Ludloff’s sign is the inability to raise the thigh while sitting, accompanied by edema and ecchymosis at the base of Scarpa’s triangle. It is typically observed in children and indicates traumatic separation of the epiphyseal growth plate of the greater trochanter.

Pathophysiology

Normal physiology:

• The iliopsoas muscle normally elevates the thigh when the hip is flexed in the sitting position.

• The greater trochanter serves as a stable point of attachment for surrounding muscles.

Abnormal physiology (epiphyseal separation):

• Trauma to the hip region may cause epiphyseal separation of the greater trochanter in children, whose growth plates are weaker than the ligaments and tendons.

• The detachment compromises the leverage and stability of the hip abductors and flexors.

• Attempted thigh elevation while sitting becomes painful or impossible.

Associated findings: Edema, ecchymosis, and localized tenderness in Scarpa’s triangle (just below the inguinal fold).

Examination Technique

• Patient positioning: Seat the child in an upright position with hips flexed at 90°.

• Test movement: Ask the patient to actively raise the affected thigh.

• Observation: Inability or marked weakness in lifting the thigh, often with discomfort.

• Inspection: Look for swelling, bruising, and tenderness at the base of Scarpa’s triangle.

• Documentation: Record side involved, severity of pain, and any coexisting trauma findings.

Clinical Features

Differential Diagnosis

Special populations

Children:

• Most commonly affected due to weaker epiphyseal plates.

• Early diagnosis prevents long-term growth disturbances or deformity.

Adolescents/Adults:

• Rare, as epiphyseal plates are closed. Similar findings may instead indicate fractures or muscle/tendon injury.

Limitations

• Requires patient cooperation; younger children may have difficulty performing the test.

• Severe pain or swelling may limit assessment.

• Must differentiate from hip joint pathologies or muscular injuries.

Patient counseling

• Explain that the sign suggests injury to the hip growth plate rather than a muscle problem.

• Stress the importance of imaging (X-ray, MRI) to confirm diagnosis.

• Recommend immobilization, orthopedic consultation, and follow-up to prevent complications such as abnormal hip growth or deformity.

• Reassure families that with proper treatment, most children recover without long-term disability.

Conclusion

Ludloff’s sign is a specific clinical indicator of epiphyseal separation of the greater trochanter in children, manifested as inability to raise the thigh while sitting with edema and bruising at Scarpa’s triangle. Recognizing this sign facilitates early orthopedic referral and management, preventing long-term sequelae.

References

1. McRae R, Esser M. Practical Fracture Treatment. 6th ed. Philadelphia: Elsevier; 2014.

2. Morrissy RT, Weinstein SL. Lovell and Winter’s Pediatric Orthopaedics. 7th ed. Philadelphia: Lippincott Williams & Wilkins; 2013.

3. Canale ST, Beaty JH. Campbell’s Operative Orthopaedics. 14th ed. Philadelphia: Elsevier; 2021.

4. Ludloff K. Über traumatische Epiphysenlösungen am grossen Trochanter. Deutsche Zeitschrift für Chirurgie. 1908;94:273–279.