Normal Preoperative Images Do Not Indicate a Poor Outcome of Surgery for Coccydynia

This is a retrospective cohort study.

To evaluate the long-term outcomes after surgery for refractory coccygodynia in patients with normal imaging studies compared with patients where imaging shows an anomaly.

Patients with coccydynia who do not respond to conservative treatment will often profit from coccygectomy. Most surgeons employ plain radiographs or magnetic resonance imaging (MRI) in their preoperative work-up. These will often show anomalies, but in some cases they do not. We investigated whether these patients do less well than those with abnormal images.

We operated on 184 patients with coccydynia during a 7-year period and 171 (93%) responded to follow-up questionnaires after 37 (range: 12-85) months. Images of 33 patients were normal and 138 showed some coccygeal pathology. Surgery was considered to have been unsuccessful when respondents stated at review that they were somewhat better, unchanged, or worse.

There were no clinically or statistically significant differences in outcome between the groups. Surgery was unsuccessful in 24% of patients with normal images and in 32% among those with abnormal images. The median pain scores (0-10) during the week before review were two (interquartile range [IQR]: 0-3) and one (IQR: 1-5) in the two groups respectively. Similar proportions in the two groups stated that they would not have consented to surgery if they had known the outcome in advance.

Patients with severe coccydynia who have not responded to conservative treatment should not be denied surgery only because their radiographs or MRI studies look normal.

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