Knee pain severity and history of injury predict a new knee injury within 12 months.
| Variables | Frequency of Injuries/total Observations, n (%) | Unadjusted OR for Injury (95% CI) | Adjusted* OR for Injury (95% CI) |
|---|---|---|---|
| Full OA initiative, 4435 participants, 877 injuries | |||
| No ipsilateral knee pain, WOMAC ≤ 2 | 441/22188 (2.0) | Reference | Reference |
| Ipsilateral knee pain, WOMAC ≥ 3 | 436/9292 (4.7) | 2.25 (1.96–2.59) | 1.94 (1.66–2.26) |
| No contralateral knee pain, WOMAC ≤ 2 | 536/22187 (2.4) | Reference | Reference |
| Contralateral knee pain, WOMAC ≥ 3 | 341/9293 (3.7) | 1.47 (1.27–1.70) | 0.98 (0.84–1.15) |
| No history of ipsilateral knee injury | 444/22321 (2.0) | Reference | Reference |
| History of ipsilateral knee injury | 433/9159 (4.7) | 2.09 (1.81–2.41) | 1.76 (1.52–2.05) |
| No history of contralateral knee injury | 518/22321 (2.3) | Reference | Reference |
| History of contralateral knee injury | 359/9159 (3.9) | 1.64 (1.42–1.91) | 1.44 (1.23–1.67) |
| Bilateral ROA, 1347 participants, 335 injuries | |||
| No ipsilateral knee pain, WOMAC ≤ 2 | 124/5533 (2.3) | Reference | Reference |
| Ipsilateral knee pain, WOMAC ≥ 3 | 211/4072 (5.2) | 2.15 (1.70–2.71) | 1.90 (1.47–2.45) |
| No contralateral knee pain, WOMAC ≤ 2 | 156/5433 (2.9) | Reference | Reference |
| Contralateral knee pain, WOMAC ≥ 3 | 179/4072 (4.4) | 1.46 (1.16–1.83) | 1.01 (0.78–1.30) |
| No history of ipsilateral knee injury | 153/6201 (2.5) | Reference | Reference |
| History of ipsilateral knee injury | 182/3304 (5.5) | 1.89 (1.49–2.39) | 1.64 (1.28–2.09) |
| No history of contralateral knee injury | 168/6201 (2.7) | Reference | Reference |
| History of contralateral knee injury | 167/3304 (5.1) | 1.83 (1.44–2.32) | 1.66 (1.29–2.12) |
| No ROA at all visits, 1204 participants, 154 injuries | |||
| No ipsilateral knee pain, WOMAC ≤ 2 | 111/7866 (1.4) | Reference | Reference |
| Ipsilateral knee pain, WOMAC ≥ 3 | 43/1723 (2.5) | 1.69 (1.16–2.45) | 1.40 (0.93–2.10) |
| No contralateral knee pain, WOMAC ≤ 2 | 116/7866 (1.5) | Reference | |
| Contralateral knee pain, WOMAC ≥ 3 | 38/1723 (2.2) | 1.47 (1.00–2.15) | 1.19 (0.78–1.82) |
| No history of ipsilateral knee injury | 90/7366 (1.2) | Reference | |
| History of ipsilateral knee injury | 64/2223 (2.9) | 2.13 (1.51–3.00) | 2.00 (1.39–2.87) |
| No history of contralateral knee injury | 107/7366 (1.5) | Reference | |
| History of contralateral knee injury | 47/2223 (2.1) | 1.41 (0.97–2.05) | 1.18 (0.81–1.74) |
↵* In addition to the variables indicated, each model was adjusted for sex, age, and body mass index at each visit. Significant OR are in bold face. OA: osteoarthritis; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; ROA: radiographic osteoarthritis.