ABNORMAL CONDITIONS OF THE KNEE-JOINT. 
Fig. 8. 
i. | 
BY 
Femur displaced inwards. Patella anchylosed. 
ae 
" elongated and was directed backwards. The 
_ ctucial ligaments were also elongated, and 
_ instead of crossing each other were untwisted 
as it were and lay side by side. The carti- 
_ Tages were altogether removed, and when the 
_ femur was forcibly separated from the tibia, 
_ there were corresponding elevations and de- 
‘pressions which marked the several points of 
_ contact between the bones, in which a species 
‘of anchylosis had occurred. The body of the 
‘tibia was greatly enlarged and hypertrophied, 
‘and round perforations existed in its head, 
om which sequestra had been discharged. 
_ Af. Asnormat conpitrons OF THE KNEE- 
‘JOINT RESULTING FROM accrDENT.— Frac- 
| tures and dislocations are the principal acci- 
| dents to which the bones of the knee-joint are 
hal The muscular and tendinous fibres 
‘common to the rectus, crurceus, and vasti are 
Occasionally torn from the patella, and the 
higament of this bone is also sometimes rup- 
} tured. The proper ligaments, too, and other 
‘Structures of the knee-joint, suffer from sudden 
‘injuries, which we must here advert to as 
| briefly as we can. 
| _ Fractures of the shaft of the femur near to 
the knee-joint may be transverse or oblique, 
or one or both of the condyles may be broken 
off from this joint. 
_ 1. When a transverse fracture is situate 
| immediately above the condyles-of the femur, 
; 
} 
67 
Fig. 9. 
Displacement backwards of the superior extremity of 
the lower fragment. 
it is the inferior fragment which is displaced, 
its superior extremity being directed backwards 
towards the popliteal space (see fig. 9) ; the an- 
terior part of the condyles and trochlea have 
their aspect directed upwards, and form a 
swelling above the patella, giving to the joint 
a singular appearance. This direction back- 
wards of the superior extremity of the lower 
fragment is the result of the action of the 
gastrocnemii, the plantaris, and _popliteus 
muscles. 
2. Oblique fractures of the lower extremity of 
the femur near the knee-joint are more serious — 
and embarrassing than transverse fractures, not 
only on account of the immediate danger of 
the penetration of the skin by the upper frag- 
ment, and of the accident being thus rendered 
compound, but also on account of the great 
difficulty which is always experienced in main- 
taining the bones in apposition during the 
treatment of the case. 
Sir A. Cooper says the appearances presented 
by the usual oblique fracture of the lower ex- 
tremity of the femur are the following :—* The 
‘lower and broken extremity of the shaft of the 
femur projects, and forms a sharp point, which 
pierces the rectus muscle, just above the pa- 
tella, threatens to tear the skin, and sometimes 
F2 
