Biodegradable interference screw augmentation reduces tunnel expansion after ACL reconstruction

This study assessed 40 patients who underwent anterior cruciate ligament reconstruction with hamstring autografts using our standard technique. Twenty patients underwent tibial fixation augmentation with a biodegradable interference screw, and the remaining 20 patients did not. Patient groups were compared using radiographic evaluation of bone tunnel diameter, physical examination, and arthrometer measurements. The two groups differed in only one way: the placement of the tibial biodegradable interference screw. Biodegradable interference screw augmentation resulted in decreased distal tibial and some femoral tunnel diameters at both 3- and 12-month follow-up. There was no significant difference in the Lachman and arthrometer testing in either group of patients at the termination of this study. These results indicate that although distal tibia tunnel diameter reduction is significant, it does not appear to have any clinical significance in the first year.