A total knee replacement is a proven cost-effective treatment for end-stage osteoarthritis, with a positive effect on pain and function. However, only 80% of the patients are satisfied after surgery. It is known that high preoperative expectations and residual postoperative pain are important determinants of satisfaction, but also malalignment, poor function and disturbed kinematics can be a cause. The purpose of this study was to investigate the correlation between the preoperative function and the postoperative patient reported outcomes PROMs) as well as the influence of the postoperative functional rehabilitation on the PROMs. 57 patients (mean 62,9j ± 10,6j), who suffer from knee osteoarthritis and who were scheduled for a total knee replacement at our centre, participated in this study. The range of motion of the knee, the muscle strength of the M. Quadriceps and the M. Hamstrings and the functional parameters (‘stair climbing test’ (SCT), ‘Sit to stand’ (STS) and ‘6 minutes walking test’ (6MWT)) were measured the night before surgery, ±6 months and ±1 year after surgery. This happened respectively with the use of a goniometer, HHD 2, stopwatch and the ‘DynaPort Hybrid’. Correlations between pre- and postoperative values were investigated. Secondly, a prediction was made about the influence of the preoperative parameters on on the subjective questionnaires (KOOS, OXFORD and KSS) as well as a linear and logistic regression.Introduction
Methods
Recently a new version of the Knee Society Knee Scoring System has been developed, adapted to the lifestyle and activities of contemporary patients with a Total Knee Arthroplasty (TKA). It is subdivided into 4 domains including an Objective Knee Score, a Satisfaction Score, an Expectations Score and a Functional Activity Score. Before this scale can be used in non-English speaking populations, it has to be translated and validated for specific populations. The aim of this study was to translate and validate the New Knee Society Knee Scoring System (new KSS) for Dutch speaking populations. A Dutch translation of the New KSS was established using a forward-backward translation protocol. 137 patients undergoing TKA were asked to complete the Dutch translation of the New KSS as well as the Dutch WOMAC, Dutch KOOS and the Dutch SF12. To determine the test-retest reliability, 53 patients were asked to fill out a second questionnaire with one-week interval. We tested the test-retest reliability of the subjective domains of the New KSS by assessing the intra-class coefficient and the Pearson correlation coefficient between the first and second questionnaires. Systematic differences between the first and second questionnaires were investigated with T-tests and non-parametric statistics. Internal consistency of the Dutch new KSS was evaluated with Cronbach's alpha. The construct validity of the Dutch New KSS was determined by comparing it to the Dutch WOMAC, Dutch KOOS and Dutch SF12 using Pearson correlation coefficients. Content validity was assessed by examining the distribution and the floor and ceiling effects of the Dutch version of the new KSS.Background:
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