Articular damage

Most clinicians favor the stepdown approach to slow or reverse the early articular damage as soon as possible. 

Like all fluoroquinolone antibacterials, ciprofloxacin (1) causes articular damage in juvenile animals. Consequently, it is not recommended for children or pregnant women. Nonetheless, more data have emerged for its pediatnc applications thanks to its high antibacterial effectiveness and convenience in oral administration. 

It is important to emphasize the difference between the previously mentioned acute oedema tests in the rat-foot, and chronic chemically-induced arthritis , an example of which is formalin arthritis . In this type of experiment, first described by Selye , two or more injections of formalin are made into the subplantar area of the foot. After the acute oedema has subsided, the surrounding skin remains hyperaemic and after a few days the peri-articular connective tissue begins to proliferate, especially in the region of the ankle joint. Other irritants, such as mustard and kaolin , have also been used to produce such chronic articular damage. 

A large number of reports have demonstrated increased joint tissue levels of MMP-1 and MMP-3 in rheumatoid joints and joint fluid, (04) leading to the implication that MMPs contribute to joint injury. MMPs have also been implicated in other types of arthritis. A more important role for aggrecanase, a member of the ADAM family of metalloproteinases, in articular damage has been proposed (A5). 

Locai injections Intra-articular injection may produce systemic and local effects. A marked increase in pain accompanied by local swelling, further restriction of joint motion, fever, and malaise is suggestive of septic arthritis. Frequent intra-articular injection may damage joint tissues. 

DNA injection directly into mouse diaphragm has also resulted in luciferase expression and there appeared to be no damage to the diaphragm due to the DNA injections (Davis and Jasmin, 1993). In a related study, /3-galactosidasc ( /3-gal)-encoding pDNA injected into the articular space of rabbit knee joints resulted in /3-gal expression in the joints (Yovandich etal., 1995). In the same study, chloramphenicol acetyltransferase (CAT) encoding pDNA injected into rat knee joints also led to reporter gene expression, with peak expression 48 hours after injection and with no detectable activity 15 days later. 

Correct choice = E. Only tetracycline is deposited in bone and thus is contraindicated in children under age 8. Ciprofloxacin damages developing articular cartilage in young experimental animals, which is why it is contraindicated In children under 18 years of age. All the other statements pertain to both antibiotics. 

Fig. 1. Schematic illustration of the major components of articular cartilage connective tissue, showing some of the known targets (asterisks) of ROI-mediated damage (cleavage, fragmentation, cross-...

The evidence for a pathophysiological role of oxidants in connective tissue injury is not confined to oxidative damage to the component macromolecules. Since there is reasonable indirect evidence that ROIs are released into the articular joint space during inflammation, it is likely that ROIs released from inflammatory cells which are adherent to or in contact with the articular cartilage surface might also damage the cellular components of articular cartilage. 

Intra-articular injection of corticosteroid (triamcinolone, hydrocortisone, prednisolone or dex-amethasone) is very effective when one joint is more affected than others. Benefit from one injection may last many weeks. Aseptic precautions must be extreme, for any introduced infection may spread dramatically. Too frequent resort to corticosteroid injection may actually promote joint damage by removing the protective limitation conferred by pain such injections in a single joint would not normally exceed three per year. Other aspects of the treatment of inflammatory arthritis are important but are outside the scope of this book. 

Even very dilute solutions of chlorhexidine can cause marked chondrolysis of articular cartilage, leading to severe permanent damage of the knee (36). 

These cases of chondrolysis did not result from accidental use of relatively concentrated solutions of chlorhexidine, but from the use of a very low concentration, 0.02%, which is widely used as an irrigation solution during surgical procedures. Chlorhexidine has a damaging effect on the articular cartilage of the knee, and should not be used, even in low concentrations, to irrigate exposed articular cartilage. 

Activation of the synovial membrane has the potential to damage articular cartilage by the liberation of inflammatory mediators and destructive enzymes and the recruitment of inflammatory cells into the joint (Goldberg Toole 1987, Lukoschek et al 1990). Common treatments for... 

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