Numerous factors affect abductor strength after Total hip arthroplasty (THA), including surgical technique, prosthesis type, postoperative rehabilitation program, and preoperative patient condition. We prospectively investigated the effects of the modified Hardinge approach on hip muscle strength, which was evaluated using the isokinetic test, functional results, and gait function of patients who underwent primary THA. The hip muscles strength were measured using an isokinetic dynamometer. The primary outcomes of the present study were measurement of isokinetic strength of hip abductor muscle strengths using an isokinetic evaluator and gait analyses preoperatively and at 6months postoperatively in 27 patients. Isokinetic muscle strength test, abductor and other hip circumference groups achieved the preoperative muscle strength at 3months postoperatively, and the postoperative sixth month values showed a statistically significant improvement compared with the preoperative and third month values. In gait analyze, our temporospatial data showed a slight regression at postoperative 3months but reached the same values at 6months postoperatively. Kinematic data showed a significant regression, but the data were not compared with those in the preoperative period. Adequate muscle strength and physiological gait pattern, similar to the preoperative status, can be achieved at 6months postoperatively. Level III.