IntroductionSurgical treatment of hip fractures leads to significant post-operative complications. Although pathologic fractures (PF) are associated with worse outcomes, most studies do not differentiate between etiology (neoplastic and non-neoplastic PF). We seek to compare 30-day complication rates between 1) native hip fractures and neoplastic PF, and 2) neoplastic and non-neoplastic PF. Materials and methodsA total of 127,819 patients with hip fractures and 5104 with PF diagnosed from 2005 to 2021 were retrieved from the NSQIP database. We included 1843 patients with neoplastic PF and 3261 with non-neoplastic PF. Demographics, pre-operative labs and co-morbidities, and post-operative outcomes were analyzed. Propensity-score matching was conducted to control for confounders. ResultsPatients with a neoplastic PF had a significantly higher rate of deep venous thrombosis (DVT) (4 % vs 1.2 %, p = 0.001) and pulmonary embolism (PE) (2.4 % vs 0.7 %, p < 0.001), than native hip fractures. Rates of post-operative bleeding were significantly higher in the neoplastic PF group (29.3 % vs 23.9 %, p < 0.001) than non-neoplastic PF. No differences in soft tissue complications were found. When comparing neoplastic and non-neoplastic PF, the former had a higher rate of PE (2.5 % vs 1.0 %, p = 0.015) and post-operative bleeding (27.6 % vs 22.0 %, p = 0.009). Unplanned readmission rates and 30-day mortality rate were also higher in the neoplastic PF group. ConclusionNeoplastic PF of the hip are associated with higher risk of thromboembolic event rates and post-operative bleeding than both native hip fractures and non-neoplastic PF. No differences in rates of soft tissue complications were found between groups.