chap, xix.] HIP JOINT. 399 



incident to this there is ( 5) apparent shortening of 

 the limb ; (6) there is real shortening of the limb. 



1. The first position depends upon the effusion 

 into the joint. If fluid be forcibly injected into a 

 hip joint the thigh becomes flexed, abducted, and 

 a little everted. In other words, the articulation 

 holds the most fluid when the limb is in this 

 position, and the patient places it there to relieve 

 pain by reducing the tension within the capsule 

 to a minimum. Flexion is the most marked feature 

 in this position. Its effect is pronounced. It relaxes 

 the main part of the Y ligament, which, when the 

 limb is straight, is drawn as an unyielding band across 

 the front of the joint. Abduction relaxes the outer 

 limb of this ligament, and the eversion slightly relaxes 

 the inner limb. The latter movement is the least 

 marked, since eversion, even in the flexed position of 

 the joint, is resisted by the outer part of the Y liga- 

 ment. Any but a moderate degree of abduction would 

 be limited by the pectineo-femoral ligament, especially 

 as that band is rendered most tense when abduction is 

 combined with flexion and rotation outwards. 



2. The apparent lengthening is due to the tilting 

 down of the pelvis on the diseased side, and is the 

 result of the patient's attempts to overcome the effects 

 of the position just described. The limb is shortened 

 by flexion and abduction, and to bring the foot again 

 to the ground and to restore the natural parallelism of 

 the limbs, the pelvis has to be tilted clown on the 

 affected side. Thus, an apparent lengthening of the 

 limb is produced, which is noticeable when the patient 

 lies upon a bed, and the abduction is made to entirely 

 disappear. Some real lengthening of the limb may be 

 produced in this disease by the effusion into the joint 

 separating the femur from the acetabulum, but it 

 must be so slight that it is doubtful if it could be ap- 

 preciated. By forcible injection into the joint Braune 



