What is Scheuermann's Kyphosis?
Scheuermann's kyphosis is a structural spinal deformity characterized by excessive forward rounding of the thoracic spine, defined radiographically as anterior wedging of 5° or more in at least 3 adjacent vertebral bodies with thoracic kyphosis exceeding 45° between T5 and T12. 1
Epidemiology and Prevalence
- Scheuermann's kyphosis affects between 0.4% to 10% of the general population, making it the most common cause of structural kyphosis in adolescents 2, 3, 4
- The condition develops during early adolescence and affects males and females equally 4
- It represents a rigid, structural deformity—not simply poor posture—though parents frequently confuse the two 1, 4
Pathophysiology and Etiology
- The exact cause remains unknown but is believed to be multifactorial with a likely genetic component 1, 5
- Current theories include alterations in mechanical stress, hormonal disturbances, growth irregularities, and poor bone quality 5, 3
- Candidate genes have been identified linking to the inheritance of Scheuermann's kyphosis 5
Diagnostic Features
Clinical Presentation
- Patients typically present with increased posterior rounding and visible deformity of the thoracic spine 1
- Back pain may be present but is not universal 1
- Parental concerns often center on cosmetic deformity and progressive nature of the condition 1
Radiographic Criteria
- Classic diagnostic criteria: Anterior wedging of ≥5° in 3 or more consecutive thoracic vertebral bodies with kyphosis >45° between T5-T12 1
- Vertebral end plate irregularities are characteristic 4
- Disk space narrowing in affected segments 4
- Additional imaging with CT or MRI may provide value in specific cases 4
Natural History and Prognosis
- The natural progression is typically gradual over years 5
- Patients with mild disease (<70°) generally have favorable prognosis with good clinical outcomes 3
- Severe deformity can be associated with significant morbidity including intractable pain, neurologic compromise, and cardiopulmonary issues 5, 3
Clinical Pitfalls
- Delayed diagnosis is common because the deformity is frequently misattributed to "poor posture" rather than recognized as a structural abnormality 2
- Unlike postural kyphosis, Scheuermann's kyphosis is rigid and does not correct with hyperextension or prone positioning 1
- The condition is progressive, particularly during periods of skeletal growth, making early recognition critical 1