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Risk Prediction of Cruciate

Ligament Rupture using Stifle

Diagnostic Imaging

Peter Muir

Introduction

Cruciate ligament rupture (CR) is a common
condition and is generally evaluated by phys-
ical examination. Over time, understanding of
the disease mechanism has increased. CR is now
recognized as a complex trait with genetic and
environmental components that contribute to
the risk of disease. As arthroscopy has been
used more widely for clinical evaluation and
surgical treatment during the past 15 years, it
has now been established that the pathogene-
sis of CR is characterized by the development
of subtle matrix damage, particularly in the cra-
nial cruciate ligament (CrCL), and an associ-
ated inflammatory response within the stifle
joint (Bennettet al. 1988; Bleedornet al. 2011).
Over time, progressive fiber tearing in the cru-
ciate ligament complex, and the CrCL in partic-
ular, over a period of weeks to potentially many
months; leads to the development of an unsta-
ble stifle and complete CR (Muiret al. 2011).
As the disease becomes chronic, development
of bilateral CR is common (Muiret al. 2011).
Clinical diagnosis is centered around physi-
cal examination of the stifle. However, CR can
sometimes be difficult to diagnose by the clas-
sical tests of clinical cranial drawer and cra-
nial tibial thrust. This is particularly true in the

early phase of the disease, when physical exam-

ination signs may be subtle, or in the chronic

phase of the disease when stifle instability may

be influenced by factors such as osteoarthritis

and periarticular fibrosis.

In dogs with stifle clinical signs suggestive

of CR, but no cranial drawer or cranial tibial

thrust, incipient CR should be suspected and

confirmed by further investigation. Dogs with

partial CR have a stable stifle (Grade I sprain).

Clinically, a soft stop to the cranial drawer test

may be identified in some dogs, suggesting

very mild cranial tibial translation (Grade II

sprain). Diagnostic imaging, particularly radio-

graphy, can be very useful to support the

diagnosis of CR, particularly in the early phase

of the disease. Recent studies have suggested

that diagnostic imaging is predictive of disease

progression (e.g., Chuanget al. 2014; Fuller

et al. 2014). This knowledge is important as it

enables refinement in patient diagnosis and

management through inference from diagnostic

imaging.

Radiography

The knowledge that subsequent contralateral

rupture is a common event in dogs with

Advances in the Canine Cranial Cruciate Ligament, Second Edition. Edited by Peter Muir. © 2018 ACVS Foundation.
This Work is a co-publication between the American College of Veterinary Surgeons Foundation and Wiley-Blackwell.

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