syn·chon·dro·sis 
(sĭng′kŏn-drōsĭs, sĭn′-)
(sĭng′kŏn-drōsĭs, sĭn′-)n. pl. syn·chon·dro·ses (-sēz)
A form of articulation in which the bones are rigidly fused by cartilage.
[New Latin synchondrōsis, from Greek sunkhondrōsis : sun-, syn- + khondros, cartilage + -ōsis, -osis.]