The scaphoid is probably the worst bone in the entire arm to break. It has a poor blood supply, it is subjected to high stresses, and it is a very important wrist bone. Scaphoid fractures are serious injuries. Textbooks have been written about them. They love to not heal (ie. ‘go on to non-union’) and/or have part of the bone die (avascular necrosis: like a heart attack of bone). And if they don’t heal, the wrist inevitably develops arthritis.
The fracture can be through the waist (middle) of the scaphoid, though its distal third (toward the thumb tip; best chance to heal) or through its proximal pole (away from the thumb tip towards the forearm; worst chance to heal). In adults, if you put a fresh non-displaced (it hasn’t moved) fracture into a cast, a distal pole fracture takes 2 months to heal, a waist fracture takes 3 months to heal, and a proximal pole fracture takes 4-6 months to heal. And many times the proximal poles won’t heal in a cast because these fractures are less stable than the others. Proximal pole fractures will almost always do better with surgical stabilization.
Scaphoid fractures often don’t show up on the initial X-rays. They may take 2 weeks to be able to be seen on X-ray. It’s very important not to miss them (see below). So if you injure your wrist and you’re tender over the scaphoid you can either be casted for two weeks until repeat X-rays show a fracture or no fracture, or get an MRI. Althought it’s more expensive, an MRI can diagnose a scaphoid fracture within 24 hours.
In order to avoid 3 months in a cast, most active patients with scaphoid waist fractures elect to have a screw placed into their scaphoid percutaneously. Percutaneously means through a very small (1-2 cm) incision. Percutaneous screw placement does not disrupt the soft tissue and blood supply around the scaphoid, allowing it to heal better and quicker than when using a traditional open incision. If the scaphoid screw is placed within 4 weeks after the fracture, percutaneous screw placement has a 95% chance of success. After 4 weeks the success rate drops. This ‘clock’ can be slowed down by casting the wrist, which is why if a scaphoid fracture is suspected, but not proven, the patient is put into a cast until we’re sure the scaphoid isn’t fractured. If the scaphoid fracture is caught quickly and fixed percutaneously, most times it heals well with no significant loss of motion; it’s almost like it never happened. Displaced fractures will not heal without surgery, and often require a formal open approach to treat.
Following surgery, if the fracture was treated early (within 4 weeks) and it was a waist fracture (which are more stable) you’ll usually only be immobilized for a few days after surgery, and then will be placed in a removeable splint to allow you to shower and bathe. Please avoid sports or heavy lifting until the fracture is healed. Proximal pole fractures are less stable, and are often casted for 6 weeks, sometimes longer. Every scaphoid fracture is different.
Many times patients don’t realize that they’ve broken their scaphoid until many years later. They think they just ‘sprained’ their wrist. The scaphoid may become temporarily stabilized by scar. Years later the scar can break due to a minor trauma. Many times the patient can’t remember how they broke their wrist. These ‘non-unions’ (non-healed fractures) are far more difficult to get to heal and often require open reduction through a standard incision combined with bone graft taken from another bone (the radius) by your wrist. After surgery, these fractures are casted until they heal. Sometimes the wrist is already arthritic due to the nonunion. Please see the ‘wrist arthritis’ section to see how these are treated.
