Adverse Events following Intramedullary Nailing in Metastatic Pathological versus Non-Pathological Femoral Shaft Fractures: A Retrospective Comparative Study

Background: Antegrade intramedullary nailing is indicated for treating metastatic pathological femoral shaft fractures. Although good functional outcomes could be obtained from internal fixation, postoperative adverse events have been reported in patients with pathological fractures and non-pathological fractures. Not only adverse events but also their consequences including, readmission and reoperation, need to be considered. Few studies have assessed the risk of postoperative adverse events, reoperation, and readmission without comparison. Therefore, this study aimed to compare the risk of in-hospital adverse events and consequences after discharge between patients with metastatic pathological and non-pathological femoral fractures undergoing intramedullary nailing.Methods: We conducted a retrospective study by extracting records from the Hospital Information System database. We accessed patients with pathological metastatic pathological and non-pathological femoral shaft fractures undergoing intramedullary nailing by the International Classification of Diseases code; from June 2006 to 2020. We then tracked the in-hospital medical and surgical adverse events postoperatively, along with the consequences after discharge. The in-hospital adverse events risk between the two groups of patients were analyzed and compared by multivariate logistic regression analysis.Results: Included patients consisted of 48 in pathological groups and 185 in non-pathological groups. Significantly higher rates of surgical and medical adverse events in patients with pathological fractures compared to patients with non-pathological fractures were observed. After adjusting for potential confounding factors in multivariate regression analysis, patients with pathological fractures had higher odds of both adverse surgical (adjusted OR 2.43, 95% CI 1.15 - 5.13) and medical adverse events (adjusted OR 2.81, 95% CI 1.13 - 7.03).Conclusions: Patients with metastatic pathological femoral shaft fractures undergoing intramedullary nailing were more likely to experience postoperative adverse events than patients with non-pathological fractures.