To The Editor:
We congratulate the authors on performing a prospective study (1) on such
an important topic. However, we found the title of the article a bit
misleading as the authors obtained data only on patients with a high
degree of clinical suspicion of septic arthritis. There are no data on the
inflammatory markers in children who were diagnosed with transient
synovitis of the hip in the first instance. Without this information it
would be very difficult to come to a conclusion on the biochemical
differences between septic arthritis and transient synovitis of the hip.
The subject population chosen by the authors is a very biased one.
Further, the authors mention that ultrasound evaluation and aspiration were performed on those children who were most likely to have septic arthritis
of the hip. They do not provide the clinical criteria that were used to
arrive at this probable diagnosis.
The results in this group of children show that only 17/48 patients had
culture proven septic arthritis. Of the 17 patients with presumed septic
arthritis, the authors do not report whether these patients underwent
arthrotomy of the hip or the results of the cultures of the aspirate at
arthrotomy. This high proportion of patients (17/48) who were negative for
culture of hip means that either the aspiration was incorrectly performed
or there were overinclusive criteria in selection of patients.
The only way to definitely identify the factors that distinguish
septic arthritis from transient synovitis of the hip is to perform
ultrasound examination, hip aspiration, blood cultures and inflammatory
markers in all children who present with a limp or hip pain with no other
identifiable causes. The chances of this kind of a study gaining ethical
committee approval is very low, indeed.
In our experience, transient synovitis of the hip usually occurs
about 2 to 3 weeks after an episode of upper respiratory infection. Hence,
the inflammatory markers in these patients are usually raised to varying
degrees. We are in the process of writing a paper which focuses on the
inflammatory markers in the transient synovitis of the hip which would
shed more light on apparent differences between these two conditions.
The author(s) of this letter to the editor did not receive payment or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the author(s) are affiliated or associated.
Reference:
1. Michelle S. Caird, John M. Flynn, Y. Leo Leung, Jennifer E. Millman,
Joann G. D'Italia, and John P. Dormans. Factors Distinguishing Septic
Arthritis from Transient Synovitis of the Hip in Children. A Prospective
Study. J Bone Joint Surg Am 2006; 88: 1251-1257.
Letters to the Editor: ![[Read Letter to the Editor]](/icons/misc/sectionDOWN.gif){kind=icon}
