A Smith fracture is a break at the end of the radius bone in your forearm, near the wrist, where the broken piece of bone shifts toward the palm side of your hand. It’s often called a “reverse Colles fracture” because the bone displaces in the opposite direction of the more common Colles fracture. While Colles fractures happen when you catch yourself with your hand bent backward, a Smith fracture typically results from the hand bending forward under the wrist at the moment of impact.
How a Smith Fracture Differs From Other Wrist Fractures
The radius is the larger of the two forearm bones, and its far end (near the wrist) is a common spot for breaks. What distinguishes a Smith fracture is the direction the broken fragment moves. In a Colles fracture, which is the most common type of distal radius fracture, the fragment tilts toward the back of the hand. In a Smith fracture, it tilts toward the palm. This distinction matters because it changes how the injury looks on an X-ray, how it needs to be set back into position, and which surgical approach works best if surgery is needed.
Beyond the main radius break, a Smith fracture can also disrupt the joint between the two forearm bones at the wrist and damage the cartilage that stabilizes that joint. Fractures of the small bony bump on the ulna (the other forearm bone) often occur alongside it.
What Causes It
The classic mechanism is a fall onto a flexed wrist, meaning your hand is curled forward when it hits the ground. This is the opposite of the instinctive “catching yourself” position that causes a Colles fracture. A Smith fracture can also happen from a direct blow to the back of the wrist or from high-energy injuries like motorcycle accidents and falls from height. Sports that involve forward falls, like cycling or skateboarding, are common culprits.
Symptoms and What It Looks Like
After the injury, you’ll typically notice immediate pain, swelling, and difficulty moving your wrist. The swelling tends to be most visible on the palm side of the wrist, and the bony bump of the ulna may stick out more prominently on the back of the wrist. Unlike the obvious “dinner fork” deformity seen with Colles fractures, the palm-ward shift of a Smith fracture can be harder to spot visually, which is one reason X-rays are essential for a proper diagnosis.
If the fracture causes enough swelling or displacement, it can put pressure on the median nerve, which runs through the wrist into the hand. When this nerve is affected, you may notice numbness at the tip of your index finger and weakness when trying to touch your thumb to your pinky finger. This is a sign that needs prompt attention because prolonged pressure on the nerve can cause lasting problems.
In rare cases, a Smith fracture can lead to acute compartment syndrome in the forearm, a serious condition where swelling within the muscle compartment cuts off blood flow. Severe, worsening pain that seems out of proportion to the injury, especially pain that increases when you try to stretch your fingers, is the hallmark warning sign.
How It’s Diagnosed
Standard X-rays taken from the front and side of the wrist are the primary tool. On the side view, the key finding is that the broken fragment angles toward the palm rather than the back of the hand. Your doctor will assess how far the fragment has shifted, whether the break extends into the wrist joint surface, and whether neighboring structures like the ulna are also damaged. In more complex cases, a CT scan may be used to get a clearer picture of the fracture pattern before deciding on treatment.
Treatment Options
Treatment depends on how far the bone fragments have shifted and whether the break involves the joint surface.
For mild fractures where the bones haven’t moved far out of alignment, a splint or cast is often enough. A splint is typically worn for three to five weeks, while a cast stays on longer, usually six to eight weeks. If the bones are displaced but can be manually guided back into position (a procedure called closed reduction, done under local anesthesia), you’ll be placed in a cast or splint afterward to hold everything in place while healing occurs.
Surgery is more likely when the fracture is unstable, the break extends into the joint surface, or the bones can’t be adequately realigned by hand. The surgical approach usually involves a plate and screws placed through an incision on the palm side of the wrist to hold the bone fragments in the correct position while they heal.
Recovery and Rehabilitation
Bone healing after a Smith fracture generally takes six to eight weeks, though full recovery of strength and range of motion takes longer. Once the cast comes off or surgical healing is confirmed, physical therapy focuses on restoring wrist flexibility first, then gradually building grip strength. Most people start with gentle range-of-motion exercises and progress to resistance exercises over several weeks.
Stiffness is common after weeks of immobilization, and it can take several months of consistent rehabilitation to regain close to your previous level of function. The timeline varies depending on your age, the severity of the fracture, and whether surgery was needed.
Risks of Improper Healing
One of the main concerns after any distal radius fracture is malunion, where the bone heals in a shifted or angled position. If a Smith fracture heals with the fragment still tilted toward the palm, it can cause a visible deformity sometimes described as a “garden spade” appearance, along with ongoing stiffness and weakness.
Malunion rates for distal radius fractures treated without surgery have been reported as high as 23.5% in some studies, though most of these don’t cause enough symptoms to require further treatment. When they do, a corrective procedure is needed in roughly 0.5% of nonsurgically treated fractures and 0.3% of those treated with surgery. The risk is higher in older adults: one study found that 88% of low-demand elderly patients who underwent casting after having their fracture set lost their initial alignment during the healing process, resulting in some degree of malunion. Patients over 60 are also more likely to experience secondary displacement of the bone fragments during nonsurgical treatment, which is one reason surgeons may recommend plate fixation earlier in this age group.
Younger, active patients generally have better outcomes with both surgical and nonsurgical approaches, though even in this group, follow-up X-rays during the healing period are important to catch any loss of alignment early enough to intervene.