Abstract
PurposeThe Korean Knee score (KKS) was designed to reflect the floor-sitting lifestyle that necessitates high knee flexion. The purpose of this study is to assess whether the KKS reflects the floor-sitting lifestyle more accurately than the previously developed Knee Society clinical rating system. In addition, the presence of ceiling effects was compared between the two rating systems.Materials and MethodsEighty-one consecutive patients (120 knees) who were assessed regularly after total knee arthroplasty (TKA) on an outpatient basis between January 2012 and December 2012 were enrolled. All patients were asked to complete a questionnaire to assess the Knee Society Knee score (KSKS), Knee Society Function score (KSFS), and KKS.ResultsAt the final follow-up, the mean KSKS, KSFS, and KKS were 91.2, 86.0, and 70.1, respectively, and the scores were similar between the ≥125° maximum flexion group and <125° maximum flexion group. However, the 'floor life' subdomain score of the KKS was significantly higher in the >125° maximum flexion group (15.13 vs. 11.24, p=0.001). The number of cases with the highest possible score was 24 (20%) for the KSKS and 47 (39%) for the KSFS, whereas none of the cases obtained the highest possible KKS. According to the standard deviation method, more substantial ceiling effects were present in the KSKS (83 cases, 69.1%) and KSFS (67 cases, 55.8%) than in the KKS (23 cases, 19.2%).ConclusionsAlthough, the KKS was effective in reducing the ceiling effect, it demonstrated limited improvement in assessing the ability to perform high knee flexion after TKA. However, the 'floor life' subdomain of KSS appeared to be valid for evaluating high flexion of the knee.
Highlights
Total knee arthroplasty (TKA) has been recognized as a successful surgical procedure for the treatment of knee arthritis refractory to conservative therapy
The Knee Society Knee score (KSKS) and Knee Society Function score (KSFS) are most commonly used for the assessment of the knee joint; they may not be reliable for the assessment of the ability to perform high flexion in Korean patients who are expected to sit on the floor more often than westerners
The purpose of this study is to investigate whether the Korean Knee score (KKS) system is useful for evaluating the ability to perform high flexion after total knee arthroplasty (TKA) and reducing the ceiling effect compared to the KSKS and KSFS
Summary
Total knee arthroplasty (TKA) has been recognized as a successful surgical procedure for the treatment of knee arthritis refractory to conservative therapy. TKA has been associated with favorable objective outcomes and high patient satisfaction1), efforts have been continuously made to improve objectivity in the clinical assessment of postoperative results by developing multiple scoring systems. Such systems assign a point value for each. The Knee Society Knee score (KSKS) and Knee Society Function score (KSFS) are most commonly used for the assessment of the knee joint; they may not be reliable for the assessment of the ability to perform high flexion in Korean patients who are expected to sit on the floor more often than westerners. Choi et al.7) reported that the most common complaints among Korean patients after TKA were the difficulty of standing up from the www.jksrr.org
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
