Postpartum coccydynia: a case series study of 57 women.

BACKGROUND: Although childbirth is a well-known cause of coccydynia, this condition has not been studied previously. AIM: To explore the characteristics of postpartum coccydynia and identify risk factors. DESIGN: A case series study. SETTING: A specialist coccydynia clinic in a department of physical medicine in a university hospital. METHODS: A series of 57 women suffering from postpartum coccydynia was analyzed and compared with a control group of 192 women suffering from coccydynia due to other causes. Dynamic radiography enabled a comparison of the coccygeal mobility in the two groups. RESULTS: 7.3% of the cases of coccydynia in female patients seen in our clinic were related to childbirth. The pain appeared as soon as the patient adopted the sitting position after delivery. The deliveries had often been performed with instruments (forceps deliveries: 50.8%; vacuum-assisted deliveries: 7.0%) or were spontaneous but described as "difficult" (12.3%). Luxation of the coccyx was observed in 43.9% of the cases and 17.0% of the controls. Fracture of the coccyx was involved in 5.3% of the cases. A body mass index >27 and ≥2 vaginal deliveries were associated with a higher prevalence of luxation of the coccyx. CONCLUSION: Postpartum coccydynia is often associated with a difficult delivery, with the use of forceps in 50.8% of cases. Luxation and fracture of the coccyx are the two most characteristic lesions. CLINICAL REHABILITATION IMPACT: Our results bring a better knowledge and should allow a better management of this specific etiology of coccydynia.