Musculoskeletal · Spinal Deformities
The facts most likely to be tested
Scheuermann kyphosis is a structural deformity characterized by anterior wedging of at least 5 degrees in three or more consecutive thoracic vertebrae.
The Adams forward bend test is the primary screening tool used to differentiate structural kyphosis from postural kyphosis.
Schmorl nodes (herniation of the nucleus pulposus into the vertebral body endplate) are a pathognomonic radiographic finding of Scheuermann disease.
Postural kyphosis is a flexible deformity that is fully correctable with hyperextension and is typically associated with poor posture.
Cobb angle measurement on a lateral spine radiograph is the gold standard for quantifying the severity of the spinal curvature.
Physical therapy and core strengthening are the first-line treatments for mild to moderate postural kyphosis.
Milwaukee bracing or surgical spinal fusion is indicated for patients with Scheuermann kyphosis who have a Cobb angle greater than 60 degrees or persistent pain.
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A 14-year-old male presents to the clinic for a routine sports physical. His mother notes that he has developed a persistent 'slouch' over the past year that does not improve when he is reminded to stand straight. On physical exam, he has a fixed thoracic hyperkyphosis that does not correct with voluntary extension. The Adams forward bend test reveals a sharp, angular deformity. Lateral spine radiographs demonstrate anterior wedging of the T7, T8, and T9 vertebrae and the presence of Schmorl nodes.
What is the most likely diagnosis?
Scheuermann kyphosis
The patient's fixed deformity, radiographic evidence of anterior wedging, and Schmorl nodes are classic diagnostic criteria for Scheuermann kyphosis, distinguishing it from postural kyphosis.
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Etiology / Epidemiology
Common in postmenopausal women due to osteoporosis and adolescents with Scheuermann's disease.
Clinical Manifestations
Presents as exaggerated thoracic curvature (hunchback) with dowager's hump and potential neurologic deficits.
Diagnosis
Lateral spine radiograph with a Cobb angle > 50 degrees is the diagnostic threshold.
Treatment
Physical therapy and core strengthening are first-line; surgery is reserved for severe, progressive cases.
Prognosis
Risk of restrictive lung disease and vertebral fractures; monitor for progressive deformity.
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Epidemiology & Etiology
Postural kyphosis is common in adolescents, while structural kyphosis is frequently linked to osteoporosis in the elderly. Scheuermann's disease is the most common cause of structural kyphosis in adolescents, characterized by rigid deformity. Congenital defects and spinal infections like Pott's disease (tuberculous spondylitis) remain critical differentials.
Pertinent Anatomy
The thoracic spine normally exhibits a mild kyphotic curve. Pathological kyphosis involves an increase in this curvature, shifting the center of gravity anteriorly and increasing stress on the vertebral bodies.
Pathophysiology
In Scheuermann's disease, irregular ossification of the vertebral endplates leads to wedging of the vertebrae. Osteoporotic kyphosis results from micro-fractures and subsequent anterior vertebral body collapse. Chronic poor posture leads to soft tissue contractures, further fixing the deformity.
Clinical Manifestations
Patients present with a visible thoracic hump and rounded shoulders. Look for dowager's hump in elderly patients with osteoporosis. Red flags include radiculopathy, bowel/bladder dysfunction, or progressive pain, which suggest spinal cord compression.
Diagnosis
The lateral spine radiograph is the gold standard for assessment. A Cobb angle > 50 degrees confirms the diagnosis. MRI is indicated if there are neurological symptoms or suspicion of infection/malignancy.
Treatment
Management focuses on physical therapy and core strengthening to improve posture. Bracing is utilized for Scheuermann's disease if the curve is 50-75 degrees. Surgery (spinal fusion) is indicated for curves > 75 degrees or refractory pain. Avoid opioids for chronic pain management.
Prognosis
Severe kyphosis can lead to restrictive lung disease due to decreased chest wall compliance. Patients require periodic monitoring for progressive deformity and neurological status.
Differential Diagnosis
Scheuermann's disease: rigid deformity with vertebral wedging
Postural kyphosis: flexible deformity correctable by patient
Osteoporotic fracture: acute onset pain with history of low bone density
Ankylosing spondylitis: morning stiffness and sacroiliitis
Pott's disease: systemic symptoms with spinal destruction