Many parents of children ask me when is the best time to have surgery for their child’s thumb dysplasia, and often parents of newborns ask this question as well, so I’m going to give a brief answer here. The function of the thumb starts to develop when the newborn is 3 months old and matures very quickly, reaching the level of an adult at about 9 months of age, allowing for complex movements such as purposeful grasping and holding. The thumb function takes up about 50% of the entire hand, so the earlier the thumb dysplasia surgery is performed, the earlier the thumb function can be rebuilt. Of course, for newborns, the surgery cannot be performed too early. Generally, the surgery can be performed when the child is in good health, weighs as much as required for anesthesia, and has no combination of other malformations or heart diseases, between the ages of 6 months and 1 year.