Page 128 - Canine Lameness

100 7 Arthrocentesis Technique

(B)

(A) (C)

Figure 7.2 Elbow: (A) aspirate the elbow joint by inserting the needle in a straight medio‐lateral direction
at a location distal and caudal to the medial epicondyle (which can easily be palpated); (B) to identify the
joint space location, imagine an equidistant triangle with the medial epicondyle (blue dot) and the caudal
aspect of the epicondylar ridge (orange dot) as the two palpable landmarks, whereby the tip of the triangle
then identifies the location of the arthrocentesis point (green dot); (C) for caudal aspiration, the needle is
inserted in a distomedial direction along the long axis of the ulna.

Video 7.2:

Procedural details for aspiration of the elbow joint.

For caudal aspiration (Figure 7.2C), the joint is held in a flexed or neutral position and the needle
is inserted alongside the olecranon and angled cranially. The needle is placed at the proximal level
of the olecranon, medial to the lateral epicondyle (i.e. between the lateral epicondylar crest and
anconeal process), and inserted in a distomedial direction along the long axis of the ulna.

7.6.3 Shoulder
The shoulder joint is most frequently aspirated laterally in an area below the acromion but can also
be aspirated from a cranial and caudal location. Regardless of aspiration location, the patient
should be placed in lateral recumbency with the affected shoulder up. It sometimes is helpful to
distend the joint by pulling the distal limb away from the body; however, a neutral position typically
provides good access.
For lateral aspiration (Figure 7.3A and Video 7.3), the needle should be inserted just below the
acromion process in most dogs. In larger dogs, placement may be slightly caudal to the acromion
process. The needle should be directed in a straight mediolateral direction, in a manner that is
perpendicular to the skin. If the joint is not penetrated, a slightly more distoproximal angle should
be attempted. Clinicians should be aware that acromion anatomy may differ in some dogs affecting
its shape and position and making joint aspiration challenging. Radiographs of the joint and evalu-