Comparison of postoperative outcomes between endoscopy assisted minimal invasive direct anterior approach and bikini direct anterior approach in total hip arthroplasty.

Background: We have innovatively developed a modified bikini direct anterior approach total hip arthroplasty (THA), endoscopy assisted minimal invasive direct anterior approach (Endo-DAA). The study compared aesthetic appearance of the scar, postoperative radiographic and functional outcomes, and complications of Endo-DAA with Bikini-DAA.

Methods: Patients who underwent primary THA using Endo-DAA or Bikini-DAA were included. The main innovation of Endo-DAA is the use of minimally invasive 5-7 cm proximal transverse incision and distal puncture with an endoscopy assisted split-type tool to complete the acetabular preparation and prosthesis implantation. Outcomes evaluated included evaluation of scar satisfaction, hip reconstruction including inclination, anteversion and leg-length discrepancy (LLD) and patient-reported outcomes including Harris Hip Scores (HHS) and Forgotten Joint Score (FJS). Follow-up time points included preoperative, 6 weeks, 6 months and 12 months.

Results: Finally, 195 hips in Endo-DAA and 207 hips in Bikini DAA completed the follow-up. The Endo-DAA group was superior to the Bikini-DAA group in the cosmetic aspects of scars. the cup anteversion angle of Endo-DAA group was significantly better than that in the Bikini-DAA group. The early HHS and FJS of the Endo-DAA group were superior to those of the Bikini-group. Operation time, blood loss, incision length, length of stay and duration to start no-assistive-device walking were also significantly better in the Endo-DAA group. Furthermore, the Bikini-DAA group had a higher incidence of complication.

Conclusion: Compared with Bikini-incision, Endo-DAA improves patients' subjective satisfaction with scar aesthetics, accelerates rapid recovery of postoperative function, and reduces postoperative complications.