Blood Loss and Transfusion Rates in the Revision of Unicompartmental Knee Arthroplasty to Total Knee Arthroplasty Are Similar to Those of Primary Total Knee Arthroplasty But Are Lower Compared With the Revision Total Knee Arthroplasty.

A total of 42 patients revised from unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) were matched with 40 aseptic patients, including both component revision TKA and 88 primary TKA patients. The hemoglobin and hematocrit levels of each patient were screened preoperatively and postoperatively. There were no statistically significant differences in the postoperative hemoglobin or hematocrit levels, calculated blood loss, or blood transfusion rates between the revision UKA and primary TKA groups, whereas the hemoglobin (P = .010) and hematocrit (P = .015) levels were lower and the calculated blood loss (P = .034) and blood transfusion rates (P = .031) were higher in the revision TKA group. Revision of a failed UKA is more similar to primary TKA with respect to blood loss and transfusion rate.