WATER-CONTENT AND GLYCOSAMINOGLYCAN DISACCHARIDE CONCENTRATION OF THECANINE MENISCUS

Objective-To determine the regional composition of water and glycosami noglycan (GAG) disaccharides of the canine meniscus. Sample Population -52 menisci from the stifle of dogs. Procedure-Regional sections of ea ch meniscus were weighed, dried, and reweighed to determine water cont ent. Dried tissue specimens were subjected to enzymatic digestion. Ana lysis and quantification of disaccharide degradation products were per formed, using high-performance liquid chromatography. Results-Water co ntent was approximately 65% in polar and central regions of the canine meniscus. Water content of the central region of the lateral meniscus was significantly higher than that of the medial meniscus (P = 0.0090 ). Chondroitinase digestion of canine meniscal tissue yielded detectab le Delta Di-HA, Delta Di-4S, and Delta Di-6S GAG disaccharides. Disacc harides specific to dermatan sulfate and chondroitin D or E sulfate we re not detected. Concentrations of Delta Di-4S and Delta Di-6S were si gnificantly greater in the lateral central region, compared with the m edial central region (P = 0.0005 and 0.0002, respectively). Conclusion -Water content and Delta Di-4S and Delta Di-6S concentrations were sig nificantly lower in the central region of the medial meniscus, compare d with the central region of the lateral meniscus. Reduced tissue hydr ation of the medial central region may have been a direct result of it s overall decrease in total GAG content. Clinical Relevance-The abilit y to evaluate subtle differences in tissue GAG composition by analytic al measurement of their constituent disaccharides may aid in the under standing of the complex material properties of the normal and diseased meniscus, which may be applied to the study of meniscal healing and b iomechanics.