Water content and glycosaminoglycan disaccharide concentration of the canine meniscus

To determine the regional composition of water and glycosaminoglycan (GAG) disaccharides of the canine meniscus.

52 menisci from the stifle of dogs.

Regional sections of each meniscus were weighed, dried, and reweighed to determine water content. Dried tissue specimens were subjected to enzymatic digestion. Analysis and quantification of disaccharide degradation products were performed, using high-performance liquid chromatography.

Water content 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 detectable delta Di-HA, delta Di-4S, and delta Di-6S GAG disaccharides. Disaccharides specific to dermatan sulfate and chondroitin D or E sulfate were not detected. Concentrations of delta Di-4S and delta Di-6S were significantly greater in the lateral central region, compared with the medial central region (P = 0.0005 and 0.0002, respectively).

Water content and delta Di-4S and delta Di-6S concentrations were significantly lower in the central region of the medial meniscus, compared with the central region of the lateral meniscus. Reduced tissue hydration of the medial central region may have been a direct result of its overall decrease in total GAG content.

The ability to evaluate subtle differences in tissue GAG composition by analytical measurement of their constituent disaccharides may aid in the understanding of the complex material properties of the normal and diseased meniscus, which may be applied to the study of meniscal healing and biomechanics.