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Three Part Question

In [children presenting with acute hip pain] is [a raised ESR] useful in [diagnosing septic arthritis]?

Clinical Scenario

A 3 year old child presents to the emergency department with a short history of limp, temperature and difficulty in weight bearing on the left leg. The pain is principally located at the hip joint and you fear this may be a septic arthritis. You wonder if an Erythrocyte Sedimentation Rate (ESR) will help in excluding the diagnosis of septic arthritis.

Search Strategy

Medline 1966-12/00 using the OVID interface.
{[(exp child OR children.mp OR pediatrics OR paediatric.mp OR pediatric.mp) AND (exp hip OR exp hip joint OR hip.mp OR exp arthritis, infectious OR exp osteomyelitis OR septic arthritis.mp)] AND (exp laboratory techniques and procedures OR laboratory techniques.mp OR exp ultrasonography OR exp blood cell count OR exp c-reactive protein)} AND maximally sensitive diagnostic filter LIMIT to human and english.

Search Outcome

334 papers found of which 329 were irrelevant or of insufficient quality. The remaining 5 papers are shown in the table.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Del Beccaro MA et al, 1992, USA	138 children age 2.5 weeks to 12 years admitted with acute hip pain	Diagnostic test study	Septic arthritis of the hip		Retrospective chart review including neonates. Gold standard not universally applied.
			Raised ESR alone	Sensitivity 79%
			Raised ESR and temperature	Sensitivity 97%
Taylor GR and Clarke NMP, 1994, UK	417 consecutive paediatric admissions with hip pain identified on retrospective chart review	Diagnostic test study	Septic arthritis of the hip		Diagnostic tests were not universally applied. Numbers do not appear to add up
			Raised ESR alone	Sensitivity 90.5%
			Raised ESR and temperature or severe spasm/tenderness	Sensitivity 97%
Fink MA et al, 1995, England	50 consecutive children age 1-10 years with acute hip pain	Diagnostic test study	Septic arthritis of the hip		Number too small to be meaningful. Only 1 case of septic arthritis found
			Raised ESR alone	Sensitivity 100%
Eich GF et al, 1999, Switzerland	114 children with acute hip pain	Diagnostic test study	Septic arthritis of the hip		14 patients excluded due to loss of data. Retrospective identification of cases.
			Raised ESR alone	Sensitivity not given
			Raised ESR and temperature or CRP	Sensitivity 100%
Kocher MS et al, 1999, USA	282 children with diagnosis of irritable hip	Diagnostic test study	Septic arthritis of the hip		Cohort identified retrospectively
			Raised ESR alone	Sensitivity not given
			Raised ESR and temperature and WCC and inabilty to weight bear	Sensitivity 99.6%

Comment(s)

An isolated ESR is of variable sensitivity and not suitable to rule-out septic arthritis, however in combination with an elevated temperature and inability to weight bear or reduced mobility it becomes a useful rule-out tool with sensitivities consistently above 95%.

Clinical Bottom Line

An isolated ESR test cannot exclude septic arthritis. In combination with temperature and ability to weight bear it can be used as a SnOut.

References

1. Del Beccaro MA, Champoux AN, Bockers T et al. Septic arthritis versus transient synovitis of the hip: the value of screening laboratory tests. Ann Emerg Med 1992;21(12):1418-22.
2. Taylor GR, Clarke NM. Management of irritable hip: a review of hospital admission policy. Arch Dis Child 1994;71(1):59-63.
3. Fink AM, Berman L, Edwards D et al. The irritable hip: immediate ultrasound guided aspiration and prevention of hospital admission. Arch Dis Child 1995;72(2):110-113.
4. Eich GF, Superti-Furga A, Umbricht FS et al. The painful hip:evaluation of criteria for clinical decision making. Eur J Pediatr 1999;158(11):923-28.
5. Kocher MS, Zurakowski D, Kasser JR. Differentiating between septic Arthritis and transient synovitis of the hip in children. JBJS (Am) 1999;81(12):1662-70.