Dysplasia, or epiphysealis hemimelica, is a developmental disorder that affects the joints in the hands and feet. The term dysplasia literally translates to "bad formation". In the hands and feet, dysplasia is characterized by expanded growth of cartilage on the end of the long bones. The disorder is extremely rare, affecting just one in every million people.

Dysplasia is a benign disorder with no cure. Symptoms of dysplasia, including bone fractures and deformities, can be treated when necessary.

Causes of dysplasia

The exact cause of dysplasia is unknown, although the disorder does not seem to be genetic. Dysplasia tends to occur in childhood, affecting children between the ages of 3 and 15.

Dysplasia symptoms

Dysplasia may be asymptomatic or it can produce the following symptoms: 

• Bone brittleness. 
• Bone deformities. 
• Bone fractures. 
• Bone lesions. 
• Bone pain. 
• Difficulty walking and running. 
• Growth of a mass on the joint. 
• Limited motion of the joint. 
• Muscle wasting. 
• Swelling.

Some symptoms will cease once the bones in the hands and feet stop growing.

Dysplasia treatment

Dysplasia is diagnosed with a physical examination or X-ray. Most cases of dysplasia are diagnosed within the first few decades of life, typically in childhood or during adolescence.

The outlook for people with dysplasia depends on the severity of the condition and the rate of progression. There is no cure for dysplasia, but treatment is available to prevent complications and deal with side effects like bone fractures.

Dysplasia does not necessarily cause any pain; the disorder can be asymptomatic for years. This can make it difficult to diagnose and treat.

If you or a family member is experiencing any unusual symptoms, such as swelling near a bone joint in the foot, consult a physician as soon as possible. A simple X-ray can go a long way toward recognizing foot abnormalities and disorders like dysplasia.