Does knee awareness differ between different knee arthroplasty prostheses? A matched, case-control, cross-sectional study.

Morten G Thomsen,Anders Troelsen,Thomas Kallemose,Roshan Latifi,Henrik Husted

doi:10.1186/s12891-016-1001-3

Abstract

BackgroundLow knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations. To accommodate this manufacturers of TKAs have developed new prosthetic designs that potentially could give patients a more natural feeling knee during activities.The purpose af this study was to compare the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) of patients treated with a previous generation standard Cruciate Retaining (CR) TKA to the scores obtained by patients treated with a newer generation CR TKA or a mobile bearing CR TKA.MethodsWe identified all patients receiving a new generation CR TKA or mobile bearing TKA at our institution between 2010 and 2012. These were matched to a population of patients receiving a standard CR TKA regarding age, gender, year of surgery, Kellgren-Lawrence (KL) grade and pre- and postoperative knee alignment. Patients were asked to complete the FJS and OKS questionnaires. Of the 316 patients completing the survey 64 standard CR TKAs to 35 new generation CR TKAs and 121 standard CR TKAs to 68 mobile bearing TKAs were matched. The FJS and OKS scores of the three TKA designs were compared.ResultsWhen comparing the new generation CR TKAs to the standard CR TKAs we found statistically significant higher OKS and FJS scores (6 (p = 0.04) and 16 (p = 0.03) points respectively) for the new generation CR TKAs. When comparing the mobile bearing TKAs to the standard CR TKAs we found a statistically significant higher OKS score (3 points, p = 0.04), and a higher but non-significant FJS score (4 points, p = 0.48) for the mobile bearing TKAs.ConclusionsPatients receiving the new generation CR TKA obtained higher FJS and OKS scores when compared to patients receiving a standard CR TKA, indicating that the use of this newer prosthetic design facilitate less knee awareness and better function after TKA.

Highlights

Low knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations
Patients receiving the new generation Cruciate Retaining (CR) TKA obtained higher Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) scores when compared to patients receiving a standard CR TKA, indicating that the use of this newer prosthetic design facilitate less knee awareness and better function after TKA
Forgotten joint score When comparing the newer generation CR and previous generation CR TKA knees, we found a statistically significant higher FJS score for the newer generation CR group by 15 points (p = 0.033) (Table 2)

Summary

Introduction

Low knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations. To accommodate this manufacturers of TKAs have developed new prosthetic designs that potentially could give patients a more natural feeling knee during activities. New prosthetic designs have been developed with the aim of giving patients enhanced knee function and a more natural feeling knee during activities of daily living (ADL). Examples of these new prosthetic designs are High-Flex-, Mobile Bearing- and gender specific TKA’s. Knee awareness describes the patients’ ability to forget the artificial joint in everyday life, which is considered to be the ultimate goal

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