Chronic coccydynia in adolescents. A series of 53 patients.

BACKGROUND: Little is known about coccydynia in adolescents. AIM: The aim of this study was to explore causes, clinical and imaging features and response to treatment of chronic coccydynia in adolescents. DESIGN: This was a cohort study. SETTING: The study included patients followed up at a specialized consultation in a university hospital. METHODS: A series of 53 adolescent patients with chronic coccydynia were followed for 1-4 years. Investigations included dynamic X-ray films, with a magnetic resonance imaging scan of the coccyx in 26/53. Treatment was by coccygeal steroid injection or non-steroidal anti-inflammatory drugs (NSAIDs). Amitriptyline or coccygectomy were used as second-line treatment. Outcomes were assessed at a consultation two months after the treatment, then between one to four years later, by telephone interview, questionnaires and by a visual analogue scale (VAS). Fifty-one adult patients with coccydynia formed the control group. RESULTS: In 20 cases (37.7%) the coccydynia was subsequent to trauma. Obesity was not a risk factor. Abnormal mobility was rarer and spicules more frequent compared to adult patients (P<0.001); 11/27 MRI scans showed a hypersignal within the disc or adjacent bone and 6/27 a hypersignal surrounding the tip of the coccyx (bursitis). Initial treatment was a coccygeal steroid injection for 41 patients and NSAIDs for 12. Ten were given amitriptyline and 3 a coccygectomy. At final assessment, there was no pain or almost no pain in 32/53 (60.4%), moderate pain and functional impairment in 12/53 (22.6%) and severe pain and functional impairment in 9/53 (17%). CONCLUSION: Coccydynia in adolescents differs from coccydynia in adults. A MRI scan is helpful and should be obligatory for diagnosis. Prognosis is relatively good. CLINICAL REHABILITATION IMPACT: Our results should help clinicians manage this rare and debilitating condition.