Section III
Clinical Features
Introduction
Over the past 25 years, veterinarians have
become increasingly aware that it is difficult
to relate the typical clinical features of cruciate
ligament rupture (CR) in dogs with the concept
that stifle osteoarthritis (OA) is simply a conse-
quence of ligament rupture and stifle instability.
Moderate to severe OA is often found at initial
presentation in dogs with CR. Advances in
diagnostic imaging, including the develop-
ment of methods for stress radiography of the
stifle, have helped to more thoroughly deter-
mine the extent of cranial cruciate ligament
fiber rupture during patient evaluation. It is
important to relate any knowledge of ligament
biomechanics to assessment of the cruciate
ligaments clinically in dogs with stifle OA. By
definition, unstable joints have experienced
complete ligament rupture. Since publication
of the First Edition of this book, several studies
have shown that radiographic changes in
partial CR stifles are quite predictive of risk for
complete CR. Collectively, these studies have
also defined a clinical model for the evaluation
of disease-modifying therapy for the early
phase of the disease. Recent research findings
have shed new light on which components of
stifle pathology in affected dogs contribute to
joint pain and lameness. This section provides
a detailed discussion of the clinical features
of CR.107