The key difference between synchondrosis and symphysis is that synchondrosis is a cartilaginous joint where bones are joined by hyaline cartilage, while symphysis is a cartilaginous joint where bones are joined by fibrocartilage.
There are cartilaginous joints between bones. These connections are important to maintain the structure of the skeletal system. Depending on the type of connection or joint, the properties of the particular joint varies. Their activity depends on the nature of the cartilage involved and the place of distribution. Synchondrosis and symphysis are two types of cartilaginous joints that connect bones. Synchondrosis joins two bones by hyaline cartilage while symphysis joins two bones by fibrocartilage.