Patients with hemophilia with decreased hematocrit and coagulation factors may be at a higher risk of increased perioperative blood loss during total knee arthroplasty (TKA), according to a new study published in Haemophilia.

“Blood management is an important issue in TKA, especially in patients with hemophilia. During the perioperative period in TKA, blood management is essential because it can affect the postoperative clinical outcome,” the authors said.

Multivariate regression analysis found that patients were at an increased risk of perioperative blood loss if their operation day hematocrit levels (odds ratio [OR]=.633; 95% CI, .511-.786; P <.001) and/or coagulation factor levels (OR=.970; 95% CI, .941-.9999; P =.046) were reduced.

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“This study is valuable as it is the first to investigate independent risk factors, including coagulation factor levels, for increased [perioperative blood loss],” the authors said.

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Using receiver-operating characteristic analysis, the cutoff value for coagulation factor levels was found to be 93.5%, yielding an area under the curve of .717, the sensitivity of 70.4%, and the specificity of 67.6% (P =.001). The cutoff for hematocrit levels was found to be 38.2% which yielded an area under the curve of .878, the sensitivity of 85.7%, and specificity of 80.6% (P <.001).

“A coagulation factor level of <93.5% or hematocrit level of <38.2% may be a significant risk factor for increasing [perioperative blood loss],” the authors concluded.

In the study, patients with hemophilia lost a mean volume of 542.3±361.7 mL during TKA. Patients who lost more than this amount were categorized as a higher blood loss group (group H; n=36) and patients below the mean were the low loss group (group L; n=56).

Univariate analysis found that in addition to coagulation factor and hematocrit levels, body mass index (P =.017) and hemoglobin levels (P <.001) were also significantly different between group H and group L. These values did not remain significant during multivariate regression analysis, however.


Kim MS, Kim JH, Kim KI. Risk factors for increased perioperative blood loss during total knee arthroplasty in patients with haemophilia. Haemophilia. Published online March 3, 2022. doi:10.1111/hae.14523