BACKGROUND: Various pre- and perioperative risk factors have been reported in association with blood loss in knee arthroplasty. However, the effect of the uncovered cancellous surface on blood loss in simultaneous bilateral total knee arthroplasty (SBTKA) by different prosthetic designs is not well elucidated. Therefore, this study aimed to compare the blood loss and transfusion rate between different knee prostheses in SBTKA and to identify risk factors that influence blood loss and transfusion after SBTKA. METHODS: Demographic and perioperative data of patients who underwent SBTKA using either a closed-box or an open-box femoral component of posterior-stabilized fixed-bearing (PS FB) knee system were retrospectively reviewed. The calculated blood loss (CBL) and blood transfusion rate were compared by using Student t-test and confirmed with multivariate regression analysis. RESULTS: There was no significant difference in preoperative parameters between 54 closed-box and 56 open-box PS FB TKAs. The CBL of the closed-box TKA group was 135.23 mL less (95% confidence interval [CI], −215.30 to −55.16; p = 0.001) than that of the open-box TKA group. However, the blood transfusion rates of the closed- and open-box TKA groups were not significantly different (24.1% and 38.5%, p = 0.11). For each additional minute of total operative time, 3.75 mL (95% CI, 1.75 to 5.76; p < 0.001) of blood loss was anticipated. For each additional mg/dL of preoperative hemoglobin, 71% (p < 0.001) reduction of blood transfusion probability was predicted. CONCLUSIONS: The use of closed- and open-box knee prostheses resulted in a significant difference in blood loss in SBTKA. Prolonged operative time also significantly increased CBL. Therefore, strategies to control the bleeding surface and shorten operative duration may be considered if blood loss is of special concern. The preoperative hemoglobin was the only factor that affects the probability of blood transfusion in SBTKA.
Arthroplasty ; Arthroplasty, Replacement, Knee ; Blood Transfusion ; Hemorrhage ; Humans ; Knee ; Knee Prosthesis ; Operative Time ; Prostheses and Implants ; Prosthesis Design ; Retrospective Studies ; Risk Factors

Methods: Data from patients who underwent minimally invasive (MI) fusion surgery for lumbar degenerative diseases at L4–L5 level was analyzed. Thirty patients each from MIS-TLIF, XLIF, and OLIF groups were recruited for propensity score matching. Visual Analog Scale (VAS) of the back and legs and Oswestry Disability Index (ODI) were evaluated preoperatively and at 1, 3, and 6 months and 1 year postoperatively. Radiographic outcomes were also compared. The fusion rate was evaluated at 1 year after surgeries. Results: The clinical outcomes were significantly improved in all groups. The disk height was significantly restored in all groups postoperatively, which was significantly more improved in XLIF and OLIF than MIS-TLIF group (p<0.001). The axial canal area was significantly increased more in MIS-TLIF versus XLIF and OLIF (p<0.001). The correction of lumbar lordotic angle and segmental sagittal angle were similar among these techniques. OLIF and XLIF groups showed less blood loss and shorter hospital stays than MIS-TLIF group (p<0.001). There was no significant difference in fusion rate among all groups. Conclusions MIS-TLIF, XLIF, and OLIF facilitated safe and effective MI procedures for treating lumbar degenerative diseases. XLIF and OLIF can achieve clinical outcomes equivalent to MIS-TLIF by indirect decompression. XLIF and OLIF showed less blood loss, shorter hospital stays, and better disk and foraminal height restorations. In single-level L4–5, the restoration of sagittal alignment was similar between these three techniques.