What Is a Scaphoid Fracture And How Is It Diagnosed?

The wrist is made up of eight small bones known as "carpal bones," and the scaphoid is one of them. Situated beneath the thumb in the shape of a kidney bean, the scaphoid (or navicular) bone is involved in wrist movement and stability.

Because of its relatively large size and positioning on the side of the wrist, the scaphoid is prone to injuries and fractures, making up the majority of carpal bone fractures in athletes (85%) and non-athletes (70%).

Injuries that result in such fractures usually occur by falling onto an outstretched hand. When falling, the instinctive reaction is to cock the wrist in order to break the fall with the hand. The wrist ends up taking on the brunt of the force and depending on its angle during impact it can hyperextend, leading to a fractured scaphoid. Other causes include a traumatic direct blow to the hand or road traffic accidents.

Common symptoms that indicate a possible scaphoid fracture are:

  • Localized swelling and bruising of the wrist
  • Acute pain during gripping or pinching
  • Tenderness of the anatomical snuffbox   
  • A flat, internal ache in the radial side of the wrist

Scaphoid Fracture Diagnosis

Scaphoid fractures are not easy to diagnose because they are not as obvious and can be mistaken for sprains. It's not uncommon for patients that have sustained such an injury to try and treat it at home only to refer to a physician when the pain increases. 

When the fracture isn't immediately immobilized, it may fail to heal leading to a nonunion of the bone that can cause complications in the long run. 

X-rays are the primary diagnostic tool; however, fresh fractures may not be visible, resulting in inconclusive results. If a physician suspects a fracture, he will recommend immobilizing the wrist for two weeks. This will allow the potential fracture to heal and show up on X-rays, especially if it's non-displaced. 

Athletes and individuals that cannot afford to wait for two weeks to repeat X-rays can opt for an MRI scan to diagnose the fracture. A CT scan is likewise useful in determining if a fracture has occurred and can also identify bone displacement.

Depending on the diagnosis results, the physician will recommend the appropriate treatment plan according to the severity of the incurred fracture.