Introduction. It has been contentious whether an anatomic double-bundle technique for anterior cruciate ligament reconstruction (ACLR)is superior to that of a single-bundle technique. It has been hypothesized in the literature that the double-bundle technique could provide function closer to that of the anatomical knee joint. The purpose of this study was to compare the long-term clinical outcomes after single-bundle ACLR versus double-bundle ACLR. We hypothesized that the double-bundle technique would not be superior to the single-bundle technique. Methods. A retrospective, non-randomized, matched-paired comparative study was performed. Patients undergoing primary anterior cruciate ligament reconstruction, using either a double-bundle or single-bundle technique, between 2003 and 2008 were included and matched 1:1. Matching included age, sex, BMI, time from injury to surgery, side of injury and type of sport. Patients who underwent revision procedures, multiligament reconstruction or other ACLR techniques were excluded. Patients were subsequently followed up, noting occurrence of graft rupture and any other complications. Results. A total of 1377 ACLRs were performed during the study period. Seven hundred and fifty-six patients were excluded, leaving 396patients to be included in the matching (198 matched pairs). Mean follow-up time was 176.7 +/− 7.7 months (range, 166–211 months). Overall, 40 patients (10.1%) suffered from a graft rupture which consisted of 22 patients (11.1%) in the single-bundle group and 18patients (9.1%) in the double-bundle group. A multivariate analysis was performed using the Cox model and demonstrated that graft failure had no significant association with the surgical technique (hazard ratio (HR), 0.857(0.457;1.609), p=0.6313). (Figure 1) Five patients (2.5%) in the single-bundle group and 7 patients (3.5%) in the double-bundle group underwent secondary surgery for cyclops syndrome(p=0.5637). Three patients (1.5%) in the single-bundle group and 2 patients (1.0%) in the double-bundle group underwent arthrolysis(p=0.6547). Seven patients (3.5%) in the single-bundle group underwent secondary meniscectomy compared to 6 patients (3.0%) in the double-bundle group (p=0.7630). Conclusion. Double-bundle ACLR is not superior to single-bundle ACLR at long-term follow up. Therefore, orthopaedic surgeons do not need to use a double-bundle technique when performing ACL reconstruction. For any figures or tables, please contact authors directly

INTRODUCTION. This study aimed to intra-operatively quantify the improvements in knee stability given both by anatomic double-bundle (ADB) and single-bundle with additional lateral plasty (SBLP) ACL reconstruction using a navigation system. MATERIALS AND METHODS. We prospectively included 35 consecutive patients, with an isolated anterior cruciate ligament injury, that underwent both ADB and SBLP ACL reconstruction (15 ADB, 20 SBLP). The testing protocol included anterior/posterior displacement at 30° and 90° of flexion (AP30–AP90), internal/external rotation at 30° and 90° of flexion (IE 30–IE90) and varus/valgus test at 0° and 30° of flexion (VV0–VV30); pivot-shift (PS) test was used to determine dynamic laxity. The tests were manually performed before and after the ACL reconstruction and the data were acquired by means a surgical navigation system (BLU-IGS, Orthokey, USA). Comparisons of pre- and post-reconstruction laxities were made using paired Student t-test (P=0.05) within the same group; comparison between ADB and SBLP groups was indeed performed using independent Student t-test (P=0.05), analysing both starting pre-operative condition and post-operative one. RESULTS. Statistically significant reduction of the global amount of laxity and global displacement was observed for both reconstructions (p<0.05) in all the performed clinical tests. Statistical differences was found between the two reconstruction considering the recovery (pre-post laxities) due to the each reconstruction, in VV0 (SBLP: 3.7±0.2° and ADB: 2.3±0.5°, p<0.0001) and in IE90 (SBLP: 9.2±3.1° and ADB: 5.0±2.8°, p=0.0022). Statistical differences were also found between the two reconstruction considering the recovery of global displacement, in particular for the lateral compartment during AP90 SBLP: 8.8±1.0 mm, ADB: 6.4±0.4 mm, p<0.0001), for the maximal lateral joint opening during VV0 (SBLP: 4.5±1.2 mm, ADB: 1.2±1.1 mm, p<0.0001) and VV30 (SBLP 3.5±1.3 mm, ADB 1.8±0.1 mm, p=0.0013) and both for the medial and lateral AP displacement during IE90 (in in medial compartment SBLP:5.6±0.6 mm, ADB: 2.7±0.7 mm, p<0.0001, in lateral compartment SBLP:8.2±1.0 mm, ADB: 3.9±0.8 mm, p<0.0001). During PS test ADB patients revealed less “hysteresis” after reconstruction (p=0.0005). Moreover SBLP patients presented more acceleration after the reconstruction compared to ADB and more evident displacement (p=0.0009). DISCUSSION. Both the reconstructions worked similarly for what concerns knee static laxity. The considered extra-articular procedure plays an important role in better controlling lateral tibial compartment displacement in drawer test and in controlling maximal lateral joint opening both at 0° and 30° of flexion. On the other hand the ADB reconstruction better restores the dynamic behaviour of the joint under PS test