Table 1.

Model parameters used in this study

Parameter	Value	Reference
E col	5 MPa (> 0) 0.5 MPa (< 0)	Bathe et al. (2005)
α 1	1.4 × 10−4M/g	Bathe et al. (2005)
α 2	4.4 × 10−6M/g2	Bathe et al. (2005)
α 3	5.7 × 10−8M2/g3	Bathe et al. (2005)
k w	1.02 × 10−12/cagg 1.559 m2/Pa/s	Comper (1993) (curve fitted)
k agg	2.7 × 10−17/cagg m2/Pa/s (minimum 4 × 10−18m2/Pa/s)
$s_{\text{agg}}^{\mathrm{M}}$	4.3 × 10−5mg/ml/s	Zhang et al. (2009)

Note: the permeability of aggrecan (k^agg) is assumed to be of a similar form to the permeability of water. The values of the aggrecan permeability (and the Robin boundary condition) were not available in the literature. In this simulation these values were chosen to give the appropriate aggrecan tissue concentration, as defined by the work of Klein et al. (2007).