The optimal skin incision for minimally invasive total hip arthroplasty performed via the anterolateral approach.

Twelve total hip arthroplasty procedures were performed in fresh cadaveric specimens via the anterolateral approach using straight 9-cm incisions placed in 2 different locations with respect to anatomical landmarks. During each procedure, the forces applied to the wound edges by each of the hip instruments and the pressures and strains generated along the wound edges were measured. Pressures ranging from 40 to 190 kPa were developed between the retractors and the wound edges during acetabular reaming and femoral rasping. The resulting strain along the wound edges averaged 28% during acetabular reaming and 34% during femoral broaching (P < .0001). Maximum strains were recorded at the ends of each incision and averaged 58% and 61%, respectively (P < .0001). These results were independent of the anatomical placement of the skin incision. In total hip arthroplasty, the mechanical trauma associated with the procedure is primarily determined by the surgical approach to the hip and the properties of the subcutaneous tissues, and not the anatomical location of the skin incision itself.