One of the main problems when performing THA via the standard transgluteal approach is the necessary injury of the gluteus medius muscle. The consecutive decrease of contractile muscle substance and the substitution by scar tissue leads to functional deficits of the pelvic-stabilizing musculature with an insufficiency limp in a large number of patients. In the long run the lack of musculature leads to a decrease in bone substance at the insertion sites of the gluteal muscles of the proximal femur. The present study has the aim of establishing a new therapy for iatrogenic gluteal muscle damage. The hypothesis of the present proposal is that intra-muscular (IM) injection of PLX-PAD into the iatrogenically injured gluteus medius muscle after THA results in an improved regeneration of the skeletal muscle tissue and consecutively in an improved functional outcome.