Comparison of Rotatory and Sagittal Laxity After Single-Bundle Versus Double-Bundle ACL Reconstruction: Outcomes at 7-Year Follow-up

Abstract

Background: Biomechanical studies have shown excellent anteroposterior and rotatory laxity control after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction, but no clinical studies have compared midterm (>5-year) residual laxity between the DB and single-bundle (SB) techniques. Purpose: To clinically compare sagittal and rotatory laxities and residual sagittal laxity on the KT-1000 arthrometer between patients treated with an SB ACL reconstruction and those treated with a DB ACL reconstruction at the 7-year follow-up. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 110 patients were included between January 2006 and December 2007. The patients were randomly assigned into 2 groups: those treated with SB ACL reconstruction (n = 63) and those treated with the DB technique (n = 47). All patients were then reviewed at a minimum of 7 years of follow-up; patients with ACL rerupture (n = 3 in the SB group and n = 2 in the DB group) were excluded from the postoperative comparative analysis. Residual anterior laxity (Lachman test), rotatory laxity (pivot-shift test), and sagittal laxity (KT-1000 arthrometer side-to-side difference) were measured and compared between the 2 groups. Results: The mean age at surgery was 23.0 ± 5.1 years for the DB group and 28.1 ± 7.0 years for the SB group, and the mean follow-up was 7.4 ± 0.8 years. No statistically significant differences were found between the 2 groups in terms of age, sex, preoperative laxity on KT-1000, preoperative Tegner score, or concomitant meniscal lesions. Residual postoperative laxity via Lachman testing ( P < .01), pivot-shift testing ( P = .042), and the KT-1000 arthrometer ( P < .01) was statistically significantly in favor of DB reconstruction. Conclusion: DB ACL reconstruction allowed better control of anterior stability during the evaluation via the Lachman test and via objective measurement on the KT-1000, as well as rotatory stability at a minimum of 7 years of follow-up.

Favorable Patient-Reported, Clinical, and Functional Outcomes 2 Years After ACL Repair and InternalBrace Augmentation Compared With ACL Reconstruction and Healthy Controls

“…Ferreira et al 17 observed an SSD of 1.1 mm for ACL-IB and 0.6 mm for ACL-R, whereas Wilson et al 61 reported a mean SSD of 1.2 mm for ACL-IB in their systematic review. In contrast, Severyns et al 45 reported a residual side-to-side laxity of 1.6 mm after single-bundle ACL-R, which is comparable with that in our cohort. In our study, each patient was asked for subjective symptoms of instability before testing, and none of the included patients reported such symptoms or had symptomatic instability during testing.…”

“…Passive ATT is considered an indicator for postoperative knee stability, 13 with SSDs reported as outcome measures in most studies. 17,45,61 In our study, ATT was significantly higher in patients after ACL-IB or ACL-R than in healthy controls but did not differ between patient groups. However, SSDs of 2.5 mm in ATT after ACL-IB and 1.4 mm after ACL-R are higher than those reported in other publications.…”

“…In our study, each patient was asked for subjective symptoms of instability before testing, and none of the included patients reported such symptoms or had symptomatic instability during testing. Although the overall SSD remained below the reported threshold of 3 mm at which knee laxity may be assumed, 5,13,42,45 some patients after ACL-IB had an SSD in ATT .3 mm. However, because ATT measurements using a Rolimeter only allow determination of 2mm increments, this accuracy may not allow us to define a clear cutoff of 3 mm as reported in the literature.…”

Trends of Publications on Single- and Double-Bundle ACL Reconstructions over the Last 20 Years: A Bibliometric Analysis of the PubMed Literature

“…Furthermore, according to recent biomechanical investigations, SB-ACLR is unable to restore healthy anterior translation or rotatory laxity [ 33 ]. DB-ACLR procedures are being promoted to more accurately mimic the native anatomy of the ACL and potentially increase the stability of the knee joint to further enhance the current SB-ACLR techniques and provide a better understanding of the ACL anatomy [ 34 ]. Although the reconstruction of both ACL bundles appears to have a theoretical advantage, there is still disagreement over whether DB-ACLR is better than the more common SB-ACLR [ 35 ].…”

“…The biomechanics of the ACL have been studied in numerous experimental settings throughout the last 10 years. However, questions about the methods chosen to restore normal knee biomechanics still exist [ 34 ]. One of the key disputes in ACLR relates to the importance of DB reconstruction in biomechanical outcomes compared with SB reconstruction, among other surgical issues such as graft types, fixation techniques, and bundle count [ 34 ].…”