Season 10 Case 21

msk Apr 28, 2022

Hx: Hand Pain

It sure would be nice to know an actual location for the patient's pain, wouldn't it?

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Gamekeeper's Thumb

Gamekeeper's thumb (ie skier's thumb) is a tear or avulsion of the ulnar collateral ligament (UCL) of the first metacarpophalangeal joint.

Radiopedia distinguishes between the two of these such as:

Skier's thumb is acute injury from traumatic hyperabduction (such as from a skier's pole planted in the ground)
Gamekeeper's thumb is chronic, non-traumatic overuse injury (such as from wringing the necks of rabbits every day -Yes, this is the real origin)

Clinically, the injury is the extremely similar (and thus I conceptualize them almost the same). Either is due to acute vs repetitive hyperabduction at the first metacarpophalangeal joint leading to a tear of the UCL or avulsion of the UCL (typically from it's insertion on the medial aspect of the base of the first phalanx).

Great illustration of the UCL and avulsion injury to it from Matt Skalaski @docskalski

Okay, so it's a ligmentous/avulsion injury. Splint it an move on right?

Well the problem is the anatomy. The UCL lies deep to the adductor pollicis aponeurosis (ie the muscle that approximates your thumb to your hand). When the UCL is torn (or avulsed) the proximal (metacarpal) piece of the UCL can displace superficial to, the adductor pollicis aponeurosis preventing approximation, healing and union.

This is termed a Stener lesion and when this happens, surgery is now required to reapproximate the ligament for healing.

Classically MRI was the modality of choice for evaluating for Stener lesions, but more recently, Ultrasound is becoming increasingly popular for it's wider availability, cost, etc.