The overlooked symptom of coccydynia: evaluation of sacrococcygeal morphologic and morphometric findings

Background Coccydynia is one of the most overlooked symptoms in daily clinical practice. Definitions for radiologic evaluation are controversial. Objectives We aimed to compare the morphology and morphometric measurements of the sacrococcygeal region with those of a healthy population to support radiologic decision-making. Materials and methods In total, 26 traumatic and 50 idiopathic cases of coccydynia as well as 74 healthy control cases were retrospectively compared. The morphologic type of the coccyx, the presence of fusion, and the number of coccygeal segments were evaluated in both groups. Morphometric parameters such as sacrococcygeal angle (SCA), sacrococcygeal joint angle (SCJA), intercoccygeal angle (ICA), sacral slope (SS), coccyx curved length (CCL), sacrum curved length (SCL), coccyx length (CL), sacrum length (SL), and sacrococcygeal total length (SCTL) were investigated. Results Significant differences were found between the coccydynia group and the healthy control group in morphologic parameters such as female gender, coccyx segment, coccyx morphology, presence of sacrococcygeal joint, and segment of sacrococcygeal joint fusion ( p < 0.05). In morphologic measurements, SCJA, SCL, SL, coccyx and sacrum curvature indexes were significantly increased ( p < 0.05). No significant difference was found in the morphologic and morphometric parameters evaluated when compared with the duration of coccydynia ( p > 0.05). Conclusion An increase in the SCJA, SCL, SL, SCI, and coccyx curvature index measurements predisposes to coccydynia. It would be more accurate to perform radiological evaluation by familiarization with these morphologic and morphometric parameters.