A healthy human spine has three gradual curves. From the side, the neck and low back curve gently inward. This is called lordosis. The thoracic kyphosis (outward curve) gives the mid back its slightly rounded appearance. These normal curves help the spine absorb forces from gravity and daily activities, such as lifting.
Background:
The angle of normal kyphosis in the thoracic spine varies. During the growth years of adolescence, a normal curve measures between 25 and 40 degrees. If the curve angles more than 40 degrees, doctors consider the kyphosis a deformity. In general, Scheuermann's disease causes the thoracic kyphosis to angle too far (more than 45 degrees). (e.g. a hunch back or hump back) but no pain.
The name of this condition comes from Scheuermann, the person who in 1921 described changes in the vertebral endplates and disc space that can occur during development and lead to kyphosis, or roundback deformity of the thoracic spine (upper back).
Pathophysiology: Scheuermann disease refers to osteochondrosis of the secondary ossification centers of the vertebral bodies.
Represents a condition where the endplates of the disc spaces are not strong enough to withstand the pressures generated within the disc spaces. This leads to disc herniations into the vertebral bodies (called Schmorl?s nodes) and causes back pain at an early age
when the front of the upper spine does not grow as fast as the back of the spine, so that the vertebrae become wedge-shaped, with the narrow part of the wedge in front. The wedge-shape of the vertebra creates an increase in the amount of normal kyphosis.
A long ligament called the anterior longitudinal ligament connects on the front of the vertebral bodies. This ligament typically thickens in patients with Scheuermann's disease. This adds to the forward pull on the spine, producing more wedging and kyphosis.
The wedging of vertebrae in Scheuermann?s kyphosis is most common in
1. The thoracic spine (upper back), with the apex of the curve typically between the T7 and T9 levels of the spine.
2. The junction between the thoracic and lumbar spine (thoracolumbar spine) or in the lumbar spine (lower back).
Frequency:
In the US: The prevalence rate of Scheuermann kyphosis is thought to be 0.4-8%.
Mortality/Morbidity: if residual kyphosis remains less than 60? at skeletal maturity, the patient has an excellent prognosis for minimal problems in adult life.
Sex: both sex but Boys are affected more frequently than girls.
Age: The condition affects children aged 13-16 years towards the end of their growth spurt.
History:
The parent brings the child to the physician because of poor posture.
Patients may complain of dull, aching and intermittent pain in the region of the kyphosis; it is related generally to activity and is relieved by rest.
Patients are tall, and have advanced skeletal versus chronologic age.Some affected children have disproportionate limb lengths.
An increased incidence of spondylolysis and spondylolisthesis also was reported in patients with Scheuermann kyphosis.
Exaggerated kyphosis can lead to an increased lordosis (inward curve) in the low back may produce low back pain.
Physical:
The normal curvature of the thoracic spine is between 20 and 40 degrees. A curvature of more than 40 degrees, where the spine has three contiguous vertebral bodies that have wedging of 5 degrees or more, constitutes Scheuermann?s disease.
Patients with upper thoracic Scheuermann disease present with a kyphotic deformity best demonstrated in the forward flexed position.
Decreased flexibility of the spine is noted, indicating the structural nature of the kyphotic deformity, in contrast to patients with flexible postural kyphosis.
Patients may have tenderness to palpation above and below the apex of the kyphosis.
A high association exists between scoliosis and Scheuermann disease. Patients also may have a hyperlordosis in the lumbar spine.
Lower thoracic kyphosis is localized at the thoracolumbar junction; in general, any kyphotic deformity present at this level must be considered abnormal.
Hamstring tightness may be present in these patients.
A careful neurologic examination is recommended, although neurologic deficits are extremely rare.
Causes:
Scheuermann himself thought a lack of blood to the cartilage around the vertebral body caused the wedging. Though scientists have since disproved this theory, the root cause of the disease is still unknown.
Mounting evidence suggests wedging develops as a problem vertebral body grows. During normal growth, the cartilage around the vertebral body turns evenly and completely to bone. If the change from cartilage to bone doesn't happen evenly, one side of the vertebral body grows at a faster rate. By the time the entire vertebral body turns to bone, one side is taller than the other. This is the wedge shape that leads to abnormal kyphosis.
Other theories of how Scheuermann's kyphosis starts include:
- genetics.
- childhood osteoporosis.
- mechanical reasons.
-Genetics:
Researchers have suggested that this disease can be passed down in families.
-Childhood osteoporosis:
One medical study found that some patients with Scheuermann's disease had mild osteoporosis (decreased bone mass) even though they were very young. Other studies did not show problems with osteoporosis. More research is needed to confirm the role of osteoporosis in Scheuermann's disease.
-Mechanical Reasons:
These include strains from bending, heavy lifting, and using poor posture. This theory makes sense because the back braces used in treating kyphosis work. If a back brace can straighten a bent spine, then perhaps mechanical forces could cause more kyphosis than naturally occurs in the spine. (Back braces are discussed in more detail later.) Scientists are not convinced that mechanical reasons cause the disease; rather, these factors likely aggravate the condition.
Imaging Studies:
Doctors start with a complete history and physical examination. However, X-rays are the main way to diagnose Scheuermann's kyphosis. Taken from the side, an X-ray may show vertebral wedging, Schmorl's nodes, and changes in the vertebral end plates. Doctors use X-ray images to measure the angle of kyphosis. Doctors diagnose Scheuermann's disease when three vertebrae in a row wedge five degrees or more and when the kyphosis angle is greater than 45 degrees.
A side-view X-ray can also show if the spine is flexible or rigid. Patients are asked to bend back and hold the position while an X-ray is taken. The spine straightens easily when it is flexible. In patients with Scheuermann's disease, however, the curve stays rigid and does not improve by trying to straighten up.
From the front, X-rays show if the spine curves from side to side. This sideways curve is called scoliosis and occurs in about one-third of patients with Scheuermann's kyphosis.
X-rays can show signs of wear and tear in adults who have extra lumbar lordosis from years of untreated Scheuermann's disease.
Computed tomography (a CT scan) may be ordered. This is a detailed X-ray that lets doctors see slices of the body's tissue.
Myelography is a special kind of X-ray test. For this test, dye is injected into the space around the spinal canal. The dye shows up on an X-ray. This test is especially helpful if the doctor is concerned whether the spinal cord is being affected.
Magnetic resonance imaging (MRI) uses magnetic waves rather than X-rays to show the soft tissues of the body. This machine creates pictures that look like slices of the area the doctor is interested in. The test does not require special dye or a needle.
Rehabilitation Program:
Physical Therapy:
The treatment of Scheuermann's disease depends upon several factors, including the age of the patient, the severity of the curve, the presence or absence of back pain, and whether or not the lungs are developing and functioning normally.
If a patient is young, has a mild curve, no back pain, and normal pulmonary function, then continued observation by a doctor is usually prescribed, with repeat clinical examinations and radiographs at regular intervals (often every year).
strengthen the muscles that support the spine Certain exercises are beneficial when used in combination with a brace. Upper back exercises, such as gentle back bends (extension) can improve posture and prevent the spine from slouching forward, Hamstring stretches and pelvis exercises improve posture by preventing extra lordosis in the low back.This type of therapy is considered an important part of ensuring the curve stays as flexible as possible, and that the muscles of the back are as strong as possible in an effort to prevent further progression. Aerobic exercise improves heart and lung health and combats pain.
reducing weight-bearing stress and avoiding strenuous activity. Exercise alone is not found to be beneficial.
When the kyphosis is more severe, recommendations include casting, a spinal brace, or rest and recumbency on a rigid bed. Orthotic management of Scheuermann kyphosis usually requires 12-24 months of treatment.
A brace is most effective when used before the skeleton matures at about age 14. Doctors commonly chose a
Pain is also addressed by the physical therapist. The therapist may apply heat, cold, ultrasound, and massage treatments. Adults who've had kyphosis for many years (and the resulting low back pain from too much lordosis) benefit from postural exercises to reduce the lumbar curve, followed by stabilization exercises to help them keep better posture. Patients benefit most when these exercises are done regularly and for a lifetime.
After Surgery
Rehabilitation after surgery is more complex. Although some patients leave the hospital shortly after surgery, some surgeries require patients to stay in the hospital for a few days. Soon after surgery, a physical therapist may visit patients who stay in the hospital. The treatment sessions help patients learn to move and do routine activities without putting extra strain on the back.
During recovery from surgery, patients should follow their surgeon's instructions about wearing a back brace or support belt. They should be cautious about overdoing activities in the first few weeks after surgery.
Many surgical patients also need physical therapy outside of the hospital. Patients normally wait up to three months before beginning a rehabilitation program after fusion surgery for Scheuermann's disease. They typically need to attend therapy sessions for eight to 12 weeks. Full recovery may take up to eight months.
Upon completing physical therapy, patients are in charge of doing their exercises as part of an ongoing home program.
Complications:
Complications that may develop from Scheuermann disease include chronic back pain, progressive deformity, and neurologic deficits. Following operative treatment, the most common complication is pseudoarthrosis, following by instrumentation failure and secondary loss of correction.
Acute myelopathy secondary to cord compression at the apex of the thoracic kyphosis has been reported.
Posted dr/Mohamed rizk
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