Spine Information
Scheuermann's Kyphosis
Table of Contents
Scheuermann's kyphosis is a "developmental" type of kyphosis,
meaning that it happens during growth. The vertebral bodies wedge
forward. Normal vertebrae are rectangular-shaped and stacked on top of
one another like building blocks, with a soft cushion between each one.
If the front of the vertebrae wedges closer together in a triangular
shape, the spine starts to curve forward more than normal. This disease
develops in adolescents while their bones are still growing. It happens
to about one percent of this age group, affecting an equal number of
boys and girls.
Learn about Scheuermann's Kyphosis including
- how the thoracic spine is affected
- what causes the condition
- what symptoms are present
- how a diagnosis is made
- what treatment options are available
In order to understand your symptoms and treatment choices, it is
helpful to start with a basic understanding of the anatomy of the mid
back. Become familiar with the various parts that make up the thoracic
spine and how they work together. Learn more about the anatomy of the
thoracic spine.
The normal spine has three natural curves. The cervical spine curves
slightly inward, the thoracic slightly outward, and the lumbar slightly
inward. This shape provides an even distribution of weight and helps
the spine withstand all kinds of forces. Even though the lower portion
of the spine holds most of the body's weight, each segment relies upon
the strength of the others to function properly.
Kyphosis refers to the natural shape of the thoracic spine, which
usually has a forward curve of 20 to 40 degrees. This rounded shape is
a normal kyphosis, a "C" curve, with the opening of the C in the front.
If this curve is more than 40 to 45 degrees, it is considered abnormal
or a spinal deformity. Sometimes this deformity is described as "round
back posture" or "hunchback."
With Scheuermann's kyphosis, the thoracic curve is usually 45 to 75
degrees. There will also be vertebral wedging greater than five degrees
in three or more vertebrae in a row. The affected vertebrae have a
triangular appearance. They wedge forward, which reduces the space
between them. The thoracic spine angles forward into more kyphosis.
With Scheuermann's kyphosis, there are typically other abnormalities
in the affected vertebrae. Schmorl's nodes are areas where the disc
(cushion) between each affected vertebra pushes through the bone
surface at the bottom and the top (endplates) of the vertebra.
Ligaments are the structures that connect bones to bones, including
vertebrae. Patients with Scheuermann's kyphosis commonly have
thickening in the ligament that runs along the front of the spine (the
anterior longitudinal ligament). Some spine specialists believe that
the tightness of this ligament may be partly responsible for the spinal
deformity. The thickened ligament may affect the growth of one or more
vertebrae during childhood. This leads to more growth on the back of
the vertebrae and less in the front, resulting in one or more wedged
vertebrae.
The cause of Scheuermann's kyphosis has not been discovered, but
there are many possible theories about its development. Scheuermann, a
Danish radiologist, proposed that the problem started because cartilage
of the spinal bone's ring died from a lack of blood supply. He
suggested that this interrupted bone growth during development, leading
to wedging of the affected vertebrae.
Most researchers think that some sort of damage to the growth area
of the vertebrae starts the process. The abnormal growth produces
wedging of the vertebrae, which eventually leads to problems of
kyphosis. For instance, there may be a vertebral disorder during the
rapid growth spurts of adolescence, which causes abnormal bone growth.
Many spine specialists also suspect that a problem with the mechanics
of the spine (the way it is put together and functions) plays a part in
Scheuermann's kyphosis. Others suggest mild osteoporosis could
contribute to the deformity. Muscle abnormalities have also been
considered as a possible cause. And there does seem to be a high
genetic predisposition to this disease (runs in families).
Scheuermann originally noticed this spinal deformity in agriculture
workers who were frequently hunched or bent over. This of course led to
the question of whether poor posture could lead to extra kyphosis.
While this is a logical question, the connection between posture and
this deformity has never been confirmed. However, poor posture has been
shown to play a role in making the problem worse. Therefore, correcting
postural problems can sometimes help improve the abnormal kyphosis.
Symptoms of Scheuermann's kyphosis generally develop around puberty,
between the ages of 10 and 15. It's hard to determine when the problem
begins because X-rays don't show the changes until the child turns 10
or 11. The disease is often discovered when parents notice the onset of
poor posture, or slouching, in their child. The adolescent might
experience pain and fatigue in the mid back. The pain is rarely
disabling or severe at this point, unless the deformity is severe.
The extra kyphosis is generally slow to develop. When it progresses
to the point the rounded curve becomes noticeable, a concerned parent
or teacher will suggest a doctor visit. This is what leads most
children to get medical help-not the presence of pain. By comparison,
adults who developed Scheuermann's early in life tend to seek help
because pain from the deformity becomes unbearable.
A rigid curve in the spine is common with Scheuermann's kyphosis.
The curve gets worse with bending over and only partially corrects when
standing up straight. Pain typically increases with time and severity
of the deformity. Some patients with Scheuermann's kyphosis also have
scoliosis-about one third. Scoliosis
is another type of spinal deformity that usually occurs in teenagers.
Looking at an X-ray from the front, scoliosis curves side to side, like
an "S" rather than a straight line. Learn more about adolescent
idiopathic scoliosis.
People who have Scheuermann's kyphosis usually don't have nerve
problems from the spinal deformity. However, a severely rounded spine
can squeeze the contents of the chest and abdomen. The disorder may
eventually put pressure on the heart, lungs, and abdomen. This can mean
chest pain, shortness of breath, and a loss of appetite.
History and Physical Exam
When you visit the doctor, you will initially be asked for a history of your
condition. After taking a history, the physician will give you a physical exam.
This helps the doctor to rule out possible causes of kyphosis,
including Scheuermann's kyphosis, and to try to determine what is
causing the spinal deformity.
Diagnostic Tests
An X-ray
of the spine will probably be taken. The extra kyphosis will show up on
the X-ray and can be measured in degrees. If the problem is simply due
to postural problems, nothing else abnormal will show up on the X-ray.
But if the kyphosis is due to Scheuermann's disease, the X-ray will
show three or more adjacent vertebra that are wedged together at least
five degrees each. In addition, the X-ray will show if there are
Schmorl's nodes (the small herniations of disc through the endplates of
the vertebrae).
Arthritis may show up on X-rays in adults with extra thoracic
kyphosis. These changes generally coincide with an increase in pain.
Treatment of Scheuermann's kyphosis is somewhat controversial. It
depends on many things such as your age, the severity of the curve, and
the flexibility of the curve.
Conservative Treatment
Bracing
If possible, the deformity will be treated without surgery. One
option is bracing. The goal of bracing is to try to "guide" the growth
of the vertebrae in order to straighten the spine. The brace will only
successfully straighten the spine in patients who are still growing.
The brace is designed to hold the spine in a straighter, upright
posture. This is thought to work by taking pressure off the front half
of the vertebra, allowing the growth of the bone in the front to catch
up with the growth in the back. A brace may be used in older patients
to support the spine and relieve pain, but it will not improve the
curve.
There are many braces are available that keep the shoulders pulled
back and the chin upright. Braces are usually effective in adolescents
with curves of less than 75 degrees. Learn more about braces used to
treat back problems.
If young patients are consistent in wearing the brace, worsening of
the curve can be limited and there may be correction of the deformity
within two years. The brace allows remodeling and corrected growth of
the developing spine. The brace is usually worn from 16 to 24 hours
each day for one year, then just at night for two years.
Physical Therapy
The doctor may prescribe physical therapy. A well-rounded
rehabilitation program assists in calming pain and inflammation,
improving mobility and strength, and making daily activities easier.
People who are prescribed a brace tend to benefit even more when
physical therapy is included.
Exercise has not proven helpful for changing the kyphotic curve in
the mid back. However, it can be helpful when combined with bracing.
Treatments address flexibility of the low back and hamstring muscles,
back strength and posture, and ways to exercise at home. Patients may
require rechecks with the physical therapist once or twice each year
during periods of growth.
The goals of physical therapy are to help
- learn correct posture and body movements to counteract the effects of kyphosis
- maximize range of motion and strength
- foster aerobic fitness
- learn ways to manage your condition
Surgical Treatment
Surgery is usually only recommended if X-rays show a kyphosis over
75 degrees. A curve less than 75 degrees is usually treated with
observation or a brace. Surgery is occasionally performed for cosmetic
reasons. Because the surgery is serious and involves the spine, it
generally is not recommended just to improve appearance.
Fusion surgery is mainly used to correct Scheuermann's kyphosis. The
operation has two parts. One operation is done on the front of the
spine (anterior), and another one is done on the back (posterior).
These two surgeries used to be done about one week apart. Now many
doctors are doing both operations on the same day.
The anterior operation is usually done to "release" tight ligaments
along the front of the spine. Cutting these ligaments and removing the
discs between the vertebrae increases flexibility in the spine. This
allows the spine to be straightened easier when rods are put in from
the back of the spine. Next, the surgeon begins the posterior procedure
by working from the back of the spine. This is where the actual
correction of the spinal curve happens. Rods are attached along the
spine to align the spine and hold the spine in its corrected position.
Because most surgeries to correct kyphosis involve a rigid spine,
both anterior and posterior procedures are generally needed. There are
some cases of kyphosis, however, that can be corrected by the posterior
procedure alone. In fact, some surgeons are performing posterior-only
surgery for Scheuermann's kyphosis regardless of the size of the curve.
For the posterior-only approach, pedicle screws are used at each
spinal level to be fused. Rods are connected to the screws, allowing a
large amount of correction to occur. When this approach is chosen, the
anterior procedure is not used. For some patients, the posterior
procedure alone can realign the spine.
The doctor will advise which type of surgery is best. The surgical
approach used will depend upon the age of the patient, the flexibility
of the spine, the location and degree of the curve, and whether there
is pressure on any of the nerve roots.
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