Fractures and non-unions of the scaphoid
The scaphoid is one of the most important carpal bones, and is also the most frequently fractured carpal bone. Scaphoid fractures occur most commonly in young adults after a fall onto an outstretched hand, quite often during sports.
The treatment of this injury presents a number of challenges:
- Quite often young people involved in sports do not realise that they have actually fractured a bone in the wrist, and the acute pain may pass within a few weeks, reinforcing the impression that the wrist had simply been sprained. A few years may then pass before the wrist is injured again and becomes painful. X-rays at that point may reveal a chronically unhealed fracture, or "non- union". The effective treatment of scaphoid non-unions is more difficult than that of acute fractures.
- If medical attention is sought, diagnosis can still be difficult in the first few weeks, as sometimes scaphoid fractures do not show up on normal X-rays. In this situation the use of more sophisticated imaging techniques, such as CT or MRI scanning, can clarify the diagnosis.
- The scaphoid has a tenuous blood supply, so fractures are in fact at significant risk of not healing. This is particularly the case if the fracture is towards the proximal pole of the bone, near the radius. Smoking has also been shown to prejudice the healing of these fractures.
Scaphoid fractures can be treated with the use of a below elbow cast, or with operative techniques which aim to reduce the fracture (i.e. bring the two parts of the bone back together) and compress it with a screw that is buried within the bone. In some cases it is possible to insert such a screw using a 'percutaneous' technique, where only a 5mm incision is required. Such a technique can speed recovery and has the advantage of minimising dissection and damage to the scaphoid's blood supply.
In cases where the fixation is delayed, or there is an established non-union, bone graft will be required. This may be taken from the nearby distal radius, or from the hip bone (iliac crest).
Factors which determine which treatment is optimal include:
- the site of the fracture within the scaphoid
- the presence of displacement
- the age of the fracture
- the presence of associated injuries to other bones or ligaments in the wrist
Mr Gidwani will be able to explain the appropriate treatment options to you, as well as their advantages, disadvantages and potential risks. As with the treatment of any broken bone, the aim is to encourage the bone to heal in a position that enhances recovery, so that in time you can regain good function of the hand and wrist. If necessary hand therapy will be used to help this process.