Comparison of Direct Lateral (Hardinge) and Direct Superior Approaches in Total Hip Arthroplasty – Effects on Perioperative Blood Loss and Transfusion Risk

Background. Total hip arthroplasty (THA) can be performed through several approaches, including the direct superior (DSA) and direct lateral (Hardinge) approach. Perioperative blood loss and transfusion requirements remain key determinants of postoperative recovery and complications. This retrospective cohort study aimed to quantitatively compare perioperative blood loss and transfusion rates between DSA and Hardinge approaches in primary THA.Material and methods. 215 consecutive adults who underwent primary unilateral THA (106 DSA, 109 Hardinge) were analysed. Perioperative blood loss (PBL) was estimated using Nadler’s formula for blood volume and Gross’s method based on perioperative haematocrit values from the preoperative day to postoperative day 2. Demographic variables and perioperative laboratory parameters were collected. Univariable and multivariable logistic regression assessed whether the Hardinge approach was associated with transfusion after adjustment for age, sex and body mass index (BMI). Results. Mean PBL was lower with DSA than with Hardinge (1.153 L [SD 0.489] vs 1.323 L [SD 0.506]; P = .013). Overall, 17 patients (7.9%) required transfusion (3.8% DSA vs 11.9% Hardinge; P = .041). In multivariable analysis, the Hardinge approach remained associated with higher odds of transfusion (adjusted odds ratio, 3.63; 95% confidence interval, 1.19–13.7; P = .034), whereas age, sex and BMI were not statistically significant predictors. The model showed modest discrimination (AUC, 0.74) and acceptable calibration.Conclusions. DSA was associated with lower PBL and a reduced likelihood of red blood cell transfusion in primary THA. These findings support the use of minimally invasive approaches such as DSA to minimise blood loss–related morbidity.