Role for magnetic resonance imaging in coccydynia with sacrococcygeal dislocation

Sacrococcygeal dislocation is among the many causes of coccydynia. The etiological diagnosis of this fairly rare condition is difficult. Dynamic imaging is the only means of documenting the dislocation. We describe two cases of sacrococcygeal dislocation in patients presenting with coccydynia. Both patients reported a history of trauma in the more or less remote past, with no clear correlation with pain onset. Magnetic resonance imaging (MRI) of the sacrococcygeal junction showed local inflammatory lesions (bursitis, sacrococcygeal arthritis), providing a rationale for a local procedure. Analgesic therapy was inadequately effective and a local glucocorticoid injection into the sacrococcygeal junction was therefore recommended. One of the patients accepted this procedure and subsequently reported complete resolution of the symptoms.