There are three types of congenital knee hyperextension and dislocation deformities: Type I: congenital knee hyperextension Type II: congenital knee hyperextension combined with tibial subluxation Type III: congenital knee hyperextension combined with total tibial subluxation Congenital knee hyperextension and dislocation deformities are often combined with other limb deformities, such as hip dysplasia. Treatment depends on the degree of knee subluxation or dislocation and the age of the child. Newborns with mild to moderate knee hyperextension or subluxation can be treated with a Pavlik sling to keep the knee in flexion and external fixation with a cast. In older children with moderate or severe subluxation or total dislocation, surgical treatment should be performed.