ACL Reconstruction Preserving the ACL Remnant Achieves Good Clinical Outcomes and Can Reduce Subsequent Graft Rupture

BACKGROUND Although anterior cruciate ligament (ACL) reconstruction techniques that preserve remnant tissues have been described, complete preservation may be difficult, with little known about its clinical advantages. PURPOSE To compare clinical outcomes in patients undergoing ACL reconstruction with and without ACL remnant preservation. STUDY DESIGN Case-control study. METHODS Of 372 patients who underwent surgical treatment of an ACL injury between September 2006 and July 2010, 154 had no remaining identifiable ligament tissue and were excluded from this study. Attempts were made to preserve the ACL remnant as much as possible in the remaining 218 patients. These patients were divided into 2 groups: those in whom the remnant was preserved (group 1, n = 85) and those in whom the remnant was not preserved (group 2, n = 98). Patients were followed for at least 24 months. Outcomes, including graft rupture, were compared in the 2 groups. RESULTS Time from injury to surgery was significantly shorter (7.3 ± 16.3 vs 16.0 ± 30.3 months; P < .05) and the preinjury Tegner activity was significantly higher (7.6 ± 1.4 vs 7.1 ± 1.2; P < .05; 95% confidence interval, 1.2-13.7) in group 1 than in group 2. The postoperative negative ratio of the pivot-shift test was similar in the 2 groups (87% vs 81%). Anterior stability of the knee, as measured by a KT-2000 arthrometer, was significantly better in group 1 than in group 2 (1.0 ± 0.8 vs 1.3 ± 1.0 mm; P < .05). ACL graft rupture occurred in 1 patient (1.1%) in group 1 and in 7 patients (7.1%) in group 2 (P < .05). Regression analysis showed that preservation of the remnant decreased the likelihood of graft rupture (odds ratio, 11.2; 95% confidence interval, 1.2-101.7). CONCLUSION These findings confirmed that preserving the remnant tissue of the ACL may facilitate recovery of function and decrease graft rupture after primary reconstruction.