Page 244 - Clinical Anatomy

ECA4 7/18/06 6:47 PM Page 229

The bones and joints of the lower limb 229

Fig. 168◊Dislocation of the hip. If the hip is forced into posterior dislocation while
adducted (a), there is no associated fracture of the posterior acetabular lip
(b). Dislocation in the abducted position (c) can only occur with a concomitant
acetabular fracture (d). (The inset figure indicates the plane of these diagrams.)

Reduction of a dislocated hip is quite simple providing that a deep anaes-
thetic is used to relax the surrounding muscles; the hip is flexed, rotated into
the neutral position and lifted back into the acetabulum. Occasionally,
forcible abduction of the hip will dislocate the hip forwards. Violent force
along the shaft (e.g. a fall from a height) may thrust the femoral head through
the floor of the acetabulum, producing a central dislocation of the hip.

The knee joint (Figs 169, 170)
The knee is a hinge joint made up of the articulations between the femoral
and tibial condyles and between the patella and the patellar surface of the
femur.