Walking Speed and Maximal Knee Flexion During Gait After Total Knee Arthroplasty: Minimal Clinically Important Improvement Is Not Determinable; Patient Acceptable Symptom State Is Potentially Useful.
BACKGROUND
Total knee arthroplasty (TKA) is the operation of choice in patients with end-stage knee osteoarthritis (OA). Up to 1 in 5 patients still encounter functional limitations after TKA, partly explaining patient dissatisfaction. Which gait ability to target after TKA remains unclear. To determine whether Minimal Clinical Important Improvement (MCII) or Patient Acceptable Symptom State (PASS) values could be derived from gait parameters recorded in patients with TKA. And, if so, to define those values.


METHODS
In this ancillary study, we retrospectively analyzed gait parameters of patients scheduled for a unilateral TKA between 2011 and 2013. We investigated MCII and PASS values for walking speed and maximal knee flexion using anchor-based methods: 5 anchoring questions based on perceived body function and patients' satisfaction.


RESULTS
Over the study period, 79 patients performed a clinical gait analysis the week before and 1 year after surgery, and were included in the present study. All clinical and gait parameters improved 1 year after TKA. Nevertheless, changes in gait outcomes were not associated with perceived body function or patients' satisfaction, precluding any MCII estimation in gait parameters. PASS values, however, could be determined as 1.2 m/s for walking speed and 50° for maximal knee flexion.


CONCLUSION
In this study, we found that MCII and PASS values are not necessarily determinable for gait parameters after TKA in patients with end-stage OA. Using anchor questions based on perceived body function and patient's satisfaction, MCII could not be defined while PASS values were potentially useful.


LEVEL OF EVIDENCE
Level III.
['Bonnefoy-Mazure|Alice|A|', 'Lübbeke|Anne|A|', 'Miozzari|Hermes H|HH|', 'Armand|Stéphane|S|', 'Sagawa|Yoshimasa|Y|', 'Turcot|Katia|K|', 'Poncet|Antoine|A|']
D019645:Arthroplasty, Replacement, Knee D005684:Gait D006801:Humans D007719:Knee Joint D020370:Osteoarthritis, Knee D012189:Retrospective Studies D000072797:Walking Speed
gait total knee arthroplasty Minimal Clinical Important Improvement Patient Acceptable Symptom State osteoarthritis knee kinematic