A New and Improved View of the Ulnar Collateral Ligament

    The repetitive extreme valgus stress that occurs during overhead throwing maneuvers puts throwing athletes – particularly baseball pitchers – at risk for injuries to the ulnar collateral ligament (UCL).

    Although magnetic resonance imaging (MRI) is used to help diagnose UCL injuries in these athletes, standard positioning for elbow MRI is often suboptimal for UCL rendering.

    A recent pilot study published in the American Journal of Roentgenology suggests that adding a new view – the flexed elbow valgus external rotation (FEVER) view – to the standard MRI sequences can improve evaluation of the UCL, specifically by allowing for better measurement of the ulnotrochlear (UT) joint space.

    The researchers included 44 pitchers from 3 Major League Baseball teams in the study. The pitchers underwent elbow MRI with both standard sequences and a coronal fat-saturated proton density-weighted sequence in the FEVER view. Specific positioning maneuvers and sandbags were used to immobilize the elbow in valgus stress while visualizing the UCL parallel to its long axis (Figure 1).

    Figure 1. Positioning for the FEVER view. Note the elevated flexed elbow and sandbags to induce valgus stress. The elbow coil is not included in this image. Courtesy of the American Roentgen Ray Society and the American Journal of Roentgenology.

    Two radiologists independently evaluated standard and FEVER views. They were tasked with measuring the UT joint space, determining if the UCL was normal or abnormal, and assessing their confidence in their UCL-related findings. Radiologists 1 and 2 classified 3 and 2 additional UCLs, respectively, as abnormal on FEVER compared with standard view. Neither radiologist classified

    “Among 44 MLB pitchers undergoing elbow MRI,” the researchers said, “the FEVER view, compared with standard view, yielded increased UT joint space width (mean increase, 1.80 mm) and increased confidence for 3 of 5 UCL-related findings (mean increase, -0.14 to 0.98).

    “The [study] findings support the FEVER view as a practical addition to standard elbow MRI protocols for achieving elbow valgus stress in throwing athletes, thereby providing functional information to complement the high-resolution anatomic assessment provided by MRI.”


    Lund PL, Waslewski G, Crenshaw K. FEVER: the Flexed Elbow Valgus External Rotation view for MRI evaluation of the ulnar collateral ligament in throwing athletes—a pilot study in Major League Baseball pitchers. AJR Am J Roentgenol. 2021 Jun 2. doi: 10.2214/AJR.21.25608. Online ahead of print.