Biochemical heterogeneity within the maturing rabbit medial collateral ligament.

The purpose in this investigation was to determine the biochemical composition of the normal rabbit medial collateral ligament (MCL) along its length during growth and maturation. Water content and hexosamine concentration as an index of glycosaminoglycan content and collagen concentration were quantified and results compared statistically for anatomically identified MCL segments at various ages. These data demonstrate differences in all parameters at different locations along the ligament and at different ages. Biochemical differences were noted between midsubstance and periinsertional areas. There were subtle differences between the two insertion sites of this ligament at all ages. These results indicate that the rabbit MCL is not homogeneous biochemically along its length and that its matrix composition changes with growth and maturation.