Causes / typical injury mechanism: Supracondylar humerus fractures are typically caused by a fall onto an outstretched arm, causing a hyperextension load on the elbow. A more uncommon mechanism of injury is a fall directly onto the olecranon of a flexed elbow.
Classic history and presentation: The classic presentation is a child who sustains a fall and trauma to the extremity, with immediate onset of pain and unwillingness to move the elbow.
Prevalence: This is the most common fracture of the elbow in children.
Age – Seen most in children aged 3-8 years.
Sex / gender – Occurs with equal prevalence in both sexes.
Pathophysiology: The olecranon hyperextends into the olecranon fossa, acting as a fulcrum and leading to anterior tension force and failure of the distal humerus anteriorly.
Grade / classification system: Modified Gartland classification of extension-type fractures
Type I – Nondisplaced
Type II – Displaced with intact posterior hinge
Type III – Completely displaced with no intact cortices
Type IV – Multidirectional instability (determined by examination under anesthesia)
Classification of vascular status
Hand well perfused (warm, pink), radial pulse present
Hand well perfused (warm, pink), radial pulse absent
Hand poorly perfused (cool, blue, blanched), radial pulse absent
ICD10CM: S42.416A – Nondisplaced simple supracondylar fracture without intercondylar fracture of unspecified humerus, initial encounter for closed fracture
SNOMEDCT: 263193000 – Supracondylar fracture of humerus
Differential Diagnosis & Pitfalls
Distal humerus epiphyseal separation
Look for associated fractures in the ipsilateral extremity.
Do not miss a vascular injury. If the hand is noted to be pulseless, immediate orthopedic referral is recommended. It is not advised to perform ED-based acute reductions as the neurovascular bundle can be entrapped in the fracture, potentially leading to transection or further injury.
If the hand remains pulseless and poorly perfused after operative reduction, immediate exploration of the brachial artery is indicated as 50% of patients will require vascular surgery and 25% may develop compartment syndrome.
Do not miss . Look for tenseness of the volar compartment, swelling at the elbow, and pain with passive finger extension and flexion. Remember the 3 As of pediatric compartment syndrome: anxiety, agitation, and analgesic requirement.