Table 4.

Summary of t-test results of comparisons of wear rates

Comparison	p value
Fixed bearing Ti tray vs CoCr tray
Backside wear depth	< 0.001
Backside linear wear rate	< 0.001
Backside volumetric wear rate	< 0.001
RP medial versus lateral wear	0.72
Fixed bearing medial versus lateral wear	< 0.001
RP CR versus PS wear rate	0.35
Fixed bearing CR versus PS wear rate	0.90

Ti = titanium; CoCr = cobalt-chrome; RP = rotating platform; CR = cruciate retaining; PS = posterior stabilized.