Ulnar Shaft (Nightstick) Fracture

Description

This is a break of the ulna — the forearm bone on the pinky side — in its shaft. It is sometimes called a “nightstick” fracture because it often happens when the forearm is raised to shield the face or head and takes a direct blow.

How it happens (the mechanism)

A direct blow to the raised forearm strikes the ulna, which sits just under the skin along the pinky side, and breaks its shaft. Because an ulna break can occasionally come with the radial head slipping out of the elbow (a Monteggia injury), the elbow is always checked — a missed dislocation is far harder to fix later than to treat now.

Symptoms

Pain, swelling, and tenderness along the pinky-side edge of the forearm.

Doctor examination and imaging

The doctor checks the forearm and confirms the elbow and radius are normal. X-rays of the whole forearm, including the elbow, show the fracture and rule out a Monteggia injury.

Treatment

A well-aligned break is treated in a cast; a significantly angled one is set back into place first. Healing usually takes about six weeks.

Recovery and long-term outlook

An isolated ulna shaft fracture typically heals well, and forearm rotation usually returns to normal.

When to call the doctor

Call the office right away if your child’s fingers become numb, pale, blue, or cold; pain keeps worsening even after raising the arm 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) — Forearm Fractures in Children: 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.