Dysplasia Epiphysealis Hemimelica: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Dysplasia Epiphysealis Hemimelica?
A primary care doctor, such as a pediatrician, is usually the first to evaluate the problem. Most children are then referred to an orthopedic surgeon who specializes in bones and joints, often one who focuses on children. A radiologist reads imaging scans and helps with the diagnosis.
What it is
Dysplasia epiphysealis hemimelica, also called Trevor disease, is a rare bone condition that a child is born with, though it often shows up later. Too much cartilage and bone grow on just the inner or outer half of a joint end, usually in the leg or foot. The extra growth is not cancer and does not spread.
Symptoms
The most common sign is a painless lump or swelling near a joint, often the ankle, knee, or wrist. Many children first come to attention because of a limp. Over time, the extra bone can limit joint movement and cause pain.
Causes and who gets it
Doctors do not know the exact cause. It happens when small areas of growing cartilage on one half of a bone end do not develop normally. It is not caused by anything the parents did during pregnancy and usually does not run in families.
How doctors diagnose it
A doctor will start by examining the joint. X-rays often show the extra bone growth clearly. An MRI can show how much of the lump is still cartilage, and a CT scan is sometimes used to plan treatment.
Treatment
Treatment depends on how much the extra bone bothers the child. If the lump is small and painless, many doctors recommend watching it with regular checkups and X-rays. If the growth causes pain, limits movement, or affects walking, surgery can remove the extra bone. Surgery usually improves movement and comfort, though the growth can come back in some children.
When to see a doctor
See a doctor if a child has a lump near a joint, walks with a limp, or favors one leg. Also seek care if a joint seems stiffer than normal or the child has pain during play or sports. Any sudden increase in pain or swelling deserves a prompt visit.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. They often have longer appointments and can examine the joint, order X-rays, and manage simple follow-up, referring to a pediatric orthopedic specialist when needed.
Common questions
Is dysplasia epiphysealis hemimelica cancer?
No. The extra growth is benign, which means it is not cancer and does not spread. Doctors may still run tests to be sure of the diagnosis.
Will my child outgrow it?
The growth often slows once the bones stop growing after puberty. Some children keep mild stiffness or a difference in limb length, so results differ from person to person.
Does it always need surgery?
No. Many children only need regular monitoring if the lump is small and painless. Surgery is considered when the growth causes pain, limits movement, or affects walking.
Can it come back after surgery?
It can return in some children, especially if surgery is done while the bones are still growing. Regular follow-up visits help catch any regrowth early.
Sources
- NIH Genetic and Rare Diseases Information Center - Dysplasia epiphysealis hemimelica
- National Organization for Rare Disorders - Dysplasia Epiphysealis Hemimelica
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
