The swelling behaviour of the general matrix of both normal and abnormally softened articular cartilage
was investigated in the context of its relationship to the underlying subchondral bone, the articular surface,
and with respect to the primary structural directions represented in its strongly anisotropic collagenous
architecture. Swelling behaviours were compared by subjecting tissue specimens under different modes of
constraint to a high swelling bathing solution of distilled water and comparing structural changes imaged at
the macroscopic, microscopic and ultrastructural levels of resolution. Near zero swelling was observed in the
isolated normal general matrix with minimal structural change. By contrast the similarly isolated softened
general matrix exhibited large-scale swelling in both the transverse and radial directions. This difference in
dimensional stability was attributed to fundamentally different levels of fibril interconnectivity between the 2
matrices. A model of structural transformation is proposed to accommodate fibrillar rearrangements
associated with the large-scale swelling in the radial and transverse directions in the softened general matrix.