Table 5.

Multivariate Cox proportional hazards analyses with time to fixation failure as outcome

Covariate	n	Hazard ratio	95% CI	p value
Calcar screws
Yes	97	1 a
No	93	8.6	(1.9 to 39.3)	0.005
Adequate reduction > 120°
Yes	179	1 a
No (residual varus)	11	4.9	(1.3 to 17.9)	0.02

^a Reference category