Wrist torus and greenstick fractures

Forearm fractures (torus and greenstick fractures combined) are very 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. Which 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 just isn’t true; while they have things in common, they also have significant differences. Read on to find out…

Torus fractures

Torus fractures and buckle fractures are the same thing 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 on to an Outstretched Hand (FOOSH). Torus fractures are very stable fractures 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 of the car 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 in to 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 falling. She is given some paracetamol at triage and you examine her. You find that her right wrist is swollen but has no obvious deformity. She is tender over the distal radius and is neurovascularly intact.You send her for an xray of the wrist and forearm.  Her xray 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, but 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 3 weeks, but can be removed or 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 risk of complications is so low. Patients may report some stiffness of the wrist 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 return to sport and usual activities: once discharged from ED these children can go back to school and can partake in usual play. However, they should avoid sport for the first 3 weeks and no contact or team sport for a total of 6 weeks.

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

This question is currently being addressed by the FORCE trial . Children with distal radius buckle fractures are being randomised to either management with a soft bandage or rigid immobilisation (splint or casting, depending on 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, usually only seen in children under 10 years old.

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 side 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:In fact 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 fairly similar to buckle fractures; there is usually a fall on outstretched hand followed by pain and swelling. However, in greenstick fractures, depending on the degree of break and bend, there may be visible deformity of the forearm. When first assessing, give adequate analgesia and remember to assess neurovascular status; check sensation to the forearm and hand as well as perfusion and muscles of the hand. Although neurovascular compromise in greenstick fractures is rare, it is occasionally seen.

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

Treatment of greenstick fractures

All greenstick fractures require immobilisation in a cast for 6-8 weeks and will require Orthopaedic follow up in fracture clinic. However, if there is significant angulation, 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 age of the child; this is because if a child has more than 2 years of bone growth left, there is greater potential for acceptable remodelling. Don’t forget, girls tend to stop growing before boys and 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 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