Aims. To validate the English language Forgotten Joint Score-12 (FJS-12)
as a tool to evaluate the outcome of hip and knee arthroplasty in
a United Kingdom population. Patients and Methods. All patients undergoing surgery between January and August 2014
were eligible for inclusion. Prospective data were collected from
205 patients undergoing total hip arthroplasty (THA) and 231 patients
undergoing total knee arthroplasty (TKA). Outcomes were assessed
with the FJS-12 and the Oxford Hip and Knee Scores (OHS, OKS) pre-operatively,
then at six and 12 months post-operatively. Internal consistency,
convergent validity, effect size, relative validity and ceiling
effects were determined. Results. Data for the TKA and THA patients showed high internal consistency
for the FJS-12 (Cronbach α = 0.97 in TKAs, 0.98 in THAs). Convergent
validity with the Oxford Scores was high (r = 0.85 in TKAs, r =
0.79 for THAs). From six to 12 months, the change was higher for
the FJS-12 than for the OHS in THA patients (effect size d = 0.21 versus -0.03). Ceiling
effects at one-year follow-up were low for the FJS-12 with just
3.9% (TKA) and 8.8% (THA) of patients achieving the best possible
score. Conclusion. The FJS-12 has strong measurement properties in terms of validity,
internal consistency and sensitivity to change in TKA and THA patients.
Low ceiling effects and good relative validity allow the monitoring
of