Table 1.

Agreement for conventional imaging and 3D printed models among all eight observers

Parameter	Conventional			Conventional + 3D
	Kappa		Agreement	Kappa		Agreement	∆ kappa		p value
Characteristic
Humeral head split	0.39	(0.17-0.60)	Fair	0.72	(0.50-0.94)	Substantial	0.33	(0.02-0.64)	0.04
Medial hinge displacement > 2 mm	0.19	(0.00-0.38)	Slight	0.35	(0.06-0.64)	Fair	0.16	(-0.19 to 0.51)	0.36
Metaphyseal extension > 8 mm	0.14	(0.00-0.31)	Slight	0.28	(0.12-0.44)	Fair	0.14	(-0.09 to 0.36)	0.24
Surgical neck fracture	0.10	(0.00-0.26)	Slight	0.27	(0.05-0.50)	Fair	0.17	(-0.10 to 0.45)	0.21
Anatomic neck fracture	0.16	(0.01-0.31)	Slight	0.29	(0.10-0.47)	Fair	0.13	(-0.11 to 0.37)	0.29
Displacement of humeral head	0.44	(0.22-0.65)	Moderate	0.35	(0.16-0.53)	Fair	0.09	(-0.37 to 0.19)	0.55
LT displacement > 10 mm	0.03	(-0.05 to 0.12)	Slight	0.16	(0.02-0.30)	Slight	0.13	(-0.04 to 0.29)	0.13
GT displacement >10 mm	0.13	(0.01-0.25)	Slight	0.16	(0.00-0.36)	Slight	0.03	(-0.21 to 0.26)	0.81
Fracture pattern
Neer classification	0.13	(0.06-0.20)	Slight	0.11	(0.05-0.17)	Slight	0.02	(-0.11 to 0.07)	0.67
Hertel classification	0.14	(0.06-0.22)	Slight	0.13	(0.07-0.19)	Slight	0.01	(-0.11 to 0.08)	0.81

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.