Objective—To evaluate the temporal pattern of
prostaglandin (PG) E2 concentrations in synovial fluid
after transection of the cranial cruciate ligament
(CCL) in dogs and to correlate PGE2 concentrations
with ground reaction forces and subjective clinical
variables for lameness or pain.
Animals—19 purpose-bred adult male Walker
Procedure—Force plate measurements, subjective
clinical analysis of pain or lameness, and samples of
synovial fluid were obtained before (baseline) and at
various time points after arthroscopic transection of
the right CCL. Concentrations of PGE2 were measured
in synovial fluid samples, and the PGE2 concentrations
were correlated with ground reaction
forces and clinical variables.
Results—The PGE2 concentration increased significantly
above the baseline value throughout the entire
study, peaking 14 days after transection. Peak vertical
force and vertical impulse significantly decreased by
day 14 after transection, followed by an increase over
time without returning to baseline values. All clinical
variables (eg, lameness, degree of weight bearing,
joint extension, cumulative pain score, effusion score,
and total protein content of synovial fluid, except for
WBC count in synovial fluid) increased significantly
above baseline values. Significant negative correlations
were detected between PGE2 concentrations
and peak vertical force (r, –0.5720) and vertical
impulse (r, –0.4618), and significant positive correlations
were detected between PGE2 concentrations
and the subjective lameness score (r, 0.5016) and
effusion score (r, 0.6817).
Conclusions and Clinical Relevance—Assessment
of the acute inflammatory process by measurement
of PGE2 concentrations in synovial fluid may be correlated
with the amount of pain or lameness in dogs.
(Am J Vet Res 2004;65:1269–1275)
Objective—To determine whether decreases in peak
vertical force of the hind limb after transection of the
cranial cruciate ligament (CrCL) would be indicative of
medial meniscal damage in dogs.
Animals—39 purpose-bred adult male Walker
Procedure—The right CrCL was transected arthroscopically.
Force plate measurements of the right
hind limb were made prior to and 2, 4, 10, and 18
weeks after transection of the CrCL. Only dogs with
≥ 10% decreases in peak vertical force after week 2
were considered to have potential meniscal damage.
Dogs that did not have ≥ 10% decreases in peak vertical
force at any time point after week 2 were
assigned to group 1. Group 2 dogs had ≥ 10%
decreases in peak vertical force from weeks 2 to 4
only. Group 3 and 4 dogs had ≥ 10% decreases in
peak vertical force from weeks 4 to 10 only or from
weeks 10 to 18 only, respectively. Damage to menisci
and articular cartilage was graded at week 18, and
grades for groups 2 to 4 were compared with those
of group 1.
Results—The percentage change in peak vertical
force and impulse area was significantly different in
groups 2 (n = 4), 3 (4), and 4 (4) at the end of each
measurement period (weeks 4, 10, and 18, respectively)
than in group 1 (27). The meniscal grade for
groups 2 to 4 was significantly higher than for group
1. A ≥ 10% decrease in peak vertical force had sensitivity
of 52% and accuracy of 72% for identifying
dogs with moderate to severe medial meniscal damage.
Conclusions and Clinical Relevance—In dogs with
transected or ruptured CrCLs, force plate analysis can
detect acute exacerbation of lameness, which may be
the result of secondary meniscal damage, and provide
an objective noninvasive technique that delineates
the temporal pattern of medial meniscal injury.
( Am J Vet Res 2005;66:156–163)
Objective—To develop an antibody that specifically
recognizes collagenase-cleaved type-II collagen in
equine articular cartilage.
Sample Population—Cartilage specimens from
horses euthanatized for problems unrelated to the
Procedure—A peptide was synthesized representing
the carboxy- (C-) terminus (neoepitope) of the equine
type-II collagen fragment created by mammalian collagenases.
This peptide was used to produce a polyclonal
antibody, characterized by western analysis for
reactivity to native and collagenase-cleaved equine
collagens. The antibody was evaluated as an antineoepitope
antibody by ELISA, using peptides ± an
amino acid at the C-terminus of the immunizing peptide.
Collagen cleavage was assayed from equine
articular cartilage cultured with interleukin-1 (IL-1), ± a
synthetic MMP inhibitor, BAY 12-9566. Cartilage
specimens from osteoarthritic and nonarthritic joints
were compared for antibody staining.
Results—An antibody, 234CEQ, recognized only collagenase-
generated 3/4-length fragments of equine
type-II collagen. This was a true antineoepitope antibody,
as altering the C-terminus of the immunizing
peptide significantly decreased competition for binding
in an inhibition ELISA. The IL-1-induced release of
type-II collagen fragments from articular cartilage was
prevented with the MMP inhibitor. Cartilage from an
osteoarthritic joint of a horse had increased staining
with the 234CEQ antibody, compared with normal
Conclusions and Clinical Relevance—We generated
an antineoepitope antibody recognizing collagenase-
cleaved type-II collagen of horses. This antibody
detects increases in type-II collagen cleavage in diseased
equine articular cartilage. The 234CEQ antibody
has the potential to aid in the early diagnosis of
arthritis and to monitor treatment responses. (Am J
Vet Res 2001;62:1031–1039)
Objective—To determine whether serum concentrations
of biomarkers of skeletal metabolism can,
in conjunction with radiographic evaluation, indicate
severity of osteochondrosis in developing
Animals—43 Dutch Warmblood foals with varying
severity of osteochondrosis.
Procedure—24 foals were monitored for 5 months
and 19 foals were monitored for 11 months. Monthly
radiographs of femoropatellar-femorotibial and tibiotarsal
joints were graded for osteochondral abnormalities.
Serial blood samples were assayed for 8 cartilage
and bone biomarkers. At the end of the monitoring
period, foals were examined for macroscopic
Results—Temporal relationships were evident
between certain serum biomarkers and osteochondrosis
severity in foals during their first year.
Biomarkers of collagen degradation (collagenasegenerated
neoepitopes of type-II collagen fragments,
type-I and -II collagen fragments [COL2-3/4Cshort],
and cross-linked telopeptide fragments
of type-I collagen) and bone mineralization (osteocalcin)
were positive indicators of osteochondrosis
severity at 5 months of age. In foals with lesions at
11 months of age, osteochondrosis severity correlated
negatively with COL2-3/4Cshort and osteocalcin
and positively with C-propeptide of type-II procollagen
(CPII), a collagen synthesis marker.
Radiographic grading of osteochondrosis lesions
significantly correlated with macroscopic osteochondrosis
severity score at both ages and was
strongest when combined with osteocalcin at 5
months and CPII at 11 months.
Conclusions and Clinical Relevance—The ability of
serum biomarkers to indicate osteochondrosis severity
appears to depend on stage of disease and is
strengthened with radiography. In older foals with
more permanent lesions, osteochondrosis severity is
significantly related to biomarker concentrations of
decreased bone formation and increased cartilage synthesis.
(Am J Vet Res 2004;65:143–150)
Objectives—To determine concentrations of matrix
metalloproteinase (MMP)-2 and -9 in synovial fluid;
and mRNA expression of MMP-1, -13, and -3; interleukin[
IL]-1α and β; and tumor necrosis factor(TNF)-α
in synovial membrane and articular cartilage from
horses with naturally occurring joint disease.
Sample Population—Synovial fluid (n = 76), synovial
membrane (59), and articular cartilage (45) from 5 clinically
normal horses and 55 horses with joint disease
categorized as traumatic (acute [AT] or chronic [CT]),
osteochondritis dissecans (OCD), or septic (S).
Procedure—Synovial fluid gelatinase concentrations
were analyzed, using zymography. Synovial membrane
and articular cartilage mRNA expression for
MMP-1, -3, and -13, IL-1α and β, TNF-α, type-II collagen,
and aggrecan were analyzed, using quantitative
reverse transcriptase-polymerase chain reaction.
Results—Synovial fluid pro-MMP-2 concentration
was significantly higher in diseased joints than normal
joints. Septic joints had significantly higher concentrations
of pro and active MMP-9. Stromelysin-1 was
expressed in ≥ 80% of synovial membrane and articular
cartilage samples and was strongly influenced by
age. Collagenases were rarely expressed, with MMP-
13 expressed only in diseased joints. Interleukin-1β
expression was significantly higher in all OCD samples
and was influenced by age. Tumor necrosis factor-
α expression was significantly higher in cartilage
from joints with AT and OCD. There was no correlation
between MMP or cytokines and type-II collagen
or aggrecan expression.
Conclusions and Clinical Relevance—Matrix metalloproteinase-
2 and -3 are abundant in naturally occurring
joint disease and normal joints. Interleukin-1β and
TNF-α may be important in the pathogenesis of OCD.
Age affects MMP and IL-1β concentrations. (Am J Vet