The thumb has two finger bones connected to a hand bone. The first finger bone (distal phalange) extends from the tip of the thumb to the knuckle. The second finger bone (proximal phalange) extends from the knuckle to the webbing between the thumb and the first finger. There, it connects with the hand bone (first metacarpal), which extends from the webbing down to the wrist.
Although a break can occur in any of these bones, the most serious breaks happen near the joints, particularly at the base of the thumb near the wrist.
These fractures have specific names, depending on the type of break. The Bennett and Rolando fractures are breaks at the base of the thumb, involving the joint between the thumb metacarpal and a specific wrist bone. Fractures that involve the joints are always more difficult to treat and are at increased risk of an unfavorable outcome.« Back to Glossary Index