Environmental Temperature and Seasonal Variations as Risk Factors for Achilles Tendon Rupture: A Multi-Center Retrospective Study in China

Wan Zhou¹Zili Chen¹Chunyun Zhuo²Jie Liu³Mi Yang¹Shunji Gao¹Huijuan Xiang¹Li Yang¹Rui Du^1*

• ¹General Hospital of Central Theater Command, No.627, Wuluo Road, Wuhan 430070, Hubei, China, Hubei, China
• ²Gao Mi People’s Hospital, No.77 Zhenfu Street, Gaomi city, Weifang, Shandong Province, China, Shandong, China
• ³International Mongolian Hospital of Inner Mongolia, No.83, University East Street, Hohhot 010020, Inner Mongolia, China, Inner Mongolia, China

Objectives: Achilles tendon rupture (ATR) is a common sports-related injury influenced by intrinsic and extrinsic factors. Environmental temperature and seasonal variations may play a role in ATR incidence, but their relationship remains underexplored. This study aimed to determine whether ambient temperature and seasonal changes are associated with the incidence of ATR. Methods: This retrospective study analyzed 379 ATR cases across three provinces in China—Hubei, Shandong, and Inner Mongolia—from October 2011 to June 2024. Temperature data were classified into five groups (-12.9~-3.3°C, -3.2~6.4°C, 6.5~16.1°C and 16.2~25.8°C, 25.9~35.5°C), and seasons were categorized into spring, summer, autumn, and winter. ATR incidence was assessed across these categories, with statistical significance evaluated using chi-squared and binomial tests. Results: ATR incidence was highest at temperatures 16.2~25.8°C, a pattern that was observed consistently across Shandong and Inner Mongolia Provinces (P<0.001), However, the highest incidence occurs at temperatures between 25.9°C and 35.5°C in Hubei. Conversely, the injury rate is lowest at temperatures ranging from -12.9°C to -3.3°C, a pattern observed in all three provinces of Hubei, Shandong, and Inner Mongolia. Seasonally, spring exhibited the highest incidence (P=0.001), while winter showed the lowest (P=0.002). Regional differences were evident, with peak ATR rates occurring in May (Hubei), June (Shandong), and September (Inner Mongolia). Patients aged 30-39 years or those who are overweight were most affected, with sports-related injuries, particularly basketball, accounting for the majority of cases. Conclusions: In this retrospective analysis of a three-province Chinese cohort, we observed that environmental temperature and seasonal variations were associated with ATR incidence, with the lowest rates at very low temperatures and higher incidence at mild-to-warm temperatures, particularly during springtime. These findings highlight the importance of validating these observations through larger, population-based studies.