Ultrasound is better than x-ray at detecting hip effusions in the limping child
Date First Published:
March 1, 2000
Last Updated:
February 19, 2003
Report by:
Nicola Wright, Medical Student (Manchester Royal Infirmary)
Search checked by:
Vince Choudhery, Manchester Royal Infirmary
Three-Part Question:
In [a child with an irritable hip] is [x-ray better than ultrasonography] at [detecting a hip effusion]?
Clinical Scenario:
A 3 year old child presents to the Emergency Department with recent onset of left-sided limp and no history of trauma. He is apyrexial, systemically well with a normal white cell count and ESR. You diagnose irritable hip and wonder whether x-ray or ultrasonography is better at detecting a joint effusion.
Search Strategy:
Medline 1966-10/99 using the OVID interface.
Search Details:
[({exp Hip joint OR exp hip OR hip$.mp} AND {exp pain OR pain$.mp OR irritable$.mp OR limp$.mp OR exp synovitis OR synovitis.mp}) AND {exp pediatric OR pediatric$.mp OR paediatric.mp OR child$] AND {exp ultrasonography OR ultrasound$.mp} LIMIT to human AND english.
Outcome:
52 papers found of which 46 irrelevant or of insufficient quality for inclusion. The six remaining papers are shown in the table.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Arthrosonography of the irritable hip in childhood: a review of 1 year's experience. Adam R, Hendry GM, Wild SR et al. 1986, UK | 87 children with irritable hip | Diagnostic | Detection of effusions | 28 of 47 children with an effusion on ultrasound had x-ray abnormalities | No universal gold standard |
| The validity of radiographic assessment of childhood transient synovitis of the hip. Rosenborg M and Mortensson W. 1986, Sweden | 58 examinations of 47 children, 40 of whom had acute unilateral transient synovitis of the hip | Diagnostic | Detection of effusions | 43% of 23 children with an effusion on ultrasound had iliopsoas fatty layer sign on plain x-ray, while 52% had and abnormal capsular fat pad sign. | No universal gold standard |
| Ultrasonography of hip joint effusions. Zieger MM, Dorr U, Schulz RD. 1987, Germany | 123 consecutive patients with suspected joint effusions | Diagnostic | Detection of effusions | USS 100% sensitive | No universal gold standard |
| Sonography of the painful hip in children: 500 consecutive cases. Miralles M, Gonzalez G, Pulpeiro JR et al. 1989, Spain | 500 children with a painful hip or a limp | Diagnostic | Detection of effusions | 58 of 235 patients with effusions on ultrasound had abnormal x-rays. 4 patients with normal ultrasounds had abnormal x-rays. | No universal gold standard |
| Change in clinical care | USS detection of effusion changed clinical care in only 6 cases | ||||
| Ultrasound examination of the irritable hip. Bickerstaff DR, Neal LM, Booth AJ et al. 1990, UK | 111 children with acute hip pain | Diagnostic | Change in clinical care | X-ray changed clinical care in only 2 cases (children with Perthes' disease) | No universal gold standard |
| Detection of effusions | Effusion detected in 71% by USS but only in 15% by x-ray. | ||||
| Ultrasound in the diagnosis and follow-up of transient synovitis of the hip. Terjesen T and Osthus P. 1991, Norway | 59 children with acute synovitis of the hip. | Diagnostic | Detection of effusions | Effusions detected in all patients by USS, but in none by x-ray. | No universal gold standard |
Author Commentary:
In all the studies found, USS was its own gold standard for the detection of hip effusions. Therefore no comment about the sensitivity or specificity of USS itself can be made. X-ray is, however, clearly less sensitive than USS at detecting hip effusions. The role of x-ray in detecting Perthes' disease should not be forgotten.
Bottom Line:
Ultrasound is more sensitive than plain x-ray at detecting hip effusions in children. It should be the first imaging investigation of the irritable hip.
Level of Evidence:
Level 2: Studies considered were neither 1 or 3
References:
- Adam R, Hendry GM, Wild SR et al.. Arthrosonography of the irritable hip in childhood: a review of 1 year's experience.
- Rosenborg M and Mortensson W.. The validity of radiographic assessment of childhood transient synovitis of the hip.
- Zieger MM, Dorr U, Schulz RD.. Ultrasonography of hip joint effusions.
- Miralles M, Gonzalez G, Pulpeiro JR et al.. Sonography of the painful hip in children: 500 consecutive cases.
- Bickerstaff DR, Neal LM, Booth AJ et al.. Ultrasound examination of the irritable hip.
- Terjesen T and Osthus P.. Ultrasound in the diagnosis and follow-up of transient synovitis of the hip.