RESUMEN
BACKGROUND: Aseptic loosening (AL) is a frequent complication after rotating hinge knee (RHK) prosthesis. Citak's ratio has recently been developed to describe and classify distal femoral morphology into 3 groups (A, B, C). It consists in a ratio between the diameters of the femoral canal at 20 cm from the knee joint line and at 2 cm from the adductor tubercle. The objective of the study was to identify whether the femoral distal anatomical shape described with this ratio represents a risk factor for AL in RHK prosthesis. METHODS: Retrospective study of patients who had undergone primary or revision RHK prosthesis, with a follow-up of minimum 4 years. Citak's ratio was calculated, and patients were classified depending on its value. Univariate and bivariate statistical analysis was performed to identify AL risk factors. Receiver Operating Characteristics (ROC) analyses were conducted to examine diagnostic quality of the parameters of interest. RESULTS: Thirty-three patients were included. Most of them females (ratio 26:7), with a mean age of 78.2 (SD 6.9). Three patients presented AL (rate of 9%), all of them classified into group C (100%). Citak's ratio was significantly related to the AL rate (p < 0.001), and so was the femoral canal diameter at 20 cm from the knee joint (p 0.010). The ROC curve analysis yielded an Area Under the Curve (AUC) of 0.922 (CI 95% 0.819-1.000) for the Citak´s ratio. CONCLUSION: The inner femoral diameter at 20 cm proximal to the knee joint line and Citak's ratio help indentify patients at risk of AL after RHK prosthesis, and thus a better planning of the surgery.
RESUMEN
BACKGROUND: The excessive routine ordering of pretransfusion tests (blood typing, screening, and cross-matching) for surgical cases incurs significant unnecessary costs and places an undue burden on transfusion services. This study aims to systematically review the literature regarding the necessity of routine pretransfusion tests before total hip arthroplasty (THA) or total knee arthroplasty (TKA) and summarize their outcomes. STUDY METHODS: A systematic review and meta-analysis were performed. The study's characteristics, the prevalence of over-ordering pretransfusion tests, transfusion rates, and potential cost savings to the healthcare system were analyzed. RESULTS: The study included 17,667 patients. Pooled results revealed a 96.3% over-ordering pretransfusion test rate (95% CI: 0.92-1.00; p < 0.001) among patients undergoing primary THA or TKA. The pooled prevalence of hospital transfusion rate was 3.6%. Notably, there were statistically significant differences in preoperative hemoglobin (Hb) levels between patients not requiring transfusion (Hb = 13.9 g/dl; 95% CI 12.59-15.20; p < 0.001) and those needing transfusion (Hb = 11.9 g/dl; 95% CI 10.69-13.01; p < 0.001) (p = 0.03). The per-patient total cost savings ranged from 28.63 to 191.27 dollars. DISCUSSION: Our study suggests that routine pre-transfusion testing for all patients undergoing primary THA or TKA may be unnecessary. We propose limiting pretransfusion test orders to patients with preoperative hemoglobin levels below 12 g/dl in unilateral primary TKA or THA. This targeted approach can result in significant cost savings for healthcare systems and transfusion services by reducing the over-ordering of pretransfusion tests in these surgical procedures.