Pediatric hip effusions: evaluation with power Doppler sonography

Area of Science:

• Pediatric Radiology
• Musculoskeletal Imaging
• Diagnostic Ultrasound

Background:

• Hip effusions in children can be infectious or non-infectious, necessitating accurate diagnosis.
• Distinguishing between septic arthritis and transient synovitis is critical for timely treatment and preventing joint damage.

Purpose of the Study:

• To evaluate the efficacy of power Doppler sonography in differentiating infectious (septic arthritis) from non-infectious (transient synovitis) hip effusions.
• To determine if power Doppler sonography can obviate the need for joint aspiration in pediatric hip effusions.

Main Methods:

• Prospective evaluation of 29 children (30 hips) with sonographically identified hip effusion.
• Power Doppler sonography was used to assess blood flow in affected hips compared to contralateral normal hips.
• Medical chart review confirmed the final diagnosis for each patient.

Main Results:

• None of 16 patients with transient synovitis showed increased flow on power Doppler sonography.
• Only one of 11 patients with septic arthritis had asymmetric increased flow; two others had probable increased flow.
• Three patients with miscellaneous diagnoses exhibited symmetric normal flow.

Conclusions:

• Power Doppler sonography did not reliably detect increased blood flow in most cases of pediatric septic arthritis.
• Normal power Doppler sonography findings do not exclude septic arthritis.
• Joint aspiration should not be precluded by normal power Doppler sonography findings when clinically indicated.