The Hip Joint. 317 



the encrusting cartilage, or in the neck, on the distal side 

 of the epiphyseal line. Senn quotes Heberern's statistics 

 to the effect that, the acetabulum alone was affected in 

 fifty and the femur alone in twenty-three out of eighty 

 cases of primary bone disease. Treves states, that exact 

 data with reference to the relative frequency of the ap- 

 pearance of the initial foci are wanting, although he says, 

 "It is generally believed to start most frequently in the 

 femur, next in the synovial membrane, and more rarely in 

 the acetabulum." The knowledge of the reflection of the 

 synovial membrane is of importance in connection with this 

 disease, since the relation of the synovial membrane to the 

 head and neck of the femur is such, that, surrounding 

 them as it does, disease in either of these situations may 

 readily involve this membrane, and this it generally does. 

 Rarely, however, the pathogenic process follows down the 

 neck to the great trochanter, and then appears on the sur- 

 face, or, on the other hand, it may spread along the Hga- 

 mentum teres to the acetabulum, and, penetrating the lat- 

 ter bone, appear as a pelvic abscess. In the latter instances, 

 the tubercular abscess may be outside the synovial sac, i.e., 

 may not involve this membrane at all. 



Symptoms. In the first stage of morbus coxae the 

 limb is, as a rule, flexed, everted and abducted. This 

 position is likely due to the attempt to lessen the pressure 

 on the inflamed synovial membrane, as explained above, 

 under synovitis. In the second stage the limb becomes 

 still more flexed, the abduction changes to adduction, and 

 the eversion to inversion. In the third or last stage ero- 

 sion or loss of substance of the bones occurs at their points 

 of contact, so that the head of the femur may be dislo- 

 cated, generally on to the dorsum of the ilium. By some, 

 the position of the limb in the first and second stages have 

 been ascribed to neuro-muscular causes, although Barwell, 



