Gamekeeper Test

Gamekeeper Test (or skier’s thumb test) is used to evaluate the Ulnar collateral ligament of the metacarpophalangeal joint (MCP joint) of thumb, a condition known as skier’s thumb or gamekeeper’s thumb.

The ulnar collateral ligament provides essential stabilization to the metacarpophalangeal joint at the thumb’s base. Abduction forces from trauma can compromise ligamentous integrity, disrupting first metacarpal stability.

How is Gamekeeper Thumb Test Performed?

• The patient is positioned in sitting.
• The clinician stabilizes the patient’s hand with one hand and takes the patient’s thumb into extension with the other hand.
• While maintaining the thumb into extension, the clinician applies a valgus stress to the metacarpophalangeal joint (MCP joint) of the thumb to stress the ulnar collateral ligament.

What does a positive Gamekeeper Test mean?

• A positive Gamekeeper Test is present if the valgus movement is greater than 30–35 degrees, indicating a complete tear of the UCL and the accessory collateral ligaments.
• If less than 30° valgus movement is there but more than the normal 15°, it indicates partial tear or ligamentous laxity.
• Differentiation between complete and partial tears is difficult to determine by physical examination alone, Stress radiographs and/or MRI may aid in the diagnosis.
• These results should be compared to the unaffected thumb. 

For testing isolated ulnar collateral ligament laxity (skier’s or gamekeeper’s thumb), 1st carpometacarpal joint is flexed to 30° and then valgus stress is applied at the metacarpophalangeal joint.

See Also: Hand Anatomy Bones & Muscles

Sensitivity & Specificity

Heymen and colleagues reported a high sensitivity but low specificity for detection of a palpable mass proximal to the MCP joint to indicate a complete tear of the UCL of the thumb:

• Specificity: 94-100%
• Specificity: 46%

Gamekeeper’s Thumb

Gamekeeper’s Thumb or Skier’s Thumb is characterized by Ulnar collateral ligament injury of thumb that usually tears at its distal attachment to the proximal phalanx. The ligament can become displaced outside of the adductor aponeurosis (Stener’s lesion) and cannot heal without operative intervention.

Clinically this injury can be identified by pain, swelling and tenderness at ulnar aspect of base of the thumb.

On valgus stress test in 30° flexion of MCP joint the joint opens up. This leads on to chronic instability compromising pinch grip when the thumb is stressed in abduction and hence functional disability. Compare with opposite thumb for abnormal movement on valgus stress.

Here’s the corrected sentence:

In acute painful situations, infiltration of local anesthesia and valgus stress testing (Gamekeeper Test), confirmed with stress X-rays, may be helpful.

Reference & More

1. Heyman P, Gelberman RH, Duncan K, et al: Injuries of the ulnar collateral ligament of the thumb metacarpophalangeal joint. Biomechanical and prospective clinical studies on the usefulness of valgus stress testing. Clin Orthop Relat Res 292: 165–171, 1993. PMID: 8519106. Pubmed
2. Madan SS, Pai DR, Kaur A, Dixit R. Injury to ulnar collateral ligament of thumb. Orthop Surg. 2014 Feb;6(1):1-7.  [PubMed]
3. Mohseni M, Sina RE, Graham C. Ulnar Collateral Ligament Injury (Gamekeeper’s Thumb) [Updated 2024 Feb 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Pubmed
4. Dutton’s Orthopaedic Examination, Evaluation, And Intervention 3rd Edition.
5. Millers Review of Orthopaedics -7th Edition book.
6. Campbel’s Operative Orthopaedics 12th edition Book.