644 HUMAN ANATOMY. 



Rupture of the fascia has, in recorded instances, been associated with rupture of 

 the ilio-psoas, the rectus, and the biceps femoris. The outer and inner intermuscular 

 septa (page 636) are of less surgical importance than the corresponding structures in 

 the arm, and have but little effect in limiting or determining the course of a cellulitis 

 or an abscess. 



On the outer side of the thigh, running from the forepart of the crest of the ilium 

 above to the outer tuberosity of the tibia and the head of the fibula below, is the 

 thickening of the fascia lata known as the ilio-tibial band, the dense, glistening fibres 

 of which bridge over the supratrochanteric space between the summit of the trochan- 

 ter and the iliac crest. Normally at this point the band offers distinct resistance to 

 pressure with the fingers. In fracture of the neck of the femur, with shortening, it 

 must be relaxed and less resistant (AUis), and this sign is of especial value in obscure 

 cases of impacted fracture of the neck in which crepitus, preternatural mobility, and 

 other of the conventional symptoms of fracture are lacking (pages 364, 367, 390). 



The relations of the muscles about the hip to dislocation (Figs. 395, 396, pages 

 377, 378) and to hip disease (page 381) have been described. Suppuration affecting 

 the iliacus or the ilio-psoas has also been dealt with (page 381). 



Strains of the ilio-psoas muscle are not infrequent, and may, especially in chil- 

 dren, give rise to a mistaken diagnosis of hip-joint disease. In sprains, however, 

 the movements of the joint that do not affect the ilio-psoas will be painless and most 

 of the other anatomical symptoms (page 380) will be absent. 



The extensive bursa between the capsule of the hip-joint and the ilio-psoas 

 muscle {ilio-psoas bursa) may enlarge and become visible at the front of the thigh 

 below the middle of Poupart's ligament. The thigh will be found flexed from reflex 

 irritation of the ilio-psoas and to lessen pressure on the bursa (page 381). As the 

 latter not infrequently communicates with the hip-joint, infectious disease of one may 

 extend to the other. 



The adductors are also often strained or overworked, particularly during horse- 

 back exercise, 'and are sometimes sprained or stretched close to their pelvic origins. 

 The latter injury may result in a sclerosis of one of the adductor tendons, possibly 

 going on to true ossification, and producing a condition seen oftenest in cavalrymen, 

 and known as " rider's bone." 



Fractures of the femur situated below the neck (page 363) and above the con- 

 dyles (page 366) are much influenced by muscular action, as might be expected from 

 the number and strength of the muscles concerned. Three of these fractures may 

 be considered in this relation : 



1. Fracture just below the trochanters (subtrochanteric fracture). This is one 

 of the most difficult of femoral fractures to manage because of the flexion, abduc- 

 tion, and outward rotation of the upper fragment, caused by the action of the ilio- 

 psoas, the gluteus minimus and medius, the obturators, quadratus, pyriformis, and 

 gemelli. The lower fragment is drawn upward by the rectus, gracilis, tensor fasciae 

 latae, and sartorius, upward and inward by the adductors, upward and a little 

 backward by the hamstrings. In the treatment, elevation and abduction of the thigh 

 — i. e. , of the lower fragment — are often resorted to for obvious reasons. 



2. Fracture of the middle of the shaft is very frequent (page 365). It is 

 usually moderately oblique from behind downward and forward. The upper frag- 

 ment is almost always in advance of the lower fragment because (a) the fracturing 

 force is more apt to be applied from in front and to the lower rather than the upper 

 part of the thigh ; {b~) the weight of the limb in the supine position would favor a 

 posterior position of the lower fragment ; {c) the ilio-psoas tends to advance the 

 upper fragment, and the adductor magnus and gastrocnemius draw the lower frag- 

 ment somewhat backward (Fig. 614). There is often a for^vard angulation or bow- 

 ing in the direction of the normal curve of the femoral shaft (page 365), thought to 

 be due to the action of the adductors which subtend the arc of the curve.. 



The shortening is produced, as usual, by the muscles running from the pelvis 

 to the thigh and leg. 



3. Fracture just above the condyles (supracondylar fracture). This is usually 

 the result of severe injury or of direct violence. It is commonly oblique from be- 

 hind forward and downward. The fracture takes place at about the point of junction 



