Comparison of general and spinal anesthesia on outcomes of direct anterior approach total hip arthroplasty: a prospective observational study

Objective: This study aimed to evaluate the impact of spinal anesthesia (SA) compared to general anesthesia (GA) on clinical outcomes in patients undergoing direct anterior approach total hip arthroplasty (DAA-THA) at a single institution. Methods: This prospective observational study was conducted at a single institution between 2014 and 2017. A total of 437 patients who underwent primary elective DAA-THA were included. Among them, 363 patients received SA, and 74 patients received GA. Demographic characteristics (age, sex), comorbidities, American Society of Anesthesiologists (ASA) scores, and preoperative hematocrit levels were recorded. The mean age was 59.4 years (range, 26-82 years), and 67.3% of the patients were female. The primary outcome measures included complication rates, estimated blood loss (EBL), changes in hematocrit, length of hospital stay (LOS), duration of surgery, acetabular and femoral component orientation, and stem subsidence. Results: No significant differences were found between the GA and SA groups regarding median EBL (0.9 L vs. 0.9 L, P=.675), hematocrit change (-8.12% vs. -7.70%, P=.727), mean duration of surgery (103 min vs. 105 min, P=.999), and LOS (3.5 days vs. 3.6 days, P=.462). Radiological outcomes, including femoral stem varus/valgus alignment (0.2° vs. 0.3°, P=.877), stem subsidence (0.9 mm vs. 1.0 mm, P=.111), and acetabular component abduction angles (42° vs. 43°, P=.475), were also comparable. The overall complication rates were 8% in the GA group and 5% in the SA group (P=.400). Conclusion: Both general and spinal anesthesia can be safely utilized in DAA-THA, providing comparable clinical and radiological outcomes. The choice of anesthesia did not significantly affect surgical time, blood loss, or complication rates. These findings are clinically relevant for optimizing anesthesia strategies in DAA-THA, offering flexibility for both surgeons and anesthesiologists without compromising patient outcomes. Level of Evidence: Level II, Therapeutic Study.