Knee arthroplasty: an international systemic review of epidemiological trends.

Background: In response to various socio-economic factors and technological advancements, knee arthroplasty procedures have steadily increased. To date, epidemiological analyses have been conducted on a single-country basis. The aims of this article are: (1) to identify arthroplasty databases by country, (2) to verify the international comparability of coding, (3) to study retrospective epidemiological trends, and (4) to analyze projections by country. The hypothesis is that countries will follow similar trends, though with varying time lags.

Materials and methods: A literature review from 2005 to 2023 was conducted following PRISMA recommendations on PubMed, Web of Science, and Cochrane, using the keywords: "Knee + Arthroplasty + Trends + Replacement + Epidemiology." Only articles featuring national analyses, based on references recognized by healthcare systems, were included.

Results: Forty-eight articles, representing 16 countries, were selected. Europe was the most represented (47% of occurrences), followed by the USA (22%), Asia (20%), Oceania (8%), and Chile (2%). The data came from national databases or representative extrapolated samples. Extraction methods used precise national codes or specific definitions. Growth rates in volume and incidence were positive but varied between countries, with distinct dynamics and different phases of growth. Females had higher volumes and incidence rates (sex ratio 2/3), but growth was faster in males. Future forecasts, based on regression models (Poisson, linear, or logistic), predicted an increase in volumes of between +30% by 2030 and +805% by 2050.

Conclusion: The analysis of census systems revealed growth in knee arthroplasties in all countries, but with varying intensities depending on the period. These multifactorial disparities appeared to follow a similar pattern, staggered over time based on the countries' economic development.

Level of evidence: IV; epidemiological review.