Bennetts fracture dislocation

What is a Bennett’s Fracture Dislocation?

Bennett’s fracture dislocation is a broken bone (fracture) at the base of the thumb bone (metacarpal), at the wrist. The metacarpal bones connect the wrist to the fingers and make up the arch of the hand. Fracture of the metacarpal to the thumb (first metacarpal) occurs at the wrist and involves the joint between the metacarpal and the wrist bones.

WOSM Hand and Wrist Experts:

How does a Bennett’s fracture-dislocation occur?

  • Direct blow, such as a striking blow with the fist
  • Indirect stress to the hand, such as that caused by twisting

What increases the risk of developing a Bennett’s fracture-dislocation?

  • Participation in contact sports such as football, rugby or soccer
  • Sports that require hitting, such as boxing or martial arts
  • History of bone or joint disease, including osteoporosis

What are the symptoms of Bennett’s fracture-dislocation?

  • Severe pain at the time of injury
  • Pain, tenderness, swelling (especially at the base of the thumb) and, later, bruising of the hand
  • Visible deformity if the fracture is complete and the bone fragments displace enough to distort normal body contours
  • Pain, weakness, and inability to grip or hold objects

How is a Bennett’s fracture dislocation diagnosed?

Your physician will conduct a thorough history and physical exam. X-rays will be taken to confirm the diagnosis.

How is it treated?

If the bones are in acceptable alignment, the initial treatment consists of ice and elevation of the injured hand at or above heart level to reduce swelling, along with medication to relieve pain. Immobilization by splinting, bandaging, casting or bracing for four or more weeks is usually recommended to protect the bones while they heal.

Surgery is often necessary because these fractures are unstable. Even if the fragments can be reduced (placed in the correct position) non-operatively, they usually do not remain reduced without something to hold them in place, such as pins or screws. This is because muscles and tendons attach to one of the fragments, causing it to continually displace.

For fractures that are displaced (out of alignment), surgery is often recommended because of instability and joint misalignment. Surgery usually involves placement of removable pins, screws or plates.