Scaphoid fracture is common in young males. Scaphoid bone is a small boat shaped bone that forms a important part of the wrist joint.
Before reading further it would be good to first see Wrist Anatomy (skip if you have already done so).
Fracture of scaphoid occurs by two mechanisms.
- Hyperextension of the wrist joint
- Axial load applied to the wrist
The first mechanism is seen when a person falls on their outstretched hand, this produces a displaced and unstable fracture. Second mechanism is seen during by the back kick of a pump handle, this produces a undisplaced and stable fracture.
Symptoms include
- pain
- swelling and tenderness over the wrist
- no obvious deformity is present hence the fracture can be mistaken for a wrist sprain
Meticulous history of the mechanism of trauma and proper clinical examination is required. One should look for tenderness in the anatomical snuff box. When ever in doubt the injury should be treated as scaphoid fracture.
Investigations required to confirm the diagnosis include
- apart from routine views a scaphoid (oblique) view and stress views (x ray under manipulation or traction) are taken
- bone scan will be positive if the fracture is not seen on routine views
- CT scan
- MRI scan
This is an oblique view x ray of the wrist joint showing a scaphoid fracture.
This is an illustration of the above x ray.
Where facilities for Bone, CT and MRI scan are not present, there x rays can be repeated after 3 weeks.Till then the injury should be managed as a fracture of scaphoid.
Scaphoid bone can fracture at different places. Most common site of fracture is the waist. (80% of all fractures) With waist and proximal third fractures the blood supply of the scaphoid is disrupted. This increases the tendency of nonunion (failure of fracture to heal) and avascular necrosis (death of bone due to interruption of blood supply).
This fracture can be classified into two types
- Undisplaced stable or hairline fracture
- Displaced unstable (fracture fragments are at least 1mm apart from each other)
This is a photo of a elderly female with a scaphoid cast.Treatment of undisplaced fractures is by plaster cast immobilization till there is confirmed evidence of union on x rays. Usual duration of immobilization is 12 weeks. This can be extended to 24 weeks if union is slow. Healing of the fracture by cast is above 95%.
Displaced fractures are initially treated by re-alignment and immobilization in a plaster cast. If proper re-alignment is not obtained then surgery is done.During surgery the fracture fragments are re-aligned by manipulation or exposure through a surgical incision. Now the fracture is stabilized by stainless steel wires or screws.
Most common complication is non-union. It is managed surgically. During surgery the the fracture is exposed through an incision, it is then aligned and stabilization is done by screws or wires along with bone grafting.
Frequently Asked Questions
What are the chances of developing non-union of the fracture?
Chances of developing non-union are more when
- there is a delay in diagnosis
- fracture is displaced
15 to 30% displaced scaphoid fractures develop non-union.
What are the symptoms of non-union?
Symptoms of non-union include
- persistent pain in the wrist joint
- weakness in the hand and wrist
In people who don't do heavy work with their hands non-union of scaphoid may produce mild symptoms only. They may not require any treatment.
How long does it take to regain full strength in the hand after union of the fracture?
It can take 2 to 4 months to regain full strength in the hand after union of the fracture.
I hope the information provided was helpful. If you have any query you can ask me at the contact me page.
This page was last updated on 6th September 2010.
Other causes of wrist pain...
De Quervain Disease
Ganglion
Carpal Tunnel Syndrome
Wrist Fracture
Madelung Deformity
Wrist Anatomy