» The Hip Joint
The stability of the hip joint owes much to the depth and extent of the acetabulum, which is considerably increased by a fibrocartilaginous rim embracing a large part of the femoral head (Fig.
24.1/4). The head is additionally secured against luxation by two ligaments. One, the ligament of the femoral head, is short and stout but is not peculiar in any important way. The other, the accessory ligament, is unique to the horse (and donkey) among domestic species. It begins as a detachment from the prepubic tendon and reaches the joint by following a shallow groove on the ventral aspect of the pubis and passes through the acetabular notch to insert on the head (see Fig. 21.3/5'). The two ligaments together place severe restrictions on rotation and abduction of the joint. In practice, movement is almost confined to flexion and extension in a sagittal plane, which is a much more limited range than the geometry of the articular surfaces suggests. The stability of the joint is partly dependent on the tension exerted by the weight of the abdominal viscera pulling on the prepubic tendon and thus on the accessory ligament (p. 536).Although the joint capsule is quite capacious, its deep location makes it relatively difficult to access. To puncture, the needle is introduced between the two parts of the greater trochanter and is directed horizontally and craniomedially, at an angle of about 40 degrees to the transverse plane.
More on the topic » The Hip Joint:
-
Veterinarian -