Outcome of total hip arthroplasty, but not of total knee arthroplasty, is related to the preoperative radiographic severity of osteoarthritis

We read the study of Tilbury et al. with great interest (Tilbury et al. 2016). Without doubt, the topic of their article, the impact of radiographic severity of hip and knee osteoarthritis on patients’ quality of life after joint replacement is important. The authors found an association between higher arthritis grading and better pain relief and functional outcome after total hip replacement. However, the PROMS analysis of 271 included total knee arthroplasty patients showed no influence of the preoperative arthritis severity on the postoperative quality of life. In 2013, we published an analysis of patients’ quality of life after total knee arthroplasty (Schnurr et al. 2013). We included 996 TKA patients into our study and used a logistic regression model to detect influence of demographic factors, operative and radiologic parameters on patients’ satisfaction after operation. In comparison to high-grade osteoarthritis Kellgren Lawrence IV°, the risk for dissatisfaction was about 2.5–3 fold elevated for the lower arthritis grades. Indeed, methods of our study and the publication of Tilbury et al. differ with view to assessment of patients’ quality of life. However, as the authors mention in their discussion other studies show better outcomes in TKA patients with a higher preoperative arthritis grade. We would like to point out, that besides our study, there are other publications, indicating better outcome for TKA patients with higher osteoarthritis severity (Merle-Vincent et al. 2011, Polkowski et al. 2013). In summary, most studies show a strong association between low osteoarthritis severity and worse outcome after total knee arthroplasty.