Table 1. Categorical variables included in the study.
Variable
Gender
Categories
N. of hips (%)
Men
44 (28)
Women
111 (72)
Preoperative diagnosis
Osteoarthritis
29 (19)
Hip dysplasia
71 (46)
Osteonecrosis
30 (19)
Traumatic
14 (9)
Inflammatory
6 (4)
SCFE
5 (3)
Charnley type
A
53 (34)
B
89 (57)
C
13 (8)
Liner geometry
Neutral
125 (81)
Hooded
30 (19)
Head material
CoCr
143 (92)
Zirconia
12 (8)
Cup relation to KL
Laterally
14 (9)
In contact
27 (17)
Medially
114 (74)
True acetabular region
Yes
123 (79)
No
32 (21)
Acetabular BD
Type I, II
44 (28)
Type III
87 (56)
Type IV, V
24 (16)
Femoral BD
Type I, II
127 (82)
Type III
25 (16)
Type IV
3 ( 2)
Legend: KL-Kohler’s line, BD-bone defects, SCFE- slipped capital femoral epiphysis.
Table 2. Continuous variables included in a stepwise logistic regression.
Variable
Mean
SD
Age at surgery (yrs.)
46.1
6.8
Height (cm)
165.5
8.6
Weight (kg)
75
14.4
Cup size (mm)
50.3
3.81
PE thickness (mm)
7.03
1.93
Abduction angle of the cup (°)
45.26
7.98
Follow-up years
6.0
1.9
Linear wear rate (mm/yrs.)
0.415
0.364
Volumetric wear rate (mm3/yrs.)
153
134
Legend: PE-polyethylene, SD-standard deviation.
Range
25 to 65
149 to 195
42 to 114
46 to 60
4.9 to 11.9
28 to 72
2.0 to 10.5
0 to 2.284
0 to 815
Median
46.3
164
73
50.0
6.9
45.0
6.0
0.346
115
Table 3. Variables associated with the probability of aseptic loosening in ABG I prosthesis.
Variable
Increasing patient’s age by 1 year
Charnley C type of patient
Primary osteoarthritis as primary diagnosis
Legend: R2 – Nagelkerke R Square.
Odds
ratio
1.07
3.61
0.162
95% confidence interval
Lower bound Upper bound
1.002
1.149
1.071
12.170
0.034
0.765
p
value
0.043
0.038
0.022
R2
0.153