Merck Manual

Please confirm that you are a health care professional

honeypot link

Metacarpal Neck Fractures


Danielle Campagne

, MD, University of California, San Francisco

Reviewed/Revised Dec 2022
Topic Resources

Metacarpal neck fractures usually result from an axial load (eg, from punching with a clenched fist).

This discussion pertains to fractures of the metacarpal bones other than the thumb metacarpal. Fractures of the neck of metacarpals 2 through 5 are common. They cause pain, swelling, tenderness, and sometimes deformity. Rotational deformity Rotational deformity due to a fracture in the hand Rotational deformity due to a fracture in the hand may occur. The 5th metacarpal is most commonly injured by punching (boxer's fracture). When these fractures result from punching someone in the mouth, human oral flora may contaminate the wound, sometimes causing infection. Patients with fight bites require antibiotics Infected Bite Wounds of the Hand A small puncture wound, particularly from a human or cat bite, may involve significant injury to the tendon, joint capsule, or articular cartilage. The most common cause of human bites is a... read more .

Rotational deformity due to a fracture in the hand

Normally, when the proximal interphalangeal joints are flexed to 90°, lines from the distal phalanges converge at a point on the proximal carpal bones. Deviation of one of these lines suggests a metacarpal fracture.

Rotational deformity due to a fracture in the hand

Diagnosis of Metacarpal Neck Fractures

  • X-rays

Metacarpal Neck Fractures

Typically, anteroposterior, lateral, and oblique views are diagnostic.

Treatment of Metacarpal Neck Fractures

  • Prophylactic antibiotics for open wounds

  • Splinting

  • For certain fractures, reduction

If patients have any wounds, particularly linear punctures, near the metacarpophalangeal joint, they should be specifically questioned about whether they punched someone in the mouth. If they did, contamination with human oral flora is possible, and measures to prevent infection (eg, wound exploration and cleaning, prophylactic antibiotics Antimicrobials Human and other mammal bites (mostly dog and cat bites, but also squirrel, gerbil, rabbit, guinea pig, and monkey bites) are common and occasionally cause significant morbidity and disability... read more ) are often required.

Treatment of a metacarpal neck fracture is with a splint (eg, an ulnar gutter splint Ulnar gutter splint Ulnar gutter splint for fractures of the 4th or 5th metacarpal), usually for at least a few weeks. Whether reduction is needed before the splint is applied depends on the fracture.

Reduction is not necessary for dorsal or volar angulation of

  • < 35° for the 4th metacarpal

  • < 45° for the 5th metacarpal

Reduction is necessary for

  • Rotational deformity of any metacarpal

  • Fractures of the 2nd and 3rd metacarpals with angulation

Usually, closed reduction is possible. Use of a hematoma block or an ulnar nerve block can help reduce the pain during reduction.

After the splint is removed, patients can gradually begin range-of-motion exercises.

How To Apply an Ulnar Gutter Splint

Ulnar gutter splint

Ulnar gutter splint

Key Points

  • Metacarpal neck fractures cause pain, swelling, tenderness, and sometimes deformity (eg, rotational deformity).

  • Take anteroposterior, lateral, and oblique x-rays.

  • If patients have wounds near the metacarpophalangeal joint, ask them whether they punched someone in the mouth; if they did, take measures to prevent infection (eg, prophylactic antibiotics).

  • Treat a metacarpal neck fracture with a splint; if angulation is significant or if rotational deformity is present, reduce the fracture first, usually using closed reduction.

NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
quiz link

Test your knowledge

Take a Quiz!