We compared the outcomes of primary consecutive THAs performed via the direct lateral approach through minimally invasive incisions (<8 cm) and through standard incisions (15~20 cm).

Eighty primary consecutive THAs were performed via direct lateral approach through minimally invasive incisions or through standard size incisions. The standard incision is Hardinge's direct lateral approach. For the MIS group, an approximately 8 cm long oblique skin incision was made centered at the tip of the greater trochanter and running anterosuperiorly to posteroinferiorly.

The surgical time was shorter (p=0.03) and the average amount of Hemovac drainage was smaller (p=0.02) in the MIS group. Alignment of the femoral stem and acetabular cup, post-operative pain and limping, HHS, and infection rate were no different between the two groups. In the MIS group, two complications (5.0%) occurred (one lateral positioning of the acetabular cup, one intra-operative acetabular fracture), and one varus stem insertion occurred.

Minimization of the skin incision length for primary THAs performed via the direct lateral approach appears to have benefits with regard to shortening the wound closing time and decreasing the amount of postoperative Hemovac suction drainage. However, the minimally exposed operative field raises technical problems, so sufficient surgical experience and training are required.