Table 1.
The number of cases of incidence and progression of definite overall structural defects of hip osteoarthritis (OA) and degeneration of individual structural features of the hip during 4–5 years’ follow‐up in each cohort*
| OAI | CHECK | |||
|---|---|---|---|---|
| Incidence cohort | Progression cohort | Incidence cohort | Progression cohort | |
| Participants, no. | 3,053 | 241 | 743 | 108 |
| Hips, no. | 5,896 | 303 | 1,377 | 129 |
| Overall structural defects of hip OA | ||||
| Total | 85 (1.44) | 0 (0.00) | 179 (13.00) | 8 (6.20) |
| Overall grade = 0 at baseline | 18 (0.30) | 0 (0.0) | 77 (5.6) | 8 (6.20) |
| Overall grade = 1 at baseline | 67 (1.14) | 0 (0.0) | 102 (7.4) | 0 (0.0) |
| Overall grade = 2 at baseline | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Overall grade = 3 at baseline | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Overall grade = 4 at baseline | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Degeneration of individual structural features of the hip | ||||
| Joint space narrowing lateral | 91 (1.54) | 38 (12.62) | 129 (9.39) | 11 (8.53) |
| Joint space narrowing medial | 170 (2.88) | 48 (15.89) | 260 (18.92) | 16 (12.40) |
| Osteophytes acetabular superior | 74 (1.26) | 27 (8.94) | 386 (28.20) | 38 (29.46) |
| Osteophytes acetabular inferior | 25 (0.42) | 17 (5.67) | 97 (7.43) | 16 (14.81) |
| Osteophytes femoral superior | 114 (1.93) | 30 (9.97) | 357 (26.19) | 40 (31.25) |
| Osteophytes femoral inferior | 25 (0.42) | 26 (8.64) | 179 (14.16) | 25 (23.58) |
| Sum of osteophyte scores | 39 (0.66) | 28 (9.33) | 244 (19.73) | 29 (30.53) |
| Subchondral cysts acetabular | 6 (0.10) | 8 (2.65) | 3 (0.23) | 1 (0.83) |
| Subchondral sclerosis femoral | 3 (0.05) | 12 (3.97) | 10 (0.77) | 4 (3.31) |
| Femoral head deformity | 1 (0.02) | 3 (0.99) | 69 (5.28) | 3 (2.48) |
*
Values are the number (%) unless indicated otherwise. The percentage calculations are based on complete case (i.e., excluding missing values). The 2 incidence cohorts consisted only of hips without definite overall structural defects of hip OA (i.e., an overall grade of <2) at baseline. The 2 progression cohorts consisted of only hips with definite overall structural defects of hip OA (i.e., an overall grade of ≥2) at baseline. CHECK = Cohort Hip and Cohort Knee (study); OAI = Osteoarthritis Initiative.