Found programs: Natural Science Foundation of Anhui Province (No . 2408085QH270) ; Health Research Project of Anhui Province (Nos . AHWJ2022b063 , AHWJ2023A30077) ; Provincial Quality Project of Colleges and Uni⁃ ond Affiliated Hospital of Anhui Medical University (No . 2022GMFY05)
Authors：Zhang Quanbing1 , 2 , Zhu Deting1 , 2 , Zhou Yun1 , 2 , Kan Xiuli 1 , 2 , Huo Lei 1 , Zhang Ruoxi2 , Xiao Han1 , 2 , Mao Jing1 , 2 , Li Xueming1 , 2 , Zhang Run1 , 2
Keywords：knee joint contracture ; fibrosis ; knee joint range of motion ; joint hemorrhage ; Wnt/β⁃catenin signa⁃ ling pathway
DOI：10.19405/j.cnki.issn1000-1492.2025.08.003
〔Abstract〕 To investigate the effect of intraarticular hemorrhage on extending knee joint contracture model in rats . Methods 18 mature male SD rats were divided into 3 groups by random number table method . The control group ( group C) was not immobilized and was killed after 4 weeks of feeding . In the simple fixation group( M1 group) , the left lower limb knee joint was immobilized in straight position for 4 weeks . The blood fixationgroup (M2 group) was injected into the knee cavity with body blood and immobilized in a straight position for 4 weeks . The knee joint motion of each group was measured by the joint motion measuring instrument under a stand⁃ard torque . The contracture degree was calculated by the joint range of motion of the knee joint before and after muscles separation . HE staining and Masson staining were used to detect the number of cells and collagen deposi⁃tion in the anterior joint capsule . The protein expressions of transforming growth factor 1 (TGF⁃ β1) , wingless⁃type MMTV integration site family , member 1 ( Wnt1) and beta⁃catenin ( β⁃catenin) in the anterior articular capsule were detected by Western blotting . Results Compared with group C , total knee contracture and arthrogenic con⁃tracture of rats in M1 and M2 groups increased , and the difference was statistically significant (P < 0. 05) . At the same time , the degree of total contracture and arthrogenic contracture in M2 group was higher than that in M1 group , and the difference was statistically significant (P < 0. 05) . Compared with group C , the number of anterior joint capsule cells and collagen deposition in M1 and M2 groups increased , and the difference was statistically sig⁃group were higher than those in M1 group , and the difference was statistically significant (P < 0. 05) . Compared with group C , the protein expressions of TGF⁃ β1 , Wnt1 and β ⁃catenin in the anterior articular capsule of rats in M1 expressions of TGF⁃ β1 , Wnt1 and β ⁃catenin in the anterior articular capsule of the knee joint in M2 group were sig⁃nificantly higher than those in M1 group , with statistical significance (P < 0. 05) . Conclusion Joint immobiliza⁃ tion can lead to joint contracture , and joint bleeding aggravates the degree of joint capsule fibrosis induced by im⁃mobilization .