Injuries to the Elbow in Children

The condyles are the articulating surface of the distal humerus — the capitellum and the trochlear. The epicondyles are the medial and lateral bony protuberances beyond the condyles. The area above this, as the widened distal humerus begins to narrow, is the supracondylar region and it is this region of the elbow that is most prone to fracture (50-70% of cases) from a fall on an outstretched hand or the point of the elbow itself.

Anterior view of an adult elbow with capsule removed [Image: Pinterest]

Apart from supracondylar fracture, other elbow injuries to consider in children are:

  • epicondylar fracture
  • fractures of the condyles (capitellum and trochlear)
  • radial head and neck fractures
  • olecranon fractures
  • osteochondritis dessicans
  • elbow dislocation
  • radial head subluxation (Nursemaid’s elbow)
  • medial epicondylar apophysitis (Little Leaguer’s elbow)
coronoid-process-of-the-ulna

Orthogonal projection of flexed elbow joint

Supracondylar Fracture

More than half of all elbow fractures in children are supracondylar — i.e. about the metaphysis of the (distal) humerus. These are generally extra-articular injuries about a region of bone that is relatively fragile.  After a fall on the outstretched arm, the (distal) fracture fragment in most cases (> 90%) gets displaced posteriorly—into extension—in which case these fractures may be complicated by anterior interosseous neuropraxia, causing weakness of the FDP to the index finger as well as the FPL muscle (unable to perform “OK” sign). Less commonly, weakness of wrist and finger extension is seen from a radial neuropraxia. Careful observation should see a neuropraxia resolve spontaneously.

A fall directly onto a flexed elbow may cause the opposite disposition, with the fragment displaced anteriorly — into flexion. This can be accompanied by loss of sensation along the little finger, from an ulnar neuropraxia. (Clawing from weakness of the intrinsic hand muscle will be a later finding).

The who’s who of the radiograph of a child’s elbow:

Ossification centres by average age of appearance (the ages may vary somewhat but the order of their appearance is consistent) may help to distinguish from an avulsion fracture. The mnemonic used is CRITOE, and while the ages may vary the sequence is said to be preserved:

  • Capitellum (capitulum) — 1 year
  • Radial head — 3 years
  • Internal (medial) epicondyle — 5 years
  • Trochlear — 7 years
  • Olecranon — 9 years
  • External (lateral) epicondyle — 11 years

AP and Lateral X-Rays

Pick a line, any line, as long as it’s the AHL or RCL

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  • posterior fat-pad sign (always pathological) and anterior sail sign (a ballooning”
  • Anterior humeral line normally runs through the middle third of the capitullum
  • Baumann’s angle (between physis of the capitellum and a perpendicular to the axis of the humerus) normally > 11°
  • Radiocapitellar line — axis of radius should run through capitellum (particularly helpful when a radial head ossification centre could be misconstrued for a physeal injury)

Gartland Classification and Care of Supracondylar Elbow Fractures

  1. Non-displaced → splint/cast elbow 3-4 weeks (not < 90° to avoid vascular compromise/compartment syndrome))
  2. Angulation with intact posterior cortex → closed reduction and percutaneous pinning
  3. Completely displaced → closed reduction and percutaneous pinning
  4. Complete periosteal disruption with instability in flexion and extension → may require open reduction

Type III fracture with pulseless hand (whether normal temperature and colour and CRT, or blue and cold) ⇒ emergent closed reduction and percutaneous pinning to restore adequate circulation, then observe and splint the elbow at 45 degrees. Failing this, emergent vascular exploration and repair is necessitated.

Complications
  • nerve injury
  • cubitus varus (cosmetic) deformity
  • vascular injury e.g. compartment syndrome
    • Volkmann’s ischaemic contracture when elbow splinted in hyperflexion

SUMMARY — Supracondylar Fracture

  • Child 3-11 years old, FOOSH
  • very painful → may require analgesia for full assessment
    • Can they do the “ok” sign?
    • Can they extend wrist and fingers?
    • Can they feel (light touch / pin prick) over the little finger?
    • Check brachial and radial (and ulnar) pulses and CRT
  • Obtain AP & lateral films looking at lines, angles, fat-pads, and ossification centres
    • consider emergent closed reduction if any of the above neurovascular signs absent
  • Avoid splinting in hyperflexion

Annotations
  • FOOSH = fall on outstretched hand
  • CRT = capillary refill time
  • AHL = anterior humeral line
  • RCL = radiocapitellar line
References
  • Simon’s Emergency Orthopaedics: 7th Edition, Scott Sherman. McGraw Hill, 2015 (New York)
  • Supracondylar Fractures Of The Humerus In Children – YouTube Video, Dr Nabil Ebraheim
Further Reading