Objective To investigate the efficacy of minimally invasive Kirschner wire tension band internal fixation under arthroscopy for the treatment of patellar fractures and analyze the factors related to postoperative complications. Methods Sixty patients with patellar fractures treated in the Orthopedic Department from January 2021 to January 2025 were selected as research subjects. The patients were randomly divided into a control group and a study group, with 30 cases in each group. The control group received open reduction and Kirschner wire tension band internal fixation treatment, while the study group received minimally invasive Kirschner wire tension band internal fixation treatment under arthroscopy. Fracture healing time, knee joint range of motion, knee joint function （Bostman score）, daily living ability （Barthel index, BI）, quality of life （life satisfaction index A scale, LISA）, pain score （visual analog scale, VAS）, and postoperative complications were compared between the two groups after treatment. Univariate and multivariate logistic regression analyses were conducted on factors related to the complications. Results After treatment, the fracture healing time of the study group was significantly shorter than that of the control group, and the improvement of knee joint range of motion and knee joint function was better than that of the control group （P<0.05）. After treatment, the BI and LISA scores of the study group were significantly higher than those of the control group, and the VAS scores were significantly lower （P<0.05）. The incidence of complications in the study group was 3.33% （1/30）, which was significantly lower than 20.00% （6/30） in the control group （P<0.05）. Univariate analysis showed that age ≥ 60 years, open surgery, and fracture healing time ≥100 d were potential factors associated with postoperative complications （P<0.05）. Multivariate logistic regression analysis showed that age ≥60 years （OR=5.236）, open surgery （OR=6.814）, and fracture healing time ≥ 100 d （OR=4.937） were independent risk factors for complications （P<0.05）. Conclusion Minimally invasive Kirschner wire tension band internal fixation under arthroscopy has significant advantages in the treatment of patellar fractures, which can effectively shorten fracture healing time, improve knee joint function and motion, enhance patients' daily living ability and quality of life, and its incidence of postoperative complications is significantly lower than that of traditional open surgery. Older age, traditional open surgery, and longer fracture healing time are independent risk factors for postoperative complications, which should be taken seriously in clinical practice.