Objective To explore the clinical efficacy of one-stage cannulated screw fixation in treatment of tibial avulsion fracture at the insertion of posterior cruciate ligament(PCL) under posterior direction version and in treatment of tibial avulsion fracture at the anterior cruciate ligament (ACL)under arthroscopy.Methods From January 2010 to June 2015,25 patients with tibial avulsion fractures of the posterior cruciate ligament combined with the anterior cruciate ligament in our hospital were retrospectively analyzed.Firstly,arthroscopic exploration was conducted in all patients in their horizontal position,aiming to observe whether combined injures existed or not and to confirm fracture fragments and the degree of tibial avulsion fractures of the cruciate ligaments.All patients recieved arthroscopic fragment fixation by using cannulated screws,then,were treated with a minimally posteromedial incision in the prone position by cannulated screw fixation.All knee joints were protected by adjustable orthopedic brace for 4-6 weeks.The clinical knee joint function of patients were measured by using International Knee Documentation Committee (IKDC) scoring scale and Lysholm scoring scale.The X-ray or CT image were used to evaluate healing process of the fractures.Results All patients were followed up for 6-24 months,the median follow-up time was 15 months.All fractures healed in one stage,time of fracture healing ranged from 9 to 24 weeks,and the median time was 12 weeks.The average IKDC scores at the finial follow-up were as follows:claudication (4.88±0.29)points,support (4.65±0.36)points,pain (4.78±0.49)points,swelling (4.88±0.52)points,squat (4.85±0.35)points,all were higher than those before operation,there were statistically significant differences when compared with those assessed before operation (P0.05).Conclusion The one-stage cannulated screw fixation in treatment of tibial avulsion fracture at the insertion of PCL under posterior direction version and in treatment of tibial avulsion fractures at the ACL under arthroscopy is easy and convenient to operate,which has the advantages of reliable fixation and satisfactory recent curative efficacy.