Can a POCUS Clinical Decision Rule Improve Reliability in the Diagnosis of Paediatric Transient Synovitis of the Hip? A Single Centre Pilot Study.

OBJECTIVES

Primary: To determine if point of care ultrasound (POCUS) combined with a clinical decision rule (CDR) improves reliability in the diagnosis of transient synovitis of the hip (TS) in paediatric patients presenting with atraumatic limp. Secondary: To describe how POCUS improves diagnostic reliability and reduces the need for further investigations for the child with atraumatic limp.

METHODS

We retrospectively applied a POCUS CDR to patients presenting to our paediatric emergency department (PED) with atraumatic limp over a 5-year period. This consisted of the following: ages 1 to 10 years old, able to weight bear, no history of fever, symptom duration for 7 days or less, and no pallor, lymphadenopathy, or hepatosplenomegaly.

RESULTS

A total of 77 out of 178 patients presenting to the PED with a diagnosis of TS underwent a POCUS examination during their clinical assessment. Of these, 67 patients had hip effusion on POCUS. Our CDR could be applied to correctly rule-in TS in 63 out of 67 patients. Ten patients did not have hip effusion; five of which were diagnosed with another cause for their limp and five were categorized as being possible TS. When POCUS was not utilised as part of clinical assessment, three cases included a misdiagnosis for children presenting with atraumatic limp.

CONCLUSION

Our POCUS CDR could be applied to correctly rule-in TS in a very high proportion of cases. The integration of POCUS into the clinical assessment of children with atraumatic limp can reduce the need for unnecessary investigations while maintaining diagnostic reliability. We recognise that a large prospective study evaluating the role of a POCUS CDR is needed to further evaluate its reliability.