Calcar screws and adequate reduction reduced the risk of fixation failure in proximal humeral fractures treated with a locking plate: 190 patients followed for a mean of 3 years

Table 4 Risk factors for fixation failure. Univariate Cox regression analysis with time to fixation failure as outcome

Covariate	n	Hazard ratio	95% CI	p value
Age, increase of 1 year	69 ^b	1.05	(1.0 to 1.1)	0.04
Sex
Women	133	1 ^a
Men	57	0.59	(0.2 to 2.1)	0.4
Smoker
No	142	1 ^a
Yes	48	0.80	(0.2 to 2.9)	0.7
Diabetes
No	169	1 ^a
Yes	21	0.61	(0.1 to 4.7	0.6
Non-compliant
No	173	1 ^a
Yes	17	5.35	(1.7 to 17.1)	0.005
ASA classification
ASA I-II	136	1 ^a
ASA III-IV	54	2.7	(1.0 to 7.7)	0.06
Fracture classification
2 part	48	1 ^a
3 or 4 part	142	2.1	(0.5 to 9.5)	0.3
Fracture dislocation
No	177	1 ^a
Yes	13	2.3	(0.5 to 10.3)	0.3
Preoperative varus < 105°
No	147	1 ^a
Yes	43	2.8	(1.0 to 8.0)	0.06
Preoperative valgus > 180°
No	155	1 ^a
Yes	35	1.8	(0.6 to 5.7)	0.3
Medial comminution
No	60	1 ^a
Yes	130	1.9	(0.5 to 6.6)	0.3
Surgical approach
Deltopectoral	82	1 ^a
Deltoid split	108	0.5	(0.2 to 1.5)	0.3
Calcar screws
Yes	97	1 ^a
No	93	6.5	(1.5 to 28.9)	0.02
Adequate reduction > 120°
Yes	179	1 ^a
No (varus)	11	5.2	(1.5 to 18.7)	0.01

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