Protective effects of intermittent hydrostatic pressure on osteoarthritic chondrocytes activated by bacterial endotoxin in vitro

Abstract

The role of continuous passive motion (CPM) in the management of septic arthritis and inflammatory arthritis remains of interest. CPM produces cyclic variations in intraarticular pressure that facilitates transport of fluid, nutrients, and solutes within and/ or across the joint and stimulates chondrocyte metabolism. However, the precise mechanisms mediating the responses of chondrocytes to joint motion remain unclear. This study tested the hypothesis that dynamic mechanical loading counteracts effects of bacterial lipopolysaccharide (LPS), an inflammatory mediator, on chondrocyte metabolism. Intermittent hydrostatic pressure (IHP) (10 MPa for 4 h) was applied to human chondrocytes pretreated with LPS (1 pg/ml for 18 11). LPS activation of chondrocytes decreased mRNA signal levels of type I1 collagen by 67% and aggrecan by 56% and increased nitric oxide by 3.1-fold, monocyte chemotactic protein-1 mRNA signal levels by 6.S-fold, and matrix metalloproteinase-2 mRNA signal levels by 1 .Hold. Application of IHP to LPS-activated chondrocytes decreased nitric oxide synthase mRNA signal levels and nitric oxide levels in the culture medium. Exposure of LPS-activated chondrocytes to IHP upregulated type I1 collagen and aggrecan mRNA signal levels by 1.7-fold, relative to chondrocytes activated by LPS and maintained without loading. In addition, application of IHP decreased the upregulation in signal levels of monocyte chemotactic factor-1 and matrix metalloproteinase-2 following LPS activation by 45% and 1 S'%, respectively. These data show that mechanical loading counteract effects of inflammatory agents, such as bacterial LPS, and suggest that postinfection sequelae are influenced by the presence or absence of joint loading. lntroduction Septic arthritis remains a potentially destructive disorder of synovial joints and often exhibits residual joint destruction [22,33]. In spite of prompt diagnosis and treatment, up to 50% of glycosaminoglycan and 37% of collagen may be lost from the cartilage matrix in infected joints [22,26,29,33]. Adjunctive treatments to ameliorate postinfectious sequelae such as nonsteroidal anti-inflammatory drugs or inhibitors of reactive oxygen species only partially lessen release of factors involved in joint tissue breakdown [15,28,29].

Effect of passive motion on articular cartilage in rat osteoarthritis

“…Callus is similar to hyaline cartilage in morphology. A previous study demonstrated that joint movement can generate periodical pressure change in the joint, favorable to the in-joint exchange of nutrients and liquid via the synovial hole, which stimulates chondrocyte metabolism and promotes the synthesis of cartilage matrix protein and internal tissue reconstruction (10). …”

Septic Arthritis in Dogs: A Retrospective Study of 20 Cases (2000-2002)

“…Over the past decades, methicillin resistance in S. aureus and Group B Streptococcus infection have become an increasing problem and vancomycin, azithromycin remains the only effective antibiotic (Tissi et al 1995). Many recent reports were published on successful methods for treating septic arthritis such as gentamicin-impregnated polymethylmethacrylate beads (Brown and Bennett 1988), combination of antibiotics (cloxacillin) and free radical trap (α-phenyl-N-tert-butyl nitrone) which acts as anti-inflammatory and antioxidant (Sakiniene and Collins 2002), treatment with antibiotics and leptin (Hultgren and Tarkowski 2001), and continuous passive motion (CPM) (Lee et al 2003). We found that each clinical sign and radiographic finding detected in our patients such as mild fever, pain, joint swelling, degree of lameness were not specific to septic arthritis, even though their sensitivities were very high.…”

Endoscopic Surgery in the Management of Contamination and Infection of Joints, Tendon Sheaths, and Bursae

“…Benefits from early instigation of exercise, in the form of continuous passive motion, have been demonstrated in experimental models (Salter et al, 1981) and reported in clinical cases in man (Parisien & Shaffer, 1990;Perry et al, 1992). Dynamic loading counteracts effects of inflammatory mediators, such as bacterial lipopolysaccharide, on chondrocyte metabolism, and it is suggested that this may have contributed to successful management of articular infection (Lee et al, 2003). Whenever possible, the authors recommend walking exercise to commence immediately after surgery and a graduated, controlled exercise program follows in line with tissue compromise.…”

“…Evidence that systemically administered therapeutic doses of nonsteroidal antiinflammatory drugs suppress deleterious effects of intrasynovial inflammatory mediators is lacking (May & Lees, 1996). These drugs may partially lessen release of factors involved in joint tissue breakdown (Lee et al, 2003), but administration of nonsteroidal antiinflammatory drugs effectively obviates use of clinical parameters, particularly lameness, in determining response to treatment (Gaughan, 1994;McIlwraith, 1983). Current opinion in assessing potential benefits of postoperative administration of nonsteroidal antiinflammatory drugs is therefore divided.…”