Intraoperative unfractionated heparin before femoral component cementation should be avoided in femoral neck fracture treated with hybrid total hip arthroplasty.

Purpose: To compare the incidence of perioperative thromboembolic events in femoral neck fracture (FNF) patients treated with hybrid total hip arthroplasty (THA) with intraoperative unfractionated heparin (UFH) versus a control group without intraoperative UFH before femoral component cementation.
Methods: We compared 139 cases without UFH (group A) versus 134 who received 10 UI/kg UFH (group B). Indication of UFH before cementation depended on the preferences of the anaesthesiologists in each case. We assessed intraoperative bone cement implantation syndrome (BCIS) and 30-day thromboembolic events, and 90-day and 1-year mortality. BCIS was classified as per Donaldson et al.'s classification according to the degree of hypotension, arterial desaturation or loss of consciousness.
Results: BCIS was observed in 51 (18%) cases, including 37 (13%) grade 1 and 14 (5%) grade 2. Forty-seven BCISs (35%) were observed in group B and 4 (3%) in group A (p < 0.001). Multivariate regression showed that intraoperative UFH (OR = 18, CI 95% 6-52) and consumption of oral anticoagulants (OR = 3.3, CI 95% 1-10) increased the risk of BCIS. Five patients further developed a 30-day pulmonary embolism in group B, while 2 presented this complication in group A (p = 0.231). No association between BCIS and 30-day thromboembolic events was found (p = 0.62). 90-day (1% each, p = 0.98) and 1-year (2% vs. 3%, p = 0.38) mortality were similar.
Conclusions: BCIS was a frequent finding in FNF patients treated with hybrid THA. We found a paradoxically significant increase in BCIS with the use of UFH. Heparin did not seem to prevent BCIS, other thromboembolic events and mortality in this group of patients.
(© 2023. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)