Table 1 Baseline patient characteristics

Mean age (range), yr.

31.5 ± 1.9 (16–47)

32.6 ± 1.7 (18–44)

0.6622

Female/ male, n

3/ 13

4/ 12

1.0000

Right/ left hip involved, n

9/ 7

10/ 6

0.7189

Body mass index (range), kg/cm²

24.9 ± 0.5 (21–27)

24.3 ± 0.5 (21–26)

0.3978

Etiology

0.4652

 Nontraumatic, n

9

11

 Traumatic, n

7

5

Duration of illness (range), mo

18.8 ± 2.0 (9–36)

20.5 ± 1.8 (11–38)

0.5379

ARCO stage (II/ III)

7/ 9

8/ 8

0.7232

 Bone marrow edema of hip (III)

5

6

0.7097

Mean operation time (range), min

80.13 ± 3.3 (56–105)

71.4 ± 3.1 (45–90)

0.0621

Mean blood loss (range), mL

180.6 ± 14.9 (110–350)

158.8 ± 13.7 (90–280)

0.2892

 Pre-operation (range)

60.3 ± 1.8 (48–72)

61.1 ± 2.0 (48–76)

0.7457

 12 months (range)

86.3 ± 0.98 (81–94)

80.8 ± 1.5 (67–90)

0.0054

 24 months (range)

85.6 ± 1.3 (70–92)

79.4 ± 1.7 (64–91)

0.0078

 36 months (range)

85.2 ± 1.7 (68–95)

78.2 ± 2.2 (64–93)

0.0173

Successful clinical results (%)

15 (94)

10 (63)

0.0325

Successful radiological results (%)

14 (88)

8 (50)

0.0221