What is Radial Longitudinal Deficiency (dysplasia)?Radial longitudinal deficiency (RLD) is a lack of formation of the thumb side of the upper extremity. It can affect the hand only (usually the thumb) or, more commonly, the hand and forearm. It is a lack of bone, muscle, tendon, nerves, and blood vessels. The severity is different in each affected child.
What are other names for RLD?The most common other name is radial clubhand. It is also sometimes called radial deficiency for short.
How does RLD happen?The arm forms between 4 and 8 weeks of gestation, sometimes before a mom even knows she is pregnant. By 8 weeks the arm is fully formed although obviously really small. If there is some insult to the developing arm, part of it may not form normally. There are different types of insults- some are genetic and some may be caused by outside influences (“environmental factors”).
Are there are medical problems associated with RLD?There can be important other medical problems associated with RLD. Because the arm and the important internal organs such as the heart, intestines, blood cells, and kidney form at about the same time, one insult can affect all organs. Therefore, problems in these other areas need to be evaluated and often treated before the arm is treated.