SF-12
The SF-12 is a generic measure of a patient’s general
physical and mental well-being [67] based on the SF-36
score [68]. Patients’ general and physical wellbeing can
influence the outcome of joint-specific scores following
TKA [69]. The SF-12 has been used extensively to measure
outcomes following TKA [69–75]. Reliability coefficients
of 0.84 and 0.80 were observed for the physical
component and mental components respectively in a
pre-operative TKA population [76]. The level of patient
satisfaction with TKA patients’ pain relief and function
correlated with the improvement in the physical component
of the SF-12 score (r = 0.51, P < 0.001 and r = 0.60,
P < 0.001) respectively. The minimal clinically important
difference (MCID) for the physical component of the
SF-12 was 4.5 points (95 % CI = 3.9 to 5.2) and 4.8
points (95 % CI = 4.2 to 5.4) for pain relief and function
component respectively