The thumb plays a major role in hand function and this ligament is the most important stabilizer of its function.
Its lesion might be caused by a sudden opening of the first web space (the one between the thumb and index): an instability of the metacarpal phalangeal joint occurs.
The lesion might involve the ligament itself or its bony insertion with an avulsion fracture. Typical is the so called “skier’s lesion thumb” caused by a fallen holding the stick.
The treatment is surgical in the majority of the cases as to restore stability.
