Effect of the Knee Replacement Surgery on Activity Level Based on Activpal: A Systematic Review and Meta-analysis Study

Background: The knee replacement (KR) surgery is done to restore the activity level and reduce the risk of experiencing disabilities. The outcomes of this surgery is evaluated mainly with subjective tools or low validity objective tools. However, the effect of the surgery on activity level using high validity objective accelerometer is still in question. Methods: : A systematic review and meta-analysis were conducted to find out if the knee replacement surgery alone could enhance the physical activity based on high validity accelerometer, ActivPAL, after at least six months of the surgery. Two independent reviewers evaluated five electronic databases (Cochrane-Central-Register-of-Controlled Trials, EMBASE, PubMed, and Web of Science, and Scopus) to find relative studies between January 2000 and October 2021. The quality assessments and risk of bias assessments were examined. Results: : Three articles were included with 202 participants (86 males, 116 females), with an average age of 64 years and an average 32 kg/m² body mass index. The results found that the number of steps was significantly improved up to 36.35% and 45.5% after six-months and one-year of the surgery, respectively. However, these changes did not meet the recommended activity level guideline and could be related to the patients' health status and their activity level before the surgery. No significant changes were seen in sedentary time, standing time, and upright time after six-months and one-year follow-up. Heterogeneity among studies was low to moderate (0%- 57%). Conclusion: The knee replacement surgery is an effective treatment to improve the quality of life in patients with severe knee injuries; however, to achieve the maximum benefit of the surgery the sedentary time should be reduced. Various factors have impacts on surgical success. Thus, further studies are needed to add these factors using high validity monitors.