Engelmann disease Health Article

Definition

Engelmann disease is a rare genetic condition that causes the long bones in the legs to become abnormally wide and may change the structure of other bones in the body. Its effects include bone pain (especially in the legs), skeletal disorders, and weak, underdeveloped leg muscles.

Description

Despite their strength and durability, human bones are living organisms. Throughout the life span, bones are constantly being broken down and rebuilt again without losing their proper size and shape. Diseases that interfere with this delicately orchestrated process (called bone remodeling) can produce pain and restrict our freedom of movement. In Engelmann disease, which was first described in 1920, the shafts of the long bones in the legs become thicker than normal. The femur (thigh bone) and tibia (shin bone) are primarily affected. These changes often cause severe bone pain and weak muscles in the legs. The weak, aching muscles associated with Engelmann disease may result in an unusual walk that resembles a "waddle." People with Engelmann may be bow-legged and have thin, elongated legs that look as if they are "wasting away."

Aside from bones in the leg, Engelmann disease can cause abnormal changes in other bones. People with Engelmann may develop scoliosis (in which the spine curves to the left or right side) or lumbar lordosis (a forward curvature of the spine). Engelmann disease can also cause bones to become abnormally hardened (a process referred to as sclerosis). This hardening can affect the bones at the base of the skull as well as those in the hands and feet. In rare cases, sclerosis may affect the jaw. Bone pain and aching, weak muscles may occur in parts of the body affected by the disease.

Engelmann can also affect internal organs and sight. The liver and spleen may become enlarged. Loss of vision may occur if bones near the eye sockets are affected. Some people with Engelmann report headaches, fatigue, and lack of appetite.

The underlying cause of Engelmann disease is unknown. It is often referred to in the medical literature as Camurati-Engelmann disease or progressive diaphyseal dysplasia (PDD). Less common names for the condition include osteopathia hyperostotica scleroticans and multiplex infantalis. Engelmann disease was sometimes referred to as ribbing disease in the past but this name is no longer used.