Radiographic and Clinical Outcomes After Direct Anterior Versus Mini Posterior Total Hip Arthroplasty

Abstract

Background

Total hip arthroplasty (THA) is a successful surgical treatment for end-stage hip arthritis. There is controversy over whether the surgical approach leads to any differences in implant sizing, implant positioning, and clinical outcomes. This study sought to compare radiographic and clinical outcomes when performing primary THA through the direct anterior approach (DAA) and posterior approach (PA).

Methods

In this retrospective cohort study of patients undergoing primary THA, 198 DAA patients were matched to 198 PA patients. Surgeries were performed by 3 fellowship-trained surgeons. Radiographic parameters analyzed were acetabular cup anteversion and abduction angles, femoral stem coronal alignment, femoral offset, and leg-length discrepancy. Postoperative complications, including periprosthetic joint infection, wound complications, periprosthetic fracture, and dislocation, were extracted from the medical record. Statistical analysis was performed to compare radiographic and clinical outcomes between groups.

Results

There were no statistically significant differences for any postoperative complications between the 2 groups. One dislocation occurred in the PA group, and no dislocations occurred in the DAA group. DAA had a longer operative time (117 vs 79 minutes, P < .01). PA had a higher increase in femoral offset compared to the contralateral limb (2.76 mm vs 1.01 mm, P < .01), higher cup anteversion (26.17° vs 23.44°, P < .001), and higher use of dual mobility components (6.06% vs 1.01%, P = .007).

Conclusions

Both DAA and PA lead to acceptable clinical and radiographic outcomes for primary THA, with significant differences noted for cup position, femoral offset, and use of dual mobility components. These differences likely represent surgeon factors to help mitigate the risk for dislocation.