going through their major adolescent growth spurt.

(b) early onset scoliosis

This is a curve that occurs in a younger child for no known reason.

Congential

A structural problem that has been present from the early formation of the spine before birth. This can be extremely variable in outcomes: ranging from no symptoms and no treatment necessary to a progressive problem that needs early surgery.

Neuromuscular scoliosis

This type of scoliosis happens because abnormal nerves or muscles are weak and failing to hold the spine up straight.

Common neurological conditions that can cause scoliosis include :

Cerebral palsy
Muscular dystrophy
Neurofibromatosis

Scoliosis: what makes it get worse?

While the reasons why the scoliosis occurred may remain a mystery, we do have much clearer information about what makes curves get worse. The combination of growth and gravity are the two forces that are drive curves to become worse. The faster the growth the more likely the scoliosis will get worse.

The bones of the spine, which should be square shaped, are each growing. If they are growing fast and under pressure from a curve they tend to grow more wedge shaped (triangular).

The shape problem becomes fixed in the shape of the individual bones and joints. Part of the assessment of the scoliosis will be to determine how much growing we expect is still remaining and what the risks are of developing a much bigger curve

What are the treatment options for Scoliosis?

Observation

Many curves are mild enough (generally less than 25 degrees) that they do not require active treatment. Although they may well not increase with time they certainly need ongoing observation with xrays until the child is skeletally mature.

It is important to remember that there is nothing weak nor brittle about your spine; you can participate in all physical activities that you want.

Physiotherapy

Physiotherapy may assist with symptoms and addressing associated asymmetries in the surrounding musculature, such as those present around the shoulder girdle, hips and spine.

There are physiotherapy scoliosis specific exercise (PSSE) methods that aim to improve the postural components of the curve, improve flexibility of the restricted regions and improving the strength of specific postural weaknesses identified. The most widely known PSSE is the Schroth based method (BSBTS).

Bracing

When do you use a brace?

For those who patients who have significant growth remaining and have an acceptable curve (usually between 25 and 40 degrees) the best way to maintain this curve is brace treatment. In recent years we have had very solid evidence that braces work in preventing worsening of the scoliosis, and avoiding the progression to a level that requires surgery.

The brace studies have shown that there is a direct relationship between the time that a brace is worn and the effectiveness of the brace. Use of the brace less than 12 hours per day does not show effectiveness.

Progressing upwards to about 20 hours per day shows a steady improvement in the results. We encourage normal physical activity and for these purposes removing the brace is a good idea to maintain strength and movement with physical exercise.

What kinds of braces are there?

There are a variety of braces available. Some are fastened at the back termed a “Boston Brace” style and some are fastened at the front called a “Rigo Cheneau “style”. In the brace trials there was no difference between the effectiveness of different styles of braces and we see excellent results with both styles. Braces do vary a lot in expense. A more expensive brace is not necessarily more effective or more comfortable.

Where do we get a brace?

Braces are made and constructed by an Orthotist who can construct the brace in a variety of different ways. Sometimes by making a direct mould of the body or other times by doing photography and Cad-Cam Design.

The most important factor in the success of the brace is the time that it is actually physically worn. Any factors that can improve tolerance or compliance with the brace are to be encouraged.

Plaster Cast

A young child may develop a scoliosis that is too severe for a brace to be expected to be successful. If they are too young to consider a surgical option occasionally we will apply a plaster cast under anaesthetic to decrease their scoliosis.

They keep the plaster cast on for 6-8 weeks and then return to theatre for another cast. This is repeated (usually 2-4 more times) until we can get their curve low enough that a brace can hopefully be successful.

A seven year old female with a severe unbraceable scoliosis. After two plasters the curve has gone from 69 degrees down to 38 degrees and she can now be fitted for a brace.

Surgery

When is an operation indicated?

Some curves grow past an acceptable cosmetic result and have progressed to a level where surgery is indicated. For the surgeon the number 1 indication for surgical treatment is when we are convinced that further progression is inevitable. One threshold that is pretty well established is 50 degrees. Some long-term studies have shown that 50 degree curves continue to progress through adult life, even if growth has finished. The long-term consequences of this is a bigger curve and potentially looking worse.

What is the best surgery for my curve?

Your surgeon will explain the rationale for your particular scoliosis surgery. In general the factors that are considered are:

Degree of curve
Location of curve
Age/maturity of patient
Underlying conditions(s)

What are the risks of surgery?

Spinal cord injury

The risk of a permanent paralysis of the spinal cord is approximately 3 in 1000 according to some worldwide figures on adolescent idiopathic scoliosis surgery. Spinal cord injury is prevented by constant monitoring of spine cord function during the operation.

A technician sits in the corner of the operating room running electrical signals from head to toe and toe to head. A problem with this conduction is alerted to the surgeon who can then modify the surgery, change the plan or in some cases cease the operation.

Blood loss

While blood transfusion may be necessary it is now uncommon as we collect the patients blood lost through the surgery through a “cell-saver” and can give it back to them.

Infection

The incidence in the idiopathic group is< 1%. It may require repeat surgery and long term antibiotics .

Further surgery

Occasionally the curve extends above or below the instrumentated region. This “adding-on” of the scoliosis can be treated by extending the fusion. In the rare event of the spine not fusing the rod can break and cause pain necessitating a revision surgery.

Pain

Occasionally the patient continues with discomfort post-operatively despite no obvious reason. This usually resolves with the help of the pain management team including physiotherapy.

Where would my surgery occur?

We perform scoliosis surgeries at the Royal Children’s Hospital in Parkville and at Cabrini Hospital in Malvern.

What happens after the surgery?

Typically, after a spine operation the patient goes back to the regular paediatric ward and stays in hospital for 4 days. There is a need for strong pain-relieving medication that is given by intravenous drip to begin with, and then medication by mouth for discharge to home. Most patients cease strong pain relievers after two weeks.

Patients feel tired after this big operation and often don’t get back to school for about six weeks. There are some initial restrictions to activity but ultimately most will be allowed to return to sport and movement with no restrictions.

What types of surgery are there?

Correction and Fusion operations

A typical scoliosis operation involves a fusion of the spine in a straighter position. This is intended to be a single operation that achieves the correction and maintains it for life. The spine is held straight with internal metal rods, which are anchored to the spine by screws, hooks or tapes. The fusion occurs by the growth of a bone graft across all of the joints of the spine.

Posterior instrumentation and fusion.

This is the most common surgical procedure used for adolescent idiopathic scoliosis.

It is performed from behind. Philosophically, we are committed to “selective” position instrumentation to ensure the levels fused are kept to a minimum.

Anterior instrumentation and fusion

With curves limited to the thoraco-lumbar junction we will often do anterior approach.

This involves going in front of the spine and removing the discs then placing single screws at each level and correcting it with a rod. This oftentimes allows us to fuse fewer levels than we would have had to do if we went posteriorly.

Non-fusion techniques

Vertebral Body tethering (VBT)

This is a new procedure that is used with the skeletally immature patient where a brace has failed or can be expected to fail.

Like anterior fusion surgery the surgery is done from the front of the spine. Rather than correct the scoliosis with a rod, a polyester tether is placed between the vertebrae to gain compression and correction.

The discs are left intact so that the vertebrae do not fuse to each other. This will allow the immature to continue growing and hopefully further improve the correction.

Why has VBT become so popular?

The early return to activity appears to be quicker with VBT than fusion techniques. The spine continues to grow with VBT which then allows further improvement of the scoliosis (as shown below). It appears that there remains movement in the instrumented spine and in addition there is improved motion in the non-instrumented lumbar spine compared to a posterior fusion.

What can go wrong with VBT: In addition to the regular spine surgery complications the two main issues have been: overcorrection of the scoliosis and the tether breaking. This can result in the necessity to have another operation to correct the specific tether issue. Why not use it then for everyone? When used in the growing spine there should be growth modulation with VBT that allows normalization of the spine and its involved vertebrae. This should in turn take the pressure off of the tether by the time growth is finished. If there is not growth remaining the spine will always be dependent on the tether for the correction and should be at increased risk of tether breakage as time goes on. With instrumentation and fusion the curve is both corrected and made solid so there is not long-term strain on the implants. The natural history of instrumented correction and fusion is well known and the mature patient can be expected to get a good result. We just do not know the natural history of using VBT in the mature patient. Bipolar instrumentation In the past, neuromuscular patients who needed instrumentation were treated with long instrumentation and fusion. But new techniques, using bipolar instrumentation, have seen excellent results. This new technology allows for a much less invasive surgery with considerably less problems for the patient (less surgery, less blood loss, less need for Intensive care). The surgery can be performed on much younger patients with much smaller and more flexible scoliosis curves. The operation is called bipolar because the rods that are inserted are put in through small incisions at the top and bottom ends of the spine with no surgery in between. This surgery allows for very minimal spine exploration as a special ‘Tanit’ screw is placed from the pelvis into the spine and then joined by the rod into the upper thoracic spine The rods that are inserted can be extended with a small operation to extend the rods as needed. This is like putting a brace on the inside of the spine to control the scoliosis during growth. It is intended that the implant would remain inside the body for life and require no further modifications or revision after the patient has stopped growing. This technique results in excellent correction without exposing the child to extensive surgical injury.

Growing Rods

These are sometimes used in the very young child whose curve is not controlled by brace/plaster and yet is too young for definitive scoliosis instrumentation (either fusion or VBT). There are two main types used:

(1) Traditional growing rods

Two rods are placed posteriorly with attachments to the spine at the top and at the bottom of the curve with no attempt to fuse the spine. Every six-nine months the child returns to theatre and the rods are lengthened. This procedure has been associated with a many problems including infection, skin breakdown, multiple surgeries and premature fusion.

(2) Magnetically controlled growth rods

One or two rods are placed posteriorly with attachments at the top and at the bottom of the curve(s)and then the rods are very slowly lengthened using an externally held magnet to gradually lengthen the rod. Whilst this requires fewer planned returns to theatre than the traditional growing rods they have not worked out as well as originally hoped for. Problems include premature fusion of the spine as well as mechanical issues with the implants.

Spine

Scoliosis

What is Scoliosis?