Page 213 - Adams and Stashak's Lameness in Horses, 7th Edition

Examination for Lameness 179

while the horse is standing, but can be done with the limb
75
flexed. Injection of the elbow is more difficult than many
VetBooks.ir anesthetic is needed for diagnostic purposes. 48
other joints in the horse, and approximately 20–30 mL of

Lateral Approach
The landmark for the lateral approach is the lateral
collateral ligament that extends across the joint from the Lateral
lateral epicondyle of the humerus to the lateral tuberos­ humeral
ity of the radius. Both of these bony landmarks are eas­ epicondyle
ily palpated. The elbow joint can be entered either
cranial or caudal to the collateral ligament. The site for Lateral Lateral
injection is two‐thirds the distance distally measured tuberosity collateral
ligament
from the lateral epicondyle of the humerus to the lateral of radius
tuberosity of the radius (Figure 2.180). 34,75 A 1.5‐inch
(3.8‐cm), 20‐gauge needle is inserted at a 90° angle to
the skin just cranial or caudal to the lateral collateral
ligament to a depth of 1 inch. 34,48 If injected cranially, it Figure 2.181. Caudolateral approach to the elbow joint just is
is important to verify that the needle is within the joint caudal to the palpable humeral epicondyle in the anconeal notch
because periarticular anesthetic may desensitize the dis­ within the humeroulnar joint.
tal branches of the radial nerve, causing temporary
paralysis of the extensor carpi radialis and common
digital extensor muscles. This will cause the horse to be
unable to lock its carpus in extension. If injected cau­
dally, the needle may enter the bursa of the ulnaris later­
alis muscle, which is thought to communicate with the
58
elbow joint. However, communication between the
bursa and the elbow joint occurred in only 9 of 24
(37.5%) of the joints examined. To avoid the ulnaris
58
lateralis bursa, the needle may be inserted more caudally
in the elbow in a palpable depression formed by the cau­ Lateral
dal epicondyle of the humerus, the caudal proximal humeral
tuberosity of the radius, and the anconeal process epicondyle
(Figure 2.181). 75 Lateral
Lateral collateral
tuberosity ligament
Caudolateral Approach of radius
The caudolateral approach is an alternative to plac­
ing the needle directly caudal to the collateral ligament
using the lateral approach. The injection site is caudal to
the palpable humeral epicondyle in the anconeal notch Figure 2.182. The approach to the large caudal outpouching of
the elbow joint is 0.5 inches (1 cm) proximal to and one‐third of the
distance measured caudally from the supracondylar eminence to the
point of the olecranon. A 3.5‐inch (8.9‐cm), 18‐ to 20‐gauge spinal
needle is directed distomedially through the triceps musculature at a
45° angle to the long axis of the limb into the olecranon fossa.
within the humeroulnar joint. This palpable V‐shaped
depression is usually just below the triceps muscles and
6–8 cm cranio‐distal from the point of the olecranon
process. 2,3,75 A 1.5‐ to 3.5‐inch (3.8‐ to 8.8‐cm), 20‐
gauge needle is inserted at a 45° angle to the skin and
Lateral directed craniomedially (Figure 2.181).
humeral
epicondyle
Lateral Caudal Approach
Lateral collateral The large caudal joint pouch of the elbow can be
tuberosity ligament
of radius entered from a more proximal location (Figure 2.182).
The landmarks are the lateral supracondylar crest of the
distal humerus and the most proximal point of the
olecranon process. 34,48,58 The injection site is 0.5 inches
Figure 2.180. The lateral approach to the elbow joint can be (1 cm) proximal to and one‐third of the distance meas­
made either cranial or caudal to the collateral ligament. ured caudally from the supracondylar eminence to the