Background: Anterior cruciate ligament (ACL) tibial avulsion fractures are a special ACL injury type, classified as intra-articular fractures. Presently, the main treatment method is arthroscopic surgery, and various fixation methods are available, including use of steel wires, high-strength sutures, cannulated screws, anchors, Kirschner wires, etc. Joint fixation using wire binding could cut through the bone tunnel. We aimed to evaluate the clinical efficacy of a novel method involving suture anchor fixation outside the tunnel to treat anterior cruciate ligament (ACL) tibial avulsion fractures in children.Methods: This retrospective study analyzed the data of 42 pediatric patients (26 boys and 16 girls; age: 7–13 years) with ACL tibial avulsion fractures. Based on the Meyers–McKeever–Zaricznyj classification of fractures, 22, 14, and 6 patients had types II, III, and IV fractures, respectively. All patients underwent arthroscopic surgery for ACL tibial avulsion fracture; during surgery, double tibial tunnels were established, and high-strength sutures were passed through the tunnels and fixed externally with an anchor. The clinical outcome was evaluated by assessing the pre- and post-operative knee joint range of motion (ROM) and by using the Lysholm knee function score and International Knee Documentation Committee (IKDC) score. Post-operative computed tomography and magnetic resonance images were reviewed to determine the status of fracture displacement, healing, and epiphyseal damage.Results: All 42 patients were followed up for 20–36 months (average of 27.8 months). Knee ROM increased from 48.2°±21.7° pre-operatively to 131.6°±8.7° at the final follow-up (t=23.119, P=0.000). The Lysholm knee function score increased from 37.6±5.2 points pre-operatively to 90.1±6.3 points post-operatively, representing a significant improvement (t=41.651, P=0.000). The IKDC score improved from 43.3±7.5 points pre-operatively to 91.3±5.7 points post-operatively (t=45.521, P=0.000). The imaging findings indicated that the fractures healed with displacement and there was no significant epiphyseal damage.Conclusions: Suture anchor fixation outside the tunnel to treat ACL tibial avulsion fracture in children reduces the cutting action of the sutures on the tunnel, minimizes epiphyseal damage, involves a simple procedure, offers firm fixation, and effectively improves knee function. This approach can enable early functional rehabilitation and achieve satisfactory clinical efficacy.