Beyond Pain Relief: Physical Activity as a Preventive Strategy After Total Knee Arthroplasty

Commentary Physical activity offers well-established health benefits, including reduced risks of cardiovascular disease, diabetes, some cancers, and premature mortality1. A recent systematic review and meta-analysis indicated that achieving approximately 7,000 steps per day was associated with a reduction in major health risks and may serve as a practical public health target2. In the current nationwide cohort study from the Republic of Korea, Park et al. present important findings that highlight the role of physical activity in modulating cardiovascular and cerebrovascular risks following total knee arthroplasty (TKA). By analyzing data from >200,000 patients using health examination and claims records, they show that individuals undergoing TKA exhibited higher incidences of vascular events compared with matched controls. More importantly, they find that higher postoperative physical activity levels and positive changes in activity from preoperative to postoperative periods were associated with a reduced risk of both cardiovascular and cerebrovascular events. These findings are clinically meaningful. Although TKA is the definitive surgical treatment for improving pain, quality of life, and functional outcomes in patients with knee osteoarthritis, it also provides a unique opportunity to increase physical activity levels, which, as this study suggests, may yield broader systemic vascular benefits. Nonetheless, several methodological considerations warrant further discussion. Previous studies investigating physical activity following TKA have reported inconsistent results; some reported improvements in physical activity levels, others observed reductions, and some detected no meaningful change3. In this study, physical activity was assessed on the basis of the frequency of moderate to vigorous activities using self-reported data from health examinations. Although self-reported questionnaires are commonly used and practical for large cohort studies, self-reported physical activity is inherently subjective, is vulnerable to recall bias, and is influenced by the type of activities assessed and the structure of the questionnaire. Moreover, it differs from validated activity measures widely adopted in arthroplasty research, such as the University of California Los Angeles (UCLA) activity score. Although the study’s conclusions remain valid, the lack of standardized and validated physical activity metrics makes it challenging to compare findings across studies and may limit the accuracy and applicability needed to inform orthopaedic clinical care. In contrast, physical activity evaluation based on step counts offers an easily measurable and understandable metric. The increasing availability of wearable devices offers a powerful tool for precise, continuous tracking of daily steps and activity intensity, enabling clinicians to monitor recovery trajectories and guide rehabilitation. Based on the cardiovascular disease incidence reported in this study, our power analysis suggests that a sample size of 4,919 patients who underwent TKA would be required to detect a meaningful difference in vascular risk. Encouragingly, 1 recent arthroplasty study using wearable technology has already enrolled >4,700 participants4, demonstrating the feasibility of larger-scale investigations. Such tools may bridge the gap between epidemiologic evidence and real-world implementation. It is also important to recognize that the effects of TKA on vascular risk and mortality rate remain a subject of debate. Some studies, including this study, have shown an increase in vascular risk and mortality rate following TKA, whereas others have observed decreased risks. Some longitudinal studies have indicated a decreased risk in the first 8 to 10 years after surgery, followed by a subsequent increase5. These discrepancies likely result from differences in patient populations, follow-up durations, sample sizes, outcome definitions, and control group selection, highlighting the need for standardized study designs and long-term surveillance. The strengths of this study include its use of a nationwide database, large sample size, and robust propensity score matching. The findings are timely and clinically relevant, especially given the growing global demand for TKA. Clinically, they reinforce the importance of incorporating physical activity counseling into postoperative care. Given the pain relief and functional improvements typically observed after TKA, clinicians should actively encourage patients to maintain or increase physical activity levels, not only to optimize joint outcomes but also to support vascular health. Tailored rehabilitation programs, combined with objective monitoring through wearable technology, may enhance patient engagement and sustain adherence over time. In conclusion, this study makes a valuable contribution to our understanding of physical activity’s role in vascular health following TKA. It also highlights a broader shift in orthopaedic care, one that incorporates the principles of preventive medicine. As orthopaedic surgeons, we have the opportunity to promote lifelong mobility and systemic health, extending our impact beyond the operating room.