2i8 INFERIOR EXTREMITY 



proceeds transversely it crosses the muscle-border, and finally 

 comes to lie on the surface of the muscle. In disease 

 of the hip-joint, the buttock loses its prominence, whilst 

 the glutaeal sulcus becomes faint. The tuberosity of the 

 ischium may be felt deep to the distal border of the glutaeus 

 maximus by placing the fingers in the medial part of the 

 glutaeal sulcus and pressing upwards. A line drawn from the 

 most prominent part of this tuberosity to the anterior superior 

 spine of the ilium is called Nelatorfs line; it passes over 

 the top of the great trochanter and crosses the centre of 

 the acetabulum and it is used by the surgeon in the diagnosis 

 of dislocations and other injuries of the hip-joint. The great 

 trochanter of the femur may be felt at a point about six inches 

 distal to the highest part of the crest of the ilium. It can be 

 seen in thin subjects, but it does not form so projecting a 

 feature of this region as might be expected from an in- 

 spection of the skeleton, because the thick tendon of the 

 glutaeus medius is inserted into its lateral surface, and it is 

 covered also by the aponeurotic insertion of the glutaeus 

 maximus. 



Reflection of Skin. Incisions. (i) From the posterior superior spine 

 of the ilium in a curved direction along the crest of the ilium, as far 

 forwards as the position of the body will permit ; (2) from the posterior 

 extremity of this curved incision obliquely downward and medially to the 

 middle line of the sacral region, and then perpendicularly to the tip of 

 the coccyx ; (3) from the tip of the coccyx obliquely distally and laterally 

 over the back of the thigh, to the junction of the upper with the middle 

 third of the posterior border of the lateral area of the thigh. 



A large flap of skin is thus marked out, and this must be raised from 

 the subjacent superficial fascia and thrown laterally. On the right side of 

 the body the dissector begins at the crest of the ilium and works distally 

 and anteriorly ; whilst on the left side he commences over the coccyx and 

 works upwards and anteriorly. 



Panniculus Adiposus (Superficial Fascia). The superficial 

 fascia is now exposed, and it is seen to partake of the same 

 characters as the corresponding layer of fascia in other parts 

 of the body (p. 5). It presents, however, certain special 

 peculiarities. It is much more heavily laden with fat more 

 particularly so in the female ; it thickens over the proximal 

 and distal margins of the glutaeus maximus, and it becomes 

 tough, elastic, and stringy over the ischial tuberosity, so as to 

 form a most efficient cushion upon which this bony promin- 

 ence rests while the body is in the sitting posture. 



Cutaneous Nerves (Fig. 83). The superficial fascia forms 



