Wrist Fractures

Original article by Tom Leach | Last updated on 4/4/2015
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Introduction

FOOSH – Fall On Out-Stretched Hand” is a common emergency department presentation that can result in a number of different fractures of the bones of the wrist.
 
The majority of fractures involve the distal radius. You should also be mindful of fracture of the scaphoid (often missed), and be wary in children of fractures that only seem to involve one of the radius or ulnar (as they require proper assessment and x-ray of the elbow too).
 
We will also look at wrist fractures that aren’t necessarily caused by a “FOOSH”.
 

Epidemiology

  • Account for about ¼ of all limb fractures
  • Most common in children and young adults as these are the populations that engage in the risk taking activities
  • A second peak incidence is seen in old age, with frail, elderly, osteoporotic patients fall

 

Anatomy

Knowing the bones of the wrist is useful, but as long as you can point out a scaphoid, and know your ulnar from your radius anything involving the other carpal bones is a bit more specialist.
 
There are two ‘rows’ of carpal bones, with four in each.
 
 
 

Basics of Management

Reduction and Manipulation

Most cases of wrist fracture are suitable for conservative management.

  • Until you have an x-ray, try to keep all patients nil by mouth, as they may require sedation for manipulation and reduction. Some sources state 1 hour of NBM is enough, but many places practice a 4 hour rule.
  • Usually, sedation is not a general anaestheitc, but conscious sedation. Suitable agents often include ketamine (especially in children) and benzodiazepines in adults (for example midazolam, or perhaps a combination of midazolam and fentanyl). The exact agent, or combination of agents will be decided by the person performing the sedation. It is also possible to perform local anaesthesia, nerve blocks, or haematoma blocks, although conscious sedation is probably the most popular method.
  • Sedation carries some (not negligible) risks, particularly related to the airway. Some individuals can have an airway compromise requiring intubation from only mild sedatives.
  • Make sure you provide adequate analgesia. In many cases this will require opiates. Bearing in mind the point above, these often shouldn’t be given via the oral route.

 

Immobilization

  • Full casts should be avoided in the first few days due to swelling (and possible compression and subsequent neurovascular compromise) that occurs in the days after the initial injury
  • The mainstay of treatment is a back slab (aka volar slab). This is a partial plaster of Paris cast that runs on the volar surface of the wrist and forearm, with crepe bandages to hold it in place. This is then usually reviewed in fracture clinic within a few days. The joint my be re-x-rayed to check the bones have not shifted and then a full cast applied
    • In scaphoid fractures, a spica thumb cast is used instead of a volar slab

 

Surgery

  • If its not possible to get an adequate reduction, or there is a reduction with a dislocation, or there is an open fracture, then its likely surgery will be required. Often there is a pin screws or wires placed to hold the pieces of bone together This is often referred to as ‘open reduction and internal fixation’ or ORIF.

 
 

Assessment

All patients who present with a FOOSH and have ongoing pain, tenderness, or neurovascular signs will require an x-ray.
A normal x-ray does not mean there is no fracture.
In the presence of a normal x-ray, a decision has to be made about the likelihood of an occult scaphoid fracture. If there is anatomical snuffbox tenderness but normal x-ray, you should still apply immobilization and have the patient re-x-rayed and assessed in out patient clinic follow up (usually 2 weeks after the event). 
 
The main points to assess are:

  • Is there a fracture?
  • Does this person need a cast?
  • Does this person need a reduction?
  • Is there neurovascular deficit requiring urgent intervention?

 
 

Scaphoid fracture

Scaphoid is the most common carpal bone fracture, and usually caused by a FOOSH.
They account for about 80% of all carpal fractures, and tend to occur in young men aged 20-30. 10% of the time there is another associated fracture.
 

Investigation

When requesting the x-ray, make sure you mention ‘?scaphoid fracture’ on the request form, as specific scaphoid views are taken.
X-ray is only about 80-90% sensitive for scaphoid fracture.
 

Treatment

You should discuss all scaphoid fractures with the orthopaedic registrar on call. Simple fractures are treated with immobilization. More complex fractures may require surgery. The most common form of surgery for scaphoid fracture is the Herbert Screw, which is a screw almost the length of the scaphoid that holds it together in one piece.
 
Immobilization if:

  • Non-displaced
  • Non-complex (e.g. no other local fractures, not open fracture etc)
  • There isn’t a visible fracture on x-ray, but there is anatomical snuffbox tenderness

Immobilization is usually in the form of a spica thumb cast. Great instructions on how to apply this cast are available courtesy of Life in the fast lane. And try to avoid doing this.
The length of time to take for healing is correlated to the location of the fracture. More proximal fractures usually take longer, and more distal fractures are quicker to heal. Typical healing time for a distal fracture is 4-6 weeks, but a proximal fracture can take up to 23 weeks!
 

Complications

Non-union / delayed union
The fragments of the scaphoid bone fail to heal and remain separated. Typically occurs in late presenting fractures. May resolve with continued immobilization (patients may require longer than the typical 6-12 weeks). Sometimes may be treated with surgery, particularly in instances where there are functional issues as a result of the complication (e.g. pain, reduced movement etc)
 
Malunion
The fragments of the scaphoid join and heal incorrectly, often in a misaligned position. This is likely to lead to pain and reduced ROM. May require surgery.
 
Avascular necrosis
Typically associated with fractures at the proximal end and the ‘waist’ of the scaphoid, as this is the site of the entrance of the blood supply, and the supply may be disrupted if fracture occurs around here.
 
Long term complications

  • Reduced grip strength
  • Increased risk of osteoarthritis of wrist joint

 
Occult Fracture
About 10% of scaphoid fractures don’t show up on x-ray. The traditional approach in all patients with FOOSH and a normal x-ray is to check for tenderness of the anatomical snuffbox, and, if present, to immobilize the wrist (user with a Spica thumb cast) and then to review them again in 2 weeks at fracture clinic. If they still have a normal x-ray with tenderness, an MRI or isotope bone scan can be performed to assess for fracture. CT is less senstivie.
 

Greenstick Fracture

Greenstick fractures occur in children to due the ‘bendy’ nature of their bones. The name derives from the way a fresh ‘green’ stick or tree branch bens and snaps, with one side often completely disrupted whilst the other remains intact.
 
In a greenstick fracture, the periosteum remains intact.
 
The treatment for these fractures depends on the degree of angulation and / or displacement.
 Management
Most cases are suitable for conservative management.
Managed with a split or simple cast if:

  • Child aged under 10, AND
  • < 15 - 20° angulation
  • OR
  • <10° angulation with or without lateral shift <2mm and shortening <2mm

In reality all these cases will likely be discussed with the orthopaedics registrar on call to confirm the management. They should be followed up in fracture clinic within a few days.
 
Require closed Reduction

  • Any displacement
  • >20° angulation

 
Closed reduction is usually performed under sedation in the emergency department or (/and) by the orthopaedics registrar.
 
Pressure should be applied to the deformity for 5-7 minutes. The purpose of the pressure is to deliberately break through the undamaged cortex to cause a full fracture, then a full arm cast applied. If there is a large degree of angulation and a reduction is not performed, the angulation can become worse whilst in the cast.
 
Reassure parents that any minor deformities will reduce and remodel over time.
 
Patients should kepp the cast on for 4-6 weeks, and advise them to avoid any activity that might result in a similar injury (monkey bars, contact sports , trampolines) for a further 4 weeks.
 

Torus Fracture (aka Buckle Fracture)

Seen in children, this is less severe than a greenstick fracture, and is noted by a ‘buckle’ (Tori = latin = protuberance) in the distal end of the radius and ulnar.
Be wary of any child that has a buckle in only one of the two bones, as they will require assessment and x-ray of the elbow too.
 
The fracture is a result of compression, and the outer margin of the bone ‘buckles’. They almost never involve a displacement.

Buckle FractureBuckle Fracture Lateral View
 

Management

Treatment is with a splint or a cast, for 3 weeks. Splint seems to be just as good as cast, and requires less follow-up (no FU appointment to remove the cast at the end of the three weeks is required. Refer patients to fracture clinic if you have seen them in ED.
 
Very rarely there may be some angulation that requires reduction.
 
Usually a volar slab is used. Life in the fast Lane has a good explanation of how to apply one.
 

Colle’s Fracture

Initially when described by Colle, this referred to a fracture of the distal radius, approximately 4cm from the articular surface. Now however, it tends to refer to any fracture of the distal radius with dorsal displacement that does not involve the articular surface.
They tend to occur in older patients with osteoporosis, although they do still occur in younger individuals too.
Usually managed conservatively. Operative management tends to give a better radiological outcome but the same functional outcome.
 

History and Examination

  • History of FOOSH
  • Characteristic dorsal displacement and deformity. Sometimes called ‘dinner fork deformity’ due to the shape of the wrist on lateral x-ray
  • Check the ulnar styloid for tenderness, and also examine the elbow, as there may be co-existing radial head fracture
  • Remember to check neurovascular function

 

Management

  • Needs to be reduced in the emergency department
  • This will be done under sedation (as discussed above) and will usually involve longitudinal traction (puling the wrist) and dorsal pressure.
  • Once an adequate external reduction is seen, apply a back slab, and re-x-ray to check bone alignment. You may need to repeat the procedure if bone alignment is not adequate
  • Severely displaced, or open fracture will require surgical (open) reduction and possibly internal fixation
  • Healing time : 6-8 weeks

 

Complications

 

Smith’s Fracture (aka Revere Colle’s Fracture)

Often results from a fall onto a flexed wrist (as opposed to Colle’s falling onto an extended wrist).
 
A fracture of the distal radius that results in volar displacement.
 
There are three types:

  • Type I – extra articular
  • Type II – intra-articular
  • Type III – fracture dislocation (aka Barton’s Fracture)

 

Management and Complications

Essentially the same as for a Colle’s
 
 

Barton’s Fracture

A fracture of the distal radius with dislocation. The same thing as a Smith’s type III  in the case of a volar displacement. Can be reduced and enlocated in the emergency department like a Colle’s or a Smith’s but this is much less likely to be effective. Surgical outcomes are very good.
Be wary of nerve, vein or artery entrapment.
 
 

Chauffer’s Fracture

A fracture of the radial styloid process, usually as a result of direct trauma.
Acquired this name around the turn of the 20th Century apparently after an increased incidence of this fracture due to misfiring of early automobiles whilst they were being ‘cranked’ as they were started. This resulted in the crank shaft causing direct trauma to the forearm of would-be patients.