Page 223 - Canine Lameness

195

14

Elbow Region

Felix Michael Duerr

Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA

14.1 Introduction and Common Differential Diagnoses

Pathology in the elbow region is probably the most frequent source of chronic thoracic limb lame-
ness in dogs. The elbow joint is a complex joint that is affected by many diseases. In general, elbow
arthritis is more common and manifests in more severe clinical symptoms when compared to ELBOW REGION
shoulder and carpal arthritis. In addition to the joint itself, soft tissue injuries of the region also
cause lameness. Therefore, definitively identifying the source of lameness within the elbow region
based on palpation can be very difficult and additional diagnostic tests are often necessary for
establishing a diagnosis. The most commonly employed tests include CT and arthroscopy for the
diagnosis of joint pathology. Figure 14.1 and Table 14.1 outline common differential diagnoses and
diagnostic steps for the elbow region.

14.2 Normal Anatomy and Arthritis

The elbow (or cubital) joint is a hinge joint (with the main motion being limited to the sagittal
plane, i.e. flexion and extension). The joint is formed by the radius, ulna, and humerus and divided
into the following joints (Figures 14.2):
Humeroradial joint, which is responsible for ~52% (Mason et al. 2005) of the weight-bearing
●
forces of the elbow joint.
Proximal radioulnar joint, which is responsible for ~48% (Mason et al. 2005) of the weight-bearing
●
forces of the elbow joint and allows for supination and pronation.
Humeroulnar joint, which is the responsible joint for restricting motion of the elbow to sagittal
●
plane motion.
The medial (i.e. trochlea) and lateral (i.e. capitulum) humeral condyles articulate with the ulna and
radial head, respectively (Figure 14.2). The trochlea is of greater size than the capitulum and sloped
more distally, which becomes relevant for the pathophysiology of condylar fractures and elbow luxa-
tions (i.e. lateral condylar fractures and luxations are more common). In some dogs, the sesamoid of

Canine Lameness, First Edition. Edited by Felix Michael Duerr.
© 2020 John Wiley & Sons, Inc. Published 2020 by John Wiley & Sons, Inc.
Companion website: www.wiley.com/go/duerr/lameness