Core definitions and voting results
| Word | Definition | Median | Minimum–maximum | Mode | Appropriateness | Votes | |
| D1. | Rehabilitation | A health strategy aimed at enabling people with a health condition reach and maintain their optimal physical, sensory, intellectual, psychological and social functional levels. It does so by providing them with the tools needed to attain independence and self-determination.* | 8 | 7–9 | 8 | Appropriate | 34 |
| D2. | Prevention | Activities that mitigate modifiable risk factors for disease/illness. These activities can focus on reducing the risk of disease†/illness in healthy individuals (primary prevention), early identification and reducing progression to disease or illness in individuals at high risk or with preclinical disease/illness (secondary prevention), or improving function and reducing disability in persons diagnosed with a disease/illness (tertiary prevention). In the context of OPTIKNEE, prevention refers to identifying and reducing progression from ‘at-risk’ to PTOA diagnosis in persons who have had a traumatic knee joint injury (secondary prevention). | 8.5 | 5–9 | 9 | Appropriate | 34 |
| D3. | Structural knee OA | Knee OA defined by the presence of structural features on imaging, or arthroscopy, which reach an established expert or consensus threshold of magnitude and character to be termed OA (eg, Kellgren and Lawrence grade, MRI-defined OA based on the MRI Osteoarthritis Knee Score and ICRS cartilage score). | 9 | 7–9 | 9 | Appropriate | 34 |
| D4. | Symptomatic knee OA | Knee OA defined by consensus-based clinical signs and symptoms (eg, ACR, NICE and EULAR definitions), excluding age restrictions, with or without the presence of structural features identified on imaging or arthroscopy. | 9 | 7–9 | 9 | Appropriate | 34 |
| D5. | Knee injury | Knee joint tissue damage or derangement resulting from a rapid or repeated transfer of kinetic energy. | 8.5 | 5–9 | 9 | Appropriate | 34 |
| D6. | Knee PTOA | Structural or symptomatic OA that develops following a traumatic knee joint injury. | 9 | 4–9 | 9 | Appropriate | 34 |
| D7. | Pre-PTOA | This definition was removed after the consensus meeting, because it was felt that it was captured by the concept of ‘at-risk’. | |||||
| D8. | Early-onset knee PTOA | Symptomatic or structural knee PTOA that develops in youth and young adults (ie, young people with old knees). Note: similar in concept to ‘early-onset’ as in ‘early-onset’ dementia. | 7 | 3–9 | 7 | Appropriate | 34 |
*Adapted from Cochrane Group: https://rehabilitation.cochrane.org.
†OA disease refers to the underlying biology and pathophysiology of OA characterised by structural alterations of the articular cartilage and subchondral bone59 60
‡OA illness refers to an individuals’ feeling, or experience of OA characterised by pain, functional impairments, muscle weakness, joint stiffness and reduced quality of life59 60
ACR, American College of Rheumatology; ICRS, International Cartilage Research Society; NICE, National Institutes for Health and Care Excellence; OA, osteoarthritis; PTOA, post-traumatic osteoarthritis.