Olecranon fractures

Cite this article as:
Becky Platt. Olecranon fractures, Don't Forget the Bubbles, 2020. Available at:
https://doi.org/10.31440/DFTB.21080

14-year old Noah was rocking on his chair while daydreaming his way through a maths lesson this morning… and fell off.  He reports that he landed directly on his left elbow and that it has been painful throughout the day.  He attends your ED this afternoon with his unamused mother.

Assessment of any child and examination of their elbow should be approached in an age-appropriate and systematic way.  In addition to examining for bony tenderness, vascular and neurological status should be tested.

You ensure Noah has been given analgesia before examining him.  His pain score is 5 and he seems comfortable after paracetamol and ibuprofen when his arm is resting.  His elbow is notably bruised and swollen. He is particularly tender over the olecranon and any movement is painful.  His neurovascular status is normal with good radial and ulnar pulses, normal sensation in the radial, ulnar and median nerve distributions and as he’s able to make the rock, paper, scissors and ok hand signs, you’re happy he has full motor function.  You order AP and lateral films of his elbow and pop him in a broad arm sling for comfort before sending him round for his x-rays.

Epidemiology and mechanism of injury

Olecranon fractures in children are rare, comprising around 5% of elbow fractures. Compare this with supracondylar fractures which comprise over half of all elbow fractures in the paediatric population. Olecranon fractures may result from a fall onto an outstretched hand (FOOSH), direct trauma or, occasionally, a stress fracture from repetitive throwing motion in athletes.

They can be classified according to the Mayo classification.

Examination findings

In addition to pain, there will almost certainly be generalised swelling around the elbow, usually with visible evidence of trauma, such as bruising or abrasion, over the olecranon process.  Point tenderness over the olecranon is often a feature, but the degree of swelling can sometimes make this difficult to appreciate.  Inability to fully extend the elbow is common, and pain on extension, supination and pronation is expected.  In those with comminuted or significantly displaced fractures it may be possible to feel crepitus over the olecranon.

Radiology

Interpreting children’s elbow x-rays can be mind boggling. Epiphyses ossify at different rates and so it can be easy to confuse a normal olecranon epiphysis with a fracture.  The olecranon epiphysis normally appears around 9 years and fuses at 15-17 years.   Be sure to refer to the CRITOE rules and if you’re not sure whether you’re seeing a normal epiphysis or a fracture, seek senior advice.  The olecranon can be best assessed on the lateral film.

This x-ray shows a normal olecranon epiphysis:

Case courtesy of Dr Jeremy Jones, Radiopaedia.org. From the case rID: 26814

Some olecranon fractures are obvious…

…but some can be incredibly subtle as illustrated in this series from Radiology Assistant:

Some olecranon fractures may only be visible on one view.  This may be the AP or the lateral.  The below elbow x-rays show a transverse olecranon fracture visible on the AP view only (arrow).  Note the raised anterior and posterior fat pads on the lateral view.  And an extra bonus point to those who spotted the subtle radial neck fracture.

Management

The majority of olecranon fractures (around 80%) are either undisplaced or minimally displaced (less than 2mm); these can be managed conservatively with an above elbow back-slab with good functional outcome.

Minimally displaced (<2mm) fracture in a 7 year old, requiring conservative management only. Case courtesy of Dr Jeremy Jones, Radiopaedia.org. From the case rID: 23650

Complications

In children with a displaced olecranon fracture, there is risk of complications including delayed or non-union, ongoing elbow stiffness and impaired function.  Refer any child who has an olecranon fracture with these features as they’re likely to require surgical intervention:

  • >2-4mm displacement
  • angulation of >30°
  • intra-articular involvement
  • extensor mechanism disruption
  • instability on extension
  • comminution

Olecranon fracture with >30 degrees of displacement, requiring surgical fixation. From Orthobullets.com.

The practitioner seeing injured children in the ED must be aware of the potential for these.  Displaced olecranon fractures can cause growth disturbances resulting in fixed flexion deformity of the elbow joint and associated morbidity into adulthood.

The ulnar nerve is particularly at risk of injury with olecranon fracture. Ensure you carry out a thorough neurovascular assessment, in particular checking sensation over the little finger and that the small muscles of the hand are functioning normally (the “scissors” sign).

A significant proportion of olecranon fractures are associated with concomitant injury, including radial neck fracture and /or supracondylar fracture and any co-existing injury is prognostic for poorer outcome.  When interpreting the x-ray, it is important therefore to have a systematic approach.

Bullets of wisdom 

  • Don’t confuse an unfused olecranon epiphysis with a fracture
  • But don’t forget that olecranon fractures can be subtle – maintain a high index of suspicion in children with direct trauma and inability to extend their elbow
  • Olecranon fractures are sometimes only visible on one view and this can be the lateral or the AP
  • Displaced fractures can have devastating consequences and must be referred to orthopaedics as they may need surgical intervention
  • Document neurovascular status and be sure to check ulnar nerve function
  • And look for a concomitant radial neck or supracondylar fracture

Noah returns from X-Ray and you review his films. He has a posterior fat pad sign and on closer scrutiny you spot an intra-articular fracture of the olecranon. You recognise that this type of fracture can be associated with complications and refer him to the orthopaedic team.  You ensure that his pain score and neurovascular status are being assessed regularly.

 

References

Cabanela M.E. & Morrey B.F. (1993) The Elbow and Its Disorders. 2nd ed. Philadelphia, PA, USA: WB Saunders cited in Sullivan, C. W., & Desai, K. (2019). Classifications in Brief: Mayo Classification of Olecranon Fractures. Clinical Orthopaedics and Related Research, 477(4), 908–910.

Caterini, R., Farsetti, P., DʼArrigo, C., & Ippolito, E. (2002). Fractures of the Olecranon in Children. Long-Term Follow-Up of 39 Cases. Journal of Pediatric Orthopaedics B, 11(4), 320–328.

Corradin, M., Marengo, L., Andreacchio, A., Paonessa, M., Giacometti, V., Samba, A., … Canavese, F. (2016). Outcome of isolated olecranon fractures in skeletally immature patients: comparison of open reduction and tension band wiring fixation versus closed reduction and percutaneous screw fixation. European Journal of Orthopaedic Surgery and Traumatology, 26(5), 469–476.

Degnan, A. J., Ho-Fung, V. M., Nguyen, J. C., Barrera, C. A., Lawrence, J. T. R., & Kaplan, S. L. (2019). Proximal radius fractures in children: evaluation of associated elbow fractures. Pediatric Radiology, 1–8.

Edgington, J. & Andras, L. (2019) Olecranon fractures – pediatric https://www.orthobullets.com/pediatrics/4010/olecranon-fractures–pediatric?expandLeftMenu=true

Hill, C. E., & Cooke, S. (2017). Common Paediatric Elbow Injuries. Open Orthopaedics Journal, 11, 1380–1393.

Kraus, R. (2014). The pediatric vs. the adolescent elbow. Some insight into age-specific treatment. European Journal of Trauma and Emergency Surgery, 40(1), 15–22.

Nicholson, L. T., & Skaggs, D. L. (2019). Proximal Radius Fractures in Children. The Journal of the American Academy of Orthopaedic Surgeons, 00(00), 1–11.

Pace, A., Gibson, A., Al-Mousawi, A., & Matthews, S. J. (2005). Distal humerus lateral condyle mass fracture and olecranon fracture in a 4-year-old female – Review of literature. Injury Extra, 36(9), 368–372.

Perkins, C. A., Busch, M. T., Christino, M. A., Axelrod, J., Devito, D. P., Fabregas, J. A., … Willimon, S. . (2018). Olecranon fractures in children and adolescents: outcomes based on fracture fixation. Journal of Children’s Orthopaedics, 12, 497–501.

Rath, N. K., Carpenter, E. C., Ortho, F., & Thomas, D. P. (2011). Traumatic Pediatric Olecranon Injury. A Report of Suture Fixation and Review of the Literature. Pediatric Emergency Care, 27(12), 1167–1169.

CRITOE Quick Quiz

Cite this article as:
Tessa Davis. CRITOE Quick Quiz, Don't Forget the Bubbles, 2014. Available at:
https://doi.org/10.31440/DFTB.4507

This quick quiz is to test your CRITOE knowledge. See this post for how to interpret an elbow x-ray.

Click on the image to see them in full size…

 

Q1: What age is this child?

Q1

View Q1 answer

This child is 6 years old.

Ossification centres develop in the order CRITOE (1, 3, 5, 7, 9, 11)

CRITOE

Capitellum (1 year)

Radial head (3 years)

Internal (medial) epicondyle (5 years)

Trochlear (7 years)

Olecranon (9 years)

External (lateral) epicondyle (11 years)

 

On these XRs you can see C, R and I (I not usually visible on the lateral) so the child is roughly 6 years old.

Q1

Understanding ossification centres order of development is crucial to recognising paediatric elbow fractures.

Q2: What is the abnormality in the XR of this child who sustained a fall onto the lateral aspect of her elbow?

lateral condyle avulsion

View Q2 answer

Lateral condyle avulsion.

The capitellum, radial head and the start of internal epicondyle are there (approx. 5 years old).  There is no trochlear or olecranon and therefore there should be no lateral epicondyle.  The small area shown in red (below) is an avulsed lateral condyle.

lateral condyle avulsion annot

Lateral condyle fractures account for 20% of all elbow fractures in children and are most common in 5-7 year olds after falling onto an outstretched arm.  All should be discussed with ortho as there is a high risk of complications if not treated properly.

The displacement (gap between the distal humerus and the fractured condyle) needs to be measured.

Undisplaced fractures can be put in a long-arm backslab (with 90 degree elbow flexion). Displaced fractures with a <2 mm gap sometimes require closed reduction.  Displaced fractures with a >2 mm gap or angulation of the lateral condyle will require surgical intervention.

Q3: What is the abnormality in this X-ray of a 12 year old boy who fell onto his outstretched hand (with the elbow extended)?

medial epicondy latmedial epicondyle ap

View Q3 answer

Medial epicondyle avulsion.

This child is 12 so should have all CRITOE ossification centres.  Checking through one by one, the medial epicondyle is missing. In fact it has been displaced.

Medial epicondyle ap annotmedial epicondyle annot lat

The yellow lines show where it should be, the red lines show where it is.

On the lateral you can actually see the medial epicondyle which you should not be able to do in a good lateral view.

Medial epicondyle fractures occur between 7-15 years (they account for 10% of elbow fractures in children). They are often associated with elbow dislocation (50%). The degree of displacement of the medial epicondyle needs to be assessed.

Undisplaced or minimally displaced (<5 mm) fractures will not need surgical repair and can be managed in a long arm backslab (with 90 degrees elbow flexion). Displacement of 5-15 mm requires ortho input – surgical intervention usually depends on multiple factors (e.g. age, dominant hand, sports involvement).  Displacement of >15 mm or neurovascular compromise (ulnar nerve palsy) will require ORIF.

Q4: What is the abnormality in this child who fell directly onto her elbow?

olecranon

View Q4 answer

Olecranon fracture.

The ossification centres in the lateral view show a capitellum but no radial head (see below).

olecranon annot

The fragment on the end of the ulnar must be an olecranon fracture as there is no ossification centre yet developed.

These fractures account for 5% of elbow fractures in children.  They are often associated with other injuries so thoroughly check the rest of XR.

Undisplaced, or minimally displaced fractures can be put into a long arm backslab (90 degree elbow flexion).  Displaced fractures should be referred to ortho as will likely need surgical intervention.