Definition
The ski thumb is usually a painful ligament injury. This usually results in a complete tear of the collateral ligament (med. ligamentum ulnare or ulnarens collateral ligament) at the metacarpophalangeal joint of the thumb.
The ligament can be torn at various points. There are three different medical localizations: Sometimes the ligament injury can be combined with a bony splintering (med. bony tear).
Occasionally, only a sprain with a torn or stretched ligament occurs.
- Either central (med. interligamentary)
- Close to the base (this is the end of the strap towards the wrist)
- Or distally (this is the direction of the thumb).
Synonyms
- Ligament injury to the metacarpophalangeal joint of the thumb
- Rupture of the ulnar collateral ligament
- Rupture of the Ligamentum collaterale ulnare
- Thumb pain
Cause
The cause is often a violent abduction (radial induction in the metacarpophalangeal joint of the thumb) of the thumb. This can be caused by a fall while skiing or by various other sports. The most common causes include falls while skiing, e.g. due to the thumb getting caught in the loop of the ski pole. But also impact injuries during ball sports can often lead to this injury. Do you have specific thumb pain?
Anatomy
The thumb collateral ligament (ulnar collateral ligament) runs along the inner side of the thumb, i.e. medically on the small finger side of the thumb. For medically interested persons, the ulnar collateral ligament runs from the dorsoulnar side of the metacarpal I head downwards and attaches to the base of the proximal phalanx on the ulnar side. The ulnar collateral ligament serves to stabilize the metacarpo-phalangeal joint and is a prerequisite for enabling fine motion sequences such as holding objects or gripping firmly.
The injury can often be felt or heard by a crack in the thumb during an accident. A short time later, both a clear swelling with a bruise (hematoma) and a swelling in the area of the metacarpo-phalangeal joint of the thumb appear. In addition, an increased opening (sign of instability) of the metacarpo-phalangeal joint of the thumb occurs, which can be determined during the clinical examination, since stabilization by the ligament is missing.
In addition, there is a painful limitation of the grasping function. Due to the pain occurring after the accident, a diagnosis cannot always be made with certainty by clinical examination. Therefore, a new examination should be performed after immobilization.
For this purpose, a side comparison for movement testing is recommended, since there is a large variance in the mobility of the metacarpo-phalangeal joint of the thumb. To rule out a bony tear, an x-ray of the thumb must be taken and, if necessary, held images must be taken for side comparison. After a few days, the symptoms may apparently improve even without treatment.
Nevertheless, it is strongly recommended to consult a specialist in orthopedics. If the ski thumb remains untreated, the constant rubbing against the joint cartilage causes wear and tear of the metacarpo-phalangeal joint (joint arthrosis). The pain that may develop as a result can cause the metacarpo-phalangeal joint to stiffen and malpositions that may develop can persist.
