Ski Thumb (Lateral Ligament Tear of Thumb): Causes, Symptoms & Treatment

Ski thumb refers to a tear of the internal collateral ligament of the thumb. This injury is typically seen in skiers, but also happens frequently in ball sports. A ski thumb must be treated or the thumb will lose its ability to function.

What is a ski thumb?

A ski thumb is a colloquial term for a tear of the lateral ligament at the base joint of the thumb. The medical term for this is ulnar collateral ligament rupture (rupture = tear) or rupture of the ulnar collateral ligament. The ulnar collateral ligament, along with other ligaments and structures, stabilizes the metacarpophalangeal joint of the thumb and runs on the side of the thumb that faces the rest of the fingers. If the thumb is extremely splayed away from the hand, it will cause excessive stretching of this collateral ligament. If the load capacity of the ligament is exceeded, it tears. The name ski thumb comes from the fact that this lateral ligament tear often happens to skiers when they fall and try to catch themselves with their hand or when they get caught with their thumb in the loop of the ski pole. In both cases, the thumb is overstretched toward the radius. The tear can occur in three different places on the ligament; close to the proximal phalanx of the thumb, in the middle, or close to the metacarpal.

Causes

The cause of ski thumb is excessive splaying of the thumb from the hand and the resulting overstretching of the lateral ligament at the base joint of the thumb. Very often this happens when skiing. However, ski thumb can also occur in other sports. If a ball thrown with force is caught during ball sports, the thumb can also be stretched so far backwards that the lateral ligament tears. Other possible causes of ski thumb are a fall that one reflexively intercepts with the splayed hand, overstretching of the thumb during floor or apparatus gymnastics, and martial arts.

Symptoms, complaints and signs

Various symptoms are caused by a tear of the collateral ligament. Often, a distinct cracking sound is heard during the accident. This is immediately followed by a sharp shooting pain in the thumb and the base joint. Since a torn ligament also affects the surrounding tissue and causes vascular injury, blood leaks into the tissue and a bruise (hematoma) forms. This in turn leads to swelling of the thumb and increased pressure sensitivity, especially in the metacarpophalangeal joint of the thumb. The joint appears unstable, is abnormally mobile and can be opened. If it can be unfolded to more than 30°, this is a significant indication of a collateral ligament tear. The thumb feels weak and also folds away to the side during movements, so that it cannot be used for grasping and pressing, or can only be used to a limited extent. Any attempt at a grasping movement is painful. If the accident takes place on the slopes, the affected person notices immediately that he or she can no longer hold the ski pole. After a few days, the pain subsides, but permanent discomfort may occur if the injury is not treated. If the instability of the thumb persists, the metacarpophalangeal joint of the thumb becomes overloaded and worn in a non-physiological way over time, which can lead to joint wear (osteoarthritis). Stiffening of the joint is also possible.

Diagnosis and progression

Ski thumb is immediately noticeable by an onset of sharp pain. Sometimes a popping sound is heard as the ligament tears. After the accident, the metacarpophalangeal joint of the thumb is no longer stable. The thumb has both an inner and outer collateral ligament. If the inner collateral ligament is now torn, the thumb can be opened outward. Since the torn ligament and possibly other injured structures bleed, a bruise (hematoma) forms after the rupture and the tissue around the thumb swells. After the initial sharp shooting pain, a permanent pain develops in the further course. A grasping movement with the thumb is no longer possible and every movement hurts. The doctor usually already suspects a rupture of the lateral ligament due to the course of the accident and the fact that the thumb can be opened. A mobility test is always difficult because it causes pain. An X-ray can be used to clarify whether additional bony injuries are present. An MRI (magnetic resonance imaging) examination can be used to diagnose ski thumb without any doubt, as the structures of the ligament are also visible here.

Complications

A ski thumb is primarily noticeable by severe pain. Further complications can occur if the injury is not treated promptly. Then, permanent movement restrictions of the thumb may occur. Paralysis and sensory disturbances are also typical. A bruise can cause skin damage or frostbite if not treated properly. Inflammation can also occur, resulting in a scar on the ball of the hand in the worst case. The collateral ligament tear itself does not otherwise pose any risks. However, it always leads to movement restrictions that significantly limit the affected person in everyday tasks. Careless behavior can lead to the injury reopening and needing to be treated again. In the surgical treatment of a torn lateral collateral ligament, the complications and risks consist primarily of possible infections. These are usually manifested by swelling and redness in the surgical area, associated with pain and disturbances in sensitivity. In individual cases, there may be injury to skin nerves in the area of the operation. As a result, nodular thickenings may form, accompanied by sensory disturbances and other discomfort. Prescribed pain medications occasionally cause side effects and interactions.

When should you see a doctor?

In addition to mouse elbow, tennis elbow or snowboarder’s ankle, ski thumb is also a typical sports injury. The lateral ligament tear of the thumb occurs preferentially in skiers. However, it can also occur in all other sports accidents in which the thumb was widely splayed. The lateral ligament (ab)rupture is due to severe overstretching. Occasionally, a piece of the thumb bone is also affected. Either way, a visit to the doctor should be made as soon as possible after the accident because the thumb is indispensable in our lives. Immediately after the accident, immobilization of the thumb or the entire hand is advised. Cooling is also useful. It prevents severe swelling. The quick visit to the doctor is therefore indispensable, because in case of non-observance consequential damages can occur. Untreated injuries can lead to arthrosis of the metacarpophalangeal joint of the thumb, permanent malpositioning of the thumb, or persistent joint instability with permanent pain and restricted movement. In most cases, surgical repair of the ski thumb becomes necessary. In some cases, conservative splinting and immobilization may suffice. However, this is only possible if there is overstretching or tearing. If a tear of the collateral ligament has occurred, surgery of the affected thumb is inevitable. Conservative treatment can be used even if there is a bone avulsion, provided the collateral ligament is intact.

Treatment and therapy

The ski thumb should first be immobilized, cooled, and elevated for acute treatment. If the ligament is not completely torn, further treatment can be conservative (without surgery). In this case, the thumb is immobilized with a splint for about four to six weeks. After that, the muscles must be slowly retrained with physiotherapy exercises to restore the thumb’s original stability and functionality. In the case of a complete tear of the collateral ligament or if additional bone parts have been torn off, surgery is unavoidable. The surgeon uses different techniques depending on the type of tear. If the ligament is torn in the middle, it is usually rejoined and fixed with a suture. Accompanying this, the joint of the thumb is temporarily fixed with a so-called Kirschner wire to ensure complete immobilization. The wire is later removed under local anesthesia. If the ligament is so torn that it can no longer be sewn together, it is replaced by a tendon from the patient’s own body. Torn bone parts are reattached with screws or wires. Even after surgical treatment of the ski thumb, a period of rest must be observed. After that, physiotherapy exercises can be started.

Prevention

You can only prevent a ski thumb to a limited extent. Since it often happens during certain sports, wearing a tape bandage around the thumb is useful to stabilize it and protect it from overstretching.

Aftercare

If the ski thumb needs surgery due to a complete ligament rupture, this is followed by several weeks of immobilization.It takes between two and six weeks before the cast can be removed. The patient then receives a special orthosis. It makes the physiotherapeutic or occupational therapy aftercare measures easier. To enable the doctor to check the surgical wound, the cast must be changed every two to three days after the operation. In the further course, the removal of the stitches takes place. To support the healing of the wound, it is recommended to apply a greasy cream to the scar during the first months. This procedure can counteract the growth of excess tissue that causes pain or tension. If movement is restricted after the surgical intervention on the ski thumb, physiotherapeutic follow-up treatment is necessary. The patient performs independent movement therapy in warm water for about six weeks. He also puts on a thumb bandage for support. It is important to note that physiotherapy must not cause pain or swelling of the affected thumb. Thus, excessive treatment is considered counterproductive. Patience is required until the hand and thumb function normally again. It usually takes several weeks before the usual everyday activities can be performed again. It usually takes three to four months before sports activities can be performed again.

Here’s what you can do yourself

In the presence of health impairments, adequate rest and recuperation of the hand as well as the joint is particularly important. The gripping function of the affected hand should be used less or not at all during the healing process. In everyday life, various tasks should therefore be restructured or the execution of activities should be modified. It is advisable to make increased use of the hand that is not affected by symptoms in order to spare the affected base joint. Situations of strain or stress are to be completely refrained from. If the lady is not sufficiently spared, the symptoms may increase and, if the disease progresses unfavorably, the joint may stiffen. This means that the grip function is irreparably damaged and remains restricted for life. It is recommended to ask relatives or people of the social environment for help with a large number of the activities performed in everyday life. It is not very beneficial for the recovery process if, despite the adversities, numerous activities are carried out with strain on the thumb. When performing occupational activities, the physical limitation should be pointed out in good time. The environment should be informed about the health impairments so that misunderstandings and conflicts can be reduced to a minimum. Skiing or other sports activities should be refrained from during the period of recovery.