The scaphoid bone is one of eight carpal bones within your wrist. The scaphoid is the most commonly fractured carpal bone. Your carpal bones are organised into two rows; a proximal row and a distal row. The scaphoid is a long, curved shaped bone which is in the proximal row on the thumb side of your wrist.
The scaphoid is often fractured from a fall onto an outstretched hand due to the force that travels through the wrist from the impact. It is more common for scaphoid fractures to occur in adults and rarely occur in children below the age of ten.
Scaphoid fractures have a retrograde blood supply which means the blood supply to the bone enters from the distal end (the end closest to the fingers) before traveling to the proximal end (the end closest to the wrist). This is an important consideration with scaphoid fractures because if the wrist is fractured, then blood supply can be compromised for the proximal pole.
To confirm whether a fracture is present within the scaphoid, x-ray imaging can be completed. Occasionally, x-rays are unable to identify the fracture and therefore further imaging may be necessary such as a CT scan or an MRI.
Definition
A fracture is the medical term for a break in the bone. The location of the fracture within the scaphoid bone can vary and can be categorised as the following:
- Distal pole fracture
- Waist fracture
- Proximal pole fracture
The fracture can then be further classified as displaced or non-displaced which indicates whether the fracture fragment has moved from its original position or not.
Non-displaced fracture: Fracture fragments are in their correct position and have not moved from their anatomical alignment. A non-displaced fracture is more likely to be treated with casting or splinting.
Displaced fracture: Fragments of the fracture have moved or slipped from their original position due to an unstable fracture pattern. Displaced fractures may require surgical intervention to realign and fixate the fracture fragments.
Causes
The scaphoid is often fractured from a fall onto an outstretched hand due to the force that travels through the wrist from the impact. It is said that approximately 80% of load travels through the radial side of the wrist and therefore it is usually the scaphoid or the distal radius that is fractured during a fall.
A scaphoid fracture can be caused from a low energy fall from a standing position, or a high energy fall such as within a sports game or from a roller-skating accident.
Signs & Symptoms
The signs and symptoms of a scaphoid fracture may vary from person to person. Some of the symptoms you may experience include:
- Swelling of the thumb, hand or wrist
- Bruising of the hand/wrist/thumb
- History of a fall onto an outstretched hand
- Pain or tenderness to touch over the base and/or side of thumb/wrist region, also known as the anatomical snuffbox
- Pain when moving your wrist
- Pain when gripping or lifting objects
- If you suspect that you may have sustained a scaphoid fracture, please present to your local general practitioner or make an appointment at Melbourne Hand Therapy.
Treatment
Depending on the severity of the fracture, scaphoid fractures may be treated via cast immobilisation, thermoplastic splinting or with surgery.
If surgery is required, the procedure will involve reduction and then fixation of the fracture. The most used method of fixation is a screw. For a successful surgery, a bone graft may be required to promote union and provide a new blood supply to the scaphoid.
If surgery is not required, then conservative treatment can proceed. A cast or thermoplastic splint can be fabricated for you which may or may not include the thumb depending on your presentation. Both splint designs have been shown to provide similar outcomes however a wrist splint may be more functional due to allowing thumb range of motion.
Complications post scaphoid fracture may include:
- Delayed union – this is where the scaphoid is slower to heal than what would be expected
- Non-union – this is where the fracture is failing to heal
- Avascular necrosis is where blood supply to the healing bone is compromised which leads to death of the bony tissue and therefore the bone is unable to heal
Melbourne Hand Therapy Can Help You
At Melbourne Hand Therapy our team works closely with your medical team and are able to assist you throughout the entire duration of your recovery. As your hand therapist we can help identify if a fracture is present and recommend an appropriate management plan.
Our team of experienced occupational therapists and physiotherapists can fabricate either a cast or thermoplastic splint to support your healing fracture and provide rehabilitation following your surgery.
Following a fracture, a period of immobilisation within a cast or post-surgery, hand therapy will be required to provide you with the necessary education and to help you to regain the range of motion in your wrist. Hand therapy will also be of benefit to rebuild your strength and help you return to the activities you enjoy.
