Objective    To evaluate more than 5-year follow-up outcome of avulsion fracture of the anterior cruciate ligament from the tibial insertion site in skeletally immature patients treated with modified arthroscopic internal fixation with cannulated screw and washer.      Methods    Thirty-nine patients with open physis were treated by modified arthroscopic internal fixation with cannulated screw and washer from March 2000 to November 2003. Regular X-ray plain films at AP and lateral views were conducted to detect the healing of avulsed fragments. Follow-up period of 31 patients was more than 5 years. Functional outcome before and after surgery was evaluated using the Lysholm Knee Score and the Tegner Activity Score. Angular deformity

or leg length discrepancy was assessed by clinical examination and anteroposterior-lateral radiographs of the knee. Instrumented knee laxity was performed using the KT-2000 arthrometer.      Results    Arthroscopic removal of implants was performed between 3 and 6 months postoperatively

when all fractures were revealed to have healed on X-ray films. No growth disturbance

angular deformation or knee instability was found in 31 patients during more than 5-year follow-up. The Lysholm score was improved from (19.2±14.8) (range 12-48) preoperatively to (98.5±3.1) (range 97-100) postoperatively

with significant statistical difference by the student-t test (t=18.395

P=0.000); The Tegner score was improved from (4.1±1.1) (range 3-5) preoperatively to (8.5±0.8) (range 7-9) postoperatively

with significant statistical difference by the student-t test (t=4.13

P=0.008). Physical examination showed Lachman test (+) in 14 of 31 patients. Instrumented knee laxity (KT-2000) showed manual-maximum side-to-side difference greater than 2 mm (range 2.1-3.8 mm)  in 14 of 31 patients.      Conclusion    Modified arthroscopic internal fixation of avulsion fracture of the anterior cruciate ligament from the tibial insertion site with cannulated screw and washer in skeletally immature patients is a simple

safe

and effective ARIF procedure without growth disturbance.