[Blood loss in total knee arthroplasty using computer-assisted navigation or 3D-printed patient-specific instruments]

Objective: To compare the perioperative blood loss in patients undergoing a total knee arthroplasty (TKA) across three different techniques: computer-assisted navigation surgery (CAS), patient specific instrumentation (PSI) and conventional instrumentation (CI). Methods: Ninety consecutive patients with severe knee osteoarthritis who underwent unilateral primary TKA in Peking University Third Hospital Orthopedics Department from January 2018 to December 2018 were enrolled in this prospective study. The patients were randomly divided into three groups (30 case in each group): CAS-TKA group, PSI-TKA group and CI-TKA group. The study measured intraoperative blood loss, total blood loss, hidden blood loss, decreases of hemoglobin and hematocrit, and the post-TKA blood transfusions in the three groups. One-way ANOVA was used to detect the differences among the cohorts, and LSD was used for the post-hoc test. Results: The overall intraoperative blood loss of all patients was 6 ml (5~8 ml). The mean total blood loss and hidden blood loss in CAS-TKA group, PSI-TKA group and CI-TKA group was (1 147.0±301.8) and (1 140.1±301.9)ml, (1 044.3±454.1) and (1 038.5±454.0)ml, (1 154.0±483.6) and (1 145.3±482.7)ml, respectively; there was no significant differences among the three groups (F=0.639, 0.616, both P>0.05). There were no patients who received allogeneic blood transfusion. There were no significant differences in decrease of hemoglobin and hematocrit among the three groups neither (both P>0.05). Conclusions: Compared with conventional TKA, CAS and PSI does not increase the total blood loss of TKA. However, they both demonstrate a potential benefit in reducing blood loss of TKA.