Table 2 Levels of metal ions over time by sex, side, and body mass index

Preoperation

 Men

0.70 (0.03)

0.949

0.72 (0.04)

0.949

0.82 (0.02)

0.564

 Women

0.70 (0.03)

0.74 (0.03)

0.83 (0.02)

 Unilateral

0.68 (0.03)

0.478

0.72 (0.04)

0.848

0.82 (0.02)

0.564

 Bilateral

0.72 (0.02)

0.74 (0.03)

0.83 (0.02)

 BMI <25 kg/m²

0.73 (0.02)

0.037

0.71 (0.02)

0.196

0.83 (0.01)

0.518

 BMI ≥25 kg/m²

0.66 (0.02)

0.76 (0.04)

0.81 (0.02)

3 months

 Men

1.06 (0.16)

0.668

1.55 (0.56)

0.116

6.26 (1.41)

0.253

 Women

1.30 (0.29)

2.01 (0.57)

7.23 (0.88)

 Unilateral

1.15 (0.21)

0.237

1.97 (0.50)

0.866

6.16 (0.78)

0.176

 Bilateral

1.31 (0.22)

1.21 (0.15)

8.86 (2.01)

 BMI <25 kg/m²

1.16 (0.22)

0.253

2.97 (1.05)

0.288

4.68 (0.56)

0.235

 BMI ≥25 kg/m²

1.20 (0.22)

1.44 (0.36)

7.41 (0.92)

12 months

 Men

1.80 (0.52)

0.487

2.16 (0.59)

0.298

6.91 (1.06)

0.817

 Women

1.81 (0.4)

3.19 (0.72)

7.10 (0.78)

 Unilateral

1.67 (0.37)

0.713

2.32 (0.55)

0.327

7.35 (0.66)

0.540

 Bilateral

2.06 (0.62)

3.50 (0.88)

6.33 (1.39)

 BMI <25 kg/m²

3.03 (1.47)

0.243

3.41 (1.86)

0.322

6.86 (3.65)

0.493

 BM I ≥25 kg/m²

1.61 (0.28)

2.60 (0.50)

7.03 (0.6)

24 months

 Men

1.20 (0.39)

0.04

2.96 (0.78)

0.661

4.67 (0.42)

0.242

 Women

1.88 (0.30)

3.09 (0.59)

5.55 (0.86)

 Unilateral

1.53 (0.27)

0.236

3.00 (0.46)

0.693

4.84 (0.48)

0.324

 Bilateral

2.08 (0.75)

3.26 (2.04)

7.23 (2.56)

 BMI <25 kg/m²

1.85 (0.45)

0.938

3.40 (0.74)

0.721

4.35 (0.74)

0.276

 BMI ≥25 kg/m²

1.47 (0.3)

2.81 (0.60)

5.75 (0.74)

60 months

 Men

1.17 (0.11)

0.584

3.60 (0.62)

0.361

7.42 (0.57)

0.584

 Women

1.24 (0.28)

2.52 (0.720

7.60 (1.32)

 Unilateral

1.33 (0.28)

0.855

2.54 (0.70)

0.465

7.04 (1.25)

0.361

 Bilateral

1.06 (0.06)

3.63 (0.66)

8.09 (0.67)

 BMI <25 kg/m²

1.29 (0.24)

1.000

2.80 (0.63)

0.850

7.12 (1.1)

0.345

 BMI ≥25 kg/m²

1.06 (0.08)

3.45 (0.87)

8.22 (0.65)