Scoliosis

Scoliosis (from Greek: skoliōsis meaning "crooked condition," from skolios, "crooked") is a medical condition in which a person's spine is curved from side to side. Although it is a complex three-dimensional deformity, on an x-ray, viewed from the rear, the spine of an individual with a typical scoliosis may look more like an "S" or a "C" than a straight line. It is typically classified as either congenital (caused by vertebral anomalies present at birth), idiopathic (cause unknown, sub-classified as infantile, juvenile, adolescent, or adult according to when onset occurred) or neuromuscular (having developed as a secondary symptom of another condition, such as spina bifida, cerebral palsy, spinal muscular atrophy or physical trauma). This condition affects approximately 7 million people in the United States.

Cause

In the case of the most common form of scoliosis, adolescent idiopathic scoliosis, there is no clear causal agent and it is generally believed to be multifactorial. Various causes have been implicated, but none have consensus among scientists as the cause of scoliosis. The role of genetic factors in the development of this condition is widely accepted.

One possible cause of scoliosis, as presented by Richard Howells, is the presence of ether in the bloodstream of the father at the moment of conception. Howells' father, Dr Wilfred Howells, was an anaethesiologist in three hospitals. As a possible consequence, Howells was born with scoliosis shown on the X ray as a hemi vertebrate. Scoliosis is more often diagnosed in females. In some cases, scoliosis exists at birth due to a congenital vertebral anomaly. Occasionally, development of scoliosis during adolescence is due to an underlying anomaly such as a tethered spinal cord, but most often the cause is unknown or idiopathic, having been inherited through multiple factors, including genetics. Scoliosis often presents itself, or worsens, during the adolescence growth spurt.

In April 2007, researchers at Texas Scottish Rite Hospital for Children identified the first gene associated with idiopathic scoliosis, CHD7. The medical breakthrough was the result of a 10-year study and is outlined in the May 2007 issue of the American Journal of Human Genetics.

Prevalence

A Scoliosis spinal columns curve of 10° or less affects 1.5% to 3% of individuals. The prevalence of curves less than 20° is about equal in males and females. It is most common during late childhood, particularly in girls.

Symptoms

Patients who have reached skeletal maturity are less likely to have a worsening case. Some severe cases of scoliosis can lead to diminishing lung capacity, putting pressure on the heart, and restricting physical activities.

The symptoms of scoliosis can include:

• Uneven musculature on one side of the spine
• A rib prominence and/or a prominent shoulder blade, caused by rotation of the ribcage in thoracic scoliosis
• Uneven hips / leg lengths
• Asymmetric size or location of breast in females
• Slow nerve action (in some cases)

Associated conditions

Scoliosis is sometimes associated with other conditions such as Ehler-Danlos Syndrome (hyperflexibility, 'floppy baby' syndrome, and other variants of the condition), Charcot-Marie-Tooth, kyphosis, cerebral palsy, spinal muscular atrophy, muscular dystrophy, familial dysautonomia, CHARGE syndrome, Friedreich's ataxia, proteus syndrome, Spina bifida, Marfan's syndrome, neurofibromatosis, connective tissue disorders, congenital diaphragmatic hernia, and craniospinal axis disorders (e.g., syringomyelia, mitral valve prolapse, Arnold-Chiari malformation).

Investigation

Patients who initially present with scoliosis are examined to determine whether there is an underlying cause of the deformity. During a physical examination, the following is assessed:

• Skin for café au lait spots indicative of neurofibromatosis
• The feet for cavovarus deformity
• Abdominal reflexes
• Muscle tone for spasticity

During the exam, the patient is asked to remove his or her shirt and bend forward. (This is known as the Adams Forward Bend Test and is often performed on school students.) If a prominence is noted, then scoliosis is a possibility and the patient should be sent for an x-ray to confirm the diagnosis. Alternatively, a scoliometer may be used to diagnose the condition. The patient's gait is assessed, and there is an exam for signs of other abnormalities (e.g., Spina bifida as evidenced by a dimple, hairy patch, lipoma, or hemangioma). A thorough neurological examination is also performed.

It is usual, when scoliosis is suspected, to arrange for weight-bearing full-spine AP/coronal (front-back view) and lateral/sagittal (side view) x-rays to be taken, to assess the scoliosis curves and the kyphosis and lordosis, as these can also be affected in individuals with scoliosis. Full-length standing spine X rays are the standard method for evaluating the severity and progression of the scoliosis, and whether it is congenital or idiopathic in nature. In growing individuals, serial radiographs are obtained at 3-12 month intervals to follow curve progression. In some instances, MRI investigation is warranted to look at the spinal cord.

The standard method for assessing the curvature quantitatively is measurement of the Cobb angle. The Cobb angle is the angle between two lines, drawn perpendicular to the upper endplate of the uppermost vertebrae involved and the lower endplate of the lowest vertebrae involved. For patients who have two curves, Cobb angles are followed for both curves. In some patients, lateral bending x-rays are obtained to assess the flexibility of the curves or the primary and compensatory curves.

Genetic testing for AIS, which has become available in 2009 and is still under investigation, attempts to gauge the likelihood of curve progression.

Prognosis

The prognosis of scoliosis depends on the likelihood of progression. The general rules of progression are that larger curves carry a higher risk of progression than smaller curves, and that thoracic and double primary curves carry a higher risk of progression than single lumbar or thoracolumbar curves. In addition, patients who have not yet reached skeletal maturity have a higher likelihood of progression (i.e., if the patient has not yet completed the adolescent growth spurt).

Genetic testing for adolescent idiopathic scoliosis

Through a genome-wide association study, geneticists have identified single nucleotide polymorphism markers in the DNA that are significantly associated with adolescent idiopathic scoliosis. Fifty-three genetic markers have been identified. Scoliosis has been described as a biomechanical deformity, the progression of which is dependent on asymmetric forces otherwise known as the Heuter-Volkmann law.

Management

The traditional medical management of scoliosis is complex and is determined by the severity of the curvature and skeletal maturity, which together help predict the likelihood of progression.

The conventional options are, in order:

1. Observation
2. Physiotherapy
3. Bracing
4. Surgery

A growing body of scientific research testifies to the efficacy of specialized treatment programs of physical therapy, which may include bracing. Debate in the scientific community about whether chiropractic and physical therapy can influence scoliotic curvature is partly complicated by the variety of methods proposed and employed: Some are supported by more research than others.

Methods of physiotherapy

The Schroth Method is one non-invasive, physiotherapeutic treatment for scoliosis which has been used successfully in Europe since the 1920s. Originally developed in Germany by scoliosis sufferer Katharina Schroth, this method is now taught to scoliosis patients in clinics specifically devoted to Schroth therapy in Germany, Spain, England and, most recently, the United States. The method is based upon the concept of scoliosis as resulting from a complex of muscular asymmetries (especially strength imbalances in the back) that can be at least partially corrected by targeted exercises.

Small curvatures between 15 and 20° during growth may be treated with the physio-logic-program, curvatures between 20 and 30° during growth spurt with „3D-made-easy“. This program has been tested in the environment of in-patient treatment as well, in curvatures exceeding 30° a combination of the methods described together with the Schroth program may be helpful. A specialized centre with trained and certified staff should be taken into account. As out-patient rehabilitation treatments today may reach the same outcome as in-patient programs, also out-patient programs may be successful when pattern specific programs are provided. A certain intensity certainly is necessary in order to allow the very best compliance with conservative treatment and in order to acquire coping strategies to allow to live with the deformity and with the conservative treatment.

The indications for treatment are depending on curve size, maturity of the patient and the individual curve pattern. Nevertheless today conservative management of scoliosis can be regarded as being evidence based, while there are not enough long-term data available for operative treatment.

Bracing

Bracing is normally done when the patient has bone growth remaining and is generally implemented to hold the curve and prevent it from progressing to the point where surgery is recommended. Braces are sometimes prescribed for adults to relieve pain. Bracing involves fitting the patient with a device that covers the torso; in some cases it extends to the neck. The most commonly used brace is a TLSO, a corset-like appliance that fits from armpits to hips and is custom-made from fiberglass or plastic. It is usually worn 22–23 hours a day and applies pressure on the curves in the spine. The effectiveness of the brace depends not only on brace design and orthotist skill, but on patient compliance and amount of wear per day. Typically, braces are used for idiopathic curves that are not grave enough to warrant surgery, but they may also be used to prevent the progression of more severe curves in young children, to buy the child time to grow before performing surgery, which would prevent further growth in the part of the spine affected. Bracing may cause emotional and physical discomfort. Physical activity may become more difficult because the brace presses against the stomach, making it difficult to breathe. Children may lose weight from the brace, due to increased pressure on the abdominal area.

The Scoliosis Research Society's recommendations for bracing include curves progressing to larger than 25 degrees, curves presenting between 30 and 45 degrees, Risser Sign 0, 1, or 2 (an x-ray measurement of a pelvic growth area), and less than 6 months from the onset of menses in girls.

Progressive scolioses exceeding 25° Cobb in the pubertal growth spurt should be treated with a pattern specific brace like the Chêneau brace and its derivates with an average brace wearing time of 16 hrs. / day (23 hrs. / day would assure the best possible result). The latest standard of brace construction is the CAD / CAM technology. With the help of this technology it has been possible to standardize the pattern specific brace treatment. Severe mistakes in brace construction are largely ruled out with the help of these systems. This technology also eliminates the need to make a plaster cast for brace construction. The measurements can be taken at any place and this is simple while the procedure is not comparable to plastering. In Germany available CAD / CAM braces are known such as the Regnier-Chêneau-brace, the Rigo-Chêneau-brace, and the Gensingen Brace according to Weiss. Many patients prefer the „Chêneau light“-brace, which has the best in-brace corrections reported in international literature and is easier to wear compared to other braces in use today. However, this brace is not available for all kinds of curve patterns.

A more recent development is the SpineCor Dynamic brace. It was developed by a research team at the St. Justine Hospital in Montreal Canada, as part of a research project funded by the Canadian government. The brace was first used in clinical application in Montreal in 1992 and is currently used in many counties throughout the world.

This brace works using a different treatment approach to rigid bracing. Rather than trying to force the spine straight using 3 points of pressure, SpineCor utilises a corrective movement. The regions of the body; shoulders, rib cage, lumbar spine and pelvis are guided to a postural position which is the inverse of the scoliotic posture. As the spine is connected to the body it must move with the body when it is repositioned via the corrective movement. Hence through the coupling of postural and spinal position it is possible to affect the geometry of the scoliotic curve.

The advantages of SpineCor are that is flexible and allows dynamic movement, thereby eliminating the muscle weakening side effects seen with rigid bracing. It is also very easily concealed under clothing. The fact that it works as both a rehabilitation device and a brace, means that corrections made in the brace are sustained over the long term in 95.7% of cases.

When correctly applied SpineCor Dynamic bracing has been shown to be one of the most a successful conservative treatments in the management of idiopathic scoliosis. The two largest bracing studies following the 2005 Scoliosis Research Society guidelines were published in the Journal of Paediatric Orthopaedics in June 2007. One study conducted at the Rainbow Children’s Hospital reported the effectiveness of TLSO and Providence bracing. The other conducted at the St. Justine Children’s Hospital reported the effectiveness of the SpineCor brace. Both studies followed the Scoliosis Research Society guidelines, meaning they used the same inclusion and reporting criteria therefore making it possible to compare the results of the 3 groups.

These results found that SpineCor was 76.5% effective in avoiding surgery, Providence night time brace was 40% effective in avoiding surgery and TSLO was 21% effective in avoiding surgery. Comparison of these results shows that SpineCor was 71% more effective in reducing the rate of surgery compared to TLSO.

Some authors have criticized the results of the SpineCor group, claiming that these results have not been reproduced by centres independent of the inventors. However independent results have been published by centres in the UK, Poland, Spain, and Greece. Each of these studies show results comparable to those achieved at the St. Justine Hospital studies.

Two studies have shown negative results using SpineCor. These two studies have been heavily criticised for their poor methodology and conflicts of interest. In one study the application of the SpineCor brace was changed by the study’s author in a way that the SpineCor brace was not designed to be used. The author also had no previous experience in fitting SpineCor and failed to declare a conflict of interest as the author had a vested commercial and intellectual interest in the brace to which SpineCor was being compared. In the second study SpineCor was applied by a group of partially trained practitioners that fitted the brace missing key components. What these two studies show, is that for SpineCor to be an effective treatment for idiopathic scoliosis, it must be applied by skilled practitioners that have completed the formal training program and fit the brace according to its indented use.

In infantile and sometimes juvenile scoliosis, a plaster jacket applied early may be used instead of a brace. It has been proven possible to permanently correct cases of infantile idiopathic scoliosis by applying a series of plaster casts (EDF: elongation, derotation, flexion) applied on a specialized frame under corrective traction, which helps to "mould" the infant's soft bones and work with their growth spurts. This method was pioneered by UK scoliosis specialist Min Mehta. Today, however CAD / CAM braces are also available for young children with a certain standard. Therefore plaster jackets are now generally regarded as outdated.

Surgery

Surgery is usually indicated for curves that have a high likelihood of progression (i.e., greater than 45 to 50 degrees magnitude), curves that would be cosmetically unacceptable as an adult, curves in patients with spina bifida and cerebral palsy that interfere with sitting and care, and curves that affect physiological functions such as breathing.

Surgery for scoliosis is done by a surgeon who specializes in spine surgery. For various reasons it is usually impossible to completely straighten a scoliotic spine, but in most cases very good corrections are achieved.

Spinal fusion with instrumentation
 
Spinal fusion is the most widely performed surgery for scoliosis. In this procedure, bone (either harvested from elsewhere in the body autograft or from a donor allograft) is grafted to the vertebrae so that when it heals they will form one solid bone mass and the vertebral column becomes rigid. This prevents worsening of the curve at the expense of some spinal movement. This can be performed from the anterior (front) aspect of the spine by entering the thoracic or abdominal cavity, or more commonly performed from the back (posterior). A combination is used in more severe cases.

Originally, spinal fusions were done without metal implants. A cast was applied after the surgery, usually under traction to pull the curve as straight as possible and then hold it there while fusion took place. Unfortunately, there was a relatively high risk of pseudarthrosis (fusion failure) at one or more levels and significant correction could not always be achieved.

In 1962, Paul Harrington introduced a metal spinal system of instrumentation which assisted with straightening the spine, as well as holding it rigid while fusion took place. The original, now obsolete Harrington rod operated on a ratchet system, attached by hooks to the spine at the top and bottom of the curvature that when cranked would distract, or straighten, the curve. A major shortcoming of the Harrington method was that it failed to produce a posture where the skull would be in proper alignment with the pelvis and it didn't address rotational deformity. As a result, unfused parts of the spine would try to compensate for this in the effort to stand up straight. As the person aged, there would be increased wear and tear, early onset arthritis, disc degeneration, muscular stiffness and pain with eventual reliance on painkillers, further surgery, inability to work full-time and disability. "Flatback" became the medical name for a related complication, especially for those who had lumbar scoliosis.

Modern spinal systems are attempting to address sagittal imbalance and rotational defects unresolved by the Harrington rod system. They involve a combination of rods, screws, hooks and wires fixing the spine and can apply stronger, safer forces to the spine than the Harrington rod. This technique is known as the Cotrel-Dubousset instrumentation, currently the most common technique for the procedure.

Modern spinal fusions generally have good outcomes with high degrees of correction and low rates of failure and infection.[citation needed] Patients with fused spines and permanent implants tend to have normal lives with unrestricted activities when they are younger, it remains to be seen whether those that have been treated with the newer surgical techniques will develop problems as they age. A notable limitation of spinal fusions is that patients who have undergone surgery for scoliosis are ineligible for service in the military of countries such as the United Kingdom, Sweden and the United States.

Pedicle screw only posterior spinal fusion may improve major curve correction at 2 years among patients with adolescent idiopathic scoliosis (AIS) as compared to hybrid instrumentation (proximal hooks with distal pedicle screws) (65% versus 46%) according to a retrospective matched cohort study. The prospective cohorts were matched to the retrospective cohorts according to patient age, fusion levels, Lenke curve type, and operative method. The two groups were not significantly different in regard to age, Lenke AIS curve type, or Riser grade. The numbers of fused vertebrae were significantly different (11.7±1.6 for pedicle screw versus 13.0±1.2 for hybrid group). This study's results may be biased due to the pedicle screw group being analyzed prospectively versus retrospective analysis of the hybrid instrumentation group.

In cases where scoliosis has caused a significant deformity resulting in a rib hump, it is often possible to perform a surgery called a costoplasty (also called a thorocoplasty) to achieve a better cosmetic result. This procedure may be performed at any time after a fusion surgery, whether as part of the same operation or several years after. It is usually impossible to completely straighten and untwist a scoliotic spine, and it should be noted that the level of cosmetic success will depend on the extent to which the fused spine still rotates out into the ribcage. A rib hump is evidence that there is still some rotational deformity to the spine.

Complications

The risk of undergoing surgery for scoliosis is estimated to be 5 % . Possible complications may be inflammation of the soft tissue or deep inflammatory processes, breathing impairments, bleeding and nerve injuries. However, according to the latest evidence the rate of complications is far beyond that rate. As early as five years after surgery another 5% require reoperation and today it is not yet clear what to expect from spine surgery in the long-term. Taking into account that signs and symptoms of spinal deformity cannot be changed by surgical intervention, surgery remains to be a cosmetic indication, only especially in patients with Adolescent Idiopathic Scoliosis (AIS), the most common form of scoliosis never exceeding 80°. Unfortunately the cosmetic effects of surgery are not necessarily stable. In case one decides to undergo surgery a specialized centre should be preferred.

Surgery without fusion

New implants have been developed that aim to delay spinal fusion and to allow more spinal growth in young children. For the youngest patients, whose thoracic insufficiency compromises their ability to breathe and applies significant cardiac pressure, ribcage implants that push the ribs apart on the concave side of the curve may be especially useful. These vertical expandable prosthetic titanium ribs (VEPTR) provide the benefit of expanding the thoracic cavity and straightening the spine in all three dimensions while allowing the spine to grow. The other alternative in the growing child is a spine-to-spine growing rod system that avoids fusing the entire curve, but requires biannual surgery through limit incisions to lengthen the rods and spine. Although these methods are novel and promising, these treatments are only suitable for growing patients.

Scoliosis Research Society

The Scoliosis Research Society is a professional organization of physicians and allied health personnel. Their primary focus is on providing continuing medical education for health care professionals and on funding/supporting research in spinal deformities. Founded in 1966, the SRS has gained recognition as one of the world's premier spine societies. Strict membership criteria ensure that the individual Fellows support that commitment. Current membership includes over 1,000 of the world's leading spine surgeons as well as some researchers, physician assistants, and orthotists who are involved in research and treatment of spinal deformities. The purpose of the Scoliosis Research Society is to foster the optimal care of all patients with spinal deformities.

Many members of this society, however have a clear conflict of interest when advising patients. The industry does not only support studies, but also individual operations. When the invention of one screw is worth a contract of more than 1.35 Billion USD, one can estimate the high gains that may be achieved with spine surgery. It has been shown that the spine is a profit centre for spine surgeons. Therefore patients should always consider, that there is no clear medical indication for undergoing surgery when being advised by a spine surgeon.