By Dr. Jeff Daniels EBS Medical Columnist

The thumb is a very important part of the body and is critical when we do anything with our hands. It’s particularly vulnerable to injury when skiing and snowboarding, as well as many other sports, because when we fall the thumb often leads the way to getting struck into the ground, icy hardpack, a rock or a tree.

The leading cause of surgery after a ski vacation is the repair of a ligament in the hand at the base of the thumb called the ulnar collateral ligament. This injury is often referred to as “skier’s thumb.” The ligament is most often torn by the grip on the handle of the ski pole, and that’s why it’s less common in snowboarders.

A person often tightens that grip while falling, and when the pole hits the ground it stretches the ligament until it breaks, sometimes even pulling out a small fragment of bone from the proximal phalanx of the thumb. This won’t heal by itself and it requires surgery.

A much less common but more devastating injury that involves the thumb occurs where the hand bone of the thumb, the first metacarpal, joins with the wrist bone called the trapezium. There are two kinds of fractures at that carpometacarpal juncture, and both of them require surgery. We rarely see them, although during one week in January we had one of each.

A Bennett fracture is the less severe version of a fracture at this joint. Most of the Bennett fractures I’ve seen have been in skiers and snowboarders, and involve a direct blow to that part of the hand, usually against a rock. Only one fracture line is seen at the proximal end of the first metacarpal, the part of the hand bone closest to the wrist and furthest from the thumb. The fracture line has to extend into the joint that the first metacarpal makes with the trapezium in order for it to be a Bennett fracture.

Most Bennett fractures need surgery in order to ensure a normally functioning hand and thumb in the future. This first metacarpal-carpal joint is particularly vulnerable to arthritis as we get older, even if we’ve never had a fracture in that area. A poorly healed Bennett fracture is likely to cause arthritis at a much younger age.

A Rolando fracture is even worse. It involves the same area of the proximal first metacarpal, but the fracture lines are multiple and always require surgery. The results of surgery are often less than perfect, so a Rolando fracture often ends up with a chronically arthritic thumb early on.

It’s important to make a diagnosis, stabilize, and get an orthopedic consultation within a week of injury, if either of these fractures occurs. These two injuries will get people into the medical clinic right off the mountain, whereas a skier’s thumb injury, especially if no fracture occurs, will often be shaken off and dealt with much later.

At the Medical Clinic of Big Sky, we use a bracing system to stabilize these fractures and ligament tears, and especially for the skier’s thumb injury, we can make skiing for the rest of the vacation safer and less painful, with the admonition that surgery is necessary upon returning home.

Dr. Jeff Daniels was the recipient of the 2016 Big Sky Chamber of Commerce Chet Huntley Lifetime Achievement Award and has been practicing medicine in Big Sky since 1994, when he and his family moved here from New York City. A unique program he implements has attracted more than 700 medical students and young doctors to train with the Medical Clinic of Big Sky.