AJSM - 2026-06-26 - Journal Article
The Effect of Smoking History on Inflammatory Biomarkers in Synovial Fluid of Patients Undergoing Arthroscopic Knee Surgery for Meniscal Injury.
Kurtz JL, Ehlers M, Montgomery SR, Kaplan DJ, Strauss EJ
Topics
Key Takeaway
In 297 patients undergoing knee arthroscopy for meniscal injury, 9 of 10 synovial fluid biomarkers differed significantly between smoking cohorts, with RANTES negatively associated with pack-years (β = -0.5115) and IL-6 positively associated with time since cessation (β = 0.3842).
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Summary
This study asked whether tobacco use history alters the intra-articular cytokine environment in symptomatic meniscal tears by prospectively collecting synovial fluid at arthroscopy from 297 patients stratified into current smokers (n=27), former smokers (n=54), and nonsmokers (n=216). ANOVA identified significant differences (P<.01) in 9 of 10 biomarkers including MCP-1, MMP-3, VEGF, TIMP-1/2, IL-1Ra, and bFGF across groups. Post hoc analysis showed former smokers differed from nonsmokers across nearly all biomarkers, and linear regression identified a dose-dependent negative association between pack-years and RANTES in current smokers and a positive association between cessation duration and IL-6 in former smokers.
Key Limitation
The cross-sectional single-timepoint synovial fluid collection cannot establish whether the observed biomarker differences precede meniscal injury, result from it, or reflect chronic smoking-induced joint changes independent of the acute tear.
Original Abstract
BACKGROUND
Smoking has been linked to alterations in cellular inflammatory pathways and adverse outcomes in orthopaedic procedures. It is unclear how patient smoking affects the intra-articular microenvironment in the setting of symptomatic meniscal tears.
PURPOSE
To investigate the association between tobacco use and variation in cytokine concentrations in knee synovial fluid in patients undergoing arthroscopic knee surgery for symptomatic meniscal injury.
STUDY DESIGN
Cohort study; Level of evidence, 3Methods:Patients who underwent knee arthroscopy for meniscal injury were prospectively enrolled between July 2011 and June 2019. Synovial fluid was aspirated and the concentrations of 10 biomarkers were measured by immunoassay. Smoking status, pack-years, and time since smoking cessation were collected. Log-normalized biomarker concentrations and smoking status were analyzed using analysis of variance (ANOVA) and linear regression.
RESULTS
A total of 297 patients (mean age, 45.7 ± 12.5 years; mean body mass index, 28.3 ± 5.3 kg/m 2 ; 55.6% male) were included. Patients were divided into current smokers (n = 27), former smokers (n = 54), and nonsmokers (n = 216). No descriptive differences between groups were found. ANOVA showed significant differences ( P < .01) in regulated on activation, normal T cell expressed and secreted (RANTES), monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1β, vascular endothelial growth factor, tissue inhibitors of metalloproteinases 1 and 2, interleukin-1 receptor antagonist (IL-1Ra), matrix metalloproteinase (MMP-3), and basic fibroblast growth factor (bFGF) between cohorts. Post hoc analysis revealed a significant difference between nonsmokers and former smokers for all biomarkers, aside from interleukin (IL)-6, that showed a significant difference on ANOVA testing. Significant differences were also found between smoker and nonsmoker cohorts for biomarkers MCP-1, MIP-1β, IL-1Ra, MMP-3, and bFGF. Linear regression analysis demonstrated a significant negative association between pack-years in the current smoker group and RANTES (β = -0.5115; P = .0358), and a positive association between time since quitting and IL-6 (β = 0.3842; P = .0084).
CONCLUSION
Smoking status was found to be significantly associated with alterations in synovial fluid biomarker profiles in patients undergoing arthroscopic knee surgery for meniscal injury. RANTES was negatively associated with pack-years in current smokers, and IL-6 was positively associated with time since smoking cessation in former smokers. These findings suggest that smoking may have lasting effects on joint inflammation after injury, and that biomarker profiles can provide insight into local tissue responses influenced by smoking history.