Hand Fractures
- The hand is a row of long thin bones (metacarpals) ending in even thinner ones (phalanges) — easy to break, easy to overlook on a busy film.
- A boxer's fracture is the classic: an angulated break of the neck of the small-finger metacarpal, courtesy of punching something solid.
- Rotation is the deal-breaker. A fracture can look almost fine on X-ray but leave fingers crossing when the hand makes a fist, and that needs fixing.
- Always demand the right views — the oblique catches breaks the front and side films hide.
- Watch for the sneaky intra-articular fractures at the thumb base and finger joints; they punch above their weight clinically.
Your hand is a marvel of engineering crammed into a tea-towel-sized space: nineteen little bones in the fingers and palm, all hinged and strapped together so you can thread a needle or throw a punch. The trouble with marvels of engineering is that they break in fiddly ways, and on a radiograph a hand can look like a fistful of breadsticks. Let me walk you through where these bones actually snap and why some innocent-looking cracks are sneakier than they appear.
The lay of the land
Quick anatomy refresher, because the names matter. The palm holds five metacarpals — the long bones you can feel as ridges on the back of your hand. Each finger then gets a string of phalanges: proximal, middle, and distal, like three knuckle-segments. The thumb skips the middle one, so it only has two.
Each long bone has the same parts: a base (the joint end nearest the wrist), a shaft in the middle, a neck, and a head (the knuckle end). When a report says "fracture of the fifth metacarpal neck," that's a precise street address — the narrow part just before the knuckle of the small finger. Knowing this vocabulary is half the battle, and it's exactly the language covered in how to describe a fracture.
The boxer's fracture
The greatest hit of hand trauma is the boxer's fracture: a break through the neck of the fifth metacarpal, the little-finger one. The mechanism is exactly what it sounds like — a closed fist meeting something that doesn't move, like a wall, a door, or (the radiologist's eternal private theory) something the patient would rather not name on the intake form.
The fractured metacarpal head tips down toward the palm, so on the side view you see the bone bent like a hockey stick. The key question isn't whether it's broken — that's usually obvious — but how angulated it is, because the small-finger knuckle naturally tolerates a surprising amount of bend before it causes trouble. The report should measure that angle so the hand surgeon can decide between a splint and the operating room.
Rotation: the trap that hides in plain sight
Here's the thing that catches people out, and it's worth tattooing on the inside of your eyelids. A finger fracture can look almost boringly aligned on a flat X-ray and still be a disaster, because the radiograph is a flat photo of a 3D problem. The villain is rotation — the fractured fragment twisted on its own axis.
Picture closing a Venetian blind: each slat is perfectly fine, but rotate one and the whole set stops lining up. A rotated finger does the same thing — when the patient curls their hand into a fist, the affected finger swings across its neighbor instead of pointing politely toward the same spot near the wrist. You often can't see this on the film at all; it's a clinical finding the examining clinician must check for.
A finger fracture that reads as "minimally displaced" on the radiograph can still be badly malrotated. Rotation is judged at the bedside by watching the fingers flex, not by squinting at the X-ray. Never let a clean-looking film talk you out of a clinical exam.
The joints are where the money is
Fractures that crack into a joint surface — intra-articular fractures — are the ones that age badly, because a joint with a step-off in its cartilage is a joint heading for early arthritis. A few worth knowing by name:
| Fracture | Where it lives | Why it matters |
|---|---|---|
| Bennett fracture | Base of the thumb metacarpal, into the joint | The thumb's strong tendons drag the main fragment out of place, so it often needs fixing. |
| Rolando fracture | Base of the thumb metacarpal, but comminuted | A messier, multi-fragment version of the same problem — harder to reconstruct. |
| Mallet finger | Avulsion at the back of the distal phalanx base | A tiny bone fleck pulled off by the tendon; the fingertip droops and can't straighten. |
The thumb-base fractures (Bennett and Rolando) are the marquee names here. The thumb does an outsized share of the hand's work, so a poorly aligned joint at its base is a long-term grievance, not a minor footnote.
A small avulsion flake near a finger joint is easy to dismiss as "just a chip." But that chip is often a tendon or ligament's bony anchor that has torn loose — a mallet finger or a volar plate avulsion — and the soft-tissue injury is the real story. The flake is a flag, not a footnote.
Get the views, then look properly
A hand series is three views — frontal (PA), oblique, and lateral. Please don't skip the oblique. On the straight-on and side views, the metacarpals stack and overlap like a pile of pencils, and a clean fracture line can vanish into the overlap. The oblique fans them apart so each bone gets its own moment in the spotlight. Many a missed fracture is really just a missing oblique.
On the lateral view the metacarpals superimpose almost perfectly — that's normal and expected. When you're hunting an individual bone, the oblique is your best friend; it's the view that pulls each metacarpal out of the crowd.
When you scan a hand film, walk bone by bone: trace each metacarpal from base to head, then each finger out to its tip. It's tedious, but tedious is how you catch the second fracture hiding behind the dramatic first one.
The one thing to remember
A hand X-ray is rarely subtle about whether something is broken — the cortex either steps or it doesn't. The skill is in the follow-up questions: how angulated, is it rotated, and does it reach a joint? Master those three, demand your oblique view, and never let a tidy-looking film stop you from looking at the actual hand. For the wrist bones just upstream — the scaphoid and distal radius — wander over to upper extremity fractures, where the misses get even sneakier.