Smith Fracture

What is a Smith fracture?

A Smith fracture occurs when the distal radius, the end of the forearm bone near the hand, breaks with the fragment displaced toward the palm. This injury represents approximately 3% of all distal radius fractures. It typically follows high-energy trauma in younger individuals or low-energy falls in older adults with compromised bone quality. Recognizing this injury early is vital because the displaced fragment can compress the median nerve and disrupt wrist stability.

What causes a Smith fracture?

Smith fractures commonly occur after a direct blow to the dorsal wrist or a fall onto a flexed wrist, which transmits axial force directly to the volar (palmar) side of the bone. This specific impact creates a fracture line that forces the distal segment anteriorly. This mechanism stands in direct contrast to a Colles fracture, which results from falling on an outstretched, extended hand. The wrist position at impact helps distinguish Colles fracture vs Smith fracture.

What are the signs and symptoms of a Smith fracture?

Affected individuals typically present with wrist pain, swelling, tenderness, limited range of motion, and sometimes a visible “garden spade” deformity. This helps differentiate a Smith fracture vs Colles fracture, as the latter produces a “dinner fork” deformity. If the displaced bone compresses the carpal tunnel, patients may experience numbness or tingling in the median nerve distribution. Clinicians should assess neurovascular status, including median, radial, and ulnar nerve function.

How is a Smith fracture diagnosed?

Diagnosis relies on physical examination paired with standardized radiographs, specifically posteroanterior (PA) and lateral views. The lateral projection confirms the volar angulation and displacement of the radial fragment. Radiographs help assess volar tilt, displacement, radial shortening, and joint involvement. If the fracture is comminuted or intra-articular, CT may be useful for surgical planning.

How is a Smith fracture treated?

Management depends on the stability of the fracture and whether the joint surface is involved. Stable, minimally displaced cases may respond to nonoperative treatment using a cast that holds the wrist in slight extension. However, an unstable or intra-articular variant typically requires open reduction and internal fixation. Surgeons frequently use volar locking plates to restore radial height and ensure the fragments heal in the correct anatomical position.

What are the most important facts to know about a Smith fracture?

• A Smith fracture is a break of the distal radius characterized by volar displacement of the bone fragment.
• The injury follows a fall on a flexed wrist, which is less frequent than the fall that causes a distal radius Colles fracture (falling on an outstretched, extended hand).
• Hallmark signs include palmar swelling and a “garden spade” deformity.
• PA and lateral X-rays are the gold standard for diagnosis, and the direction of displacement helps differentiate a Smith vs Colles fracture.
• Treatment involves specialized casting or surgical fixation with plates to prevent median neuropathy and long-term joint dysfunction.