deep posterior sacrococcygeal ligament

deep pos·te·ri·or sa·cro·coc·cyg·e·al lig·a·ment

the continuation of the posterior longitudinal ligament uniting the sacrum and coccyx. Synonym(s): ligamentum sacrococcygeum posterius profundum [TA], ligamentum sacrococcygeum dorsale profundum ☆ , deep dorsal sacrococcygeal ligament