Gamekeeper's Thumb Anatomy
To better understand skier's thumb, it helps to understand the anatomy of the thumb.
The collateral ligaments support the sides of the thumb joints. The ulnar collateral ligament supports the side next to the index finger of the first joint of the thumb.
- Harper MT, Chandnani VP, Spaeth J, Santangelo JR, Providence BC, Bagg MA. Gamekeeper thumb: diagnosis of ulnar collateral ligament injury using magnetic resonance imaging, magnetic resonance arthrography and stress radiography. J Magn Reson Imaging. 1996 Mar-Apr;6(2):322-8. 
- Plancher KD, Ho CP, Cofield SS, Viola R, Hawkins RJ. Role of MR imaging in the management of "skier's thumb" injuries. Magn Reson Imaging Clin N Am. 1999 Feb;7(1):73-84, viii. 
- Zeman C, Hunter RE, Freeman JR, Purnell ML, Mastrangelo J. Acute skier's thumb repaired with a proximal phalanx suture anchor. Am J Sports Med. 1998 Sep-Oct;26(5):644-50.