Skier's Thumb

What is skier's thumb?

Skier's thumb involves damage to the ligament that supports the base of your thumb, called the ulnar collateral ligament, which normally keeps the joint steady when you pinch or grip. It usually happens when you fall onto an outstretched hand while gripping something, such as a ski pole, which wrenches the thumb away from the rest of your hand and strains or tears the ligament.

What are the symptoms of skier's thumb?

Symptoms usually appear within a few hours of the injury and typically include:

• pain and tenderness around the thumb's lower joint, particularly in the web between your thumb and index finger
• swelling and bruising around the joint
• pain that worsens when you try to grip or pinch something
• reduced movement in the thumb, and sometimes pain spreading into the wrist
• a feeling of weakness or looseness in the joint.

If the injury builds up gradually from repeated strain on the thumb, rather than a single fall, it's sometimes called 'gamekeeper's thumb' instead – the main complaint here tends to be a loss of pinching or gripping strength rather than sudden pain.

What causes skier's thumb, and who is at risk?

The classic cause is a fall onto an outstretched hand while holding something firmly, so that whatever you're holding wrenches your thumb sideways and backwards, away from your palm, putting more force through the ligament than it can withstand.

Skiing is the best-known cause, since a ski pole strapped to the wrist can't be let go of during a fall, but the same injury happens in many other sports and situations, including football, hockey, basketball and volleyball, or simply falling awkwardly.

This injury accounts for the large majority of cases where the lower thumb joint is hurt, and around 6 in 10 people affected are men. Where it develops gradually rather than from a single incident, it's the result of repeated stretching of the ligament over time, historically seen in gamekeepers whose job involved repetitive wringing motions of the thumb.

Are there different types of skier's thumb?

Yes, and the distinction matters for treatment. Injuries are generally grouped by how much the ligament is damaged:

• A sprain: This is where the ligament is stretched but not torn, and the joint stays stable
• A partial tear: This tends to hurt more, though the joint itself usually stays steady
• A complete tear: This is where the joint becomes unstable.

Complete tears are then split further, since this affects whether they can heal without surgery. If the torn ligament stays roughly in its normal position, it can often still heal with a period in a cast. If it has slipped out of position, trapped on the wrong side of nearby tissue (known as a Stener lesion), it physically cannot reattach and heal on its own, however long you wait, so surgery becomes the recommended option.

How is skier's thumb diagnosed?

Your doctor will ask how the injury happened and examine your thumb, gently testing how far it moves sideways compared with your uninjured thumb – a lot more movement than on the other side suggests the ligament is torn rather than just sprained. This can be uncomfortable on a swollen, painful thumb, so a local anaesthetic injection is sometimes used first to allow a more accurate examination.

An X-ray is often taken, mainly to check for a small chip of bone pulled away where the ligament attaches, rather than to see the ligament itself – a normal X-ray doesn't rule out a significant tear.

If there's still doubt about how unstable the joint is, an ultrasound scan can look at the ligament directly and compare both sides, and occasionally an MRI scan is used, which is the most accurate way to confirm a tear.

How is skier's thumb treated?

Treatment depends on whether the joint is stable or unstable, and if unstable, whether the ligament has moved out of position.

Non-surgical treatment

Straight after the injury, rest, ice, and support (such as a firm bandage and keeping the hand raised) can help with pain and swelling. For a sprain or a partial tear, where the joint remains stable, treatment is usually:

• a splint or cast holding the thumb still, typically for around 4 to 6 weeks
• over-the-counter anti-inflammatory painkillers to ease pain and swelling in the meantime
• a course of exercises once the splint comes off, to gradually restore movement and strength.

Even with the ligament healing well, forceful pinching is usually best avoided for around 3 months, and some aching or swelling can linger for up to 6 months after the injury. A complete tear where the ligament hasn't moved out of position can sometimes also be managed this way, usually with a plaster cast for about 4 weeks, since the ligament is still in a position where it's able to heal.

Surgical treatment

Surgery is recommended when the ligament has completely torn and shifted out of its normal position, since it has no way of healing back to the bone by itself, and for larger, displaced bone fragments where the ligament attaches. It's generally best done without a long delay, as ligaments left unrepaired for more than around 6 weeks can retract and become harder to reattach, sometimes needing additional tissue or a tendon graft to reconstruct.

The operation is usually done as a day case, through a small cut at the side or back of the thumb joint, re-attaching the ligament with stitches, sometimes with the help of a small anchor; if a bone fragment is involved, a pin or screw may be used to hold it in place.

Afterwards, your hand goes into a splint or cast for several weeks, followed by a hand therapy programme to rebuild movement and strength. Heavy gripping, pulling or lifting is generally avoided for around 3 months and noticeable improvement is usual by this point, though it can take up to 6 months to reach your best overall result.

When should I see a doctor?

See a doctor promptly after any thumb injury involving pain, swelling or bruising at its base, particularly following a fall while gripping something. It's especially important not to just wait and see if:

• there's an obvious deformity or you suspect a broken bone alongside the ligament injury
• the thumb feels notably loose or unstable when your doctor or therapist examines it
• pain, weakness or instability continues once your splint or cast has come off.

Getting an early, accurate diagnosis matters here – a complete tear that's left too long before treatment can become significantly harder to repair, so it's worth having any suspected skier's thumb assessed within the first few days rather than waiting for it to settle on its own.