Patient satisfaction after total knee arthroplasty is affected by their general physical well-being

Purpose

We hypothesise that patients with a worse post-operative generic physical health, and those with a subclinical improvement, will have a greater rate of dissatisfaction with their total knee arthroplasty (TKA) despite improvement in their knee function.

Methods

Prospectively complied data for 2,330 primary TKA were used. Patient demographics, comorbidity, and pre- and post-operative (1 year) Oxford knee scores (OKS) and Short Form (SF-) 12 scores were collected. Patient satisfaction was also assessed 1 year post-operatively. The satisfaction rate of patients with a poor post-operative SF-12 physical component summary (PCS score) (≤40 points) and those with a subclinical improvement (<4 points) in the score were compared to those with a score of more than 40 and a clinically significant improvement, respectively.

Results

More than half of the patients (n = 1,220) had a poor post-operative SF-12 PCS, and a third (n = 722) had a subclinical improvement in their general physical health after TKA. These patients were more likely to be older in age, suffer with concomitant back pain, and pain in other joints, and have a significantly worse pre-operative mental well-being score (SF-12) and OKS (all p < 0.04 on regression analysis). Both groups had a clinically significant improvement in their OKS post-operatively (p < 0.001), but it was 10 and 8 points less, respectively, than those patients with a SF-12 PCS of more than 40, and a clinical significant improvement in their PCS score (p < 0.001). Logistic regression analysis demonstrated that patients who had a poor post-operative SF-12 PCS (odds ratio 7.9, p < 0.001) and those with a subclinical improvement in their general physical health (odds ratio 5.1, p < 0.001) after TKA were significantly less likely to be satisfied.

Conclusion

Despite benefitting from a significant improvement in their OKS after TKA, patients with a poor post-operative SF-12 PCS and those with a subclinical improvement in their general physical well-being are significantly less likely to be satisfied at 1 year.

Level of evidence

Retrospective comparative study, Level III.