Scheuermann Juvenile Kyphosis

Scheuermann juvenile kyphosis is a structural, fixed thoracic (or, less commonly, thoracolumbar) kyphosis occurring in adolescence. It results from abnormal vertebral body growth and wedging affecting multiple contiguous vertebrae. It is the commonest cause of structural, as opposed to simple postural, kyphosis in adolescents.

The key diagnostic distinction is from simple postural round-back posture, which is correctable with active effort or on prone hyperextension. Management implications differ.

The underlying cause remains incompletely understood. It is believed to reflect genetic predisposition combined with mechanical factors affecting the growth pattern of the anterior vertebral body growth plates during the adolescent growth spurt.

Pathophysiology

• Abnormal growth of the anterior vertebral body growth plates, relative to the posterior elements, produces progressive anterior wedging of the affected vertebral bodies.
• Wedging occurs across multiple (generally at least three) contiguous vertebrae. It produces the structural, fixed kyphotic deformity that defines the condition. Simple postural kyphosis, by contrast, is a functional, correctable pattern without structural vertebral abnormality.
• Schmorl nodes (focal herniation of intervertebral disc material through the vertebral body endplate into the adjacent vertebral body) and irregular vertebral endplates frequently accompany the wedging. They are characteristic radiographic findings.
• Proposed contributing factors are genetic predisposition, with a recognised but incompletely characterised familial tendency, and mechanical factors.
• Mechanical factors include relatively increased loading on the anterior vertebral growth plates during rapid growth, potentially exacerbated by specific activities or postural patterns. No single causal mechanism has been definitively established.

• The characteristic presentation is a progressive, structural thoracic kyphosis ("round back" deformity), typically becoming apparent in early to mid-adolescence. It is often first noticed by a parent or identified on routine screening examination.
• The deformity is fixed and not fully correctable on active postural effort, which distinguishes it from simple postural round-back posture.
• Back pain, typically mild to moderate and localised to the apex of the kyphosis, occurs in a substantial proportion of affected adolescents. Some remain asymptomatic, with the deformity as the sole concern.
• On examination the thoracic kyphosis persists, or is only partially correctable, on active extension or with the adolescent prone.
• The prone position is a useful manoeuvre. The deformity persists in Scheuermann kyphosis, whereas simple postural kyphosis characteristically corrects substantially.
• Compensatory lumbar hyperlordosis and tight hamstrings are frequently associated.
• A degree of associated scoliosis may coexist in a proportion of adolescents, so assess the whole spine for this additional deformity.

• Diagnosis rests on the characteristic clinical findings with confirmatory standing lateral spinal radiography.
• Radiography shows anterior wedging, generally defined as at least 5 degrees of wedging across at least three contiguous vertebrae, together with endplate irregularity and Schmorl nodes.
• Measure the kyphotic angle by the Cobb technique, as for scoliosis, on standing lateral radiography. It gives an objective, quantifiable measure of severity and supports monitoring of progression over time.
• Magnetic resonance imaging is generally reserved for significant, atypical or progressive neurological symptoms. These are unusual in straightforward Scheuermann kyphosis and warrant consideration of an alternative or additional pathology.
• Magnetic resonance imaging is not routinely required for standard diagnostic evaluation.

• Observation, with periodic clinical and radiographic reassessment, is appropriate for mild, non-progressive deformity. This applies particularly to an adolescent at or approaching skeletal maturity, as further progression is generally limited once growth is substantially complete.
• Physiotherapy is a reasonable, generally recommended adjunct for symptomatic relief and postural support. It focuses on postural education, core and extensor muscle strengthening, and hamstring stretching.
• Evidence is limited for a substantial direct effect of physiotherapy on the structural deformity or its rate of progression.
• Bracing may be considered for moderate, progressive deformity in a skeletally immature adolescent with substantial remaining growth potential. It aims to limit progression during growth. The brace is typically a thoracolumbosacral orthosis or an extension-focused design.
• The evidence base and indications for bracing are somewhat less robust than its role in idiopathic scoliosis.
• Surgical correction (typically posterior spinal instrumentation and fusion) is reserved for severe, significantly progressive deformity, generally exceeding a substantial kyphotic angle threshold.
• It is also used for deformity with significant, persistent pain not responding to conservative management or, rarely, with neurological compromise. It is a substantial undertaking reserved for a relatively small proportion of the most severely affected adolescents.
• Educate patients and families that the condition is generally benign, though occasionally cosmetically and, less commonly, symptomatically significant.
• Reassurance and periodic follow up to monitor progression during remaining growth underpin proportionate management of this common adolescent spinal condition.