DOS 2020

174 · DOS Abstracts Prognostic factors predictive of poor outcome following coccygectomy for patients with persistent coccydynia Mads Moss Jensen, Stefan Milosevic, Gustav Østerheden Andersen, Mikkel Mylius Rasmussen, Leah Carreon, Ane Simony, Mikkel Østerheden Andersen Cense-Spine, Department of Neurosurgery, Aarhus University Hospital; Center for Spine Surgery & Research, Middelfart Hospital Background: Coccydynia is pain originating in the coccyx and surrounding tis- sue. Coccygectomy, which is surgical amputation of the coccyx, is a way to relieve patients from their debilitating symptoms if nonoperative therapy fails to do so. The authors investigate prognostication in a prospective cohort of 134 coccygectomized patients who all suffered from persistent coccydynia and were diagnosed with instability of the coccyx. At present, no tool to improve patient selection is available. Purpose / Aim of Study: The purpose of this study is to identify prognostic factors predictive of poor outcome following coccygectomy on patients with persistent coccydynia due to instability of the coccyx. Materials and Methods: Through DaneSpine, the Danish National Spine Registry, 134 consecutive patients were identified from a single center experi- ence on coccygectomy performed from 2011 to 2019. Patient demograph- ics, including age, gender, body-mass- index (BMI), smoking status, work sta- tus, welfare payments as well as patient-reported outcomes (PROs), including pain VAS-score (0-100), Oswestry Disability Index (ODI), Euro-QoL-5D (EQ- 5D), Short Form-36 (SF-36) Physical Component Score (PCS) and Mental Component Score (MCS) were obtained at baseline and at 1-year follow-up. In addition, patient satisfaction with the procedure was obtained at follow-up. Findings / Results: A minimum of 1-year follow-up was available in 112 pa- tients (84%). Mean age was 41.9 years (range 15-78) and 97 of the patients were female (87%). Patients were divided into three groups based on satis- faction. Regression showed no statistically significant association between the investigated prognostic factors and a poor outcome following coccygectomy. The satisfied group showed a statistically significant improvement in PROs at 1- year follow-up from baseline, whereas the not satisfied group did not show a significant improvement. Conclusions: We did not identify factors prognostic for a poor outcome fol- lowing coccygectomy. This suggests that neither of the included parameters should contradict treatment with coccygectomy for patients who suffer from persistent coccydynia with instability of the coccyx. 153.