Subjective evaluation before and after total knee arthroplasty using the 2011 Knee Society Score

Patient satisfaction has been recognized as an important evaluation of total knee arthroplasty (TKA). Therefore, the 2011 Knee Society Knee Scoring System (2011 KSS) was developed in order to quantify patient satisfaction, expectations, and physical activities following TKA. However, very few reports have described subjective evaluation before TKA using the 2011 KSS, as the scoring system is still relatively new. Therefore, the degree of improvement and change over time after TKA has not been evaluated.

Forty-nine consecutive patients (79 knees) with a mean age of 74.8 ± 7.3 years were prospectively included in the study and evaluated preoperatively and one year postoperatively. The following questions were assessed using the 2011 KSS: (1) Do patient-derived clinical scores improve after TKA? (2) Do patient-derived clinical scores before TKA correlate with those after TKA? and (3) Are there correlations among each category of the 2011 KSS score?

The majority of categories showed significant improvements after TKA. The preoperative functional activities score was positively correlated with the postoperative symptoms, functional activities, and objective score. Each category of the 2011 KSS score correlated with others postoperatively.

All patient-derived scores except for patient expectation significantly improved postoperatively. The more functionally active patients before receiving TKA acquired more successful objective and functional outcomes, and the postoperative knee condition was directly influenced by each subscale of the 2011 KSS.