Triplane Fracture (Ankle)

Description

A triplane fracture is a more complex ankle fracture that occurs in older adolescents as the ankle growth plate is in the middle of closing. The break travels through the bone in three different planes — hence the name — and a CT scan is often used to map it.

How it happens (the mechanism)

[DR. WEY — dictate mechanism] (ankle physis closes from medial → central → lateral; during that window the fracture is funneled through the still-open portions in three planes; near end of growth so the priority is the joint surface, not growth; CT to map; non-displaced cast / displaced anatomic fixation.)

What matters

Because these happen near the end of growth, growth problems are usually not the concern — there is little growth left to disturb. The focus shifts to restoring the smooth joint surface of the ankle, which is why the fracture is mapped with a CT and the joint is aligned precisely.

Symptoms

A painful, swollen ankle after a twisting injury, with difficulty bearing weight.

Doctor examination and imaging

The doctor examines the ankle and its circulation and feeling; X-rays show the fracture and a CT scan maps the three-plane pattern to guide treatment.

Nonsurgical treatment

A well-aligned fracture is treated in a cast, with X-rays to confirm it stays in position.

Surgical treatment

A displaced fracture, especially through the joint surface, is realigned — often through a small operation with screws — to restore a smooth ankle.

Recovery and long-term outlook

Outcomes are generally reassuring, since growth is nearly complete; restoring the joint surface is what protects long-term ankle health.

When to call the doctor

Call the office right away if your child’s toes become numb, pale, blue, or cold; pain keeps worsening even after raising the leg and giving medicine; swelling does not improve with elevation; the cast feels too tight, cracked, or wet, or smells bad; or your child develops a fever.

Learn more

OrthoInfo (AAOS) — Growth Plate Fractures: orthoinfo.aaos.org

This information is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. For specific concerns about your child, consult a board-certified, fellowship-trained pediatric orthopaedic surgeon.