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

Long-term gait analysis in patients after total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Gait abnormalities have been described in patients after total knee arthroplasty (TKA), leading to the development of inter-joint coordination abnormalities and increased risk of falling. Such impairments have been reported to persist in the long-term, although the majority of studies assessed gait pattern especially in the first months after TKA.

RESEARCH QUESTION

What are the long-term gait impairments in patients after TKA compared to healthy age-matched subjects?

METHODS

A systematic search was conducted on MEDLINE/PubMed, EMBASE, CENTRAL and Scopus databases. Observational studies or randomized controlled trials investigating gait spatial-temporal, kinematic and kinetics parameters in a time-window longer than 6 months in patients with TKA compared to healthy age-matched subjects were included. Methodological quality was assessed using the modified Downs and Black (D&B) checklist and participants' characteristics, surgical procedures details and outcome measures were extracted. Pooled or un-pooled findings were categorized into "6 months - 1 year" and "more than 1 year" timepoint categories.

RESULTS

Twenty-eight studies (976 patients) were included. Overall quality was fair with a mean modified D&B score of 63.5 %. Reduced speed, stride length, cadence and longer stance phase were found in patients when compared to healthy individuals at "6 months - 1 year" follow-up. Spatial-temporal parameters deficits were also found at more than 1 year after TKA, where lower single-limb support and longer double-limb support durations were detected. These impairments occurred in concomitance with decreased knee range of motion along the sagittal and frontal planes and altered kinetic parameters. Hip kinematic and kinetic long-term impairments were also detected after TKA.

SIGNIFICANCE

These findings highlighted long-term gait pattern alterations in patients with TKA compared to age-matched healthy subjects. Future studies should identify interventions able to reduce long-term gait pattern alterations and improve function in patients after TKA.

Comparison of physical function, proprioception, muscle strength, postural balance, and walking in older women with and without total knee arthroplasty

The benefit of total knee arthroplasty (TKA) is that it alleviates pain caused by osteoarthritis; however, other postoperative effects on physical function are unclear. This study aimed to investigate the differences in physical function, proprioception, muscle strength, postural balance, and walking in older women with and without TKA. A total of 36 participants were included in this study; the TKA group comprised older women who underwent TKA (n = 18) and the non TKA group comprised older women who did not undergo TKA (n = 18). All the participants were evaluated for physical function, proprioception, muscle strength, postural balance, and walking. The outcome measures were compared between the 2 groups using an independent t test. Correlations were assessed using Pearson correlation coefficients. Participants in the TKA group had significantly reduced physical function, postural balance, and walking ability compared with those in the non TKA group (P < .05). In the TKA group, physical function was statistically correlated with proprioception, postural balance, and walking (P < .05); in particular, it had a strong correlation with proprioception (R > .60). In the non TKA group, postural balance was significantly associated with muscle strength and walking (P < .05). In particular, it was strongly correlated with walking (R > .90). This study demonstrated that older women undergoing TKA need to actively perform interventions to improve physical function, postural balance, and walking compared with older women with osteoarthritis.

EMG-EMG coherence during voluntary control of human standing tasks: a systematic scoping review

Background

Intra- or inter-muscular (EMG-EMG) coherence is a simple and non-invasive method for estimating central nervous system control during human standing tasks. Although this research area has developed, no systematic literature review has been conducted.

Objectives

We aimed to map the current literature on EMG-EMG coherence during various standing tasks to identify the research gaps and summarize previous studies comparing EMG-EMG coherence between healthy young and elderly adults.

Methods

Electronic databases (PubMed, Cochrane Library, and CINAHL) were searched for articles published from inception to December 2021. We incorporated studies that analyzed EMG-EMG coherence of the postural muscles in various standing tasks.

Results

Finally, 25 articles fulfilled the inclusion criteria and involved 509 participants. Most participants were healthy young adults, while only one study included participants with medical conditions. There was some evidence that EMG-EMG coherence could identify differences in standing control between healthy young and elderly adults, although the methodology was highly heterogeneous.

Conclusion

The present review indicates that EMG-EMG coherence may help elucidate changes in standing control with age. In future studies, this method should be used in participants with central nervous system disorders to understand better the characteristics of standing balance disabilities.

Investigating Knee Joint Proprioception and Its Impact on Limits of Stability Using Dynamic Posturography in Individuals with Bilateral Knee Osteoarthritis-A Cross-Sectional Study of Comparisons and Correlations

(1) Background: Proprioception and limits of stability can significantly impact static and dynamic balance. Knee proprioception and limits of stability may be impaired in individuals with knee osteoarthritis (KOA). Impaired knee proprioception may impact the limits of stability, and understanding the associations between these factors is important for formulating treatment strategies in this population. The objectives of this study are to (a) compare the knee joint position error (JPE) and limits of stability between KOA and asymptomatic individuals and (b) assess the correlation between knee JPE and the limits of stability in KOA individuals. (2) Methods: This cross-sectional study included 50 individuals diagnosed with bilateral KOA and 50 asymptomatic individuals. Knee JPE was measured using a dual digital inclinometer at 25° and 45° of knee flexion (in the dominant and nondominant legs). The limits of stability variables, including reaction time (s), maximum excursion (%), and direction control (%), were evaluated using computerized dynamic posturography. (3) Results: The magnitude of the mean knee JPE is significantly larger in KOA individuals (p < 0.001) compared to asymptomatic individuals assessed at 25° and 45° of knee flexion in both the dominant and nondominant legs. The limits of stability test showed that KOA group individuals had a longer reaction time (1.64 ± 0.30 s) and reduced maximum excursion (4.37 ± 0.45) and direction control (78.42 ± 5.47) percentages compared to the asymptomatic group (reaction time = 0.89 ± 0.29, maximum excursion = 5.25 ± 1.34, direction control = 87.50 ± 4.49). Knee JPE showed moderate to strong correlations with the reaction time (r = 0.60 to 0.68, p < 0.001), maximum excursion (r = -0.28 to -0.38, p < 0.001) and direction control (r = -0.59 to -0.65, p < 0.001) parameters in the limits of stability test. (4) Conclusions: Knee proprioception and limits of stability are impaired in KOA individuals compared to asymptomatic individuals, and knee JPE showed significant relationships with the limits of stability variables. These factors and correlations may be considered when evaluating and developing treatment strategies for KOA patients.

A comparison of balance and fall risk in patients with unilateral and bilateral total knee arthroplasty

BACKGROUND

Static or dynamic postural control cannot be fully restored in patients with knee osteoarthritis, even after total knee arthroplasty (TKA), which may contribute to an increased risk of falls in the elderly.

OBJECTIVE

To evaluate balance and the fall risk before and after TKA in patients with bilateral knee osteoarthritis. Secondary outcomes were patient-reported and performance-based activity limitations.

METHODS

A total of 45 patients were separated into two groups as unilateral TKA (UTKA, n= 24) and bilateral TKA (BTKA, n= 21) groups. All the patients received standard postoperative physical therapy for 3 months. Balance and fall risk (Biodex Balance System SD), patient-reported and performance-based functionality (WOMAC, 30-second chair-stand test, 9-step stair climbing test and 40-meter fast-paced walk test) and Short Form-12 (SF-12) were evaluated at preoperatively, and at 3 months postoperatively.

RESULTS

There was no difference between the groups in postoperative fall risk and balance (p> 0.05). The BTKA group obtained better results in the sit-to-stand test and SF-12 physical dimension (p< 0.05).

CONCLUSIONS

UTKA and BTKA interventions and the standard postoperative rehabilitation were seen to improve balance and quality of life, and reduce the fall risk, patient-reported and performance-based activity limitations. However, despite improvements in balance, the risk of falling persists.

Nonlinear and Linear Measures in the Differentiation of Postural Control in Patients after Total Hip or Knee Replacement and Healthy Controls

Primary osteoarthritis treatments such as a total hip (THR) or knee (TKR) replacement lead to postural control changes reinforced by age. Balance tests such as standing with eyes open (EO) or closed (EC) give a possibility to calculate both linear and nonlinear indicators. This study aimed to find the group of linear and/or nonlinear measures that can differentiate healthy people and patients with TKR or THR from each other. This study enrolled 49 THR patients, 53 TKR patients, and 16 healthy controls. The center of pressure (CoP) path length, sample entropy (SampEn), fractal dimension (FD), and the largest Lyapunov exponent (LyE) were calculated separately for AP and ML directions from standing with EO/EC. Cluster analysis did not result in correct allocation to the groups according to all variables. The discriminant model included LyE (ML-EO, ML-EC, AP-EC), FD (AP-EO, ML-EC, AP-EC), CoP-path AP-EC, and SampEn AP-EC. Regression analysis showed that all nonlinear variables depend on the group. The CoP path length is different only in THR patients. It was concluded that standing with EC is a better way to assess the amount of regularity of CoP movement and attention paid to maintain balance. Nonlinear measures better differentiate TKR and THR patients from healthy controls.

Symptoms and signs of long COVID: A rapid review and meta-analysis

Background

Long COVID is defined as symptoms and signs related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that are present at least four weeks following acute infection. These symptoms and signs are poorly characterised but may be associated with significant morbidity. We sought to synthesise the evidence on their incidence to guide future research, policy and practice.

Methods

We searched Medline and Embase for longitudinal cohort studies from January 2020 to July 2021 that investigated adults with long COVID at least four weeks after acute infection. Risk of bias was assessed using the Joanna Briggs Institute checklist for cohort studies. Random-effects meta-analyses were performed with subgroup analysis by follow-up time (4-12 vs more than 12 weeks).

Results

19 studies were included, 13 of which included patients hospitalised with COVID-19. The total sample size was 10 643 and the follow-up time ranged from 30 to 340 days. Risk of bias was assessed as high in one study, moderate in two studies and low in the remaining 16 studies. The most common symptoms and signs seen at any time point in long COVID were fatigue (37%; 95% confidence interval (CI) = 23-55), dyspnoea (21%; 95% CI = 14-30), olfactory dysfunction (17%; 95% CI = 9-29), myalgia (12%; 95% CI = 5-25), cough (11%; 95% CI = 6-20) and gustatory dysfunction (10%; 95% CI = 7-17). High heterogeneity was seen for all meta-analyses and the presence of some funnel plot asymmetry may indicate reporting bias. No effect of follow-up time was found for any symptom or sign included in the subgroup analysis.

Conclusions

We have summarised evidence from longitudinal cohort studies on the most common symptoms and signs associated with long COVID. High heterogeneity seen in the meta-analysis means pooled incidence estimates should be interpreted with caution. This heterogeneity may be attributable to studies including patients from different health care settings and countries.