Description of BOKS, FOA and MOST participants
| BOKS (224 knees from 224 subjects) | FOA (1159 knees from 985 subjects) | FOA (428 knees with measured alignment from 350 subjects) | MOST (1621 knees from 1381 subjects) | |
|---|---|---|---|---|
| Age, mean (SD), years | 66.7 (9.4) | 63.4 (8.8) | 65.0 (8.9) | 62.1 (8.0) |
| BMI, mean (SD), kg/m2 | 30.7 (4.8) | 28.6 (5.6) | 29.2 (5.5) | 30.0 (4.9) |
| Female, N (%) | 92 (41.1) | 564 (57.3) | 196 (56.0) | 843 (61.0) |
| Knee pain, N (%) | 200 (94.0) | 268 (23.7) | 124 (29.6)* | 537 (33.2) |
| Radiographic PF OA, N (%) | 142 (64.0) | 88 (7.8) | 67 (15.7)* | 288 (18.0) |
| PF JSN grade, N (%) | ||||
| 0 | 109 (49.1) | 1085 (96.4) | 403 (94.6)* | 1396 (87.1) |
| 1 | 68 (30.6) | 24 (2.1) | 12 (2.8)* | 84 (5.2) |
| 2–2.5 | 30 (13.5) | 13 (1.2) | 8 (1.9)* | 80 (5.0) |
| 3 | 3 (6.8) | 4 (0.4) | 3 (0.7)* | 43 (2.7) |
| TF KL grade, N (%) | ||||
| 0 | 17 (7.6) | 863 (76.4) | 220 (51.4)* | 667 (41.2) |
| 1 | 40 (17.9) | 53 (4.7) | 19 (4.4)* | 301 (18.6) |
| 2 | 51 (22.8) | 105 (9.3) | 98 (22.9)* | 316 (19.5) |
| 3 | 70 (31.2) | 69 (6.1) | 59 (13.8)* | 276 (17.1) |
| 3.5–4 | 46 (20.5) | 38 (3.4) | 32 (7.5)* | 59 (3.6) |
| TF alignment, N (%) | ||||
| Varus | 140 (62.5) | NA | 213 (49.8) | 777 (47.9) |
| Neutral | 48 (21.4) | NA | 183 (42.8) | 532 (32.8) |
| Valgus | 36 (16.1) | NA | 32 (7.5) | 312 (19.3) |
In accordance with the Osteoarthritis Research Society International (OARSI) atlas, PF ROA was identified when a definite osteophyte (OARSI score >2) was visible at the PF joint, or when PF Joint Space Narrowing (JSN) (OARSI score >1) was present along with any PF osteophyte, sclerosis or cyst (OARSI score >1).
↵* Indicates a significant difference (p<0.05) between the entire FOA cohort and FOA participants with measured knee alignment, using crude linear regression, logistic regression and proportional odds models with adjustment for correlation between two knees of a subject.
BMI, body mass index; BOKS, Boston Osteoarthritis of the Knee Study; FOA, Framingham Osteoarthritis Study; KL, Kellgren and Lawrence; MOST, Multicenter Osteoarthritis Study; OA, osteoarthritis; PF, patellofemoral; TF, tibiofemoral.