Gibbus deformity is included in a subset of structural kyphosis that is distinguished by a higher-degree angle in the spinal curve that is specific to these forms of kyphosis. Other conditions within this subset include Pott's disease and Scheuermann kyphosis, but gibbus deformity is marked by an especially sharp angle. Viewed from behind, the resulting hunchback is more easily seen when bending forward.[10] A kyphosis of >70° can be an indication of the need for surgery and these surgeries can be necessary for children as young as two years old, with a reported average of 8 years of age.[2]