Table 4.

Association of pelvic osteolytic lesion volume on CT with patient, implant, and radiographic parameters

Factor	Univariate analysis		Multivariate analysis
	Correlation coefficient (r)	p value	Incremental r2	p value
Patient factors
Gender (male = 1, female = 0)	0.28	0.01		0.60
Preoperative diagnosis
Osteoarthritis	0.11	0.36		0.24
Osteonecrosis	−0.09	0.41		0.78
Developmental hip dysplasia	0.02	0.86		0.39
Posttraumatic arthrosis	−0.08	0.50		0.33
Inflammatory arthritis	−0.009	0.94		0.45
Age at surgery	−0.14	0.22		0.19
Height	0.09	0.44		0.65
Weight	−0.10	0.40		0.65
Body mass index	−0.17	0.14		0.74
Physician-assessed activity level
Heavy	0.54	0.0000003	0.05	0.00003
Moderate	−0.20	0.08		0.40
Light	−0.22	0.06		0.37
Semisedentary	−0.11	0.32		0.97
Implant factors
Polyethylene liner geometry
4 mm lateralized	−0.003	0.98		0.05
Standard	0.06	0.61		0.08
10° lip	−0.11	0.35		0.52
Terminal sterilization
Gas plasma	−0.37	0.0008		0.18
Gamma-in-air standard dose	0.48	0.00001		0.02
Gamma-barrier standard dose	−0.07	0.56		0.29
Gamma-barrier low dose	−0.06	0.62		0.74
Shelf storage duration for gamma-in-air liners	0.38	0.0007		0.09
Femoral head material (ceramic = 1, CoCr = 0)	0.07	0.54		0.74
Femoral head diameter	0.15	0.19		0.25
Cup outer diameter	0.19	0.10		0.23
Hole eliminator
Plug with positive stop	−0.25	0.03		0.84
Plug without positive stop	0.17	0.14		0.90
Not used	0.14	0.21		0.67
Radiographic factors
Years between surgery and CT	0.50	0.000003		0.94
Volumetric wear	0.51	0.000002	0.02	0.002
Volumetric wear rate	0.31	0.005		0.19
Linear wear	0.53	0.0000006		0.84
Linear wear rate	0.30	0.007		0.21
Number of followup radiographs used to compute wear rate for each hip	0.42	0.0001		0.08
Cup abduction angle	−0.18	0.12		0.45
Depth of acetabular seating	0.11	0.34		0.33
Days between radiographs and CT	−0.21	0.06		0.59
Femoral lysis area on radiograph	0.16	0.15		0.74
Pelvic lysis area on radiograph	0.89	4 × 10−18	0.80	4 × 10−18