TRAUMA-INDUCED COAGULOPATHY FOLLOWING HIP FRACTURE SURGERY COMPARED WITH ELECTIVE TOTAL HIP ARTHROPLASTY

Venous thromboembolism (VTE) is a common postoperative complication following orthopaedic surgeries. Patients undergoing elective total hip arthroplasty (THA) face a VTE risk of 0.5–1.5%, while those undergoing hip fracture surgery (HFS) are at a significantly higher risk of 2.5–3.7%, contributing to increased morbidity and mortality. Current clinical guidelines provide inconsistent thromboprophylaxis recommendations, often treating both groups similarly, despite differing VTE rates, suggesting the need for a tailored approach. Trauma-induced coagulopathy refers to the abnormal coagulation response triggered by trauma, which affects both THA and HFS patients, but to varying extents. While coagulopathy in THA is primarily a result of the surgery itself, patients undergoing HFS face additional coagulation challenges due to the traumatic injury that caused their fracture. Thrombelastography (TEG) is a point-of-care hemostatic assay that quantifies coagulation status, where an elevated maximal amplitude (MA) indicates hypercoagulability and increased VTE risk (Gary et al., 2016). This study aimed to compare coagulation differences between patients undergoing THA and HFS to determine the influences of surgery and trauma on coagulation status. This single-centre prospective cohort study compared patients undergoing primary THA and urgent HFS. Exclusion criteria included a history of VTE, anticoagulant use, bleeding disorders, or active malignancies. Serial whole blood samples were collected preoperatively and up to 12 weeks postoperatively and analyzed using a TEG6s hemostasis analyzer (Haemonetics Corporation, Braintree, MA). Hypercoagulability was defined as a MA ≥ 65mm (Gary et al., 2016). Thromboprophylaxis was standardized to aspirin 81mg daily for 28 days following THA, and given at the discretion of the surgeon for HFS, with most patients receiving tinzaparin for 35 days. Mann-Whitney U tests compared mean MA values at each timepoint and to the hypercoagulability threshold. The study included 37 patients undergoing THA and 169 undergoing HFS, with mean ages of 68.4 (± 9.0) years for THA and 77.5 (± 11.0) years for HFS (p At admission, neither group demonstrated hypercoagulability (MA = 62.8 for THA, 62.6 for HFS, p = 0.71). On postoperative day 1, HFS patients were significantly more hypercoagulable than THA patients (MA = 64.0 vs. 61.5, p Complications of VTE occurred in two (5.3%) THA patients and 11 (5.3%) HFS patients, with 92% of events happening between postoperative days one and four; while one THA patient had a VTE at 10 weeks postoperatively. This study revealed a similar overall trend in coagulation patterns between patients undergoing THA and HFS, with HFS patients showing greater hypercoagulability in the early postoperative period. The increased hypercoagulability in the HFS group coincided with a higher incidence of VTE events. Given that the MA parameter reflects both fibrin and platelet contributions to clot strength, patients undergoing HFS may benefit from adjunctive antiplatelet therapy, such as aspirin, to mitigate the risk of VTE. Future studies using TEG-based Platelet Mapping are needed to further elucidate the early role of platelets in coagulation and antiplatelet use to mitigate VTE risk in these populations.