Direct Anterior Approach In Lateral Decubitus Position Versus Supine Position For Unilateral Total Hip Arthroplasty: A Comparative Study

Objective To compare the clinical efficacy of the direct anterior approach in lateral decubitus position (L-DAA) and supine position (S-DAA) for unilateral total hip arthroplasty.Methods A retrospective study was conducted on 89 patients who underwent primary unilateral total hip arthroplasty in our department between August 2016 and December 2017. There were 46 patients who underwent L-DAA and 43 patients who underwent S-DAA. The body mass index (BMI), operation time, blood loss, preoperative Hb, first day and third day postoperative Hb, incision length, hospital stay, preoperative and postoperative Harris score, preoperative and postoperative visual analogue scale (VAS) score, radiological evaluation, intraoperative and postoperative complication, postoperative absolute length difference of lower extremity were recorded and analyzed. P < 0.05 was set as the significant difference.Results All patients were followed up for 8-23 months, with an average of 15.6 months. No significant differences were found in preoperative and postoperative Harris scores, preoperative Hb, incision lengths, radiological evaluations, preoperative and postoperative VAS scores, and hospital stay (P > 0.05). However, significant differences were detected in BMI, blood loss, first day and third day postoperative Hb, and operation time (P < 0.05). There were no postoperative complications in the L-DAA and S-DAA groups. During the operation, two cases of proximal femoral fracture occurred in the L-DAA group, four in the S-DAA group, and the difference was statistically significant. There were significant differences found in the postoperative absolute length difference of lower extremity between the two groups.Conclusion Compared with the S-DAA approach, the L-DAA approach had the advantages of shorter operation time and less blood loss. Compared with S-DAA, it was easier to expose the proximal femur, and lower BMI was required in L-DAA. However, it was more difficult to compare the length of both lower extremities in the L-DAA approach than in the S-DAA approach.