Intrasound vibration testing in acute ankle injuries.
OBJECTIVE
To determine the accuracy of intrasound vibration testing (IVT) in comparison with plain radiography in the diagnosis of acute ankle fractures.


METHODS
A group-sequential, nonrandomized, double-blind, observational study design was used. A convenience sample of patients were studied, aged > or = 10 years, with acute ankle injuries, undergoing ankle radiography, evaluated at a community teaching hospital ED. Excluded were cases involving injuries of > 24 hours' duration, inadequate documentation, protocol violation, or positive IVT on the uninjured ankle. IVT was performed with the intrasound apparatus placed on the anterior and posterior aspects of the medial and lateral malleoli of the uninjured and injured ankles; positive IVT was defined as patient withdrawal secondary to pain.


RESULTS
Of 105 patients enrolled, 8 were excluded; 1 for inadequate documentation, 5 for protocol violation, and 2 for positive IVT of the uninjured ankle. Of the 97 patients analyzed, 13 had fractures identified by radiography, including 9 lateral malleolar, 1 medial malleolar, 1 bimalleolar, and 2 talar fractures. Only 5 of the 13 fractures were detected with IVT (sensitivity = 39%; 95% CI: 14-68%). Seventy of 84 nonfractured ankles had negative IVT (specificity = 83%; 95% CI: 74-91%). Of the 19 with positive IVT, 5 had fractures (positive predictive value of 26%; 95% CI: 9-51%). Of the 78 with negative IVT, 70 had no fracture (negative predictive value of 90%; 95% CI: 81-96%). Overall, 75 of 97 IVTs were correct (77%), most of which were among patients without fractures.
Plewa
M C
MC
Vincent Medical Center, Toledo, OH 43608, USA. mcplewa@msn.com
Otto
R
R
Verbrugge
J
J
Buderer
N M
NM
Vaughn
G
G
Mattevi
P
P
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004311:Double-Blind Method; D004635:Emergency Medicine; D005260:Female; D050723:Fractures, Bone / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013639:Tarsal Bones / Q000293:injuries*; D013997:Time Factors; D014732:Vibration