Both DAA and micro-PA have their own advantages and disadvantages. Because of the fast recovery, both DAA and mini-PA were successfully used in outpatient THA. Furthermore, supine positioning during DAA facilitates the use intraoperative fluoroscopy to improve component positioning, while mini-PA and micro-PA utilize lateral decubitus position and achieve the safe zone of Lewinnek in only 60% of cases for cup positioning. In the learning curve of DAA, despite of the muscle-sparing advantage, there may be high early revision rate of THA. Therefore, both DAA and micro-PA have their own enthusiasts. To our knowledge, there were no studies comparing the results of DAA THAs with micro-PA THAs. Thus The investigators conducted a single-surgeon propensity-score matching study to compare these two approaches. Our hypothesis is that DAA THAs may have better results than micro-PA THAs in component positions and other clinical outcomes. The purpose of this study were to compare (1) the radiographic component positions, (2) the clinical outcomes, such as length of hospital stay, operative time, blood loss, perioperative pain scale, dislocation rates, and functional scores between DAA and micro-PA for THA.