RESUMO
PURPOSE: The aim was to compare the muscle damage and functional outcomes between patients who underwent total hip arthroplasty through a direct anterior (49 patients) or a lateral approach (50 patients). METHODS: A randomized, controlled, prospective study. The study variables were muscle damage based on post-operative levels of serum markers (citokynes and acute phase reactants) and MRI, and Harris hip score. RESULTS: Post-operatively, there were significantly higher mean levels in the lateral group related to interleukin 6 and 8, and tumor necrosis factor-alpha up to fourth postoperative day. By MRI at six post-operative months, the fatty atrophy in the gluteus muscles was more in the lateral group, but similar in the other muscles. The mean thickness of the tensor fasciae latae was significantly lower in the anterior group. Functional outcome was similar between groups at three and 12 post-operative months. CONCLUSIONS: Muscle damage due to the surgical approach had no influence on functional outcome after three post-operative months. Both anterior and lateral approaches for THA are similarly safe and feasible, so the choice depends only on the preference and experience of the surgeon.