Objective—To examine longitudinal changes in serum and synovial fluid concentrations of keratan sulfate (KS) and hyaluronan (HA) after cranial cruciate ligament (CCL) transection in dogs.
Animals—12 clinically normal adult mixed-breed dogs.
Procedure—Following CCL transection in the right stifle joint, KS and HA concentrations were determined in serum and neat (undiluted) synovial fluid prior to and 1, 2, 3, and 12 months after surgery. Postsurgical dilution of synovial fluid was corrected by use of urea as a passive marker.
Results—Synovial fluid KS and HA concentrations decreased at 1, 2, and 3 months after surgery in operated stifle joints, compared with baseline values. Synovial fluid KS concentration decreased in unoperated stifle joints at 1 month. A decrease in synovial fluid KS concentration was found in operated stifle joints, compared with unoperated stifle joints, at 2 and 3 months, and a decrease in synovial fluid HA concentrations was also found in operated stifle joints, compared with unoperated stifle joints, at 1, 2, and 3 months. Serum KS concentrations increased from baseline values at 3 months after surgery. Hyaluronan concentrations in operated stifle joints were lower than baseline values at 1, 2, and 3 months. Urea-adjusted synovial fluid concentrations revealed that dilution did not account for the decline in biomarker concentrations.
Conclusions and Clinical Relevance—The initial decrease and subsequent increase in synovial fluid concentrations of HA and KS may be caused by an acute inflammatory response to surgical intervention that negatively affects cartilage metabolism or an increase in production of immature proteoglycans.
Objective—To examine the ability of preemptive administration of a proprietary neurokinin-1 (NK1) receptor antagonist to attenuate limb dysfunction associated with monosodium urate–induced synovitis in the stifle joints of dogs.
Animals—16 clinically normal adult mixed-breed dogs (8 males and 8 females).
Procedures—A crossover study was conducted in 2 phases. Dogs were assigned to 2 groups (8 dogs/group) and orally administered an NK1 receptor antagonist (3 mg/kg) or a control substance once daily for 4 days. Synovitis was then induced in the left stifle joint by intra-articular injection of monosodium urate. Investigators were not aware of treatment group assignments. Dogs were evaluated by use of subjective lameness scores during standing, walking, and trotting and by use of ground reaction force data 3, 6, 9, 12, and 24 hours after urate injection. After a 21-day washout period, the experiment was repeated with each dog administered the other treatment and injected with monosodium urate in the contralateral stifle joint.
Results—No significant differences were detected between the NK1 receptor antagonist and control treatments with regard to peak vertical force, vertical impulse area, or subjective evaluations of lameness during standing, walking, or trotting, except during walking 24 hours after monosodium urate injection.
Conclusions and Clinical Relevance—Preemptive administration of an NK1 receptor antagonist failed to significantly improve subjective or objective outcome measures in dogs with monosodium urate–induced synovitis.
Objective—To assess effects of in vitro meloxicam exposure on metabolism in articular chondrocytes from dogs with naturally occurring osteoarthritis
Sample—Femoral head cartilage from 16 dogs undergoing total hip replacement
Procedures—Articular cartilage samples were obtained. Tissue sulfated glycosaminoglycan (SGAG), collagen, and DNA concentrations were measured. Collagen, SGAG, chondroitin sulfate 846, NO, prostaglandin E2 (PGE2), and matrix metalloproteinase (MMP)-2, MMP-3, MMP-9, and MMP-13 concentrations in culture medium were analyzed. Aggrecan, collagen II, MMP-2, MMP-3, MMP-9, MMP-13, ADAM metallopeptidase with thrombospondin type 1 motif (ADAMTS)-4, ADAMTS-5, tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-2, TIMP-3, interleukin-1β, tumor necrosis factor-α, cyclooxygenase-1, cyclooxygenase-2, and nducible nitric oxide synthase gene expression were evaluated. Comparisons between tissues cultured without (control) and with meloxicam at concentrations of 0.3, 3.0, and 30.0 μg/mL for up to 30 days were performed by means of repeated-measures analysis.
Results—Meloxicam had no effect on chondrocyte SGAG, collagen, or DNA concentrations. Expression of ADAMTS-5 was significantly decreased in all groups on all days, compared with the day 0 value. On day 3, culture medium PGE2 concentrations were significantly lower in all meloxicam-treated groups, compared with values for controls, and values remained low. Culture medium MMP-3 concentrations were significantly lower on day 30 than on day 3 in all meloxicam-treated groups.
Conclusions and Clinical Relevance—Results suggested that in vitro meloxicam treatment of osteoarthritic canine cartilage for up to 30 days did not induce matrix degradation or stimulate MMP production. Meloxicam lowered PGE2 release from this tissue, and effects on tissue chondrocyte content and matrix composition were neutral.
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.