OVERVIEW
They might not look like much, but they are classified as the “super tools” of the human body: it is the opposable thumbs that make humans stand out from the other animals that have hands. In fact, several scientists believe that when one loses their thumb, it is like losing at least half the functionality of the hand.
Although they are made to withstand stress, they may stop working properly for a variety of reasons. One of these reasons is the partial or complete disruptions of the lateral collateral ligaments, caused by forces that deflect the finger in an angulation. The rupture of the ulnar collateral ligament (UCL) of the metacarpophalangeal joint (MCP) - this is one of the two collateral ligaments which are present in the joint of the thumb with the first metacarpal bone, and they are important stabilizers of the thumb. So, in case of injury, holding a heavy object by hand is very difficult.

HIGH RISK GROUPS
In the international bibliography this particular disruption, or the detachment of the ligament from its insertion in the central phalanx of the digit, is also known as skier’s thumb, since it is considered a sports injury, common in those involved in skiing. But it is also known as gamekeeper’s thumb, a straightforward reference to the Scottish gamekeepers or hunter operation managers. The injury in them was related to the habit of breaking the prey’s neck using the thumb and index finger against the ground.

WHICH ARE THE SYMPTOMS?
Today, the most common mechanism of injury is the fall upon the stretched thumb which leads it to an excessive abduction. Ulnar collateral ligament disruption symptoms are pain and swelling in the joint area, but also the patient’s inability to hold objects.

WHICH IS THE BEST TREATMENT?
Initially, the orthopaedist shall ask for x-rays and / or an MRI in order to exclude the case of an avulsion fracture, and then, using a local anesthetic, he will perform an abduction test to find out if the disruption is complete or partial. Treatment is determined depending on the injury and the activity level of the patient, but, in general, partial disruptions are treated conservatively by immobilizing the joint with a rigid splint for 2-4 weeks, and a gradual mobilization.
Complete ligament disruptions require immediate surgical reconstruction, especially in athletes and manual workers, because, if left untreated, the ability of the hand to catch is significantly affected. During surgery, the ligament is sutured (primary repair), and if it is detached from its adhesion, it is reattached onto its anatomical position. In cases where the injury comprises an avulsion fracture, and an osteosynthesis with a small screw is performed.
Postoperatively, the metacarpophalangeal joint of the thumb is immobilized for 4-6 weeks, and then the rehabilitation period begins. The patient returns to all their activities within 3 months.