Common names or abbreviations:
closure of the distal ulnar physis
closure of the ulna
Description or definition:
dog’s forelimb from the elbow to the wrist is comprised of two bones
called the radius and the ulna. Distal is a directional
term used to mean the farthest from the body. The
physis is an area of cartilage and bone cell production (a growth
plate). If the ulnar growth plate closes too soon the ulna will
not grow to its proper length. The
radius, however, will continue to grow. This uneven growth can
force the radius to “bow.” The condition is sometimes referred
to as radius curvus or angular
limb deformity. Even in
less severe forms of the condition where deformity of the forelimb is
not apparent, failure of the radius and the ulna to grow at the same
rate produces joint
in the elbows, which can lead to elbow dysplasia.
For futher information see the separate GTF listing for elbow
closure of the ulna can be the result of an injury to the lower growth
plate of the ulna. However, in large breed dogs the condition can
also be caused by abnormal cartilage turnover. This results in
retained cartilage in the distal ulnar physis that can be seen
radiographically (with an x-ray). The condition may be associated
with osteochondrosis and may appear in conjunction with osteochondritis
dessicans. For further information see the separate entry
for osteochondrosis in the GTF library.
addition to injury, over-nutrition (excess calcium, calories,
supplementation or a puppy that is overweight) is speculated to play a
role in onset and progression of the disease in dogs that are
genetically predisposed to the condition.
some cases, the abnormal curvature of the forelimb may be visible to the
naked eye. In other cases the growth disparity between the radius
and the ulna does not result in visible deformity. Many dogs with
this condition bear weight on the affected limb but experience
intermittent lameness. The lameness can be caused by the rotation of
the limb which forces the dog to walk on the sides of its foot.
Sometimes, because this area is not padded, ulcers form on the sides of
the paw. Lameness and pain can also be caused by elbow subluxation
(joint looseness) or the onset of arthritis. In severe cases the
forelimb may actually become flaccid due to lack of stability at the
definitive diagnosis of premature closure of the ulna, radius curvus, or
angular limb deformity, requires X-ray, CAT scan, or MRI.
of this condition often involves surgery. If the condition has been
diagnosed when the puppy is young and still possesses a significant amount of
growth potential, a surgical technique is used that relieves the restraining
effect of the ulna and allows continued growth of the radius. This
procedure allows the growing limb to elongate in an almost normal manner.
In dogs that are more mature, there are other forms of surgery that can be
done to correct bone length and curvature and restore congruency to the elbow.
If the condition is discovered before degenerative changes in the joints are
observed, a corrective osteotomy (cutting the bones and straightening them) is
sometimes done to provide the dog with better joint function and decrease the
likelihood of degeneration of the wrist and elbow joints. However,
post-operative surgical care and recovery is difficult and lengthy for both
the dog and owner. If the condition has progressed to the point of elbow
subluxation (joint looseness) or luxation (looseness to the point of
dislocation), reconstructive surgery may not be effective in managing this
more information about this condition, or if your dog is experiencing
lameness, consult your veterinarian for advice.
Links to sites about this disease:
This summary provided by:
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All rights reserved. Revised: January 2008
The information on this website was written by ISSR breeders and other
concerned individuals, however we are are NOT veterinarians. This
information is being provided as a general overview, from information we
were able to find about each disease through our own research. These
summaries are not intended to be relied upon as medical or veterinary
advice, nor do we consider ourselves experts in the veterinary field or in
any of these conditions. While we do our best to provide the most up to
date information, new research is constantly being done on these diseases.
We recommend that you do further study and talk to your veterinarian on
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posted here is the most current information available. This site was
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