COMPARISON BETWEEN SINGLE AND DOULBE BUNDLE ACL RECONSTRUCTION. A RANDOMISED CLINICAL TRIAL.

Abstract

Introduction : The purpose of the study is to compare in a randomised clinical double blind trial two methods of hamstring ACL reconstruction, the SIngle Bundle (SB) and the Double Bundle (DB).

Materials and methods: Seventy patients, with a chronic ACL insufficiency, were randomized to receive a unilateral single or double bundle ACL reconstruction. All the operations were performed by the same surgeon using the same two incision outside-in technique. The tibial guide wire was introduced with a 65 degrees Howell guide in extension to avoid impingment. To introduce the second tibial wire (posterolateral wire) a prototype guide that lets you place the wire with a fixed angulation and a fixed distance (9 mm) from the first was used. On the femoral side we used a modified Rear Entry guide. In a SB reconstruction the 10.00 o’clock position (right knee), intermediate between the two anatomic bundles, was used. In a DB reconstruction the first wire was placed in the anteromedial insertion area, close to the “over the top” position on the lateral wall and for the second wire the same prototype guide that gives you the correct angulation and distance with the first (10 mm) was used. The direction was chosen in order to exit 5 mm close to the posterior cartilage. The graft was prepared and pretensioned as to have two arms of the same diameter. It was fixed on the cortex of the tibia by means of a titanium ring bridge when doing a SB and looped around a cortical bony bridge when doing a DB. Tensioning and femoral fixation of the SB was done at 20 degrees, while in the DB tensioning and fixation of the PL bundle was achieved first after cycling at 10–15 degrees and of the AM bundle at 40–45 degrees. Femoral fixation was obtained via RCI titanium interference screws and one additional cortical titanium staple. The same moderately aggressive rehabilitation was utilized in both groups. Outcome assessment was performed by an indipendent observer, blinded to the involved leg and type of reconstruction, using the new IKDC form, the KOOS score, the KT-1000 arthrometer.

Results: All patients reached a minimum follow-up of one year. No difference was found in terms of overall KOOS and IKDC subjective scores. A significant difference was found (p< .001) in KT data and in IKDC final ojective scores (Excellent-A-result: 73% SB and 95% DB). he DB group showed a tred to less pivot shift (glide).

Conclusion: In the short period the DB reconstruction offered better knee stability and better objective results than the 10.00 o’clock SB. Longer follow up and accurate instrumented in vivo rotational stability assessment is probably needed to further disclose small but important differences.