INFLUENCE OF VARIOUS IRRIGATION FLUIDS ON ARTICULAR-CARTILAGE

When bovine articular cartilage was incubated in Ringer's solution, co nsiderable amounts of proteoglycan were washed out of the cartilage. T hus, 4% of the proteoglycan was lost into the medium during an incubat ion of 4 hours. Subsequently, it was found that ionic aqueous media li ke saline or Ringer's solution extracted much more proteoglycan than i on-free media like distilled water or a variety of carbohydrate contai ning solutions. In separate experiments, it could be shown that soluti ons of 20% sorbitol and 2% mannitol exhibited particularly low proteog lycan extracting properties. It was found that the extraction of prote oglycan was dependent on the ion concentration in the aqueous media. T he extraction of proteoglycan by sodium chloride was negligible at NaC l concentrations of 0.1% and lower. Proteoglycan loss from cartilage w as only induced at 0.9% NaCl. Using intact rat femoral heads it could be shown that the elution of proteoglycan from cartilage occurred as w ell when the cartilage was intact. Here, the elution occurred at a slo wer rate but the differences between ionic and ion-free solutions were greater. By electronmicroscopic examination of bovine cartilage incub ated in different media, it was observed that Ringer's solution induce d a more uneven and rougher appearance of the cartilage surface than d id 10% mannitol solution, indicating that probably a denudation of col lagen fibers occurs on the loss of proteoglycan from the cartilage. Be cause the observed proteoglycan washout occurred within rather short p eriods of contact of the cartilage with the medium, it is concluded th at this may be of relevance for the clinical situation during arthrosc opic procedures. The use of preferably isotonic carbohydrate solutions like 5% mannitol is suggested to prevent unnecessary loss of proteogl ycan from hyaline cartilage.