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Gamekeeper's thumb. The joint
most affected by laxity in the metacarpophalengeal joint of the thumb.
Tears of the ulnar collateral ligament are common and disabling.
The injury was said to be sustained by keepers while breaking the necks
of small game - hence the name. Now the injury most commonly
results from falling on the outstretched hand - a combined extension and
radially deviating stress - often with some additional force applied by
something wrapper around the thumb itself, as in skiing. The
injury involves avulsion of the collateral ligament from the base of the
proximal phalanx with or without a fragment of bone together with
tearing of the palmar plate and accessory collateral ligament. The
differs from the proximal interphalangeal joint where rupture is much
more common proximally. The torn ligament in the thumb may come to
lie superficial to the adductor expansion, which normally overlies it,
eliminating any chance of healing - the Stener lesion (see figures to
the left). Since a stable thumb is essential, these should be
explored and repaired at the time of injury, the ony necessary
indication being laxity and bruising. However, they are frequently
ignored by the patient or splinted by his physician. When he
presents later the patient will have painful weakness if his thumb and
show radial instability and some palmar subluxation on
examination. The palmar plate offers some stability with the joint
in extension, so with lesser degrees of instability the stress should be
applied with the joint in flexion. As mentioned previously, care should
be taken to prevent rotation of the proximal bone when applying lateral
stress to a flexed joint, lest an incorrect diagnosis of instability be
made. in the future arthrography may become a routine part of the
investigation, helping to predict the pathology more accurately.
Depending on the state of the joint surfaces the choice lies between
reconstruction and arthrodesis.
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Acute Ulnar
Collateral Ligament Injuries (Gamekeeper's Thumb, Skier's Thumb)