Total Versus Robotic Assisted Unicompartmental Knee Replacement

Oxford knee score

Knee specific functional outcome measure. It consists of twelve questions assessed on a Likert scale with values from 0 to 4, to give a summative score. This is measured on a scale from 0 (worst) to 48 (best).

Oxford knee score and Activity and Participation Questionnaire

The Oxford knee score is a knee specific functional outcome measure. It consists of twelve questions assessed on a Likert scale with values from 0 to 4, to give a summative score. This is measured on a scale from 0 (worst) to 48 (best). The additional Activity and Participation Questionnaire is a higher functioning supplementary questionnaire consisting of a further eight questions scored 0 (worst) to 4 (best).

Forgotten Joint Score

Knee specific functional outcome. It uses a five-point Likert response format, consisting of 12 equally weighted questions with the raw score transformed to range from zero (worst) to 100 (best) points.

Patient satisfaction

Patient satisfaction will be assessed following surgery by asking four questions with a different focus: i. "Overall how satisfied are you with the results of your knee replacement surgery?" ii. "How satisfied are you with the results of your knee replacement surgery for improving your ability to do housework or yard work (such as cooking, cleaning, or gardening and raking leaves)?" iii. "How satisfied are you with the results of your knee replacement surgery for improving your ability to do recreational activities (such as taking walks, swimming, bicycling, playing golf, dancing, going out with friends)?" iv. "How satisfied are you with the results of your knee replacement surgery for relieving your pain?" The response to each question will be recorded using a four point Likert scale: very satisfied, somewhat satisfied, somewhat dissatisfied, and very dissatisfied.

EQ-5D-3L

Quality of life will be assessed using the EQ-5D-3L general health questionnaire which evaluates five domains (-5D), which include: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. This is a two page questionnaire that consists of five dimensions, with the responses recorded at three levels (3L) of severity (no problems; some problems or extreme problems). The utility index is on a scale of -0.594 to 1, where 1 represents perfect health and a negative value represents a state perceived as worse than death. The second page consists of a standard vertical 20cm visual analogue scale (EQ-5D VAS) which is transformed to a scale of 0 (worst) to 100 (best) measuring current health-related quality of life. Each patient's health state, derived from the EQ-5D, will be measured before and after their surgery to determine the change in their health gain or loss after their knee replacement surgery.