BackgroundThe present study examines Patient Reported Outcomes Measurement Information System (PROMIS) Computer Adaptive Test (CAT) scores for domains of physical function (PF) and pain interference (PI) in patients undergoing elective THA from either a direct anterior or posterior surgical approach. MethodsA total of 1358 patients who underwent THA at our institution from 1/1/2015 to 12/1/2018 were identified. Visual analog scale (VAS) pain scores, PROMIS CAT PF and PI data were collected at the last preoperative visit as well as 6 weeks, 6 months, and 1-2 years postoperatively. Literature-derived minimum clinically important difference (MCID) for PROMIS CAT PF metric with regard to THA was used for data comparison. ResultsFour hundred nine patients were included in the final analysis. Fifty-one percent underwent a posterior approach, and 49% underwent a direct anterior approach. Both approaches led to a significant improvement in PROMIS CAT PF and PI scores. Patients undergoing a direct anterior approach had significantly higher preoperative and postoperative PROMIS CAT PF scores as well as significantly lower preoperative PROMIS CAT PI scores. Each approach yielded similar interval improvements of PROMIS CAT PF and PI. One hundred three direct anterior approach THA patients (51%) and 119 posterior approach THA patients (57.5%) achieved PROMIS PF MCID at 1- to 2-year follow-up. ConclusionNeither the direct anterior nor posterior THA surgical approach conferred an advantage to postoperative improvements of PROMIS CAT PF and PI scores. Adult reconstructive surgeons should continue to execute the direct anterior or posterior THA surgical approaches based upon personal preference. Despite surgeon confidence in THA, the potential for further innovation exists given the number of THA patients who failed to achieve PROMIS PF MCID.