330 THE ARTICULATIONS, OR JOINTS 



asserts, in the displacement on to the dorsum, the head of the bone travels up behind the acetab- 

 ulum, in front of the muscle; while in the dislocation into the sciatic notch, the head passes 

 behind the muscle, and is therefore prevented from reaching the dorsum, in consequence of 

 the tendon of the muscle arching over the neck of the bone, and so remains in the neighbor- 

 hood of the sciatic notch. Bigelow, therefore, distinguishes these two forms of dislocation by 

 describing them as dislocations backward, " above and below," the Obturator internus. 



The iliofemoral ligament is rarely torn in dislocations of the hip, and this fact is taken advan- 

 tage of by the surgeon in reducing these dislocations by manipulation. It is made to act as 

 a fulcrum to a lever of which the long arm is the shaft of the femur, and the short arm the 

 neck of the bone. 



The hip-joint is rarely the seat of acute synovitis from injury, on account of its deep position 

 and its thick covering of soft parts. Acute inflammation may, and does, frequently occur as 

 the result of constitutional conditions, as rheumatism, pyemia, etc. When, in these cases, 

 effusion takes place, and the joint becomes distended with fluid, the swelling is not very easy 

 to detect on account of the thickness of the capsule and the depth of the articulation. It is 

 principally to be found on the front of the joint, just internal to the iliofemoral ligament; or 

 behind, at the lower and back part. In these two places the capsule is thinner than elsewhere. 

 Disease of the hip-joint is much more frequently of a chronic character and is usually, of tuber- 

 culous origin. It begins either in the bones or in the synovia! membrane, more frequently in the 

 former, and probably, in most cases, in the growing, highly vascular tissue in the neighborhood 

 of the epiphyseal cartilage. In this respect it differs very materially from the tuberculous arthritis 

 of the knee, where the disease often commences in the synovial membrane. 



In chronic hip disease the affected limb assumes an altered position, the cause of which it 

 is important to understand. In the early stage of a typical case the limb is flexed, abducted, 

 and rotated outward. In this position all the ligaments of the joint are relaxed the front of 

 the capsule by flexion; the outer band of the iliofemoral ligament by abduction; and the inner 

 band of this ligament and the back of the capsule by rotation outward. It is, therefore, the 

 position of the greatest ease. The condition is not quite obvious at first upon examining a 

 patient. If the patient is laid in the supine position, the affected limb will be found to be ex- 

 tended and parallel with the other. But it will be found that the pelvis is tilted downward on 

 the diseased side and the limb apparently longer than its fellow, and that the lumbar portion of 

 the vertebral column is arched forward (lordosix). If now the thigh is abducted and flexed, the tilt- 

 ing downward and the arching forward of the pelvis disappears. The condition is thus explained. 

 A limb which is flexed and abducted is obviously useless for progression, and, to overcome the 

 difficulty, the patient depresses the affected side of his pelvis in order to produce parallelism 

 of his limbs, and at the same time rotates his pelvis on its transverse horizontal axis, so as to 

 direct the limb downward instead of forward. In the latter stages of the disease the limb becomes 

 flexed, adducted, and inverted. The position probably depends upon the muscular action, 

 at all events as regards the adduction. The Adductor muscles are supplied by the obturator 

 nerve, which also largely supplies the joint. These muscles are therefore thrown into reflex 

 action by the irritation of the peripheral terminations of this nerve in the inflamed articulation. 

 Osteoarthritis is not uncommon in the hip-joint, and it is said to be more common in the male 

 than in the female, in whom the knee-joint is more frequently affected. It is a disease of middle 

 age or more advanced period of life. 



Congenital dislocation is more commonly met with in the hip-joint than in any other articula- 

 tion. The displacement usually takes place on to the dorsum ilii. It gives rise to extreme 

 lordosis, and a waddling gait is noticed as soon as the child commences to walk. 



Excision of the hip may be required for disease or for injury, especially for gunshot wound. 

 It may be performed either by an anterior or an external incision. The former one entails 

 less interference with important structures, especially muscles, than the posterior one, but 

 permits of less efficient drainage. In the operation in front the surgeon makes an incision 

 three or four inches in length, starting immediately below and external to the anterior superior 

 spinous process of the ilium, downward and inward between the Sartorius and Tensor fasciae 

 femoris, to the neck of the bone, dividing the capsule at its upper part. A narrow-bladed saw 

 now divides the neck of the femur, and the head of the bone is extracted with sequestrum forceps. 

 All diseased tissue is carefully removed with a sharp spoon or scissors, and the cavity thoroughly 

 flushed with a hot aseptic fluid. 



The external method consists in making an incision three or four inches long, commencing 

 midway between the top of the great trochanter and the anterior superior spine, and ending 

 over the shaft, just below the trochanter. The muscles are detached from the great trochanter, 

 and the capsule opened freely. The head and neck are freed from the soft parts and the bone 

 sawed through just below the top of the trochanter with a narrow saw. The head of the bone is 

 then levered out of the acetabulum. In both operations, if the acetabulum is eroded, it must be 

 freely gouged. 



