Anterolateral approach may be superior to posterolateral approach in controlling postoperative lower limb discrepancy in primary total hip arthroplasty: A single-center, retrospective cohort study

Objectives: This study aims to investigate the possible association and comparison between anterolateral approach (ALA) and posterolateral approach (PLA) and postoperative lower limb discrepancy (LLD) in selective total hip arthroplasty (THA). Patients and methods: April 2021 and July 2021, a total of 266 consecutive patients (126 males, 140 females; mean age: 46.7±13.6 years; range, 22 to 60 years) who underwent unilateral primary THA via the ALA or the PLA were retrospectively analyzed. The operations were performed by a single surgical team. All patients were divided into two groups according to the approach: ALA group (n=66) and PLA group (n=200). Relevant data were recorded. Diagnosis including hip osteoarthritis, developmental dysplasia of the hip (DDH), aseptic avascular necrosis (AVN), and inflammatory arthritis were noted. Perioperative follow-up radiographs were evaluated and measured to compare the postoperative LLD and offset. The association between two approaches and postoperative LLD and offset was analyzed using the univariate and multivariate linear regression analysis. Results: The mean follow-up was 20±3.7 (range, 16 to 25) months. Univariate analysis revealed that the postoperative LLD, the postoperative acetabular offset, and hospital costs were lower in the ALA group than the PLA group (p <0.01). However, the offset and length of stay were comparable between the two groups (p>0.05). Multivariate analysis revealed that the PLA (β=4.71; 95% confidence interval [CI]: 1.78 to 7.64), preoperative LLD (β=0.29; 95% CI: 0.21 to 0.37), DDH (β=5.01; 95% CI: 1.47 to 8.55), and AVN (β=3.81; 95% CI: 0.50 to 7.12) were the main contributors to the postoperative LLD. Conclusion: Our study results suggest that the ALA may be superior to the PLA in controlling the postoperative LLD among some of the selective unilateral primary THA patients. Both the ALA and the PLA were comparable in terms of the restoration of offset.