January 03, 2024

Ultrasound Evaluation of Gamekeeper's Thumb aka Skier's Thumb

Written by: Casey Green

Ultrasound Evaluation of Gamekeeper's Thumb aka Skier's Thumb - Jon Jacobson, MD, RMSK

Ultrasound Evaluation of Gamekeeper's Thumb or Skier's Thumb

Gamekeeper's thumb, also known as skier's thumb, involves an injury to the ulnar collateral ligament of the thumb. Today's tip from the Gulfcoast Ultrasound Institute sheds light on key points in assessing this condition.

Placing the Ultrasound Probe

Positioning is fundamental when evaluating the ulnar collateral ligament. Placing the ultrasound probe in the coronal plane relative to the thumb is essential. To achieve this, a simple yet effective technique involves positioning the thumb overhanging the edge of a rolled-up towel. This positioning facilitates the direct placement of the transducer in the coronal plane, optimizing imaging quality.

Identifying Bone Landmarks

Recognition of characteristic bone contours is pivotal for proper imaging orientation. Observing a concavity at the first metacarpal and a smaller concavity at the proximal phalanx ensures correct alignment within the imaging plane. These landmarks serve as anchors for assessing the ulnar collateral ligament.

Visualizing the Ulnar Collateral Ligament

The normal appearance of the ulnar collateral ligament presents as a hyperechoic and fibular structure, connecting the previously mentioned bone landmarks. However, it's important to note that the ligament might appear slightly hypoechoic due to surrounding structures.

Assessing the Adductor Aponeurosis

Another significant structure to visualize is the overlying adductor aponeurosis, which requires a dynamic approach. By passively moving the interphalangeal joint, a thin hyperechoic structure covering the ulnar collateral ligament becomes apparent. This becomes crucial in identifying a tear in the ulnar collateral ligament.

Dynamic Evaluation

A dynamic evaluation involves inducing slight valgus stress across the metacarpophalangeal (MCP) joint. This stress maneuver aids in widening the joint, potentially assisting in fluid visualization within a ligament tear.


Understanding the intricate details of ultrasound evaluation for gamekeeper's thumb or skier's thumb is invaluable in clinical practice. From proper probe placement to identifying critical bone landmarks and assessing dynamic changes, each step contributes to an accurate diagnosis and effective treatment planning.

Learning Resources

For more information on Musculoskeletal Ultrasound, Gulfcoast Ultrasound Institute offers Live and Online courses, 

Contact Gulfcoast Ultrasound Institute at 

111 2nd Ave NE, #800 

St. Petersburg, FL 33701

Phone: 727-363-4500 

   Musculoskeletal Ultrasound Courses and Products


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