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  • Paediatric elbow fractures pose diagnostic and therapeutic challenges.
  • Six ossification centres appear and fused to the main bones at varying timings. These can be confused with fractures.
  • CRITOL is a useful pneumonic helpful in remembering the progression of radiographic appearance of the ossification centres:
  • Capitellum = 1-2 years
  • Radial head = 3-5 years
  •  Internal (or medial) epicondyle=5-6 years
  • Trochlea= 7-8 years (often appears fragmented due to being bi/tripartite)
  • Olecranon= 9-10 years
  • Lateral epicondyle= 11-12 years.

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Lateral and AP x-ray of a child with flexion type SCH fracture treated with closed reduction and 3 lateral k-wires.

  • Comprise 50% to 70% of all elbow fractures seen most frequently in children aged 3 and 10 years.
  • The high incidence of residual deformity and the potential for neurovascular complications make these fractures a serious injury.
  • Fall on an outstretched hand with elbow hyperextension is the main mechanism of injury, enabling the olecranon process to act as a fulcrum for injury.
  • A posteriorly applied force with the elbow in flexion creates a flexion-type SCH (2-5% cases) (figure 6.5.1).
  • Several radiographic features have been proposed to confirm a subtle supracondylar fractures, differentiate SCH # and condylar fractures and predict the operative difficulty that surgeons may encounter while stabilizing these fractures (figure 6.5.2).
  • Wilkins modification of the Gartland Classification for supracondylar fractures (Figure 6.5.4).
  • Undisplaced (Type I). In the absence of a clear bony injury, a posterior fat pad sign is an important sign of an occult intra-articular or supracondylar fracture. Very young children may have severe injuries with very little bony abnormality due to the lack of ossification
  • Angulated (Type II)with intact posterior cortex (IIA= angulation only, IIB= with rotation)
  • Complete displacement (Type III) (IIIA= posteromedial, IIIB=posterolateral)

6.5.2.png

Radiological features of the paediatric elbow: image 1-Bauman’s angle formed by the capital physeal line and the long axis of the humerus (normally is 75-80°). The carrying angle, it is the natural valgus of the elbow joint. It can be measured by subtracting the Bauman’s angle from 90°. Image 2-The teardrop or the hour glass, the narrow part represent the coronoid fossa. The inferior portion of the teardrop is the ossification center of the capitellum. On a true lateral projection, this teardrop should be well defined (useful sign of true lateral projection).Image 3- The anterior humeral line drawn along the anterior border of the distal humeral shaft, it should pass through the middle third of the ossification center of the capitellum. Image 4- shaft-condylar angle which is the angle between the long axis of the humerus and the long axis of the lateral condyle (normally 40°). Image 5- Coronoid Line directed proximally along the anterior border of the coronoid process should barely touch the anterior portion of the lateral condyle. Images are courtesy of Postgraduate paediatric orthopaedic, Cambridge University Press.

 

  • Undisplaced SCH fractures can be treated non operatively in an above elbow cast and a sling. The sling should be a full time and it is part of the stabilizing steps.
  • In extension type fractures, flexing the elbow to more than 90° increase stability ( by converting the triceps force to compress the fracture rather than extending it; however care needs to be taken as excessive flexion may compromise circulation and clinical judgment needs to be exercised effectively to avoid occurrence of neurovascular damage or compartment syndrome.
  • Protection is for 3-4 weeks time.
  • Displaced fractures need reduction and stabilisation. This includes all type III and most type II fractures.

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Wilkins modification of the Gartland Classification for supracondylar fractures.

  • Patient is supine on table with the hand stretched over a hand table. Ensure the head position is in a safe place and if pulled off the table, it will stay over the nad table.
  • X-ray positioned in a way that you can see AP and lateral without having to turn the elbow ( very important in very unstable fractures)
  • Two people gentle, gradually increasing traction to restore length. Daylight sign is a useful indicator to move to the next stage of reduction ( this may takes up to 5 minutes- do not rush this stage)
  • Medial or lateral displacement of the distal fragment is next corrected while traction maintained. Varus deformity is more common therefore need to pronate arm to reduce the risk that distal fragment falls in varus.
  • Flex the elbow while pushing distal fragment anteriorly to reduce it. Intact posterior acts as a hinge. Good reduction can be inferred if fingers can touch the shoulder.
  • X-ray screen ( ask radiographer to magnify once or twice) AP, Jones view, oblique medial and oblique lateral initially- if these are ok, get true lateral of the elbow either by turning the elbow in one piece or turning the C-arm depending on the stability of the fracture.
  • Once reduced, SCH fracture should be stablised (Pirone, Graham et al. 1988).
  • The reduced position can be taped using sleek or can be hold reduced by an assistant. There are pros and cons of each option and not all fractures can be kept reduced by a tape.
  • Several surgical techniques have been described from k-wires of various configurations, flexible nailing to external fixator
  • Our preferred method is to use 2 mm (unless the child is very small when 1.6 mm is more appropriate), two lateral crossed wires. The first wire goes through the captillum, physis, olcranoon fossa then exsit through the medial cortex ( to get 6 cortices)- see figure  of 2 mm. The second wire through the lateral column.
  • Then we screen the elbow, if it is stable, we apply the cast and sling, but if not, we either supplement the stablisation with either a third lateral wire or medial wire depending on the fracture configuration and the position of the first two wires.
  • A systematic review pooling all data from previously published case and comparative series reports an iatrogenic nerve injury rate of 1.9% for lateral entry pins and 3.5% for crossed pins (among 1909 patients), and a loss of reduction rate of 0.7% for lateral entry pins and 0% for crossed pins (among 1455 patients)(Brauer, Lee et al. 2007).
  • Kocher published a small randomized trial showing no difference in outcome between crossed or lateral entry pins either from displacement or ulna nerve injury (Kocher, Kasser et al. 2007), but the trial was underpowered to detect differences in ulnar nerve injury which is a rare outcome.

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Pinning a SCH fracture.

  • Any neurovascular or skin comprise should prompt surgeon to do the operation as emergent
  • Grade III with no neurovascular comprise has attracted significant controversy on whether it should be done as an emergent or could be left for the next day trauma list.
  • Several retrospective cohort studies (Level III evidence) showed similar outcomes (complications, compartment syndromes, rates of conversion to open reduction, pin infections, and iatrogenic nerve injuries) between early surgery (<8 hours after presentation) versus late (>8 hours after presentation) surgery of closed SCH (Mehlman, Strub et al. 2000; Ponce, Hedequist et al. 2004; Sibinski 2006).
  • A single study showed a higher rate of  open reduction when fractures were operated on after 8 hours, 33% open reduction rate in 45 patients. They also had a higher rate of open reduction for those operated within 8 hours, 11.2% of 126 patients, which brings into question their threshold for open reduction (Walmsley 2006).
  • These can be divided into:
    • Absent radial pulse with pale and cold hand
    • Absent radial pulse with well-perfused hand, good capillary refill, good skin colour, and a warm extremity.
  • pulseless hand that does not improve after reduction should be explored and the brachial artery identified and repaired if necessary.
  • There is a controversy on the best management of absent radial pulse with well perfused hand. One study managed all injuries with a pink pulseless hand with observation (Garbuz, Leitch et al. 1996) and reported that all patients did well, with no circulatory problems at follow-up. (14).
  • Another study compared patients that were explored and had vascular repair, and those that were not. At follow-up ten patients were imaged using magnetic resonance angiography, five showed occlusion or re-stenosis of the brachial artery despite repair, all had a radial pulse present (Sabharwal, Tredwell et al. 1997).

6.5.5.png

Neurovascular exploration of supracondylar fracture.

  • Most nerve injuries in SCH fractures are transient neurapraxias that can be managed expectantly.
  • AIN is the commonest nerve to be injured (video link)

https://www.youtube.com/watch?v=2TqnEodvlHo

  • It is worth considering that if there is neurological compromise pre-operatively and it is not possible to achieve a perfect reduction, then the nerve may be lodged in the fracture site (figure 6.5.5).
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