Optimum anatomic socket position and sizing for the direct anterior approach: impingement and instability.

A comprehensive strategy is important for ensuring reproducible and safe acetabular component sizing and positioning. Presented here is our approach for anatomic acetabular component positioning in direct anterior total hip arthroplasty. This strategy has evolved with our understanding of the ramifications of socket sizing and positioning on instability and impingement. Data collected by a single surgeon (J.A.R.) between 2009 and 2011 influenced our current paradigm. We compare the sizing and positioning parameters of the anterior and posterior approach, thus demonstrating how the 2 are different. By highlighting these differences, we hope to provide a clear, defined approach to acetabular placement and sizing for direct anterior-approach total hip arthroplasty.