GLUTEAL REGION 287 



glutaeus maximus is supplied by the inferior gluteal nerve. The 

 glutseus maximus is an extensor of the hip joint and a 

 lateral rotator of the thigh. Its upper fibres can abduct 

 the thigh, acting with the tensor fasciae, and the lower fibres 

 assist in producing adduction. 



Dissection. Reflection of the Glutseus Maximus. As the 

 glutaeus maximus is reflected the dissector must be careful not 

 to injure the vessels and nerves which lie closely subjacent to 

 it. The nerves most liable to injury are the posterior cutaneous 

 nerve of the thigh, which has already been identified and secured 

 if previous instructions have been followed (see p. 284), and the 

 perforating cutaneous nerve, which is very liable to injury when 

 the fibres of the glutseus maximus are being raised from the 

 sacro-tuberous ligament. 



The incision through the muscle should extend from a point 

 on its superior border 3 cm. above the trochanter major to a point 

 on the inferior border 2.5 cm. medial to the insertion of the muscle 

 into the femur. The procedure differs on the two sides. On 

 the right side the dissector should detach the superior border of 

 the muscle from the fascia on the glutseus medius at the point 

 selected, and then pass one or two fingers downwards, on the 

 deep surface of the muscle, along the line of incision. The part 

 of the muscle thus freed from the deeper structures must then 

 be divided with the scalpel, and the process must be repeated 

 until the lower border of the muscle is reached. On the left 

 side the dissector must commence at the inferior border, and, 

 adopting the method above described, divide the muscle from 

 below upwards. When the muscle is divided, reflect the lateral 

 part to its insertion, the inferior fibres to their attachment to 

 the gluteal tuberosity, the upper fibres to their attachment into 

 the ilio-tibial tract. As the upper fibres of the muscle are 

 followed to the aponeurotic insertion two bursse will come into 

 view, one between the aponeurotic insertion of the muscle and 

 the lateral surface of the trochanter major, and a second, more 

 distally placed, between the aponeurotic insertion and the 

 lateral surface of the tendon of origin of the vastus medialis. 

 Open both bursse and examine their extents with the tip of the 

 index finger. Then turn to the medial part of the muscle and 

 reflect it towards its origin. As the reflection proceeds keep 

 the edge of the scalpel close to the deep surface of the muscle 

 to avoid injuring the posterior cutaneous nerve of the thigh, 

 and as soon as the vessels and nerves which enter the deep 

 surface of the muscle appear clean them and turn them medially 

 with the muscle. As the upper part of the muscle is followed to- 

 wards the ilium, branches of the superficial division of the superior 

 gluteal artery will be met with, accompanied by their voluminous 

 venae comites. Clear the veins away, but keep the arteries. 

 As the lower fibres are turned towards the tuberosity of the 

 ischium branches of the inferior gluteal vessels and nerve will 

 be found entering the deep surface of the muscle. Clear away 

 the veins, but clean and keep the arteries and nerves. Between 

 the muscle and the tuber ischii lies a mucous bursa. If it has 

 not already been removed by the dissector of the perineum, open 

 it. It is frequently multilocular, and its walls are closely 



