Table 4 Hip MRI measurements by activity level
| Â | High activity with sports | Low activity with or without sports | ||
|---|---|---|---|---|
Baseline N = 32 | 24 months N = 28 | Baseline N = 4 | 24 months N = 4 | |
Diameter of femoral head, mean (SD) | 43.97 (3.39) | 46.35 (3.17) | 40.78 (2.32) | 41.53 (2.65) |
Lateral centre-edge angle, mean (SD) | 24.94 (5.33) | 27.71 (5.55) | 30.50 (8.58) | 29.00 (7.62) |
Acetabular inclination angle, mean (SD) | 6.84 (4.06) | 7.51 (5.00) | 4.43 (3.34) | 5.75 (4.27) |
Posterior acetabular sector angle, mean (SD) | 85.89 (6.83) | 90.36 (4.68) | 88.63 (8.88) | 91.5 (6.24) |
Anterior acetabular sector angle, mean (SD) | 63.7 (5.37) | 60.82 (6.33) | 59.68 (4.08) | 55.25 (4.11) |
Acetabular anteversion angle—upper third, mean (SD) | -1.68 (5.48) | 1.84 (6.67) | 2.50 (9.33) | 3.50 (8.96) |
Acetabular anteversion angle—centre, mean (SD) | 11.30 (3.64) | 15.04 (3.92) | 15.75 (6.95) | 21.00 (10.3) |
Cranial acetabular retroversion, n (%) | ||||
 Yes | 15 (47) | 6 (21) | 1 (25) | 1 (25) |
 No | 15 (47) | 22 (79) | 3 (75) | 3 (75) |
Acetabular depth (mm), mean (SD) | 4.78 (1.60) | 5.74 (1.88) | 4.70 (0.48) | 5.25 (0.6) |
Alpha angle, mean (SD) | ||||
 12:00 | 45.06 (5.92) | 44.99 (5.98) | 43.95 (6.09) | 46.25 (3.59) |
 1:00 | 49.63 (6.73) | 56.48 (9.44) | 48.13 (3.57) | 49.18 (4.31) |
 1:30 | 52.8 (5.99) | 57.64 (6.83) | 51.93 (2.41) | 54.18 (3.81) |
 2:00 | 52.58 (4.25) | 56.54 (6.94) | 52.43 (1.95) | 57.13 (6.86) |
 3:00 | 48.94 (5.44) | 45.57 (6.36) | 47.50 (3.87) | 43.00 (4.97) |
Neck shaft angle, mean (SD) | 132.81 (5.31) | 133.04 (4.93) | 133.75 (3.1) | 132.5 (3.11) |
Femoral offset, mean (SD) | ||||
 12:00 | 6.74 (1.67) | 6.80 (1.41) | 6.00 (1.28) | 5.90 (0.75) |
 1:00 | 5.74 (1.4) | 4.81 (0.94) | 5.45 (0.98) | 4.73 (0.68) |
 1:30 | 5.77 (1.22) | 4.70 (0.92) | 4.78 (0.55) | 5.10 (0.62) |
 2:00 | 5.91 (1.23) | 4.94 (1.26) | 4.55 (0.79) | 5.23 (0.46) |
 3:00 | 8.03 (1.24) | 7.65 (1.61) | 7.40 (1.88) | 7.60 (2.05) |
Femoral offset ratio, mean (SD) | ||||
 1:00 | 0.13 (0.03) | 0.10 (0.02) | 0.13 (0.03) | 0.11 (0.01) |
 1:30 | 0.13 (0.03) | 0.13 (0.13) | 0.12 (0.01) | 0.12 (0.01) |
 2:00 | 0.13 (0.03) | 0.11 (0.03) | 0.11 (0.02) | 0.13 (0.01) |
 3:00 | 0.18 (0.02) | 0.17 (0.03) | 0.18 (0.04) | 0.18 (0.05) |
Modified MAHORN classification, n (%) | ||||
 Partial-thickness cartilage lesion | 2 (6) | 7 (25) | 0 (0) | 1 (25) |
 No cartilage lesion | 28 (88) | 21 (75) | 4 (100) | 3 (75) |
Labral tears present, n (%) | ||||
 Yes | 11 (34) | 16 (57) | 1 (25) | 2 (50) |
 Anterior | 7 (22) | 9 (32) | 0 (0) | 0 (0) |
 Superior/lateral | 4 (13) | 11 (39) | 1 (25) | 2 (50) |
 No | 19 (59) | 12 (43) | 3 (75) | 2 (50) |
Herniation pits present, n (%) | ||||
 Yes | 1 (3) | 5 (18) | 0 (0) | 1 (25) |
 No | 29 (91) | 23 (82) | 4 (100) | 3 (75) |
FAI type, n (%) | ||||
 Cam | 6 (19) | 18 (64) | 1 (25) | 1 (25) |
 Pincer | 1 (3) | 1 (4) | 0 (0) | 0 (0) |
 None | 25 (78) | 9 (32) | 3 (75) | 3 (75) |