IDIOPATHIC COCCYGODYNIA - LATERAL ROENTGENOGRAMS IN THE SITTING POSITION AND COCCYGEAL DISCOGRAPHY

Study Design. The authors hypothesized that the source of coccydynia w as a lesion of the coccygeal disc. Objectives. This study analyzed the motion of the painful coccyx in the sitting position as compared with the lateral decubitus in a patient and a control group and reported t he first results of coccygeal discography (dynamic study).Summary of B ackground Data. Coccydynia are usually attributed to soft tissue injur ies or psychologic disturbances. No previous study has assessed the co ccygeal discs as a source of pain. Methods. Fifty-one patients with co ccydynia and 51 controls sustained a dynamic study. Coccygeal mobility was documented by superimposing graph paper with a double reading. Th e accuracy of the measurement was +/-2.6-degrees intra- and interobser ver variations 15.3 and 12.5%. This dynamic study was followed by cocc ygeal discography in the patient group. Results. An abnormal motion (l uxation or hypermobility) of the coccyx that occurred in the sitting p osition and spontaneously was reducible when placed in the lateral dec ubitus position was found in 25 patients. Such lesions could be respon sible for the pain because no similar findings were seen in the contro ls and coccygeal discography was positive in these cases. Of the 26 pa tients with a normal dynamic study, coccygeal discography, using a com bination of provocation and anesthetization, was positive in 15 of 21. Conclusions. Common coccygeal pain could come from the coccygeal disc in approximately 70% of cases.