Complications after intramedullary nail fixation of pathological versus non-pathological femoral shaft fractures: a retrospective cohort study in 233 patients.

BACKGROUND Postoperative adverse events after intramedullary nailing have been reported in patients with metastatic pathological and non-pathological femoral fractures. Other consequences to be considered are readmission and reoperation. Few studies have compared the risks of postoperative adverse events, reoperation, and readmission after intramedullary nailing of pathological and non-pathological femur fractures. This study was designed to test the hypothesis that patients with pathological femoral fractures had more adverse events, readmission, and reoperation following surgical fixation than non-pathological femoral fractures. METHODS This was a retrospective observational cohort study, conducted at an academic medical center in Thailand. The data from patients with femoral shaft fractures undergoing long intramedullary nailing, from June 1, 2006, to June 30, 2020, were included. Patients who had a pathological fracture from a primary bone tumor, metabolic bone disease, or inadequate/missing information were excluded. Patients with pathological fractures from metastatic bone disease were assigned to be the pathological group whereas those with traumatic fractures were assigned to be the non-pathological group. The primary outcome was the risk of inpatient adverse events as compared between the two groups. The secondary outcome was the risk of consequences after discharge as compared between the two groups. Outcomes were analyzed by using multivariate logistic regression analysis. RESULTS The total number of patients was 48 in the pathological fracture group and 185 in the non-pathological group. There were significantly higher rates of surgical and medical adverse events in patients with pathological fractures compared to patients with non-pathological fractures. 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.