A proportion of TKA recipients following TKA are dissatisfied with their outcome. Our hypothesis is that patient satisfaction with TKA and perception of success of surgery are associated with patient comorbidities and overall health status, surgical and anaesthetic techniques as well as processes of post-operative care after TKA. The aims were to (i) measure the incidence of patient unfavourable outcomes-defined as dissatisfaction with the surgery or lack of joint-specific global improvement-1 year after TKA, and to explore the differences between these two outcomes of interest; (ii) assess the relationship between the development of these unfavourable outcomes and patient-reported knee function and overall quality of life; (iii) explore the associations between pre- and peri-operative variables and the development of these unfavourable outcomes 1 year after TKA.
This study includes analysis of data from a prospective cohort of 1017 TKA recipients. Pre-operative patient variables, surgical and acute-care data were collected. The Oxford knee score and the global perception of improvement were used to assess satisfaction and success 365 days post-surgery.
From 1017 patients (56% female), mean age 68 years and BMI 32, 68 pts (7%) were dissatisfied with the outcome of surgery, 141 pts (14%) believed surgery was unsuccessful 1 year after TKA. A negative outcome was noted in 151 (15%) patients for either satisfaction or success, and 58 (6%) of patients reported neither good satisfaction nor success after surgery. Dissatisfied patients reported worse mean OKS (26.4 [SD 8.03] vs 42.3 [SD 5.21], p < 0.001) and mean EQ VAS (64.9 [SD 19.49] vs 81.8 [SD 14.38], p < 0.001) than satisfied patients. Patients who reported unsuccessful surgery also showed significantly lower mean OKS (30.9 [SD 9.29] vs 42.9 [SD 4.39], p < 0.001) and mean EQ VAS (68.2 [SD 18.61] vs 82.7 [SD 13.77], p < 0.001). Univariate analysis of predictors of unfavourable outcome post-TKA showed that financial status, obstructive sleep apnoea (OSA), ASA class > 2 and not resurfacing the patella were factors associated with the development of dissatisfaction with TKA and with patient perceived unsuccessful results of TKA. Multivariable logistic regression of patient satisfaction and success of TKA showed that compensation cases (OR 26.91, p < 0.001 for dissatisfaction and OR 11.49, p = 0.001 for unsuccessful TKA), obstructive sleep apnoea (OR 2.18, p = 0.04 for dissatisfaction and OR 1.82, p = 0.04 for unsuccessful TKA), ASA grade > 2 (OR 1.83, p = 0.04 for dissatisfaction and OR 1.57, p = 0.03 for unsuccessful TKA)and the development of a complication after TKA (OR 3.4, p < 0.001 for dissatisfaction and OR 2.39, p < 0.001 for unsuccessful TKA) were associated with the development of a negative outcome in both groups. Patella preservation (OR 1.96, p = 0.03) was associated with dissatisfaction, whereas the use of cruciate retaining femoral prosthesis was associated with less successful results of TKA (OR 1.78, p = 0.009).
An unfavourable outcome occurs in approximately 7-15% of patients following TKA. The incidence varies with how an unfavourable result is defined and many factors are associated with this outcome though prosthetic design or patella resurfacing do not appear to be important.