Table 3.

Agreement for conventional imaging and 3D printed models among four attending surgeons

Parameter	Conventional			Conventional + 3D
	Kappa		Agreement	Kappa		Agreement	∆ kappa		p value
Characteristic
Humeral head split	0.37	(0.05-0.69)	Fair	0.75	(0.48-1.00)	Substantial	0.38	(-0.04 to 0.79)	0.08
Medial hinge displacement > 2 mm	0.38	(0.05-0.70)	Fair	0.62	(0.24-1.00)	Substantial	0.24	(-0.26 to 0.74)	0.34
Metaphyseal extension > 8 mm	0.00	(-0.18 to 0.17)	Slight	0.16	(-0.02 to 0.33)	Slight	0.16	(-0.09 to 0.40)	0.20
Surgical neck fracture	0.22	(-0.16 to 0.59)	Fair	0.54	(0.10-0.98)	Moderate	0.33	(-0.25 to 0.90)	0.27
Anatomic neck fracture	0.13	(-0.09 to 0.34)	Slight	0.42	(0.17-0.66)	Moderate	0.29	(-0.03 to 0.61)	0.08
Displacement of the humeral head	0.58	(0.36-0.81)	Moderate	0.69	(0.41-0.97)	Substantial	0.11	(-0.25 to 0.47)	0.55
LT displacement > 10 mm	-0.11	(-0.23 to 0.02)	Poor	0.11	(-0.05 to 0.28)	Slight	0.22	(0.01-0.42)	0.04
GT displacement > 10 mm	-0.01	(-0.15 to 0.13)	Poor	0.13	(-0.14 to 0.40)	Slight	0.14	(-0.16 to 0.45)	0.36
Fracture pattern
Neer classification	0.13	(-0.01 to 0.27)	Slight	0.05	(-0.04 to 0.13)	Slight	0.08	(-0.25 to 0.08)	0.32
Hertel classification	0.09	(-0.02 to 0.20)	Slight	0.06	(-0.01 to 0.19)	Slight	0.03	(-0.18 to 0.12)	0.68

A kappa value less than 0 indicates poor agreement; a ∆ kappa value less than 0 indicates that agreement for conventional imaging with 3D models is lower than conventional imaging only; LT = lesser tuberosity; GT = greater tuberosity.