Objective We aimed to compared matrix metalloproteinase-13 (MMP-13) and transforming growth factor-β1 (TGF-β1) in synovial fluid,the phosphorylation level of Smad3 in articular cartilage (P-Smad3),and their correlation with traditional Chinese medicine (TCM) patterns in patients with knee osteoarthritis (KOA) of liver-kidney deficiency pattern and pattern of intermingled phlegm and blood stasis.Methods Using a cross-sectional field investigation method,KOA patients hospitalized in the Orthopedics Department of Dongzhimen Hospital,Beijing University of Chinese Medicine from September 2019 to February 2023 were collected. A total of 112 KOA patients were included,among which 63 cases were diagnosed with liver-kidney deficiency pattern,and 49 cases were diagnosed with pattern of intermingled phlegm and blood stasis. The intensity of knee pain,function,and X-ray imaging result were quantified using the Visual Analogue Scale (VAS),Lysholm Knee Scoring Scale,and Kellgren-Lawrence (K-L) Grading Scale,respectively. The TCM pattern was identified and quantified using a TCM Pattern Scoring Scale. Immunohistochemistry was used to determine the phosphorylation characteristics of Smad3 in articular cartilage,and ELISA was used to measure the contents of MMP-13 and TGF-β1 in synovial fluid. The level characteristics and their correlation with the degree of syndrome were analyzed.Results (i) There was no statistically significant difference in VAS scores,Lysholm scores,and K-L grades between KOA patients with different TCM patterns. (ii) Compared with KOA patients with pattern of intermingled phlegm and blood stasis,patients with pattern of liver-kidney deficiency had higher levels of MMP-13 in synovial fluid and lower levels of TGF-β1 in synovial fluid (P<0.05). (iii) In KOA patients with liver-kidney deficiency pattern,there was a positive correlation between the level of MMP-13 in synovial fluid and the score of TCM pattern (r=0.292,P=0.020),while there was a negative correlation between the level of TGF-β1 in synovial fluid and the score of TCM pattern (r=-0.781,P<0.001). In KOA patients with pattern of intermingled phlegm and blood stasis,there was also a positive correlation between the level of MMP-13 in synovial fluid and the score of TCM pattern (r=0.936,P<0.001). (iv) The mean optical density value of P-Smad3 in articular cartilage was lower in KOA patients with liver-kidney deficiency pattern than in pattern of intermingled phlegm and blood stasis (P<0.05).Conclusion KOA patients with liver-kidney deficiency pattern or pattern of intermingled phlegm and blood stasis have different levels of TGF-β1 and MMP-13 in synovial fluid,as well as varying degrees of Smad3 phosphorylation in articular cartilage,which is consistent with the analysis of etiology and pathogenesis under different patterns. The levels of TGF-β1 and MMP-13 in synovial fluid of patients with liver-kidney deficiency pattern can reflect the severity of the pattern to a certain extent,and the mechanism may be related to the inhibition of the activation level of the TGF-β/Smad signaling pathway. This study enriches the research content of the material basis of TCM patterns.