Regarding Salter-Harris type I growth plate injuries, which ONE of the following statements is FALSE?
Answer: C: In Salter-Harris type I injuries the fracture goes through the growth plate, completely separating the epiphysis from the metaphysis. However, the epiphysis is not always displaced, hence there may not be any abnormalities visible on X-ray. The epiphysis is displaced when the periosteum is damaged or torn. Usually the displaced epiphysis is easily reduced as the two surfaces are covered with cartilage.
In Salter-Harris type V injury, the growth plate is crushed, all or in part. Other mechanisms have been described for type V injury. It may be associated with a long bone fracture away from the growth plate injury such as a midshaft femur fracture. Consequently, growth arrest at the growth plate may occur, resulting in limb length discrepancy or angular deformity at the joint (e.g. angular deformity at the wrist due to normal growth of the ulna and growth arrest of the radius).
Type l and V injuries are difficult to differentiate clinically and there may not be any X-ray changes. The history might give a clue where a type I injury is due to shearing or avulsion forces and a type V injury is due to axial compression.
References:
Regarding physeal (growth plate) injuries in children, which ONE of the following statements is INCORRECT?
Answer: B: The most common site of a Salter-Harris type III fracture is the distal end of tibia (Tillaux fracture). As type III fractures occur in partially closed growth plates, the distal tibia is affected towards the end of growth when the medial half of the growth plate is closed. Type III fractures are intra-articular, therefore, requires accurate reduction – often open reduction. As the growth plate is already closing growth arrest is not a major concern.
Type lV injuries (fracture line passes from the joint surface across the epiphysis, growth plate and into the metaphysis) most commonly affect the lateral condyle of the humerus. Accurate reduction, usually open with internal fixation, is required for this fracture because any failure will produce growth arrest, nonunion, causing joint deformity and stiffness.
The growth plate is injured in approximately one-third of all bony injuries in children. When fracture separation occurs, some epiphyses such as head of femur and head of radius are prone to avascular necrosis. However, most epiphyses (e.g. distal radius, distal tibia and distal femur) survive because their circulations are maintained.
Regarding a diagnosis of nerve injuries when assessing a child with a supracondylar fracture of the humerus, all of the following statements are correct EXCEPT:
Answer: D: The assessment for a potential nerve injury is essential in every child who presents to the ED with a supracondylar fracture. In displaced supracondylar fractures the rate of nerve injury is reported to be 15%. The most commonly affected nerve is the anterior interosseous branch of the median nerve, but median, radial and ulnar nerve injuries may occur.
The following screening tests can be used in a young child to check the motor function of the individual nerves:
When assessing these movements it is important to provide the child with adequate analgesia first, but any deficit should not be attributed to the presence of pain.
Reference:
Regarding emergency department (ED) management of a supracondylar humeral fracture in a child, which ONE of the following is the MOST appropriate step?
Answer: C: Gartland classification of extension type (98%) supracondylar fractures:
Gartland type I fractures (undisplaced fractures) can be managed with elbow immobilisation using a simple plaster slab or collar and cuff because they are stable. Gartland type lla fractures may be managed conservatively with orthopaedic input at the time of presentation. Under sufficient analgesia the elbow should ideally be flexed to at least 90 degrees and the forearm should be kept at a neutral position. However, increasing flexion may cause vascular compromise because of the associated swelling of the elbow. If the radial pulse is lost during hyperflexion of the elbow, the elbow should be extended until the radial pulse is palpable again and a further relaxation of 10 degrees is advised before splinting is applied. Once the pulse is palpable and vascular supply is established, a plaster slab can be applied. The child can usually be discharged home with appropriate advice and a definitive arrangement to follow up within the next 24 hours.
Children with Gartland type IIb and III fractures should be referred for admission under orthopaedics for manupulation under anaesthetic (MUA) in the OT, internal fixation or open reduction and management of any associated complications.
Splinting the elbow in a relative extension is an acceptable method for a grossly swollen elbow to prevent compartment syndrome while waiting for MUA.
Regarding vascular compromise associated with supracondylar fracture, which ONE of the following statements is INCORRECT?
Answer: A: Vascular compromise due to supracondylar fracture is most likely to be associated with Gartland type III fractures where there is complete displacement of the distal fragment with no intact cortical contact. Brachial artery injuries include arterial entrapment, laceration, intimal tear and compression due to compartment syndrome developing in the forearm. The brachial artery injury may occur in up to 15% of this type of fracture.
The child may present with a pulseless hand. The hand should be closely assessed to determine whether it is warm and pink or cool and pale. When the hand is cool and pale, the fracture needs emergent reduction and stabilization with K wires in the OT. This will usually establish the arterial supply to the forearm and hand. This should be achieved in the OT with the use of an image intensifier; however, only in circumstances where this is practically impossible to achieve, the reduction should be attempted in the ED to reestablish the vascular supply. On repeated attempts it is likely that the artery can be injured further; therefore, failure to establish blood supply requires emergent transfer to the OT. Vascular surgeons should be alerted in such cases.
If the hand is pulseless but warm and pink, there is a little more time for the emergency clinician to arrange definitive management on an urgent basis. The arm should be splinted to prevent further vascular compromise. In these children the collateral branches of the brachial artery maintain an adequate blood supply to the forearm and hand despite the injury to the brachial artery.
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