Ortho X-Ray

Fat Pads


Fat Pads of the Elbow

    • Look For

    • Presence and elevation of the anterior and posterior fat pads on the lateral elbow x-ray.
    • Interpretation

    • Visible anterior fat pad - radiolucency anterior to the distal humerus, normally visible
    • Visible posterior fat pad - radiolucency posterior to the olecranon, normally hidden behind olecranon and thus presence indicates effusionOccult fracture
    • Sail sign - raised anterior fat pad due to effusionOccult fracture, usually of radial head

Fat Pads of the Knee

    • Look For

    • The suprapatellar and prefemoral fat pads, normally next to each other on the lateral knee x-ray
    • Interpretation

    • Separation of fat pads - indicates joint effusionLigamentous / menisceal injury, intra-articular fracture, arthritis, infection, tumour
    • Lipohaemarthrosis - fat-fluid level within fat padsIntra-articular fracture
Last updated on January 25th, 2020
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