Trethowan's sign

Trethowan's Sign

Trethowan's sign is a clinical indicator used in the diagnosis of slipped capital femoral epiphysis (SCFE), a condition affecting the hip joint in adolescents. It is named after the British surgeon John Trethowan, who first described the sign.

Description

Trethowan's sign is identified on an anteroposterior (AP) X-ray of the pelvis. It involves drawing a line along the superior border of the femoral neck (known as Klein's line) and observing its intersection with the epiphysis of the femoral head. In a normal hip, Klein's line should intersect the lateral aspect of the femoral head. In the presence of SCFE, the line does not intersect the epiphysis, indicating a slippage of the femoral head.

Clinical Significance

The presence of Trethowan's sign is a key diagnostic feature of SCFE, which is a common hip disorder in adolescents, particularly during periods of rapid growth. Early detection of SCFE is crucial to prevent further slippage and to avoid complications such as avascular necrosis of the femoral head or osteoarthritis in later life.

Diagnosis and Management

The diagnosis of SCFE is typically confirmed through radiographic imaging, with Trethowan's sign being a critical component of the assessment. Once diagnosed, the management of SCFE often involves surgical intervention to stabilize the femoral head and prevent further slippage. Common surgical procedures include in situ pinning or more complex reconstructive surgeries depending on the severity of the slip.

Related Pages

• Slipped capital femoral epiphysis
• Hip joint
• Avascular necrosis
• Osteoarthritis

References

• Loder, R. T., & Skopelja, E. N. (2011). The epidemiology and demographics of slipped capital femoral epiphysis. ISRN Orthopedics, 2011.
• Kelsey, J. L., & Keggi, K. J. (1981). An epidemiological study of slipped capital femoral epiphysis. Clinical Orthopaedics and Related Research, (156), 43-47.

Images

Trethowan's sign as seen in SCFE on an X-ray.