ConditionInjuries & poisoning
Metacarpal Fracture (Broken Hand Bone)
A metacarpal fracture is a break in one of the five long bones in the palm that connect the wrist to the fingers. The most common is a boxer's fracture, a break near the knuckle of the little finger, usually from punching a hard surface. Signs include pain, swelling, bruising, a sunken knuckle and difficulty making a fist. Most metacarpal fractures heal well in a splint or cast in about 4 to 6 weeks. Fractures that are badly angled, rotated or involve the joint may need surgery.
Also called: Broken hand bone, boxer's fracture (fifth metacarpal neck), hand fracture, Bennett fracture (thumb base)
At a glance
- What it is
- A break in one of the five long palm bones.
- Most common
- Boxer's fracture of the little finger metacarpal, from punching.
- Signs
- Pain, swelling, bruising, a dropped knuckle, a finger that overlaps another when making a fist.
- Diagnosis
- Examination and X-rays.
- Treatment
- Splint or cast for 3 to 6 weeks. Surgery for displaced, rotated, multiple or joint fractures.
When to get help
Call 911 or go to the ER
- Bone visible through the skin, or a deep wound over the break
- Fingers that are pale, cold, blue or numb
- Severe, increasing pain and tightness in the hand despite elevation, especially after a crush injury (possible compartment syndrome)
See a doctor within a day or two
- A cut or tooth wound over the knuckle after punching someone (a "fight bite"), which has a high risk of serious infection and needs same-day care
- Hand pain, swelling and bruising after a punch, fall or crush injury
- A finger that rotates or crosses over another finger when you make a fist
- A sunken or flattened knuckle
- Pain at the base of the thumb after an injury
Book a routine appointment
- Hand stiffness or weakness that is not improving after the splint or cast is removed
- Pain or swelling that persists beyond 6 to 8 weeks
Usually safe to manage at home
- A mild bump to the hand with minimal swelling, full movement and no deformity that improves within a few days
What to do right after a hand injury
- Remove rings, watches and bracelets right away before swelling makes it impossible.
- Apply ice wrapped in a cloth for 15 to 20 minutes every 2 to 3 hours.
- Raise the hand above heart level.
- Keep the hand still, in a sling or on a pillow, until it can be assessed.
- Clean and cover any wound, especially over the knuckles. Any wound from contact with teeth needs medical care the same day.
- Pain relief: acetaminophen (paracetamol) or ibuprofen at the label dose.
Types of metacarpal fractures
| Type | Location | Notes |
|---|---|---|
| Neck fracture (boxer's fracture) | Just below the knuckle, usually the 5th metacarpal | Most common. Knuckle drops, some angulation is acceptable |
| Shaft fracture | Middle of the bone | Can shorten or rotate. Rotation is important to correct |
| Base fracture | Near the wrist | May involve the joint. 5th metacarpal base fractures can be unstable |
| Head fracture | Into the knuckle joint | Often needs surgery to restore the joint surface |
| Thumb base (Bennett or Rolando fractures) | First metacarpal, into the joint | Usually needs surgery |
Causes
- Punching a wall, person or hard object (the most common cause of boxer's fracture)
- Falls onto the hand
- Crush injuries in machinery, doors or sports
- Direct blows during contact sports
- Car and motorcycle crashes
Symptoms
- Pain and tenderness over the back of the hand
- Swelling and bruising
- A knuckle that looks sunken or missing
- Difficulty making a fist or gripping
- A finger that points in the wrong direction or overlaps its neighbor when you make a fist (rotational deformity)
- A shortened finger
- Numbness if nerves are affected or swelling is severe
Diagnosis
A clinician examines the hand, checking for tenderness, wounds, nerve and blood supply, and rotation by having you slowly make a fist: the fingertips should point toward the same spot near the base of the thumb. X-rays from several angles confirm the fracture and show angulation, shortening and joint involvement. CT is occasionally used for complex joint fractures. A scaphoid fracture or wrist fracture should be excluded if there is wrist pain.
Treatment
Non-surgical treatment
Most metacarpal fractures heal without surgery:
- Reduction: if the bone is angled, it may be gently realigned under local anesthetic.
- Splint or cast: an ulnar gutter splint for boxer's fractures, or a hand-based cast or brace, usually for 3 to 6 weeks. Some stable boxer's fractures are treated with buddy taping and early movement.
- Hand therapy: exercises to restore movement and strength after immobilization.
A boxer's fracture can heal well even with some angulation of the little finger knuckle, because that finger is mobile. A slightly less prominent knuckle is common and usually does not affect function.
Surgery
Surgery may be recommended for:
- rotation of the finger
- significant shortening or angulation, especially in the index and middle fingers
- open fractures
- fractures entering the joint
- multiple metacarpal fractures
- unstable fractures, such as thumb base fractures
Options include pins (K-wires), screws, plates or intramedullary screws.
Fight bites
A wound over the knuckle from contact with someone's teeth can carry bacteria into the joint or bone. It needs cleaning, antibiotics, and sometimes surgical washout, even if it looks small. See human bite.
Recovery
- Bone healing usually takes about 4 to 6 weeks.
- Light use of the hand often begins after 3 to 6 weeks, guided by your clinician.
- Full strength and return to contact sports or heavy manual work may take 8 to 12 weeks.
- Stiffness is common and improves with exercises and hand therapy.
Complications
- Stiffness and reduced grip strength
- Malunion: healing in a rotated or angled position
- Nonunion (rare)
- Infection, especially with open fractures or fight bites
- Tendon irritation from hardware after surgery
- Post-traumatic arthritis if the joint was involved
Frequently asked questions
What is a boxer's fracture?
A boxer's fracture is a break in the neck of the fifth metacarpal, the bone below the little finger knuckle. It usually happens when punching a hard object with a closed fist. Signs include pain, swelling and a sunken knuckle. Most heal well with a splint.
How long does a metacarpal fracture take to heal?
Most metacarpal fractures heal in about 4 to 6 weeks. You may wear a splint or cast for 3 to 6 weeks, then do exercises to restore movement. Return to full strength and contact sports typically takes 8 to 12 weeks.
Do metacarpal fractures need surgery?
Most do not. Surgery is usually needed if the finger is rotated, the bone is significantly shortened or angled, the fracture enters a joint, several bones are broken, the bone has broken through the skin, or the thumb base is involved.
How do I know if my hand is broken?
Signs include significant pain, swelling, bruising, difficulty making a fist, a sunken knuckle or a finger that points the wrong way. You cannot be sure without an X-ray, so get your hand checked if you have these signs after an injury.
Sources
This guide was written from current patient and clinical guidance, including:
- American Academy of Orthopaedic Surgeons (OrthoInfo): Hand fractures
- American Society for Surgery of the Hand: Metacarpal fractures
- MedlinePlus: Hand fracture aftercare
- American Academy of Family Physicians: Metacarpal fractures
- NHS: Broken finger or thumb; Broken hand