Desault’s sign is an orthopedic sign indicative of intracapsular fracture of the femur. It involves an alteration of the normal rotational arc of the greater trochanter during passive rotation of the femur. In a healthy hip, the greater trochanter describes a circular arc when the femur is rotated. In the presence of an intracapsular femoral fracture, the greater trochanter rotates only about the axis of the femur, producing a markedly reduced arc of motion.

Pathophysiology

• Intracapsular femoral fractures disrupt the structural continuity of the femoral neck within the hip joint capsule.

• The greater trochanter normally traces a wide arc during rotation due to the intact lever mechanics of the femoral neck and head.

• Fracture fixation within the capsule prevents full rotation of the proximal femur, resulting in:

  • Restricted rotational movement of the hip

  • Reduced excursion of the greater trochanter

  • Pain during passive motion

Examination Technique

1. Patient Positioning: Supine on the examination table with the affected leg relaxed.

2. Passive Rotation: Gently rotate the femur internally and externally while observing the movement of the greater trochanter.

3. Assessment: Compare the arc of the greater trochanter’s motion with the contralateral (unaffected) hip.

   • Positive Desault’s sign: The arc of the greater trochanter is significantly smaller than normal, suggesting an intracapsular fracture.

Clinical Utility

• Indicator of intracapsular femoral fractures: Often complements other signs such as shortening, external rotation, and pain on hip movement.

• Preoperative assessment: Helps in localizing the fracture and planning surgical intervention.

• Adjunct to imaging: Positive Desault’s sign supports radiographic evaluation when fractures are not immediately obvious on X-ray.

Differential Diagnosis

Pediatric considerations

• Rarely assessed in children; similar principles apply for proximal femoral injuries.

• Careful handling is essential to avoid iatrogenic injury.

Geriatric considerations

• High relevance in elderly patients prone to osteoporotic hip fractures.

• Early detection using Desault’s sign can prompt timely surgical management, reducing morbidity.

Limitations

• Pain and muscular spasm may limit assessment, giving false negatives.

• Should be used alongside imaging for definitive diagnosis.

• Requires comparison with the contralateral hip to account for individual anatomical variations.

Patient counseling

• Explain that the test assesses hip rotation to detect fractures.

• Emphasize the need for gentle movement to avoid aggravating pain or causing further injury.

• Discuss next steps, including radiographic imaging and possible surgical intervention if positive.

Conclusion

Desault’s sign is a clinically valuable orthopedic marker of intracapsular femoral fractures. When combined with other physical signs and imaging, it enhances the early recognition and management of hip fractures, particularly in the elderly and trauma patients.

References

1. Rockwood CA, Green DP, Bucholz RW, Heckman JD. Rockwood and Green’s Fractures in Adults. 9th ed. Philadelphia: Wolters Kluwer; 2020.

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

3. Desault JB. Traité des Maladies des Os et des Articulations. Paris: 1798.

4. Browner BD, Jupiter JB, Levine AM, Trafton PG. Skeletal Trauma: Basic Science, Management, and Reconstruction. 5th ed. Philadelphia: Elsevier; 2020.

5. Court-Brown CM, Heckman JD. Rockwood and Green’s Fractures in Adults: Hip Fractures. Philadelphia: Lippincott Williams & Wilkins; 2015.