Kyphosis and Scheurmann’s Disease
What is Kyphosis?
Kyphosis represents an anterior concave curvature of the spine, which is normally seen in the thoracic and sacral spine. Lordosis represents a posterior concave curvature of the spine, which is normally seen in the cervical and lumbar spine. A normal thoracic kyphosis ranges between 20° and 40°.
How do you get Kyphosis?
Several disorders are associated with kyphosis measuring greater than 40°. These include paralytic disorders, ankylosing spondylitis, myelomeningocele, osteoporosis, trauma, Scheuermann's kyphosis, infections, congenital kyphosis, malignancy, and postural kyphosis. If left untreated, kyphosis can lead to lumbar spondylosis, back pain, and neurologic compromise.
Postural kyphosis has a slightly higher prevalence among young girls and is especially apparent in patients during their growth spurt. In contrast, congenital kyphosis is rare.
Scheuermann's kyphosis is estimated in approximately 1% to 8% of the population, with a slightly higher incidence among men.
Osteoporosis, a common disorder leading to kyphosis due to multiple vertebral compression fractures, is common in elderly patients, females, and patients who use steroids and are of Caucasian or Asian decent. In addition, scoliotic curves ranging between 10° and 20° are present in 33% of these patients.
Numerous etiologies exist for the development of kyphosis. Stretching of the posterior ligaments is thought to cause postural kyphosis. Anterior wedging of the vertebrae causes kyphosis in Scheuermann's kyphosis, which occurs mainly in adolescence. In congenital kyphosis, patients have the disorder at birth and present with hemivertebrae or anterior fusion of the vertebrae. Kyphosis develops in patients with osteoporosis due to loss of anterior vertebral body height as a result of vertebral compression fractures in the thoracic spine. Lastly, patients with tuberculosis develop kyphosis resulting from the destruction of the vertebral body.
How is Kyphosis diagnosed?
Typical Scheuermann's kyphosis is characterized by more than 5° of anterior wedging of three or more consecutive vertebrae and the apex located between T7 and T9. Atypical Scheuermann's kyphosis is associated with Schmorl's nodes, disk space narrowing, and changes to the vertebral end plates with the apex usually located distal to T9.
Several laboratory tests should be performed when specific situations arise. When infection is suspected, a complete blood count, sedimentation rate, and blood culture should be obtained. If tuberculosis is suspected, then a purified protein derivative test should be performed. Patients who are suspected to have vertebral compression fractures due to osteoporosis should be evaluated with a DEXA (dual energy x-ray absorptiometry) scan. In addition, the possibility of multiple myeloma should be considered and ruled out in the appropriate patients with serum protein electrophoresis and urine protein electrophoresis studies. One should keep in mind that laboratory results are usually normal in patients with kyphosis, even when osteoporosis is present. The presence of ankylosing spondylitis is confirmed by evaluating for antibodies to HLA-B27.
How is Kyphosis treated?
The treatment of patients with kyphosis is based on the suspected etiology or diagnosis.
One can prevent postural kyphosis from developing by emphasizing proper posture. The prevention of osteoporosis helps prevent kyphosis due to multiple vertebral compression fractures and is based on appropriate calcium and vitamin D supplementation, as well as bisphosphonates or estrogens in appropriate patients.
Patients with discomfort relating to benign causes of kyphosis may benefit from physical therapy and analgesic medications (nonsteroidal agents or paracetamol). Those with postural kyphosis can perform postural exercises. A combination of strengthening and stretching exercises should be performed, especially strengthening of the abdominal muscles as well as the back extensors.
Bracing can be used in specific circumstances but is not a treatment option in correcting congenital kyphosis. Bracing may be effective in treating patients with Scheuermann's kyphosis, as well as for symptomatic relief in some patients with acute osteoporotic fractures.
Several options for the surgical treatment of kyphosis exist. Congenital kyphosis should be treated with surgery to prevent neurologic disorders as a result of the progression of the curvature of the spine. Current treatment options include fusion or osteotomy with anterior or anterior/posterior instrumentation.
In Scheuermann's kyphosis, surgery should be performed only when pain persist after nonoperative measures have failed. Treatment includes either posterior or anterior/posterior fusion with osteotomy; this decision is based on the magnitude of the kyphotic deformity.
In patients with osteoporotic vertebral compression fractures, kyphoplasty (Kyphoplasty tutorial) provides reliable pain relief and may help with height restoration. If pain is the only concern, then a vertebroplasty can be performed.
Patients with malignant or infectious lesions can be treated with decompression, correction of the deformity, and stabilization. Patients with tuberculosis are usually treated with multidrug therapy.