MRI versus ultrasonography to assess meniscal abnormalities in acute knees.
While magnetic resonance imaging (MRI) is often considered the "gold standard" diagnostic imaging modality for detection of meniscal abnormalities, it is associated with misdiagnosis in as high as 47% of cases, is costly, and is not readily available to a large number of patients. Ultrasonographic examination of the knee has been reported to be an effective diagnostic tool for this purpose with the potential to overcome many of the shortcomings of MRI. The purpose of this study is to determine the clinical usefulness of ultrasonography for diagnosis of meniscal pathology in patients with acute knee pain and compare its diagnostic accuracy to MRI in a clinical setting. With Institutional Review Board approval, patients (n = 71) with acute knee pain were prospectively enrolled with informed consent. Preoperative MRI (1.5 T) was performed on each affected knee using the hospital's standard equipment and protocols and read by faculty radiologists trained in musculoskeletal MRI. Ultrasonographic assessments of each affected knee were performed by one of two faculty members trained in musculoskeletal ultrasonography using a 10 to 14 MHz linear transducer. Arthroscopic evaluation of affected knees was performed by one of three faculty orthopedic surgeons to assess and record all joint pathology, which served as the reference standard for determining presence, type, and severity of meniscal pathology. All evaluators for each diagnostic modality were blinded to all other data. Data were collected and compared by a separate investigator to determine sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), correct classification rate (CCR), likelihood ratios (LR[+] and LR[-]), and odds ratios. Preoperative ultrasonographic assessment of meniscal pathology was associated with Sn = 91.2%, Sp = 84.2%, PPV = 94.5%, NPV = 76.2%, CCR = 89.5%, LR(+) = 5.78, and LR(-) = 0.10. Preoperative MRI assessment of meniscal pathology was associated with Sn = 91.7%, Sp = 66.7%, PPV = 84.6%, NPV = 80.0%, CCR = 81.1%, LR(+) = 2.75, and LR(-) = 0.13. Ultrasonography was two times more likely than MRI to correctly determine presence or absence of meniscal pathology seen arthroscopically in this study. Ultrasonography is a useful tool for diagnosis of meniscal pathology with potential advantages over MRI. Based on these data and available portable equipment, ultrasonography could be considered for use as a point-of-injury diagnostic modality for meniscal injuries.
Comparative Orthopaedic Laboratory, University of Missouri, Columbia, Missouri.
James L
JL
Cook
Comparative Orthopaedic Laboratory, University of Missouri, Columbia, Missouri.
Cristi R
CR
Cook
Missouri Orthopaedic Institute, Department of Orthopaedic Surgery, University of Missouri, Columbia, Missouri.
James P
JP
Stannard
Department of Orthopaedic Surgery and Rehabilitation, Appalachian Regional Orthopaedic and Sports Medicine Center, Boone, North Carolina.
Gavin
G
Vaughn
Missouri Orthopaedic Institute, Department of Orthopaedic Surgery, University of Missouri, Columbia, Missouri.
Nichole
N
Wilson
Arthrex Inc. Naples, Florida.
Brandon L
BL
Roller
Comparative Orthopaedic Laboratory, University of Missouri, Columbia, Missouri.
Aaron M
AM
Stoker
Department of Physical Medicine and Rehabilitation, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
Prakash
P
Jayabalan
Department of Diagnostic Medical Ultrasound, University of Missouri, Columbia, Missouri.
Moses
M
Hdeib
Comparative Orthopaedic Laboratory, University of Missouri, Columbia, Missouri.
Keiichi
K
Kuroki
D059787:Acute Pain / Q000209:etiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D018771:Arthralgia / Q000209:etiology*; D001182:Arthroscopy; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis* / Q000000981:diagnostic imaging; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging*; D008875:Middle Aged; D000070600:Tibial Meniscus Injuries; D014463:Ultrasonography; D055815:Young Adult