Musculoskeletal System ORGAN SYSTEMS

Ulnar collateral ligament (UCL) injury


Ulnar collateral ligament (UCL) injury of the thumb, also known as gamekeeper’s thumb or skier’s thumb.


CS Campbell, an orthopaedic surgeon, originally coined the term gamekeeper’s thumb in 1955, after he observed this condition in a series of 24 Scottish gamekeepers. The injury appeared to occur as a result of the particular manner in which they killed small animals such as rabbits; the animals were placed on the ground, and their necks were broken as the gamekeeper exerted downward pressure with the thumb and index finger. This manoeuvre would place a valgus force upon the abducted metacarpophalangeal (MCP) joint. Over time, this would lead to insufficiency of the ulnar collateral ligament (UCL) of the thumb.

Clinical features

  • Instability of the MCP joint (thumb)
    • Accompanied by pain & weakness of pinch grasp
  • Signs:
    • Pain, swelling, and ecchymosis around the thenar eminence, and esp. over the MCP joint of the thumb



Avulsion fractures of the ulnar base of the proximal phalanx of the thumb (Gamekeeper’s fracture) | James Heilman, MD – CC BY-SA 3.0,


Severity and management type (by No. of injuries) for ulnar collateral ligament injuries among athletes aged 11 to 22 years | Zaremski, J. L., McClelland, J., Vincent, H. K., & Horodyski, M. (2017). Trends in Sports-Related Elbow Ulnar Collateral Ligament Injuries. Orthopaedic Journal of Sports Medicine, 5(10), 2325967117731296–2325967117731296.
A post-operative photo of repair of a complete rupture of the ulnar collateral ligament. Note the K-wire to brace the joint. | Jhapeman – CC BY 3.0,

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