Kyphosis: Description and Diagnosis
What Is Kyphosis?
Kyphosis is a progressive spinal disorder that can affect children or adults. This disorder may cause a deformity described as humpback or hunchback. Kyphosis can be in the form of hyperkyphosis or sharp angular gibbus deformity (see 'Gibbus Deformity' below). Abnormal kyphotic curves are more commonly found in the thoracic or thoracolumbar spine, although they can be cervical.
Frequent causes of kyphosis are:
- Postural round-back
- Scheuermann's Disease
- Congenital Kyphosis
- Kyphosis associated with neuromuscular disorders
- Kyphosis secondary to trauma, tumors, infection, and arthritis
Kyphosis in the thoracic spine means exaggerated kyphotic angle from the spine's normal kyphotic curve. Normal lordotic curves in the cervical and lumbar regions may also be diminished to contribute to the overall pitched-forward posture. The spine's natural curves position the head over the pelvis and work as shock absorbers to distribute mechanical stress during movement.
Postural and Structural Kyphosis
Kyphosis is classified as either postural or structural. Postural means the kyphosis is attributed to poor posture, usually presenting a smooth curve, which can be corrected by the patient. Structural kyphosis is caused by an abnormality affecting the bones, intervertebral discs, nerves, ligaments, or muscles.
Kyphosis with a structural pathology may require medical intervention because the patient alone cannot control curve progression.
A Gibbus Deformity is a form of structural kyphosis. The posterior (from behind) curve presents sharply angled; the curvature is not smooth. This deformity may result in a humpback found to be more prominent when bending forward.
This term is used to describe 'excessive' (hyper) curvature exceeding the normal range. Hyperkyphosis occurs in the thoracic spine. In adults, osteoporosis is a common cause often involving several vertebrae.
Congenital means the disorder is found at birth. Congenital kyphosis is a structural abnormality.
Scheuermann's Disease is juvenile (adolescent) thoracic kyphosis. Although the cause is unknown, it may be familial. This disease can cause decreased intervertebral disc space and vertebral wedging resulting in an excessive curve described as stiff or rigid. The classic definition of Scheuermann's is anterior (front) vertebral wedging of at least 5 degrees involving three consecutive vertebrae. The neck and head may present in an abnormal forward position. The onset usually begins (or is noticed) between the ages of 12 and 15 years affecting females more often than males. For many patients (up to 50%), pain is a common complaint.
Deformity and pain often motivates the patient to visit their physician. Early treatment is important to control curve progression especially in adolescents.
A thorough physical examination reveals a lot about the health and general fitness of the patient. The exam provides a baseline from which the physician can measure the patient's progress during treatment. The physical exam will include:
- Observation of the posture may reveal round-back or gibbus deformity. The sagittal balance or balance of the head and trunk over the pelvis viewing from the side can be assessed. Any associated scoliosis will be observed.
- Adam's Forward Bending Test requires the patient to bend forward at the waist. This may reveal a thoracolumbar kyphosis.
- Palpation determines spinal abnormalities by feel. Often the paraspinal musculature is tender. When Scheuermann's Disease is present, the hamstring muscles may be tight.
- Range of Motion measures the degree to which a patient can perform movements of flexion, extension, lateral bending, and spinal rotation. Asymmetry is also noted. The deformity is palpated during range of motion to assess flexibility or rigidity of the curve.
A neurological evaluation includes an assessment of the following symptoms: pain, numbness, paresthesias (e.g. tingling), extremity sensation and motor function, muscle spasm, weakness, and bowel/bladder changes.
Full-length AP (anterior/posterior, front/back) x-rays are taken of the spinal column. The patient stands with arms extended forward while keeping the head erect. To determine curve flexibility, x-rays may be taken with the patient supine. These x-rays are used to evaluate vertebral wedging and end plate irregularities, characteristic of Scheuermann's Disease.
An MRI may be ordered if the spinal cord has been compromised (or suspected). The Cobb Angle Method measures the kyphotic curve in degrees using a standard full-length AP x-ray.