Table 3.

Probability values from multivariable GEEs examining the relationship between damage and head size, taper, length of implantation, material combination, and location

Variable	Head fretting	Head corrosion	Stem fretting	Stem corrosion
Head size	0.247	0.837	0.471	0.868
Taper design	0.028*	0.031*	0.005*	0.107
Length of implantation	< 0.001*	0.329	0.044*	0.072
Material combination	0.326	0.681	< 0.001*	0.432
Location (proximal/distal)	0.106	0.477	< 0.001*	0.043*
Location (quadrant)			0.001*	0.048**
Location (proximal/distal* quadrant)			0.013*	–
Head size* location (quadrant)			–	0.017*

Interaction terms are included only where significant; * p < 0.05; GEEs = generalized estimating equations.