Study design: Randomized open study.
Objective: To evaluate the efficacy of intrarectal manual treatment of chronic coccydynia; and to determine the factors predictive of a good outcome.
Summary of background data: In 2 open uncontrolled studies, the success rate of intrarectal manipulation of the coccyx was around 25%.
Methods: Patients were randomized into 2 groups of 51 patients each: 1 group received three sessions of coccygeal manipulation, and the other low-power external physiotherapy. The manual treatment was guided by the findings on stress radiographs. Patients were assessed, at 1 month and 6 months, using a VAS and (modified) McGill Pain, Paris (functional coccydynia impact), and (modified) Dallas Pain questionnaires.
Results: At baseline, the 2 groups were similar regarding all parameters. At 1 month, all the median VAS and questionnaire values were modified by -34.7%, -36.0%, -20.0%, and -33.8%, respectively, in the manipulation group, versus -19.1%, -7.7%, 20.0%, and -15.7%, respectively, in the control (physiotherapy) group (P = 0.09 [borderline], 0.03, 0.02, and 0.02, respectively). Good results were twice as frequent in the manipulation group compared with the control group, at 1 month (36% vs. 20%, P = 0.075) and at 6 months (22% vs. 12%, P = 0.18). The main predictors of a good outcome were stable coccyx, shorter duration, traumatic etiology, and lower score in the affective parts of the McGill and Dallas questionnaires.
Conclusions: We found a mild effectiveness of intrarectal manipulation in chronic coccydynia.