Front Matter

Chapter 12 Disorders of the Canine Thoracic Limb: Diagnosis and Treatment 317

incongruity, and, in extreme cases, luxation of
the proximal ulna (Boudrieau, 2003).
Diagnosis of radius curvus is based on physi­
cal examination and radiographs (Figure 12.24).
Characterization and quantification of the
deformity can be made by comparing radio­
graphs or CT images of the affected and nonaf­
fected limbs (Crosse & Worth, 2010).
The decision to intervene surgically depends
on the patient’s functional mobility and degree
of elbow incongruity, which will lead to osteoar­
thritis despite surgery (Boudrieau, 2003; Crosse
& Worth, 2010). The surgical technique depends
on the age of the patient at the time of growth
arrest and surgeon preference (Boudrieau, 2003).
When closure of the distal ulnar physis is diag­
nosed prior to significant radial deformity, and
substantial growth of the limb remains, a distal
ulnar ostectomy can be performed to remove the
tethering effect of the ulna (Boudrieau, 2003).
After radial deformity has occurred, a dynamic

or static corrective ostectomy/osteotomy of the

radius can be performed along with ulnar ostec­

tomy (Boudrieau, 2003). If considerable length

discrepancy exists between the limbs, distraction

osteogenesis can be performed along with cor­

rection of the deformity.

Carpal, metacarpal, and digit injuries

Injuries of the manus (carpus, metacarpal

bones, phalanges, and sesamoid bones) are less

common than those of the shoulder or elbow in

performance dogs; however, they can be just as

challenging to diagnose and treat. The anatomy

of the manus is complex with fibrous, ligamen­

tous, and tendinous components that not only

act as shock absorbers for the thoracic limb dur­

ing weight bearing but also help to maintain

appropriate flexion and extension of the limb

throughout the gait cycle. Many of the mecha­

nisms of injury to the manus and the best

treatment options are poorly understood.

Furthermore, the scientific literature is based

largely on observational studies and in vitro

biomechanical studies.

Figure 12.23 Shih Tzu with radius curvus.

Figure 12.24 Radiographs of a dog with radius curvus.