THE LOWEE EXTREMITY. 1455 



palmar aspect of the terminal phalanges is connected by fibrous processes with the 

 periosteum ; hence the frequency of necrosis of the terminal phalanx in suppurative 

 inflammations in this region. 



THE LOWEE EXTEEMITY. 

 THE BUTTOCK. 



The region of the hip or buttock extends from the crest of the ilium above to 

 the gluteal fold below. The highest point of the iliac crest, situated a little 

 i posterior to its middle, is on a level with the fourth lumbar spine ; the anterior 

 superior spine of the ilium is directed forwards, and belongs to the groin, which 

 it limits laterally; the posterior superior spine, situated at the bottom of a 

 dimple or small depression, is on a level with the second sacral spine, and corre- 

 sponds, therefore, to the middle of the sacro-iliac joint. Two and a half inches 

 behind the anterior superior spine is a prominence upon the outer lip of the 

 iliac crest ; this prominence, which is termed the tubercular point, is the most lateral 

 part of the crest, and has been referred to in dealing with the surface anatomy 

 of the abdomen. A hand's breadth below the tubercle of the crest is the greater 

 trochanter of the femur, the most lateral bony landmark of the hip ; its anterior 

 and posterior borders are best felt between the fingers and thumb, while the 

 limb is slightly abducted to relax the ilio-tibial tract, and if the thigh is now 

 rotated, it will be noted that the trochanter rotates round the segment of a 

 circle, the radius of which is formed by the head and neck of 'the femur; in non- 

 impacted fractures of the neck of the femur the trochanter rotates round the 

 segment of a much smaller circle. Nelatoris line, drawn from the anterior superior 

 spine to the most prominent part of the ischial tuberosity, crosses the hip at the 

 level of the proximal border of the greater trochanter ; this line is employed to 

 ascertain the presence or absence of upward displacement of the trochanter. 

 : Chiene demonstrates the relative height of the trochanters by stretching two 

 tapes across the front of the pelvis, one between the anterior superior spines, 

 and the other between the proximal borders of the trochanters; the lower tape 

 will converge towards the upper on the side of the upward displacement. A line 

 ' prolonging the anterior border of the greater trochanter vertically upwards touches 

 , the iliac crest at the tubercular point. The sciatic tuberosity, in the erect posture, 

 is overlapped by the distal border of the glutseus maximus ; its most prominent 

 part is felt a little proximal to the medial part of the gluteal fold. If the hip is 

 . rotated medially, the lesser trochanter of the femur may be felt by deep palpa- 

 tion proximal to the lateral end of the gluteal fold ; it corresponds to the interval 

 between the distal border of the quadratus femoris and the proximal border of the 

 adductor magnus, and therefore, also, to the level of the medial circumflex artery 

 of the thigh. 



The lower border of the glutseus maximus lies a little above the gluteal fold 



medially, crosses it about its middle, and is continued distally and laterally to 



meet the proximal end of the furrow of the lateral intermuscular septum, at 



: the junction of the proximal and middle thirds of the femur. The medial borders 



jjof the two great gluteal muscles are separated by the deep gluteal cleft, which 



'\ extends upwards and backwards from the perineum to the level of the fourth 



sacral spine, where it opens out into the triangle upon the back of the sacrum. 



| Anteriorly the buttock is limited by the prominence of the tensor fasciae latae 



muscle, which extends distally and somewhat backwards from the anterior end of 



the crest, to join the ilio-tibial tract distal to the root of the greater trochanter. 



The superior gluteal artery reaches the buttock immediately below the upper 

 II border of the greater sciatic foramen, opposite a point corresponding to the junction 

 [ of the upper and middle thirds of a line drawn from the posterior superior iliac 

 \{ spine to the upper border of the greater trochanter. To expose the vessel the 

 1 3 incision should be made along this line, which has the advantage of running parallel 

 \l to the fibres of the glutseus maximus, as well as parallel to the interval between 

 the glutseus medius and piriformis muscles. 



