Upon implantation of a hip prosthesis by total hip arthroplasty (THA), clinical criteria are not always sufficient for an objective assessment of the functional outcome. Thus, functional improvement of gait behavior was comparatively validated by instrumented 3D gait analysis for a current, minimally invasive surgical approach (MIS; anterolateral approach) and a conventional, transgluteal approach (KONV). In selected cases, disturbed motion sequences were registered by measuring the muscle activity via high-resolution, monopolar surface electromyography (S-EMG) above the operation area. Despite continuous and significant improvement of practically all analyzed kinematic and kinetic gait parameters for both surgical approaches already after 5 weeks but in particular after 6 and 12 months, no significant differences were detected between the 2 procedures for any parameter or time point. The S-EMG demonstrated non-physiological muscle activation on the operated, but also on the non-operated side, even at 6 months after surgery. Advantages of the MIS approach thus seem primarily restricted to early, post-operative results, such as more rapid pain reduction and rehabilitation.