Table 1 Baseline characteristics of patients

Age at surgery (y)

42.7 ± 7.8

43.2 ± 8.5

43.1 ± 8.4

44.5 ± 8.5

Gender (male/female)

30/4

108/17

138/21

138/21

Body mass index (kg/m²)

24.9 ± 4.8

23.9 ± 3.6

24.2 ± 3.9

23.8 ± 2.9

Etiology

 Alcohol abuse

24 (70.6%)

80 (64.0%)

104 (65.4%)

104 (65.4%)

 Corticosteroid use

7 (20.6%)

18 (14.4%)

25 (15.7%)

25 (15.7%)

 Idiopathic

3 (8.8%)

27 (21.6%)

30 (18.9%)

30 (18.9%)

Modified Ficat and Arlet stage

 Stage I

2 (5.9%)

14 (11.2%)

16 (10.1%)

16 (10.1%)

 Stage II A

10 (29.4%)

92 (73.6%)

102 (64.2%)

102 (64.2%)

 Stage II B

22 (64.7%)

19 (15.2%)

41 (25.8%)

41 (25.8%)

Asymptomatic/sypmptomatic

23/11

77/48

100/59

93/66

Preoperative Harris score

88.2 ± 4.9

87.4 ± 5.1

87.6 ± 5.1

87.5 ± 8.1

Necrotic location

 A

2 (5.9%)

20 (16.0%)

22 (13.8%)

32 (20.1%)

 B

1 (2.9%)

45 (36.0%)

46 (28.9%)

34 (21.4%)

 C1

12 (35.3%)

47 (37.6%)

59 (37.1%)

55(34.6%)

 C2

19 (55.9%)

13 (10.4%)

32 (20.1%)

38 (23.9%)

Extent of necrotic lesion

  < 15%

2 (5.9%)

64 (51.2%)

66 (41.5%)

66 (41.5%)

 15–30%

6 (17.6%)

49 (39.2%)

55 (34.6%)

55 (34.6%)

  > 30%

26 (76.5%)

12 (9.6%)

38 (23.9%)

38 (23.9%)

Bone marrow edema (no. of hips)

15 (44.1%)

13 (10.4%)

27 (17.0%)

20 (12.6%)

Alpha angle

47.8 ± 7.1

48.2 ± 7.2

48.1 ± 7.1

50.1 ± 6.9

CAM type FAI (no. of hips)

3 (8.8%)

14 (11.2%)

17 (10.7%)

25 (15.7%)

Hip dysplasia (no. of hips)

3 (8.8%)

13 (10.4%)

16 (10.1%)

12 (7.5%)

Medial joint space (mm)

9.1 ± 2.2

9.4 ± 2.0

9.3 ± 2.2

9.5 ± 2.2

Superior joint space (mm)

4.6 ± 0.9

4.6 ± 1.1

4.6 ± 1.0

4.5 ± 1.0

Postoperative Work intensity

 Grade 0–1

14 (41.2%)

109 (87.2%)

123 (77.4%)

111 (69.8%)

 Grade 2

12 (35.3%)

10 (8.0%)

22 (13.8%)

35 (22.0%)

 Grade 3–4

8 (23.5%)

6 (4.8%)

14 (8.8%)

13 (8.2%)

Bone grafting (no. of hips)

17 (50.0%)

51 (32.1%)

Failure (no. of hips)

34 (21.4%)

49 (30.8%)