A randomized, prospective study of 3 minimally invasive surgical approaches in total hip arthroplasty: comprehensive gait analysis.

Purported advantages of total hip arthroplasty performed with minimally invasive surgical (MIS) approaches are less muscle damage and faster recovery. There are little data scientifically evaluating these claims. Twenty-four consecutive hips were randomized to total hip arthroplasty through 1 of 3 MIS approaches (2-incision, mini-posterior, and mini-anterolateral). Each patient underwent preoperative and postoperative gait analysis. Gait parameters included vertical ground reaction force, velocity, single-leg stance time, limb-loading rate, and abductor torque. All 3 groups demonstrated overall improvements in gait parameters at 6 weeks postoperatively. The anterolateral approach patients showed a decrease in the vertical ground reaction force at mid-stance, whereas the 2-incision and posterior approaches demonstrated no significant change. These results fail to demonstrate any significant advantage of the 2-incision approach over the posterior approach in kinetic gait parameters. Furthermore, the anterolateral approach demonstrates a gait pattern consistent with abductor muscle injury in the early recovery period, despite the MIS approach.