A healthy living blog from Marshfield Clinic Health System

Common finger injuries: Simple strains to dislocations

Illustration of woman with a black eye - Eye injuries in sports

Each finger contributes to your hand’s dexterity and ability to respond to a ball or other physical contact during sports play. Too often finger injuries go unreported, or a significant lapse in time occurs between the injury and treatment.

A quick response to reset a dislocated finger is not enough. Appropriate medical attention can help prevent long-term reduced mobility or stiffness.

Mallet finger

Mallet finger is the inability to extend the knuckle farthest from the hand (called the distal knuckle), in any one finger. It occurs because of stretching of the tendon that lies on top of the finger. A ball may hit the outstretched fingertip forcing the distal joint to bend. The tip of the finger and distal joint will be painful. Ice should be applied to the injury and an orthopedic or sports medicine specialist should provide medical evaluation.

Jersey finger

Jersey finger is the inability to actively flex the distal knuckle of any one finger. The injury can be attributed to either a stretch or an avulsion (fracture) of the tendon on the palm side of the bottom of the finger. The injury’s name comes from the action that typically causes it: when an athlete grasps another athlete’s jersey. This action forces the finger into extension as the athlete is trying to flex it and hold on to their opponent. Ice should be applied to the injury, and an orthopedic or sports medicine specialist should provide medical evaluation.

Metac​arpophalangeal (MCP) sprain

Metacarpophalangeal (MCP) sprain is an injury to ligaments surrounding the knuckle of the finger closest to the hand or MCP joint. The injury usually occurs to the collateral ligaments on either side of the joints. Stress to the ligament and joint cause a sprain. It is painful and may include dislocation. Severity is difficult to determine using stress tests usually used for collateral ligament injuries. Medical evaluation is recommended to determine severity and appropriate treatment that may include physical therapy.

Boutonniere deformity

Boutonniere deformity appears as extension of the first knuckle closest to the base of the finger, flexion of the second knuckle and then extension of the distal knuckle (furthest from the base of the hand).The finger resembles an ocean wave with the knuckles up and down. This injury is caused by a rupture of the central extensor tendon, which can slip to either side of the finger instead of lying on top of the finger as it should. Athletes usually describe a longitudinal force as the injury cause, such as being struck with a ball. Pain occurs at the middle knuckle and the deformity is visible. In chronic cases, the deformity will take time to develop and may not be visible right away. For acute injury, ice should be applied with medical evaluation as soon as possible. Medical treatment will vary for more chronic cases.

Gamekeeper’s thumb

Gamekeeper’s thumb is a sprain to the ulnar collateral ligament (UCL) of the thumb. The UCL is located in the web between the thumb and the point finger. The injury can be an acute sprain or from repetitive stress to the ligament. Its name comes from the stretching of this ligament suffered by gamekeepers while performing the duty of breaking the necks of small animals while hunting. The injury is usually caused by excessive stretching of the web space between the thumb and point finger (hyper abduction) or hyperextension. The chief complaint is usually pain over the ligament and an inability to forcefully grip or pinch smaller objects. It is an injury commonly seen in skiers and football and basketball players. Treatment is based on severity. A milder injury may require a splint for four to six weeks, while a complete rupture of the tendon usually requires surgery.

Share comments or questions on this information. E-mail sports.medicine@marshfieldclinic.org​.

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One Response
  1. Jan 20, 2023

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