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Ulnar Collateral Ligament Injury (Skier's Thumb)


Skiers thumb is a partial or complete tear of the Ulnar Collateral Ligament (UCL) of the thumb. It is most commonly associated with skiing but can happen in other sports.

The UCL connects two of the thumb bones (the metacarpal and proximal phalanx) on the inside of the thumb. It helps to stabilise the thumb and therefore give it strength when gripping.

UCL injuries occur when the thumb is pulled away from the fingers (e.g.: by ski pole or football tackle). As a result, the UCL may be stretched (sprain), completely pulled off, or may pull off a fragment of bone with it.

Sometimes, the ligament pulls away from the bone and sits on a band of tissue (Adductor aponeurosis). The band of tissue stops the ligament from healing back onto the bone. This is known as a Stener’s lesion.

Sometimes these injuries are not recognised immediately and treated as sprains/jammed fingers.



Sporting injuries are the most common causes where the thumb is pulled away and ligament is stretched. This include:

  • Skiing – Falling with pole in hand
  • Football tackle

Signs and symptoms

Diagnosis is based on examination of the thumb and scans.

Swelling / Bruising

On the inner aspect of thumb base

Tenderness / Pain

Tenderness will be on inner side of thumb where ligament attaches

Instability / Laxity

If the ligament is torn completely, there will be increased side to side laxity of the thumb and the thumb can be forced sideways easily.



This can demonstrate if the ligament has pulled off a fragment of bone causing an avulsion fracture


This can show the tear of the ligament and can demonstrate if there is a Stener’s lesion.


MRI is more sensitive than ultrasound in demonstrating UCL and Stener’s injury.

Non-surgical treatment

This is reserved for minor or partial tears of the ligament. It involves fulltime wearing of a splint for 4-6 weeks. The splint is then worn part time for a further 6 weeks.

The success rate of non-operative treatment for partial tears is approximately 95%.


Ulnar Collateral Ligament (Skier's Thumb) Repair