One hundred patients with hip osteoarthritis, osteonecrosis of the femoral head (Ficat IIIB/IV), and Crowe type I or II dysplasia who were undergoing a unilateral total hip arthroplasty (THA) via a direct anterior approach (DAA) were randomized to either receive oblique “bikini” incision (n=50) or a longitudinal incision (n=50). Primary outcomes of interest included the following: aesthetic appearance of the scar measured using the the scar cosmesis assessment and rating (SCAR) scale, patient satisfaction with the appearance of the scar, pain during motion (hip flexion 45 degrees) which was evaluated using the visual analogue scale (VAS), ambulation distance/day while in the hospital, the Oxford Hip Score (OHS), and the University of California Los Angeles (UCLA)-activity level rating. Secondary outcomes of interest included the following: serum markers of muscle damage (i.e. creatine kinase, C-reactive protein), inflammatory markers (i.e. interleukin-6), hemoglobin drop, and implant stability. In addition, incidence of complications (i.e. nerve and wound healing) were also recorded. The primary outcomes of SCAR assessment and patient satisfaction with the scar aesthetic were evaluated at 6 months post-surgery. VAS pain was measured at 6, 12, 24, and 48 hours post-surgery, whilst ambulation distance/day was measured at 24 and 48 hours post-surgery. All other primary outcomes were measured at 1, 3, and 6 months post-surgery, and all secondary outcomes were measured at 24, and 48-hours post surgery except for implant stability, which was measured at 6 weeks after surgery. Results of this randomized controlled trial demonstrated that the SCAR assessment was statistically significantly improved in the bikini incision group compared to the longitudinal incision group (p<0.001). On average, patient satisfaction was also statistically significantly higher in the bikini incision group across all groups (p=0.013). However, all secondary outcomes were not statistically significantly different between the 2 groups (p>0.05). No statistical significant difference was observed between the 2 groups with respect to incidence of complications (p>0.05).