By Edward Fink, M.D.
Trigger thumb arises when the sheath surrounding the tendon controlling thumb flexion becomes constricted and does not allow the tendon to glide freely as the thumb flexes and extends.
This condition may occur in any digit and can arise from repeated trauma to the base of the thumb, although most often there is no precipitating cause. The tendon sheath constriction causes the tendon to become bulbous, and pain occurs at the site of this swelling.
Gamekeeper’s thumb, on the other hand, arises when ligaments on the inside base of the thumb become stretched and attenuated, causing pain and at times weakness and instability of the thumb, particularly with gripping.
This condition is named for the keepers of the game in England (game referring to fowl), who would kill the birds by gripping and breaking their necks, producing recurrent stresses to the inside base of their thumbs.
In modern times, ski poles instead of fowl necks precipitate these injuries by stressing the thumb, often during a fall. This condition is much less common than a trigger finger or thumb.
While both conditions can cause pain, the diagnosis and treatment alternatives are vastly different.
The pain produced by a trigger thumb can be minimized with gloves sufficiently padded to protect the swollen area. Alternatively, one can modify positions of the hand when gripping the handlebars.
A painful trigger thumb at times may respond to steroid injections into the tendon sheath. Yet, if unsuccessful, an out-patient surgical release of the offending tendon sheath, a 30-minute procedure, is recommended. The rate of recurrence is extremely low, and the painful thickening of the tendon promptly recedes.
Treatment for a chronic gamekeeper’s thumb is significantly more complex. As Coach Fred mentioned, a thumb brace can be worn that restricts painful movements and stresses to the thumb, and most people find this exceedingly helpful.
If that is not successful, surgical reconstruction of the ligaments is often required.
Dr. Edward Fink is a pediatric orthopedic surgeon and avid road cyclist who recently moved to Phoenix, Arizona, from Washington, D.C. He specializes in trauma, works and teaches in developing countries, and promotes cultural competence in medicine.