Acute buckle fracture of the distal radius

Buckle fractures are injuries that occur to either the radius, ulna or both usually due to a fall in young children. Buckle fractures are NOT what most people think of when they think of a fracture or broken bone. The fracture does not go through the entire bone. Because of this, buckle fractures are very stable fractures, so we do not have to worry about them moving out of alignment. They also heal more quickly than a typical fracture.

Bones are like pipes in that the strongest portion of the bone is around the sides (called the cortex or cortices for plural). In a buckle fracture, one or two cortices are compressed during the fall resulting in very slight bending on one side, but the other side of the bone is not injured. As such, the bone is NOT broken into two pieces.

Arrows point to the buckle in the cortex. Notice that there is not a fracture line extending across the bone.

How are Buckle Fractures Treated?

Because buckle fractures are not complete fractures, they are very stable fractures and heal quickly. A cast is not usually necessary, and we typically treat these with a removable Velcro® wrist brace. The brace can be removed for bathing but should otherwise be worn at all times while the patient has pain. As the pain improves, the brace may be removed for sleeping and even swimming. It should be worn at all other times for a total of 3 to 4 weeks. At 3 to 4 weeks, the parent can give the child’s wrist a firm squeeze. If the patient does not have pain at that point, he or she may quit using the brace and resume normal activities.

What is the Long-Term Outcome?

Buckle fractures do not involve the growth plate, so there are no complications with a difference in the lengths of the forearms or with deformity. Buckle fractures do not put a patient at higher risk for another fracture in the future.

Buckle injury: Compression injury failure of bone resulting in the cortex bulging outwards (unilateral or bilateral). Also known as a torus injury. Although there is a disruption to the cortical bone, the integrity of the bone is minimally compromised, resulting in different patient management from other fractures

See fracture education module  for more information

Anteroposterior (AP) view

Lateral view

Complete: A fracture that extends through both cortices. Most complete metaphyseal fractures involve both the radius and ulna. The radius is commonly a complete fracture. The ulna may have a complete fracture, greenstick fracture, or a plastic deformity

AP view

Lateral view

3. How common are they and how do they occur?

Metaphyseal fractures have a peak incidence during the adolescent growth spurt (girls aged 11-12 years, boys 12-13 years) due to weakening through the metaphysis with rapid growth.

Up to 13% incidence of other arm injuries (hand, forearm, elbow) occur on the same side.

The most common mechanism of injury is a fall on an outstretched hand. Extension of the wrist at the time of injury causes the distal fragment to be displaced dorsally (posteriorly). Volar (anterior) displacement of the distal fragment is usually the result of a fall on a flexed wrist.

These injuries can occur in conjunction with more proximal forearm fractures, such as Monteggia fracture-dislocations, supracondylar humeral fractures and hand fractures.

4. What do they look like - clinically?

There is usually pain and tenderness directly over the fracture site, and limited range of motion in the wrist and hand.

Deformity depends on the degree of fracture displacement. Buckle injuries present with no or minimal deformity. Buckle injuries are often misdiagnosed as a wrist sprain. An x-ray of the wrist should be ordered to clarify the diagnosis.

5. What radiological investigations should be ordered?

A 'wrist x-ray' request will provide AP and lateral views of the distal forearm and wrist. If the injury is to the mid forearm or the pain is poorly localised, a 'forearm x-ray' should be ordered. Avoid ordering 'x-ray arm' as it is better to have images focused to the region of local tenderness. If there are any elbow joint symptoms, an 'elbow x-ray' should be ordered as some fractures around the elbow can be difficult to detect.

6. What do they look like on x-ray?

Buckle injury

Figure 1: Lateral and AP x-ray of a five year old who sustained a buckle injury of the distal radius.Buckle injuries are often subtle radiographically.They are best viewed on the lateral x-ray. Bilateral or unicortical cortical bulging can occur.

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Minimally displaced complete metaphyseal fractures can be mistaken for buckle injuries (Figure 2). These fractures are potentially unstable and need to be managed in a well moulded cast.

Figure 2:  Six year old with complete metaphyseal fracture.  On the lateral view, there is a minimally displaced radial metaphysis, which could be mistaken for a buckle fracture.  However on the AP view, it shows that both cortices are broken (i.e. it is a complete fracture).

Complete fracture

Figure 3: AP and lateral x-ray of 15 year old with complete metaphyseal fracture of radius and ulna. Most metaphyseal fractures displace posteriorly.

7. When is reduction (non-operative and operative) required?

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As a rule of thumb, if the deformity is clinically visible, reduction may be indicated.

Acceptable angulations are dependent on the age of the child. Table 1 shows the acceptable angulations for distal radius metaphyseal fractures. Fractures angulated more than these values usually need to be reduced. Angulation in the coronal plane (as seen on AP x-ray) is less tolerated as it does not remodel as well as angulation in the sagittal plane (as seen on the lateral x-ray).

X-rays should be taken post-reduction. Angles should be within the same parameters for acceptable angulation.

Table 1: Acceptable angulations for distal radius metaphyseal fractures.

 Age

Acceptable angulation

0-5 years

<20 degrees

5-10 years

<15 degrees

10-15 years*

<10 degrees

* As girls mature earlier, acceptable angulations may be less.

Bayonet apposition is acceptable in children up to age of six as long as angulation alignment parameters are acceptable. For children aged 6-10 years, if the fracture is still in bayonet position after reduction, ask the orthopaedic on call service to review the post-reduction x-rays to check if the position is acceptable. Children aged 11 years and above need to have apposition at the fracture site.

Figure 4: Bayonet apposition refers to a fracture in which the two bone fragments are aligned side-by-side rather than in end-to-end contact.

8. Do I need to refer to orthopaedics now?

Indications for prompt consultation include:

1. Open fractures
2. Fractures with associated neurovascular compromise
3. Inability to achieve an acceptable reduction (including if ED is not experienced in fracture reduction, splinting or casting)
4. An associated arm fracture in the same upper limb or opposite limb

9. What is the usual ED management for this fracture?

Treatment options depend on the fracture type, age of patient (years of remaining growth) and the amount of displacement (Table 2).

Table 2: ED management of metaphyseal distal radius fracture.

Fracture type

Type of reduction

Immobilisation method & duration

Buckle injury

No reduction required

Below-elbow fibreglass/plaster backslab or removable wrist splint for 3 weeks

Complete - undisplaced or minimally displaced fractures

No reduction required

Below-elbow cast for 6 weeks

Complete - displaced fractures

Closed reduction

This fracture is suitable for a local anaesthetic, manipulation and plaster (LAMP)or procedural sedation in the ED, provided that there are appropriate resources and accredited personnel at your health service

Below elbow plaster cast for 6 weeks. For young children, above-elbow casts may be applied

Fractures where the distal fragment is angulated dorsally should have a cast with three point moulding with slight wrist flexion

Fractures where the distal fragment is angulated volarly should have casting with three point moulding with slight wrist extension

10. What follow-up is required?

• Buckle injury: No follow-up is required by GP or fracture clinic. Radiographic follow-up is not required. Instruct parent to remove backslab or splint in 3 weeks. Provide parent with buckle injury fact sheet. Ensure parents understand signs for concern (ongoing pain, etc.).
• Complete fractures: All complete fractures should be reviewed in fracture clinic within 7 days with an x-ray in cast at first appointment.

11. What advice should I give to parents?

Distal metaphyseal fractures of the radius have very good remodelling potential because of the proximity to the growth plate. There is a very low risk of growth arrest.

For complete metaphyseal displaced fractures and fractures involving both the radius and ulna, the need for close follow-up should be emphasised due to the risk of loss of reduction.

12. What are the potential complications associated with this injury?

The main early complication is loss of reduction. One in ten (10%) will lose position and will need a re-reduction. Contributing factors are poor cast technique and residual angulation/displacement after the initial reduction. Loss of position and the opportunity for re-reduction can only happen with appropriately timed follow-up.

Another complication is compartment syndrome due to restriction by cast.

See fracture clinics for other potential complications.

13.  Parent information fact sheet

References (ED setting)

Bae D. Pediatric distal radius and forearm fractures. J Hand Surgery 2008; 33: 1911-23.

Bohm ER, Bubbar V, Yong Hing K, Dzus A. Above and below the elbow plaster casts for distal forearm fractures in children: A randomized controlled trial. J Bone Joint Surg Am 2006; 88: 1-8.

Crawford SN, Lee LSK, Izuka SH. Closed treatment of overriding distal radial fractures without reduction in children. J Bone Joint Surg Am 2012; 94: 246-52.

Herring JA. Upper extremity injuries. In Tachdjian's Pediatric Orthopedics, 4th Ed. Saunders, Philadelphia 2008. p.2536-68.

Kennedy SA, Slobogean GP, Mulpuri K. Does degree of immobilization influence refracture rate in the forearm buckle fracture? J Pediat Ortho B 2010; 19(1): 77-81.

Rang M, Stearns P, Chambers H. Radius and ulna. In Rang's Children's Fractures, 3rd Ed. Rang M, Pring ME, Wenger DR (Eds). Lippincott Williams & Wilkins, Philadelphia 2005. p.135-50.

Stutz C, Mencio G. Fractures of the distal radius and ulna: metaphyseal and physeal injuries. J Pediat Ortho 2010; 30: S85-9.

Waters PM, Bae DS. Fractures of the distal radius and ulna. In Rockwood and Wilkins' Fractures in Children, 7th Ed. Beaty JH, Kasser JR (Eds). Lippincott Williams & Wilkins, Philadelphia 2010. p.292-346.

Webb GR, Galpin RD, Armstrong DG. Comparison of short and long arm plaster casts for displaced fractures in the distal third of the forearm in children.J Bone Joint Surg Am 2006, 88(1): 9-17.

What is an acute buckle fracture?

How long does a radius buckle fracture take to heal?

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Does a buckle fracture in the wrist need a cast?