Article
In-vivo kinematics and patient reported clinical outcomes of three different total knee replacement designs during a step-up motion: A randomised control trial
Search Medline for
Authors
-
Theresa Wallner
- Trauma and Orthopaedic Research Unit, Canberra Hospital, Universitätsklinikum Carl Gustav Carus, Canberra, Australia
-
Joseph Lynch
- Trauma and Orthopaedic Research Unit, Canberra Hospital, Canberra, Australia
-
Diana Perriman
- Trauma and Orthopaedic Research Unit, Canberra Hospital, Canberra, Australia
-
Mark Pickering
- University of New South Wales, Canberra, Australia
-
Jennie Scarvell
- University of Canberra, Canberra, Australia
-
Catherine Galvin
- Australian National University, Canberra, Australia
-
Paul Smith
- Trauma and Orthopaedic Research Unit, Canberra Hospital, Canberra, Australia
| Published: | October 23, 2023 |
|---|
Outline
Text
Objectives: While total knee replacements (TKR) are, in general, a successful procedure to alleviate joint pain, and restore function, select patients experience continuing discomfort as well as unsatisfactory functional outcomes postoperatively [1], [2]. These deficits are particularly evident in highly demanding kinematic movements such as stair-ascent. The aim of this study was to compare the kinematics of three common TKR designs during a step-up motion. Secondly, this study examined the relationships between patient outcomes and step-up kinematics.
Methods: This study was a prospective randomised control trial. 68 patients were randomised to receive one of three TKR implants: cruciate-retaining fixed bearing (CR-FB), cruciate-retaining rotating platform (CR-RP) or posterior-stabilised fixed bearing (PS-FB). Patients performed a step-up task which was imaged via a single-plane fluoroscopy at 12- and 24-months postoperatively. Implant models were registered to the fluoroscopy using bespoke software (OrthoVis), generating kinematic data. Patient reported outcome measures (PROMs) were assessed using the Oxford Knee Score (OKS) and a visual analogue scale (VAS) for pain and satisfaction. Linear models were used to test the effect of implant design on clinical outcomes, kinematic ranges, terminal flexion kinematics, and throughout the flexion range.
Results and conclusion: 49 patients with a minimum 1-year follow-up were included in the final analysis. This analysis showed that there were no significant differences in any clinical outcomes for the three different implant types. There were also no differences in the total range of rotation and translation for any kinematic parameters between designs (Table 1 [Tab. 1]). However, CR-FB designs started and remained more posterior on the tibia during the step-up motion.Furthermore, the CR-RP design consistently demonstrated greater external femoral rotation. More internal femoral rotation at terminal extension was associated with improved Oxford Knee scores, as well as VAS pain and satisfaction scores (p= 0.07 β= -0.36; p= 0.03 β= -0.6; p= 0.00 β= 2.03, respectively).
The findings of this study provide insights into the function of different knee replacement designs during a step-up motion. Future research could consider how implant design influences other complex movements and how this is related to patient reported outcomes. These results provide clinicians with a more kinematically informed choice for implant selection, which may allow for better management of a patient's functional expectations.
References
- 1.
- Bourne RB, Chesworth BM, Davis AM, Mahomed NN, Charron KD. Patient satisfaction after total knee arthroplasty: who is satisfied and who is not? Clin Orthop Relat Res. 2010 Jan;468(1):57-63. DOI: 10.1007/s11999-009-1119-9
- 2.
- Nakahara H, Okazaki K, Mizu-Uchi H, Hamai S, Tashiro Y, Matsuda S, Iwamoto Y. Correlations between patient satisfaction and ability to perform daily activities after total knee arthroplasty: why aren't patients satisfied? J Orthop Sci. 2015 Jan;20(1):87-92. DOI: 10.1007/s00776-014-0671-7
