Jumbo cup in hip joint renovation may cause the center of rotation to increase

Table 1 Measured values and mean values

	Maximum values	Minimum values	Mean values
Diameter of acetabular cup (mm)	60.00	72.00	65.0000
Height of rotating center (mm)	5.60	39.80	23.0273
Height of contralateral rotating center (mm)	5.60	24.70	15.4011
Differences (mm)	-6.60	19.50	7.6261
Horizontal distance of jumbo cup (mm)	25.30	48.60	36.4398
Contralateral horizontal distance (mm)	28.00	47.60	35.9398
Differences (mm)	-11.50	14.00	0.5000
Abduction angle (°)	28.10	63.00	40.6011

Table 2 Significant difference of rotating center in revision hip

	Mean values	SD	t	Degree of freedom	Significance (two tail)
Differences of vertical height	7.62614	5.58741	12.804	87	0.000
Differences of horizontal height	0.50000	5.07586	0.924	87	0.358

Table 3 Significant analysis of foreign standard groups

	Mean values	SD	t	Degree of freedom	Significance (two tail)
Differences of vertical height	7.50926	6.24353	8.838	53	0.000
Differences of horizontal height	0.76667	4.96030	1.136	53	0.261

Table 4 Comparison of domestic and foreign standards

	The test of variance equivalence		Mean isotropic t-test
	F	Significance	t	Degree of freedom	Significance (two tail)
Differences of height
Assumed equivariance	988	0.322	0.116	140	0.908
No assumed equivariance			0.113	102.772	0.911
Differences of horizon
Assumed equivariance	0	0.997	-0.307	140	0.76
No assumed equivariance			-0.308	114.256	0.758