Effects of total knee arthroplasty for primary knee osteoarthritis on postural balance: A systematic review

Knee osteoarthritis is often related to physical function impairment. Although total knee arthroplasty is considered effective for advanced cases of knee osteoarthritis, its effects on postural balance is a topic of debate.

What are the effects of total knee arthroplasty for primary knee osteoarthritis on postural balance compared to preoperative status and/or to healthy controls?.

Longitudinal studies (with more than 1-month follow-up) assessing postural balance measures (either clinical-based such as balance scales or laboratory-based such as postural sway) were considered eligible and selected in a 2-phase process. Six main electronic databases were searched, complemented by 3 grey literature sources. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Tools.

A total of 19 studies were included for qualitative synthesis, of which 14 had low and 5 had a moderate risk of bias. The follow-up period ranged from 1-24 months. Most studies (n = 11) presented comparisons to preoperative status only. From these, 7 studies reported relevant improvements in postural balance, 2 reported partial improvements, and 2 no improvements. The remaining studies (n = 8) presented comparisons to healthy controls and, although improvements following total knee arthroplasty were consistently observed, only one study reported postural balance measures comparable to that of controls.

The majority of studies reported relevant improvements (especially in clinical-based measures) compared to preoperative evaluations, although inconsistencies were found possibly due to variability in studies' populations, assessment tools, and follow-up times. Despite this, persistent deficits in postural balance were commonly observed when compared to healthy controls.

This evidence synthesis could better inform clinicians and researchers about the therapeutic effects and limitations of total knee arthroplasty concerning postural balance. Standardization of assessment tools is recommended to strengthen the certainty of cumulative evidence.