Gluteus medius accessorius and gluteus quartus scansorius in one specimen: case report of two rare variations

The gluteal muscles have all the same embryo-logical origin and therefore show typical variations. The gluteus medius has its origin on the external surface of the ilium and inserts at the major greater trochanter. It lies between the gluteus maximus and minimus. Variations included in this case are the gluteus medius accessorius and the gluteus quartus or scansorius. Various sources of literature have described these two muscles on anthropoids and in man, but never with the two very rare varia-tions appearing in one specimen, as we have found in this right lower limb of a 53-year-old wom-an. The gluteus medius originates from the iliac crest between the gluteus medius and the gluteus minimus and inserts onto the greater trochanter. The gluteus quartus arises from the anterior por-tion of the gluteus minimus and the fascia lata and inserts into the tip of the greater trochanter. As a clinical consequence, the occurrence of these muscles might lead to instability in the hip joint on the contralateral side, and these anatomical varia-tions are also important to be known during differ-ent approaches of total hip replacement surgery.