Ninety-nine patients undergoing total hip arthroplasty for hip fracture or femoral head necrosis were randomized to receive one of three interventions: 20 mL of 0.5% ropivacaine (Group A, n=30), 20 mL of 0.25% ropivacaine (Group B, n=30), or 10 mL of 0.5% ropivacaine (Group C, n=30). The primary outcome was the incidence of postoperative quadriceps motor block at 6 hours. Secondary outcomes included motor block incidence at 0, 12, 24, and 48 hours, pain scores, time to first walk, need for rescue analgesia, adverse events, and patient satisfaction. Outcomes were assessed at various postoperative time points up to 48 hours. Overall, the study revealed that a lower volume of ropivacaine (Group C) significantly reduced motor block incidence at 6 and 12 hours compared to higher-volume groups, while pain control and patient satisfaction were similar across all groups. The findings suggest that using a lower volume (10 mL) of 0.5% ropivacaine provides effective analgesia while minimizing motor block.