Clinical Classification
There are four different stages of the ski thumb:
- Sprain with smaller fiber tears of the band. One also speaks of a distortion
- Complete tearing of the ligament (rupture)
- Bony ligament rupture
- Dislocation (luxation) in the metacarpophalangeal joint of the thumb
Complication
In the case of a ski thumb shape, part of the ligament residue may strike against the edge of a tendon plate (tendon aponeurosis of the adductor pollicis muscle). This is known as the Sterner lesion. In this type of injury, anatomical healing is no longer possible because the ligament remains cannot approach.
The consequence is the development of chronic instability. A fundamental distinction is made between therapy for acute injuries and therapy for chronic instability. Acute injuries can be treated conservatively or surgically.
There are no reliable diagnostic characteristics for the decision which therapy option to choose. In general, an opening of 35° is considered to be the surgical indication for slightly bent joints. Based on clinical experience, hardly any ski thumb needs to be surgically treated.If the conservative approach is chosen, the thumb is immobilized in a thumb forearm cast for 3 weeks.
After 3 weeks, careful mobilization is started. After two more weeks, the load is steadily increased. After 10-12 weeks, the thumb should be able to bear the full weight again.
Alternatively, the injury can be immobilized with a tape bandage or a thumb splint. The thumb splint is the method of therapy favored by many doctors. If surgery is indicated, there are different procedures to choose from depending on the type of tear.
On the one hand, the ends of the tape can be sutured, but treatment with a special wire suture is also possible. If there is a bony tear, it is refixed with special wires. After the operation the thumb is immobilized for 6 weeks.
After this time, physiotherapy exercises are performed to restore normal joint function. If there is chronic instability, ligamentoplasty is usually performed. The palmaris longus tendon is often used for this. If there is still instability in the joint or if post-traumatic arthrosis develops (arthrosis as a result of an accident), the metacarpophalangeal joint of the thumb is stiffened, since stability is crucial for the good function of the joint.