Table 1 Clinical characteristics of each group

Hips included (n)

18

Male (4), female (14)

18

Male (8), female (10)

Diagnosis (n)

16 Primary osteoarthritis

1 Congenital hip dysplasia

1 Post-traumatic arthritis

17 Primary osteoarthritis

1 Avascular necrosis

Age at surgery, years (n = 36)

Mean (range)

69 (57–78)

69 (59–77)

Weight (include patients), kg

Mean (range)

75 (60–90)

78 (52–98)

Lost to follow-up (n)

4

Missing baseline RSA examination (2)

Death of patient before 2-year follow-up (2)

4

Missing baseline RSA examination (2)

Did not attend arranged RSA examinations (2)

Returning for follow-up (n)

3 months (n = 14)

6 months (n = 10)

1 year (n = 16)

3 months (n = 13)

6 months (n = 10)

1 year (n = 16)

Hips attending at 2-year follow-up (n)

14

Male (2), female (12)

14

Male (5), female (9)

Diagnosis at 2-year follow-up (n)

13 Primary osteoarthritis

1 Congenital hip dysplasia

13 Primary osteoarthritis

1 Avascular necrosis

Age at surgery, years (n = 28)

(2-year follow-up population)

Mean (range)

69 (62–77)

70 (59–74)

Weight at surgery, kg (n = 28)

(2-year follow-up population)

Mean (range)

74 (60–85)

76 (52–90)