Kristen Elizabeth McClure MD, Presenter: Nothing to Disclose

William B. Morrison MD, Abstract Co-Author: Medical Advisory Board, ONI Medical Systems, Inc Medical Advisory Board, General Electric Company Consultant, Apriomed AB

Christopher Geordie Roth MD, Abstract Co-Author: Nothing to Disclose

Adam C. Zoga MD, Abstract Co-Author: Nothing to Disclose

Diane Bergin MD, Abstract Co-Author: Nothing to Disclose

Secondary signs of meniscal tear on MRI can aid in diagnostic certainty, particularly if the meniscal signal abnormality is equivocal or borderline, or when the study is degraded by artifact. Indirect evidence of meniscal tear includes adjacent cartilage loss, meniscal extrusion, parameniscal soft tissue edema, parameniscal cyst, joint effusion, and subchondral bone marrow edema. Prior studies show some of these signs have high specificity but they have not been tested in cases where primary findings of meniscal signal were borderline by criteria. This study is performed to find the incidence of secondary findings in these borderline cases.

A search of our radiology database was performed for patients with MRI of the knee and reported borderline meniscal tears based on criteria. Two musculoskeletal radiologists reviewed the MR images and noted the presence or absence of adjacent cartilage loss, meniscal extrusion, parameniscal soft tissue edema, parameniscal cyst, joint effusion, and rounded or linear subchondral bone marrow edema.

Seventy one knees with borderline meniscal tear were reviewed, including 48 medial menisci (68%) and 23 lateral menisci (32%). The average patient age was 48 years, with 37 males and 34 females. Findings included adjacent cartilage loss in 51 cases (72%), meniscal extrusion in 16 cases (23%), adjacent collateral ligament edema in 8 cases (11%), parameniscal soft tissue edema in 27 cases (33%), parameniscal cysts in 3 cases (4%), joint effusions in 48 cases (68%), and subchondral bone marrow edema in 30 cases (42%): of these, 21 had rounded subchondral bone marrow edema (70%) and 9 had linear subchondral bone marrow edema (30%).

There is a relatively high prevalence of secondary findings in knee MRI exams with findings that are borderline by criteria for meniscal tear.

Relatively high prevalence of secondary signs in knee MRI exams with borderline criteria for meniscal tear suggests that these signs may be useful for definitive diagnosis. 

McClure, K, Morrison, W, Roth, C, Zoga, A, Bergin, D, "Borderline" Meniscal Tears: Incidence of Secondary Soft Tissue and Osseous Findings on MRI.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11016875.html