Expectation fulfillment is associated with good outcomes and patient satisfaction after knee arthroplasty: a prospective study in a multi-ethnic Asian population

We aimed to evaluate the relationship between patient expectations and outcomes after knee arthroplasty (KA) in an Asian population in Singapore. We recruited consecutive patients with severe knee osteoarthritis (KOA) scheduled for KA. Pre-operatively, patients provided socio-demographic data and completed the Hospital for Special Surgery Knee Replacement Expectations Survey (HSS-KRES) for baseline pre-operative expectations and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for baseline pain and function. Telephone interviews were conducted at 6- and 12-months post-operatively to collect the WOMAC, satisfaction with KA, and the extent to which pre-operative expectations had been fulfilled. We included 1136 patients (mean age 65.9 years, 69.9% female), of which 1103 and 1089 completed the telephone interviews at 6- and 12-months post-KA respectively. In the multivariable models, expectation fulfilment was consistently associated with improvements in WOMAC pain and function at 6- and 12-months post-operatively, but not the baseline expectations. In the sensitivity analyses, expectation fulfilment was also found to be significantly associated with the achievement of minimal clinically important difference (MCID) for WOMAC pain and function at both 6- and 12-months. Expectation fulfilment was associated with patient satisfaction in the adjustment models at both 6- and 12-months after KA. The fulfilment of expectations, rather than pre-operative expectations, is associated with improvements in WOMAC pain, function and overall satisfaction at 6- and 12-months after KA.