Clinical Outcomes of Coccygectomy for Coccydynia: A Single Institution Series With Mean 5-Year Follow-Up.

BACKGROUND: Prior studies of coccygectomy consist of small patient groups, heterogeneous techniques, and high wound complication rates (up to 22%). This study investigates our institution's experience with coccygectomy using a novel "off-center" wound closure technique and analyzes prognostic factors for long-term successful clinical outcomes.

METHODS: Retrospective review of all patients who underwent coccygectomy from 2006 to 2019 at a single center. Demographics, mechanism of injury, conservative management, morphology (Postacchini and Massobrio), and postoperative complications were collected. Preoperative and postoperative Oswestry Disability Index (ODI), visual analog scale (VAS), Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29), and EuroQol-5D (EQ-5D) were compared. Risk factors for failing to meet minimum clinically importance difference for ODI and PROMIS-physical function/pain interference were identified. Risk factors for remaining disabled after surgery (ODI <20) and factors associated with VAS and EQ-5D improvement were investigated using stepwise logistic regression.

RESULTS: A total of 173 patients (77% women, mean age = 46.56 years, mean follow-up 5.58 ± 3.95 years). The most common etiologies of coccydynia were spontaneous/unknown (42.2%) and trauma/accident (41%). ODI, VAS, and several PROMIS-29 domains improved postoperatively. Older age predicted continued postoperative disability (ODI <20) and history of prior spine surgery, trauma etiology, and women had inferior outcomes. No history of spine surgery (cervical, thoracic, or lumbar) prior to coccygectomy was found to predict improved postoperative VAS back scores. No outcome differences were demonstrated among the coccyx morphologies. Sixteen patients (9.25%) were noted to have postoperative infections of the incision site with no difference in long-term outcomes (all P <0.05).

CONCLUSIONS: This is the largest series of coccygectomy patients demonstrating improvement in long-term outcomes. Compared to previous studies, our cohort had a lower wound infection rate, which we attribute to an "off-center" closure.

CLINICAL RELEVANCE: Patients should be counseled that their surgical history, along with age, gender, and etiology of pain can influence success following coccygectomy. These data can help surgeons set realistic expectations following surgery.

LEVEL OF EVIDENCE: 3.