Wrist torus and greenstick fractures

Forearm fractures (torus and greenstick fractures combined) are common in children and happen in about 1 in 100 children. Wrist and forearm fractures account for half of all paediatric fractures.

They are often discussed alongside each other as they have several things in common. They are both almost exclusively seen in children due to the cartilaginous, compressible, soft nature of young bones. This means you will often hear people say “they are the same thing” (in fact, if you google “buckle fractures”, they often offer up beautiful examples of…greenstick fractures!). But that isn’t true; while they have things in common, they also have significant differences. Read on to find out…

Torus fractures

Torus and buckle fractures are the same, and the terms can be used interchangeably.

Torus fractures can, in theory, occur in any soft, compressible bone, but the term “torus fracture” is most frequently used in the context of radius or ulna fractures.

They are a common fracture of the distal radius +/- ulna where only one side of the bone buckles, but the other side of the bone is unaffected. They are caused by a longitudinal force through a long bone, usually from a Fall Onto an Outstretched Hand (FOOSH). Torus fractures are stable as the cortex crumples and buckles rather than snaps in two. Much like when the front of a car drives into a lamp post, the front will crumple.

This buckling of the bone happens because the paediatric bone is soft.

To me, the name “buckle fracture” is very descriptive and visual, so I favour it over “torus fracture”…until I found out that “torus” is the Greek for “bulge” (ish).  For those familiar with the Greek columns outside BMA House and the Royal College of Surgeons in London, the bulgy bit at the top or bottom of the straight column is known as the “torus” of the column.

Compare and contrast the straight Greek column with the radius, both with a torus at one end.

A 7-year-old girl comes into your Emergency Department on the first day of the Christmas holidays, having fallen over when ice skating at Somerset House.

She remembers feeling like she was going to fall and put out her right hand to stop herself from falling. She is given some paracetamol at triage, and you will examine her.

You find that her right wrist is swollen but has no obvious deformity. She is tender over the distal radius and neurovascularly intact. You send her for an X-ray of the wrist and forearm. Her X-ray shows a buckle fracture, which you immobilise with a removable splint.

Treatment of buckle fractures: the controversy

Buckle fractures are treated with analgesia, rest and support.

At the moment, there is a degree of international (and national) variation in what people do for “support,” so do check your local policy. However, current evidence suggests immobilising with a removable splint will result in excellent healing. In really young children, if there is no splint small enough, they will be put in a plaster cast.

The splint should be worn for three weeks but can be removed earlier if the child is pain-free. These fractures will heal with minimal or no complications and do not require follow-up in a face-to-face trauma or fracture clinic. Many centres follow up in virtual fracture clinics; some don’t follow up at all as the risk of complications is so low. Patients may report some wrist stiffness when the splint comes off, but they shouldn’t need formal physiotherapy.

Buckle fractures have a risk of refracture, so it is important to counsel patients about returning to sports and usual activities: once discharged from ED, these children can return to school and partake in usual play. However, they should avoid sports for the first three weeks and no contact or team sports for six weeks.

But, the question has been raised about whether we need to immobilise these types of fractures.  Although a removable splint possibly ensures maximal comfort with the theoretical advantage of minimising refracture, the flip side is that function is restricted. Add to this the growing acceptance that splints may not improve pain control or affect complication rates. The question starts to emerge: do we need to immobilise these fractures?

The FORCE trial is currently addressing this question. Children with distal radius buckle fractures are being randomised to either management with a soft bandage or rigid immobilisation (splint or casting, depending on the current practice of the treatment centre). The team are looking at pain, functional improvement and complications. Watch this space for results. It could be interesting.

Greenstick fractures

Greenstick fractures are unique to paediatrics and are usually only seen in children under 10.

Imagine walking in the woods, picking up a stick and bending it*; the tough bark on one side will break, but the bark on the other remains intact.  This is what happens in paediatric greenstick fractures: they are partial fractures where the cortex is broken on only one side of the bone. Again, like the torus fracture, this is the result of the softer bones of children.

(Editors note: Emily did just this: she took her two young nephews romping in the woods and bent a lot of sticks, all in the name of medical science.)

The history is usually somewhat similar to buckle fractures; there is typically a fall on an outstretched hand followed by pain and swelling. However, in greenstick fractures, depending on the degree of break and bend, the forearm may have a visible deformity. When first assessing, give adequate analgesia and remember to evaluate neurovascular status; check sensation in the forearm and hand, as well as perfusion and hand muscles. Although neurovascular compromise in greenstick fractures is rare, it is occasionally seen.

Greensticks can be very subtle on x-rays. Or they can be very dramatic! You will usually see a bending injury and a fracture line that does not go through the bone.

Treatment of greenstick fractures

All greenstick fractures require immobilisation in a cast for 6-8 weeks and an Orthopaedic follow-up in the fracture clinic. However, if significant angulation exists, reduction or surgery may be required to realign the bone before immobilisation.

As a broad rule of thumb, if the arm looks deformed clinically from the end of the bed, it will likely need reduction before immobilisation. But to be more specific… we accept different degrees of angulation depending on the child’s age because if a child has more than two years of bone growth left, there is greater potential for acceptable remodelling. Don’t forget that girls tend to stop growing before boys, so acceptable angulation may be less in girls.

Whether the reduction is done in your ED or in theatre depends on your local policies and ability to sedate in the ED.

Don’t forget to get a repeat x-ray after immobilisation to check the acceptable position.

Most greenstick fractures heal well with no complications. However, complications (including refracture, complete fracture and displacement) can occur if the initial fracture is not properly immobilised and followed up.

Conclusion

There are similarities; greensticks and buckles commonly happen in the forearms of children, and they rarely need surgery. However, due to the instability of the greenstick fractures, they need immobilisation in a cast, whereas buckle fractures can be treated with a removal splint (or perhaps a soft bandage – we await the results from the FORCE trial).

References

Orthokids.org- Pediatric Orthopaedic Society of North America

Atanelov Z, Bentley TP.  “Greenstick fracture overview” [Updated 2019 May 4]. In: StatPearls [Internet].Treasure Island (FL) StatPearls Publishing; 2019 Jan

Noonan KJ, Price CT “Forearm and distal radius fractures and distal radius fracures in children” J Am Acad Orthop Surg.  1998 May-June; 6(3): 146-156

Plint AC, Perry JJ, Correll R, Gaboury I, Lawton L. “A Randomized, controlled trial of removable splinting versus castin for wrist buckle fractures in children” Pedistrics.  2006; 117 (3): 691-7

Primavesi, P. “Sticks and stones and broken bones” Can Fam Physician. 2011 Jan; 57(1): 45-46