Anatomy of the Thumb

There are two bones in the thumb. The distal phalange extends from the tip of the thumb to the knuckle. The proximal phalange extends from the knuckle to the base of the thumb—this is the area of webbing between the thumb and first finger. The thumb connects with the hand at the first metacarpal bone.

What is a Thumb Fracture?

Although a fracture can occur anywhere in the thumb, the most serious happen near the joints, especially at the base of the thumb near the wrist. A fractured or broken thumb can be especially difficult because it affects the ability to grasp items.

Symptoms

Symptoms of a fractured thumb include:

  • Severe pain
  • Swelling
  • Limited motion or inability to move the thumb
  • Extreme tenderness
  • Misshapen or deformed appearance
  • Sensation of numbness or coldness in the thumb

What Causes a Fractured, or Broken, Thumb

Thumb fractures are usually a result of direct stress, such as from a fall or catching a baseball without a glove. Fractures may be caused indirectly from twisting or muscle contractions, which can occur during wrestling, hockey, football, skiing or other activities. A history of bone disease or calcium deficiency increases your risk. Developing hand strength and using protective equipment such as padding or tape can help prevent this injury.

Diagnosis

If you believe your thumb may be fractured, have it examined immediately. Delayed treatment may make treatment more difficult and could lead to a less desirable outcome. Your physician will assess the injury by performing a thorough examination that commonly includes an X-ray. Once the type of fracture is determined, appropriate treatment can be recommended.

Nonsurgical Treatment

A specially designed cast (spica cast) may be used to hold the fragments of broken bone in place. This cast is typically worn for at least four to six weeks. During that time, periodic X-rays may be needed to ensure that the bone remains properly aligned as it heals.

Surgery

Depending on the location of the fracture and the amount of movement between the broken fragments of bone, your orthopaedic surgeon may use one of several operative fixation techniques to realign the bone fragments and hold them in place during healing. Internal fixation techniques include the use of wire, pins, plates or screws inside the body, while external fixation techniques include the use of pins in bone that are held in place through their attachment to a device outside the body. A cast or splint will also be worn for two to six weeks after surgery.

Recovery

Once the cast is removed, hand therapy may be required. Exercising your thumb can help restore motion. As you soak your hand in warm water, try moving your thumb in a circular motion, or touching your little finger to your thumb. Regular use of a spring-type hand squeezer can also help you improve strength. Following any joint injury, there is an increased tendency to develop arthritis. Regaining full use of the hand may take three months or more, depending on the severity of the injury.