Lavery LA, Armstrong DG, Peters EJ, Lipsky BA, et al.
Diabetes care. Date of publication 2007 Feb 1;volume 30(2):270-4.
1. Diabetes Care. 2007 Feb;30(2):270-4.
Probe-to-bone test for diagnosing diabetic foot osteomyelitis: reliable or relic?
Lavery LA(1), Armstrong DG, Peters EJ, Lipsky BA.
Author information:
(1)Department of Surgery, Scott and White Hospital, 703 Highland Spring Lane,
Georgetown, TX 78628, USA. llavery@swmail.sw.org
OBJECTIVE: We sought to assess the accuracy of the probe-to-bone (PTB) test in
diagnosing foot osteomyelitis in a cohort of diabetic patients with bone culture
proven disease.
RESEARCH DESIGN AND METHODS: In this 2-year longitudinal cohort study, we
enrolled 1,666 consecutive diabetic individuals who underwent an initial
standardized detailed foot assessment, followed by examinations at regular
intervals. Patients were instructed to immediately come to the foot clinic if
they developed a lower-extremity complication. For all patients with a
lower-extremity wound, we compared the results of the PTB test with those of a
culture of the affected bone. We called PTB positive if the bone or joint was
palpable and defined osteomyelitis as a positive bone culture.
RESULTS: Over a mean of 27.2 months of follow-up, 247 patients developed a foot
wound and 151 developed 199 foot infections. Osteomyelitis was found in 30
patients: 12% of those with a foot wound and 20% in those with a foot infection.
When all wounds were considered, the PTB test was highly sensitive (0.87) and
specific (0.91); the positive predictive value was only 0.57, but the negative
predictive value was 0.98.
CONCLUSIONS: The PTB test, when used in a population of diabetic patients with a
foot wound among whom the prevalence of osteomyelitis was 12%, had a relatively
low positive predictive value, but a negative test may exclude the diagnosis.
DOI: 10.2337/dc06-1572
PMID: 17259493 [Indexed for MEDLINE]
