What is the role of clinical tests and ultrasound in acetabular labral tear diagnostics?
OBJECTIVE
An acetabular labral tear is a diagnostic challenge. Various clinical tests have been described, but little is known about their diagnostic sensitivity and specificity. We investigated the diagnostic validity of clinical tests and ultrasound as compared with MR arthrography.


METHODS
We examined 18 patients (18 hips, 2 men, median age 43 (32-56) years) with impingement test, FABER test, resisted straight leg raise test, ultrasound, and MR arthrography. They had had previous periacetabular osteotomies due to symptomatic, acetabular dysplasia. All hips showed no or only slight signs of osteoarthritis (Tönnis grade 0-1).


RESULTS
MR arthrography identified labral tears in 17 of the 18 hips. Ultrasound had a sensitivity of 94%, a positive predictive value of 94%, and was false negative in only 1 case compared to MR arthrography. The impingement test had the best diagnostic ability of the clinical tests, with a sensitivity of 59% and a specificity of 100%. The positive predictive value was 100% while the negative predictive value was 13%.


CONCLUSIONS
The impingement test is helpful in identifying acetabular labral tears. If this test is negative and if a labral tear is still suspected, ultrasound can reliably diagnose most tears of the acetabular labrum. MR arthrography is indicated in cases where ultrasound is negative, but the patient suffers continued, specific symptoms.
Orthopaedic Research Unit, Aarhus University Hospital, Denmark. a_troelsen@hotmail.com
Anders
A
Troelsen
Inger
I
Mechlenburg
John
J
Gelineck
Lars
L
Bolvig
Steffen
S
Jacobsen
Kjeld
K
Søballe
D000077:Acetabulum / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000473:pathology*; D000328:Adult; D005260:Female; D006617:Hip Dislocation / Q000000981:diagnostic imaging / Q000473:pathology; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011859:Radiography; D012680:Sensitivity and Specificity; D014463:Ultrasonography