Collateral Ligament Thumb

Tears of the ulnar collateral ligament of the thumb, referred to as gamekeeper s or skier s thumb are frequently encountered as a result of skiing injury. The torn ligament may become interposed beneath the adductor aponeurosis resulting in the... 

The thumb has a distinct anatomy, with a bony structure similar to a finger without the metacarpal, i.e. the physis is located at the proximal end of the distal phalanx, middle phalanx and metacarpal (Kozin 2006). The collateral ligament insertions are different at the interphalangeal joint and the metacarpophalangeal... 

Fig. 19.25. Avulsion fracture of the ulnar collateral ligament at the thumb metacarpophalangeal joint...

The lateral aspect of the elbow is best examined with both elbows in extension, thumbs up, palms of the hands together (Barr and Babcock 1991). When examining the radial collateral ligament and the capsule, the elbow should be extended, keeping the hand pronated. Along the lateral elbow, high-resolution US can demonstrate the common extensor tendon, the lateral ulnar collateral ligament, the radial nerve with its superficial and deep (posterior interosseous nerve) branches, and the radio-capitellar joint. 

The metacarpophalangeal joint of the thumb plays a major role in handgrip. Similar to the other fingers, the radial and ulnar collateral ligaments of the thumb join the metacarpal head to the base of the proximal phalanx, limiting translational movements of the thumb in the coronal plane. From the functional point of view, the ulnar collateral ligament plays the most important role because it prevents exces-... 

Fig. 11.60. Gamekeeper s thumb. Schematic drawing illustrates the mechanism of ulnar collateral ligament tear. Typically, the ligament rupture is the end result of a vigorous valgus stress (curved arrow) applied on the metacarpophalangeal joint leading to excessive tension (black arrows) on the ligament. Note the relationship of the ulnar collateral ligament (in black) with the extensor poUicis longus tendon (epl) and the adductor pollicis aponeurosis (open arrows)...

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