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 investigate effects of osteochondral injury on high-mobility group box chromosomal protein 1 (HMGB-1) concentrations in synovial fluid (SF) from Thoroughbreds and to compare these results with radiographic and arthroscopic scores of severity of joint injury.
Animals—40 clinically normal rested Thoroughbreds (group 1) and 45 Thoroughbreds with osteochondral injury as a result of racing.
Procedures—SF was obtained from the metacarpophalangeal (MCP) joints, metatarsophalangeal (MTP) joints, middle carpal joints, and radiocarpal joints. For group 2, radiographic and arthroscopic scores were determined. Concentrations of SF HMGB-1 were determined by use of an ELISA.
Results—SF HMGB-1 concentrations in osteochondral-injured MCP-MTP joints were significantly higher than in normal MCP-MTP joints. Similarly, SF HMGB-1 concentrations in osteochondral-injured carpal joints were significantly higher than in normal carpal joints. Radiographic and arthroscopic scores were not correlated with SF HMGB-1 concentrations. Synovial fluid HMGB-1 concentrations ≥ 11 ng/mL for MCP-MTP joints and ≥ 9 ng/mL for carpal joints discriminated osteochondral-injured joints from normal joints. Horses with HMGB-1 concentrations ≥ 11 ng/mL for MCP-MTP joints were twice as likely to have an osteochondral injury, and horses with HMGB-1 concentrations ≥ 9 ng/mL for carpal joints were 4 times as likely to have an osteochondral injury.
Conclusions and Clinical Relevance—Osteochondral injury was associated with a significant increase in SF HMGB-1 concentrations in MCP-MTP and carpal joints, compared with results for clinically normal Thoroughbreds. Analysis of SF HMGB-1 concentrations may be useful for evaluation of joint injury in horses.
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 determine the effects of horse age, osteochondral injury, and joint type on a synthesis biomarker and 3 degradative biomarkers of type II collagen in Thoroughbreds.
Animals—Healthy rested adult (3- to 12-year-old) Thoroughbreds (n = 19), yearling (1- to 2-year-old) Thoroughbreds (40), and Thoroughbred racehorses (2 to 7 years old) undergoing arthroscopic surgery for removal of osteochondral fragments that resulted from training or racing (41).
Procedures—Samples of blood and metacarpophalangeal, metatarsophalangeal, or carpal joint synovial fluid (SF) were collected from all horses. Commercially available assays were used to analyze SF and serum concentrations of type II collagen biomarkers of synthesis (carboxy propeptide of type II collagen [CPII]) and degradation (cross-linked C-telopeptide fragments of type II collagen [CTX II], neoepitope generated by collagenase cleavage of type I and II collagen [C1,2C], and neoepitope generated by collagenase cleavage of type II collagen [C2C]).
Results—Osteochondral injury affected concentrations of CPII, CTX II, C1,2C, and C2C in SF, serum, or both, compared with concentrations in healthy adult horses. Compared with adult horses, yearling horses had increased SF or serum concentrations of degradative biomarkers (CTX II, C1,2C, and C2C). Concentrations were higher in carpal than metacarpophalangeal or metatarsophalangeal joints for all biomarkers in osteochondral-injured horses. Variable differences in SF concentrations between joint types were detected in healthy adult and yearling horses.
Conclusions and Clinical Relevance—Horse age, osteochondral injury, and joint type all significantly affected type II collagen biomarker concentrations in SF and serum of Thoroughbreds.
Objective—To investigate the effects of exercise and osteochondral injury on concentrations of carboxy-terminal telopeptide fragments of type II collagen (CTX-II) in synovial fluid (SF) and serum of Thoroughbred racehorses and to compare findings with radiographic and arthroscopic scores of joint injury severity.
Animals—78 Thoroughbreds with (n = 38) and without (40) osteochondral injury.
Procedures—Serum and metacarpophalangeal or carpal joint SF samples were collected from noninjured horses before and at the end of 5 to 6 months of race training (pre- and postexercise samples, respectively) and from horses with osteochondral injury (1 joint assessed/horse). Synovial fluid and serum CTX-II concentrations were determined by use of an ELISA. Radiographic and arthroscopic scores of joint injury severity were determined for the injured horses.
Results—The CTX-II concentrations in SF and SF:serum CTX-II ratio were significantly higher for horses with joint injuries, compared with pre- and postexercise findings in noninjured horses. Serum CTX-II concentrations in postexercise and injured-horse samples were significantly lower than values in pre-exercise samples. On the basis of serum and SF CTX-II concentrations and SF:serum CTX-II ratio, 64% to 93% of serum and SF samples were correctly classified into their appropriate group (pre-exercise, postexercise, or injured-joint samples). In horses with joint injuries, arthroscopic scores were positively correlated with radiographic scores, but neither score correlated with SF or serum CTX-II concentration.
Conclusions and Clinical Relevance—Results suggested that serum and SF CTX-II concentrations and SF:serum CTX-II ratio may be used to detect cartilage degradation in horses with joint injury.
Objective—To determine whether stromal cell-derived factor-1 (SDF-1) concentrations in serum, plasma, and synovial fluid differed among untrained, race-trained, and osteochondral-injured Thoroughbred racehorses.
Animals—22 racehorses without osteochondral injury and 37 racehorses with osteochondral injury.
Procedures—Horses without osteochondral injury were examined before and after 5 to 6 months of race training. Horses with osteochondral injury were undergoing arthroscopic surgery for removal of osteochondral fragments from carpal or metacarpophalangeal or metatarsophalangeal joints (fetlock joints). Serum, plasma, and fetlock or carpal synovial fluid samples were obtained and analyzed for SDF-1 concentration by use of an ELISA.
Results—In horses with fetlock or carpal joint injury, mean synovial fluid SDF-1 concentrations were significantly higher, serum SDF-1 concentrations were significantly lower, and synovial fluid-to-serum SDF-1 ratios were significantly higher than in untrained and trained horses. Synovial fluid SDF-1 concentrations were not significantly different between trained and untrained horses. Plasma SDF-1 concentrations were not different among the 3 groups. Results obtained with serum, compared with synovial fluid and plasma, had better sensitivity for differentiating between osteochondral-injured horses and uninjured horses. In horses with fetlock joint osteochondral injury, serum SDF-1 concentrations were correlated with radiographic and arthroscopic inflammation scores, but not arthroscopic cartilage scores.
Conclusions and Clinical Relevance—Results suggested that serum SDF-1 concentrations were more sensitive than plasma and synovial fluid concentrations for detection of osteochondral injury in the fetlock or carpal joint of racehorses. Analysis of serum and synovial SDF-1 concentrations in horses with experimentally induced joint injury may help define the onset and progression of post-traumatic osteoarthritis and aid in the evaluation of anti-inflammatory treatments.
Objective—To evaluate effects of zoledronate on
markers of bone metabolism in dogs after transection
of the cranial cruciate ligament (CrCL).
Animals—21 adult dogs.
Procedure—Unilateral CrCL transection was performed
arthroscopically. Dogs were allocated to 3
groups (control group, low-dose zoledronate
[10 µg/kg, SC, q 90 d for 12 months], and high-dose
zoledronate [25 µg/kg, SC, q 90 d for 12 months]).
Serum osteocalcin (OC), serum bone-specific alkaline
phosphatase (BAP), and urine pyridinoline and
deoxypyridinoline concentrations were measured at
0, 1, 3, 6, 9, and 12 months after surgery. Bone mineral
density (BMD) was determined in the distal portion
of the femur and proximal portion of the tibia via
computed tomography at each time point. Data were
analyzed by a repeated-measures ANOVA.
Results—Zoledronate inhibited OC in the high-dose
group at 9 and 12 months and at 12 months in the low-dose
group, compared with the control group. High-dose
zoledronate decreased BAP concentrations 3 and 9
months after surgery. In the control group, BMD was
decreased in the femoral condyle and caudal tibial
plateau. Zoledronate prevented significant BMD decreases
starting 1 month after transection, compared with
control dogs. In the caudomedial aspect of the tibial
plateau, both zoledronate groups had significant increases
in BMD after 3 months, compared with control dogs.
Conclusions and Clinical Relevance—Zoledronate
may reduce subchondral bone loss and effect markers
of bone metabolism in dogs with experimentally
induced instability of the stifle joint and subsequent
development of osteoarthritis. (Am J Vet Res
Objective—To assess effects of zoledronic acid on biomarkers, radiographic scores, and gross articular cartilage changes in dogs with induced osteoarthritis.
Animals—21 purpose-bred hound-type dogs.
Procedures—The left stifle joint of each dog was examined arthroscopically to determine initial articular cartilage status, which was followed by cranial cruciate ligament (CrCL) transection to induce osteoarthritis. Dogs were assigned to 3 groups (control group, low dose [10 μg of zoledronic acid/kg], or high dose [25 μg of zoledronic acid/kg). Treatments were administered SC every 3 months for 1 year beginning the day after CrCL transection. Serum and synovial fluid samples and radiographs were obtained 0, 1, 3, 6, 9, and 12 months after transection. At 12 months, each joint was scored for cartilage defects. Serum and synovial fluid biomarkers of bone and cartilage turnover (bone-specific alkaline phosphatase, type I and II collagen, carboxy-propeptide of type II collagen, and chondroitin sulfate 846) were analyzed with ELISAs.
Results—The high-dose group had fewer total articular defects and lower severity scores in CrCL-transected stifle joints than did the control group. In addition, the high-dose group had significantly less change in collagenase cleavage of type I or II collagen in the synovial fluid at 1 and 3 months after CrCL transection than did the control group and also had greater changes in bone-specific alkaline phosphatase in synovial fluid at 3 months after CrCL transection than did the control group.
Conclusions and Clinical Relevance—Zoledronic acid had a chondroprotective effect in dogs with a transected CrCL.
Objective—To characterize lameness during training and compare exercise variables and financial returns among yearling Thoroughbreds that were bought for the purpose of resale for profit.
Animals—40 yearling Thoroughbreds.
Procedures—Horses purchased at yearling sales (summer 2004) were trained prior to resale at 2-year-olds in training sales (spring 2005). Horses were monitored daily for diagnosis and treatment of lameness during training. Selected variables, including sex, age, purchase price, lameness, distance (No. of furlongs) galloped during training, and financial returns, were compared among horses that had performance speeds (assessed at 2-year-olds in training sales) classified as fast, average, or slow.
Results—37 of 40 horses became lame during training, most commonly because of joint injury. Eighteen of the lame horses had hind limb injuries only; 5 horses had injuries in forelimbs and hind limbs. The frequency of new cases of lameness increased as the date of the 2-year-olds in training sales approached. At the sales, 4, 21, and 15 horses were classified as fast, average, or slow, respectively; median financial return was slightly (but significantly) different among horses classified as fast ($14,000), average ($0), or slow (–$8,000).
Conclusions and Clinical Relevance—Incidence of lameness during training in yearling horses purchased for the purpose of resale for profit was high. Lameness more commonly affected hind limbs than forelimbs and was attributable to joint injury in most horses. Financial returns differed between horses classified as fast and average or slow at the 2-year-olds in training sales.