The scaphoid bone is a small bone within the wrist joint. A fracture to the scaphoid is well known among hand specialists as being potentially problematic, due to peculiarities of the bone itself and that it is often undetected or misdiagnosed by other medical practitioners. Fortunately, if detected at the right time there are appropriate treatments for scaphoid fracture.
What is the scaphoid bone?
The scaphoid is a small bone in the wrist almost completely covered in cartilage. It has a special function within the wrist joint - a 'ball bearing' role, helping other bones to move around it as the wrist twists and flexes.It takes a lot to break the scaphoid bone, nearly twice as much force as it would take to break the one of the bigger forearm bones. Despite this, it is the most common fracture of the small wrist bones, as it most often occurs when we stretch out our hand to break a fall. It is a common sporting injury, with men being ten times more likely to fracture the scaphoid than women - football and other contact sports, car and motorcycle accidents are frequent culprits.
Why is scaphoid fracture serious?
First, scaphoid fractures are often overlooked. Often, following a fall or accident, the initial symptoms may not seem to suggest a fracture. Swelling can be minor and may subside within a few days. The injury may feel no more severe than a sprain and so may not be properly diagnosed by doctors. Even if you have an X-ray taken, the fracture may not be apparent at first.
Second, scaphoid fractures can be slow to heal. Because the bone does not receive much blood supply, the course of healing can be unpredictable. If a fracture causes this blood supply to be interrupted or closed off, the scaphoid bone is vulnerable to becoming fragile and causing other problems within the wrist. Part of the bone can die off (avascular necrosis).
Third, because of the anatomy of the wrist, the poor blood supply and the forces that occur during hand movement, there is a risk of the fracture not uniting (healing), as the bone may not be able to be held together easily. The healing may be delayed or impeded altogether (non-union).
If you suspect a scaphoid fracture, there are several means of diagnosing and treating it.
Treatment for scaphoid fracture
It is usual to assess the injury with a wrist X-ray, although it is important to note that the fracture may not be visible on images taken within a day or two of the injury. Some patients with a suspected scaphoid fracture will need a different type of scan to establish whether the bone is broken; this is usually taken 3 or more days afterwards. This may be an MRI scan or, in some cases, a bone scan.
Where the fracture has not completely separated the scaphoid bone, it is usual for this to be successfully treated with a wrist cast. If the fracture is complete, particularly if the pieces of the bone are displaced, cast treatment can take much longer, perhaps 3 months or more. There is a chance that healing may not take place which brings us on to other treatment options.
We will be able to discuss with you several surgical treatments. For example, if the fracture is recent it may be possible to stabilise the scaphoid bone with a special type of screw. The wrist is kept in a cast until it is safe to resume some strength and flexibility exercises. This may take 8 to 12 weeks.
In cases where a previous scaphoid fracture has not healed, other surgical interventions may be required. For example, it may be necessary to take a bone graft from the pelvis or radius to stimulate the old fracture to begin the healing process again.