Evaluating the Clinical Impact of the Prehabilitation and Recovery for Enabling Potential (PREP) Clinical Care Pathway

Correlation of Baseline PANAS score and primary outcome - the Oxford Knee Score

To evaluate the association between baseline Positive and Negative Affect Schedule (PANAS) score and the Oxford Knee Score (OKS), and determine whether observed effects are sustained up to 12 months post-surgery The PANAS is a 20-item self-report measure to assess positive affect (PA) and negative affect (NA). PA is associated with pleasurable engagement with the environment, whereas NA reflects a dimension of a variety of negative states such as anger, guilt, or anxiety. 10 questions relate to PA and 10 to NA, each question is scored from 1 (Very slightly or not at all) to 5 (Extremely). PA scores are combined and range from 10-50, higher scores representing higher levels of positive affect. NA scores are combined and range from 10-50, lower scores representing lower levels of negative affect. The study will assess: Whether better outcome at 12 month (using the OKS; higher scores indicate better knee health) is observed in patients with higher PA and lower NA baseline scores.

Time frame: From baseline, up to 12 months post-surgery

Correlation of Baseline PANAS score and the PROM - The Western Ontario and McMaster Universities Arthritis Index (WOMAC) Osteoarthritis Index

To evaluate the association between baseline PANAS score and the WOMAC Osteoarthritis Index. The PANAS is described in 3. above. The WOMAC is widely used in the evaluation of Knee Osteoarthritis. The self-administered questionnaire consists of 24 items divided into 3 subscales: pain (5 items), Stiffness (2 items) and Physical Function (17 items). Questions are scored on a scale of 0-4, which correspond to: None (0), Mild (1), Moderate (2), Severe (3), and Extreme (4). Scores for each subscale are summed up, with a possible score range of 0-20 for Pain, 0-8 for Stiffness, and 0-68 for Physical Function. The sum of the scores for all three subscales gives a total WOMAC score; higher scores indicating worse pain, stiffness, and functional limitations. The study will assess: Whether better clinical outcome at 12 months post surgery (using the WOMAC Index; lower scores indicate better knee health) is observed in patients with higher PA scores and lower NA scores at baseline.