Finger Dislocation

What Is It?

When a dislocation occurs in a finger joint, the finger bones move apart or sideways so the ends of the bones are no longer aligned normally. Finger dislocations usually happen when the finger has been bent backward beyond its normal limit of motion. In the most typical finger dislocation, the bone farthest from the wrist is forced out of the joint in the direction of the knuckle.

The bones in the fingers are known by the medical terms phalanges and metacarpal bones. Every knuckle in the hands and fingers contains a joint between two of these bones, and any of these joints can be dislocated in an injury:

• Distal interphalangeal joints are in the finger knuckles closest to the fingernails. Most dislocations in these joints are caused by trauma, and there is often an open wound in the location of the dislocation.
• Proximal interphalangeal joints are the middle joints of the fingers. A dislocation of this joint is also known as a jammed finger or coach's finger. It is the most frequent hand injury in athletes, and is especially common among those who play ball-handling sports, such as football, basketball and water polo. In most cases, the dislocation happens because the fingers are bent backward when an athlete tries to catch a ball or block a shot. Proximal interphalangeal joint dislocations also can happen when an athlete's fingers are twisted or bent by an opponent, especially when two athletes wrestle or grab for control of a ball.
• Metacarpophalangeal joints are joints within the knuckles of the hand, where the bulk of the hand joins to the fingers. These joints connect the metacarpal bones in the palm and the first row of phalanges in the finger. Because these joints are very stable, metacarpophalangeal joint dislocations are less common than the other two types. When metacarpophalangeal dislocations do occur, they are usually dislocations of either the index finger or little finger (pinky).

Overall, finger dislocations and other soft-tissue finger injuries account for more than 82 percent of all traumatic injuries to the hand. In athletes, treatment of a finger dislocation often begins on the playing field, when the athlete straightens the crooked finger or allows a coach or trainer to do it.

Symptoms

A dislocated finger is crooked, painful and swollen, and its surface skin may be cut, scraped or bruised. If a dislocated finger has been straightened on the playing field, it may feel abnormally loose, weak or unstable afterwards.

Diagnosis

Your doctor will suspect that your finger is dislocated if it appears deformed. In some cases, your doctor may order an X-ray of the finger to look for fractures. When a finger bone is pulled away from connected tendons, it is common for a fragment of bone to separate from the main bone and stay with the tendon, a condition known as an avulsion fracture. Your doctor will check the feeling and movement of your finger to check whether any nerves or tendons have been damaged.