Procedure—Joint casting was performed by placement
of colored polymethylmethacrylate in the elbow
joint cavity followed by loading in a materials testing
system at physiologic angle and load. Joint casting
was performed in unaltered specimens, after 10°
medial opening wedge osteotomy, and after lateral
sliding osteotomy of the proximal portion of the
humerus. Computer-aided analysis of photographs of
proximal radial and ulnar articular surfaces after each
casting procedure was performed.
Results—The lateral sliding humeral osteotomy and
10° medial opening wedge osteotomy significantly
altered joint surface contact regions of the canine
elbow joint. Osteotomies resulted in a reduction in
the size of the radial, ulnar, and combined radioulnar
contact areas. Both osteotomies also resulted in craniolateral
migration of the radial contact area and craniomedial
recession of the ulnar contact area. Although
the reduction in ulnar contact area with these treatments
is consistent with our hypotheses, the reduction
in radial contact area was not anticipated.
Conclusions and Clinical Relevance—Humeral
osteotomies alter joint surface contact areas of the
canine elbow joint in vitro. Humeral osteotomies may
decrease contact areas on the diseased region of the
joint in dogs with elbow dysplasia; however, the overall
decrease in joint surface contact area suggests
that these procedures may induce focal increases in
pressure that may cause iatrogenic cartilage damage
when applied in vivo. (Am J Vet Res 2003;64:506–511)
Objective—To determine the distribution of force
between the articular surfaces of the humerus and
radius and between the humerus and ulna in normal
Sample population—12 cadaveric canine right forelimbs.
Procedure—Transarticular force maps were created
by placing a tactile array pressure sensor into the
elbow joint cavity and loading cadaveric forelimbs in a
materials testing system. Mean joint forces were
determined at loads of 50, 100, 150, and 200 N.
Results—All tests produced 2 distinct areas of high
load that corresponded with the proximal articular surfaces
of the radius and ulna. Mean forces for the radial
proximal articular surface were slightly but significantly
greater than for the ulna, averaging 51% to
52% of total force for all applied loads.
Conclusions and Clinical Relevance—The proximal
articular surface of the ulna contributes substantially
to load transfer through the canine elbow joint.
Abnormalities, which increase this load, might contribute
to canine elbow joint dysplasia, specifically
fragmentation of the medial coronoid process and
osteochondritis dissecans of the medial aspect of the
humeral condyle. In the treatment of these conditions,
the normal force distribution within the canine
elbow joint should be taken into consideration. (Am J Vet Res 2005;66:132–135)
Objective—To compare activities of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and matrix
metalloproteinase (MMP)-3 and contents of sulfated
glycosaminoglycan (S-GAG) in joint fluid obtained
from dogs with hip dysplasia (HD) and clinically normal
dogs, evaluate correlations among these markers
in joint fluid obtained from dogs with HD, and evaluate
correlations between each marker and clinical and
Animals—26 dogs with HD (clinical group) and 43
clinically normal Beagles (control group).
Procedure—Joint fluid was aseptically collected from
the hip joints of all dogs. For each dog in the clinical
group, age, duration of lameness, radiographic
osteoarthritis (OA) score, and Norberg angle in each
affected joint were recorded. Activities of IL-1β, IL-6,
TNF-α, and MMP-3 and S-GAG contents were measured.
Values were compared between groups by use
of Mann-Whitney U tests, and the Spearman rank correlation
test was used to evaluate correlations among
markers and between each marker and clinical or
Results—Values of all markers were significantly
higher for the clinical group, compared with values for
the control group. There was a moderate positive correlation
between lameness duration and IL-6 activity
and a strong negative correlation between the
Norberg angle and IL-1β activity.
Conclusions and Clinical Relevance—Analysis of
our results indicated that there was a significant
increase in markers of OA in dogs with HD. Activities
of IL-1β and IL-6 in joint fluid of dogs with HD may be
influenced by the severity of laxity in the hip joint and
lameness duration, respectively. (Am J Vet Res
To investigate the effect of an excessive tibial plateau angle (TPA) and change in compressive load on tensile forces experienced by the cranial cruciate, medial collateral, and lateral collateral ligaments (CCL, MCL, and LCL, respectively) of canine stifle joints.
16 cadaveric stifle joints from 16 orthopedically normal Beagles.
Stifle joints were categorized into unchanged (mean TPA, 30.4°) and excessive (mean TPA before and after modification, 31.2° and 41.1°, respectively) TPA groups. The excessive TPA group underwent a TPA-increasing procedure (curvilinear osteotomy of the proximal aspect of the tibia) to achieve the desired TPA. A robotic system was used to apply a 30- and 60-N compressive load to specimens. The craniomedial band of the CCL, caudolateral band of the CCL, MCL, and LCL were sequentially transected; load application was repeated after each transection. Orthogonal force components were measured in situ. Forces on ligaments were calculated after repeated output force measurements as the contribution of each component was eliminated.
Increasing the compressive load increased tensile forces on the craniomedial and caudolateral bands of the CCL, but not on the MCL or LCL, in specimens of both groups. At the 60-N load, tensile force on the craniomedial band, but not other ligaments, was greater for the excessive TPA group than for the unchanged TPA group.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that stress on the CCL may increase when the compressive load increases. The TPA-increasing procedure resulted in increased tensile force on the CCL at a 60-N compressive load without affecting forces on the MCL or LCL.