This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Supracondylar Fracture, Subject name: Orthopaedics
Most common type of supra condylar fracture in children - 
Select and explain. 
A. Posteromedial extension, B. Posterolateral extension, C. Anteromedial flexion, D. Anterolateral flexion
A: Posteromedial extension
Answer: A: Posteromedial extension 
Explanation: Ans. is 'a' i.e., Posteromedial extensionSupracondylar fracture of humeruso Supracondylar humeral fractures are the most common elbow fractures in children. Most common age group affected is 5-8 years. Boys are affected more than girls. Left side is more common than right.Mechanism of injuryo Mostly it occurs due to hyperextension injury.o Fracture is caused by a fall onto the outstretched hand with hyperextension at elbow.Types of supracondylar fractureo Supracondylar fracture is broadly classified into extension type and flexion type.Extension typeIt is the most common type (97 - 99%).Distal fragment is extended (tilted backward/posteriorly) in relation to proximal fragment.Occurs due to hyperextension injury after fad on outstretched hands.Generally, displacement of distal fragment may be : -Posteromedial (70-80%)Posterolateral (20-30%)Flexion typeIt is less common type (1-3 %)Distal fragment is flexed (tilted forward/anteriorly) in relation to proximal fragments.The mechanism of injury generally is believed to be a fall directly onto the elbow rather than a fad on outstretched hand.o As the extension type fracture is more common (97 - 99%), the most common elbow injury in children is extension type of supracondylar fracture.Clinical features of supracondylar fractureo Following a fall, the child is in pain and elbow is swollen.o In extension type of injury, 'S'shaped deformity of the elbow is obvious,o There is loss of both active and passive movements of elbow,o Symptoms relating to vascular and nerve injury may be seen.o Unusual posterior prominence of the point of elbow (tip of olecrenon) because of backward tilt of the distal fragment.o Three point bony relationship is maintained as the fracture is above the level of condyles,o Dimple sign due to one of the spikes of proximal fragment penetrating the muscle and tethring the skin.