The dog knocked our eight-year-old over in a tug-of-war game they were playing. He ended up breaking his arm just above the elbow. I guess technically it’s considered an elbow fracture. The question we have is why did they put pins through the bone when he’s already in a cast?

It sounds like he may have a displaced supracondylar humeral fracture. Displaced means that after the bone broke, it separated or pulled apart. Pins are usually used to hold the bone ends together until they heal. That’s important in this type of fracture because the jagged edges of bone can poke into nerves in and around the elbow causing nerve damage.

For those who don’t know, a supracondylar humeral fracture is a break in the upper arm bone just above the elbow. It’s the most common type of elbow fracture in children but is relatively rare in adults. In fact, at least half and as many as 70 per cent of elbow fractures in children are supracondylar humeral fractures.

The fracture is caused most often by a fall on an outstretched hand. As the hand hits the ground, the elbow is hyperextended or hyperflexed resulting in fracture above the condyles. The condyles are the bumps you feel on either side of your elbow. Supracondylar means the break is just above those bumps (condyles).

Pin fixation isn’t needed when the bone is broken but remains reduced (together). In that case, a cast may be all that’s needed to treat the break. Pins stabilize the fracture but the cast is also necessary to keep the arm from moving and disrupting the healing fracture site.