What are the benefits and risks of different treatments for elbow fractures in children?

Key messages

- A child with a supracondylar elbow fracture (a broken bone in the upper elbow, approximately 5 cm above the elbow joint) may have a lower risk of nerve injury if two or more wires are inserted from the outside of the elbow rather than having one wire inserted from the inside of the elbow and one from the outside (crossed wires). The method used by the doctor to manually move the bones back into position may not increase or reduce the risk of nerve injury, but using a closed method may reduce the risk of an infection.

- Because we did not find enough studies about other treatments for these elbow fractures, their benefits and risks are unclear. 

- More, well-designed studies are needed to give better estimates of the benefits and harms of other treatments. These studies should focus on outcomes related to elbow movement, as well as quality of life and how upset the child is.

What are supracondylar elbow fractures?

This type of broken bone is in the upper arm bone, approximately 5 cm above the elbow joint. It is the most common broken bone in the elbow during childhood, and can affect a child's day-to-day function as well as their ability to play and do sport.

How are these broken bones treated?

Treatment varies according to whether the bone has moved out of position. If it has moved, the doctor may manually move it back into a normal position. Doctors do this using a 'closed reduction' (without opening up the skin) or 'open reduction' (after the skin has been opened up). 

During surgery, metal wires are used to hold the bone in place whilst it heals. Doctors may use different types and numbers of wires, which are inserted from different angles. 

If the bone has not moved, surgery may not be necessary. In which case, treatments to hold the bone in place whilst it heals include using a plaster cast, a sling, or using traction (with weights, ropes and pulleys).

What did we want to find out?

We wanted to find out: 

- which types of treatments work best to heal the bone effectively; and

- whether these treatments are associated with any unwanted effects.

What did we do?

We searched for studies that compared a range of treatments. The most common treatments were:

- surgical treatments using different types of metal wires after the bone has been put back into position;

- open reduction or closed reduction;

- surgery or non-surgical treatments; and

- different non-surgical treatments.

We compared and summarised their results, and rated our confidence in the evidence, based on factors such as study methods and sizes.

What did we find?

We found 52 studies with 3594 children. Most children were about 5 to 8 years of age and most were boys. The studies were conducted in countries around the world; 33 studies were conducted in countries in South-East Asia. Very few studies reported how they were funded.

Main results

- Wires inserted only from the outside of the elbow may reduce the risk of nerve injury compared with crossed wires (inserted from the outside and also from the inside of the elbow). However, there is probably little or no difference between these treatments in the number of children who develop an infection where the metal wires have been inserted (pin site infections). We do not know if either of these treatments affect elbow function, the risk of needing additional surgery, or any long-term elbow deformity (where the elbow is no longer the normal shape). 

- The initial method used to move the bone back into position may make little or no difference to the risk of nerve injury. However, children may have fewer pin site infections when closed reduction is used.

- There may be little or no difference between using metal wires to fix the bone or holding the bone in place with a cast in the need for additional surgery, nerve injury, pin site infections, or elbow deformity. But we are uncertain of these findings. 

- We do not know if a plaster cast compared to a sling has any effect on the risk of nerve injury or pin site infections.

What are the limitations of the evidence?

Most of the studies were either not well-designed or did not clearly report how they were conducted. This meant that we either had little confidence or no confidence in their findings. Our confidence was also reduced because there were not enough children in the studies to be certain about their findings. It is also possible that the studies that we found had exaggerated findings and that some studies with alternative results may be missing. 

How up to date is this evidence?

The evidence is up to date to March 2021.

Authors' conclusions: 

We found insufficient evidence for many treatments of supracondylar fractures. Fixation of displaced supracondylar fractures with retrograde lateral wires compared with crossed wires provided the most substantial body of evidence in this review, and our findings indicate that there may be a lower risk of nerve injury with retrograde lateral wires. In future trials of treatments, we would encourage the adoption of a core outcome set, which includes patient-reported measures. Evaluation of the effectiveness of traction compared with surgical fixation would provide a valuable addition to this clinical field.  

Read the full abstract...
Background: 

Elbow supracondylar fractures are common, with treatment decisions based on fracture displacement. However, there remains controversy regarding the best treatments for this injury.

Objectives: 

To assess the effects (benefits and harms) of interventions for treating supracondylar elbow fractures in children.

Search strategy: 

We searched CENTRAL, MEDLINE, and Embase in March 2021. We also searched trial registers and reference lists. We applied no language or publication restrictions.

Selection criteria: 

We included randomised and quasi-randomised controlled trials comparing different interventions for the treatment of supracondylar elbow fractures in children. We included studies investigating surgical interventions (different fixation techniques and different reduction techniques), surgical versus non-surgical treatment, traction types, methods of non-surgical intervention, and timing and location of treatment.

Data collection and analysis: 

We used standard methodological procedures expected by Cochrane. We collected data and conducted GRADE assessment for five critical outcomes: functional outcomes, treatment failure (requiring re-intervention), nerve injury, major complications (pin site infection in most studies), and cosmetic deformity (cubitus varus). 

Main results: 

We included 52 trials with 3594 children who had supracondylar elbow fractures; most were Gartland 2 and 3 fractures. The mean ages of children ranged from 4.9 to 8.4 years and the majority of participants were boys. Most studies (33) were conducted in countries in South-East Asia.

We identified 12 different comparisons of interventions: retrograde lateral wires versus retrograde crossed wires; lateral crossed (Dorgan) wires versus retrograde crossed wires; retrograde lateral wires versus lateral crossed (Dorgan) wires; retrograde crossed wires versus posterior intrafocal wires; retrograde lateral wires in a parallel versus divergent configuration; retrograde crossed wires using a mini-open technique or inserted percutaneously; buried versus non-buried wires; external versus internal fixation; open versus closed reduction; surgical fixation versus non-surgical immobilisation; skeletal versus skin traction; and collar and cuff versus backslab.

We report here the findings of four comparisons that represent the most substantial body of evidence for the most clinically relevant comparisons. 

All studies in these four comparisons had unclear risks of bias in at least one domain. We downgraded the certainty of all outcomes for serious risks of bias, for imprecision when evidence was derived from a small sample size or had a wide confidence interval (CI) that included the possibility of benefits or harms for both treatments, and when we detected the possibility of publication bias. 

Retrograde lateral wires versus retrograde crossed wires (29 studies, 2068 children)

There was low-certainty evidence of less nerve injury with retrograde lateral wires (RR 0.65, 95% CI 0.46 to 0.90; 28 studies, 1653 children). In a post hoc subgroup analysis, we noted a greater difference in the number of children with nerve injuries when lateral wires were compared to crossed wires inserted with a  percutaneous medial wire technique (RR 0.41, 95% CI 0.20 to 0.81, favours lateral wires; 10 studies, 552 children), but little difference when an open technique was used (RR 0.91, 95% CI 0.59 to 1.40, favours lateral wires; 11 studies, 656 children). Although we noted a statistically significant difference between these subgroups from the interaction test (P = 0.05), we could not rule out the possibility that other factors could account for this difference.

We found little or no difference between the interventions in major complications, which were described as pin site infections in all studies (RR 1.08, 95% CI 0.65 to 1.79; 19 studies, 1126 children; low-certainty evidence). For functional status (1 study, 35 children), treatment failure requiring re-intervention (1 study, 60 children), and cosmetic deformity (2 studies, 95 children), there was very low-certainty evidence showing no evidence of a difference between interventions.

Open reduction versus closed reduction (4 studies, 295 children)

Type of reduction method may make little or no difference to nerve injuries (RR 0.30, 95% CI 0.09 to 1.01, favours open reduction; 3 studies, 163 children). However, there may be fewer major complications (pin site infections) when closed reduction is used (RR 4.15, 95% CI 1.07 to 16.20; 4 studies, 253 children). The certainty of the evidence for these outcomes is low. No studies reported functional outcome, treatment failure requiring re-intervention, or cosmetic deformity. The four studies in this comparison used direct visualisation during surgery. One additional study used a joystick technique for reduction, and we did not combine data from this study in analyses.

Surgical fixation using wires versus non-surgical immobilisation using a cast (3 studies, 140 children)

There was very low-certainty evidence showing little or no difference between interventions for treatment failure requiring re-intervention (1 study, 60 children), nerve injury (3 studies, 140 children), major complications (3 studies, 126 children), and cosmetic deformity (2 studies, 80 children). No studies reported functional outcome.

Backslab versus sling (1 study, 50 children)

No nerve injuries or major complications were experienced by children in either group; this evidence is of very low certainty. Functional outcome, treatment failure, and cosmetic deformity were not reported.