Table 1 Baseline Characteristics (N = 99)

Age (years, mean [SD])

32.9 (11.8)

32.9 (9.1)

32.9 (10.5)

Gender:

Male

31 (63%)

26 (52%)

57 (58%)

Female

18 (37%)

24 (48%)

42 (42%)

Current smoker:

Yes

5 (10%)

5 (10%)

10 (10%)

No

41 (84%)

44 (88%)

85 (86%)

Missing

3 (6%)

1 (2%)

4 (4%)

Hip side to be considered for treatment:

right

22 (45%)

24 (48%)

46 (46%)

left

27 (55%)

26 (52%)

53 (54%)

Bilateral symptoms:

Yes

9 (18%)

11 (22%)

20 (20%)

No

40 (82%)

39 (78%)

79 (80%)

Duration of hip symptoms (mths, median [min, max])

24.0 (2.0, 84.0)

18.0 (2.5, 120.0)

20.0 (2.0, 120.0)

Type of FAI:

Pincer

9 (18%)

9 (18%)

18 (18%)

Mixed

10 (20%)

9 (18%)

19 (19%)

Cam

30 (61%)

32 (64%)

62 (63%)

Units of alcohol in average week (median [min, max])

3.0 (0.0, 16.0)

2.0 (0.0, 12.0)

2.0 (0.0, 16.0)

Diabetic:

Yes

1 (2%)

1 (1%)

No

46 (94%)

49 (98%)

95 (96%)

Missing

2 (4%)

1 (2%)

3 (3%)

Diagnosed chronic renal failure:

No

47 (96%)

49 (98%)

96 (97%)

Missing

2 (4%)

1 (2%)

3 (3%)

Physical activity (UCLA score, mean [SD])

7.5 (2.6)

7.2 (2.8)

7.3 (2.7)

HOOS pain (mean [SD])

59.4 (18.4)

57.4 (18.9)

58.4 (18.6)

HOOS Symptom (mean [SD])

49.7 (17.5)

50.7 (20.9)

50.2 (19.2)

HOOS ADL (mean [SD])

69.2 (18.0)

65.9 (20.4)

67.5 (19.3)

HOOS Sport & Recreation (mean [SD])

47.9 (22.4)

46.9 (23.6)

47.4 (22.9)

HOOS Quality of Life (mean [SD])

33.6 (16.1)

30.1 (17.6)

31.8 (16.9)

Hip related Quality of Life (i-HOT-33, (mean [SD]))

43.5 (17.6)

40.4 (20.0)

41.9 (18.8)

SF-12 PCS (mean [SD])

40 (7.8)

39 (8.4)

39 (8.1)

SF-12 MCS (mean [SD])

49 (11.2)

48 (10.8)

49 (10.9)

EQ-5D-5L index score (mean [SD])

0.575 (0.21)

0.544 (0.23)

0.559 (0.22)

EQ-5D-5L VAS (mean [SD])

68.9 (16.3)

68.8 (14.2)

68.8 (15.2)

Maximum MRI alpha angle (mean [SD])

70.2 (11.9)

70.6 (15.6)

70.4 (13.9)

dGEMRIC Combined (mean [SD])

679.6 (118.6)

667.0 (127.4)

673.6 (121.8)

dGEMRIC Acetabular ROI (mean [SD])

661.2 (121.1)

637.2 (145.3)

649.7 (132.4)

dGEMRIC Femoral ROI (mean [SD])

698.9 (137.0)

698.4 (125.4)

698.7 (130.2)

dGEMRIC Z-score (mean [SD])

−0.49 (0.70)

−0.45 (0.67)

− 0.47 (0.68)

Total AP anterior coverage (%, mean [SD])

27.2 (8.2)

24.7 (6.2)

25.9 (7.3)

Total AP posterior coverage (%, mean [SD])

47.4 (8.1)

45.0 (8.3)

46.2 (8.3)

Total Femur coverage (%, mean [SD])

82.4 (7.6)

81.0 (7.3)

81.7 (7.4)

LCE (%, mean [SD])

37.1 (5.4)

34.7 (6.6)

35.8 (6.2)

LCE

< 25

2 (4%)

2 (2%)

25+

47 (96%)

48 (96%)

95 (96%)

Missing

2 (4%)

2 (2%)

Radiographic Measurements

Acetabular Index (%, mean [SD])

2.5 (4.2)

4.7 (4.8)

3.6 (4.6)

ACM angle (%, mean [SD])

45.0 (2.5)

44.7 (3.6)

44.8 (3.1)

Extrusion Index (%, mean [SD])

15.0 (4.5)

17.0 (5.7)

16.0 (5.3)

Cross-over-sign

Yes

31 (63%)

38 (76%)

69 (70%)

No

16 (33%)

12 (24%)

28 (28%)

Missing

2 (4%)

2 (2%)

Retroversion Index (%, median [min, max])

6.7 (0.0, 46.0)

11.1 (0.0, 54.7)

10.2 (0.0, 54.7)

Posterior wall sign

Yes

29 (59%)

37 (74%)

66 (67%)

No

18 (37%)

13 (26%)

31 (31%)

Missing

2 (4%)

2 (2%)