Hidden blood loss in total hip arthroplasty: A comparison of the direct anterior versus posterolateral approach.

OBJECTIVES

This study aims to compare the volume and impact of hidden blood loss (HBL) following total hip arthroplasty (THA) performed via the direct anterior approach (DAA) versus the posterolateral approach (PLA).

PATIENTS AND

METHODS

Between January 2016 and January 2024, a total of 134 patients (63 males, 71 females; mean age: 69.7 ± 7.7 years; range, 48 to 79 years) who underwent primary THA were retrospectively analyzed. The patients were stratified into two cohorts according to surgical approach: DAA group (n = 63) and PLA group (n = 71). Preoperative blood volume and visible blood loss (VBL) were quantified for both cohorts. Total blood loss (TBL) was derived from hematocrit (Hct) levels measured preoperatively and on postoperative Day 3, which subsequently allowed calculation of HBL and its proportion relative to TBL. Intergroup comparisons were performed for these parameters.

RESULTS

The most common etiology for THA was hip osteoarthritis. The mean operative time was 120.4 ± 10.2 min in the DAA group and 117.7 ± 8.2 min in the PLA group, indicating no statistically significant difference between the two groups (p = 0.093). The mean TBL was 366.3 ± 54.3 mL in the DAA group and 477.0 ± 71.6 mL in the PLA group (p < 0.001), while the mean HBL was 206.3 ± 40.4 mL and 318.9 ± 44.9 mL, respectively (p < 0.001). The reductions in Hb and Hct were significantly lower in the DAA group compared to the PLA group (p < 0.001 for both).

CONCLUSION

During the perioperative period of THA, HBL represents a considerable clinical concern regardless of the surgical approach employed. Compared to the PLA, the DAA is associated with a significant reduction in both HBL and TBL.