[Anatomical ACL reconstruction by a double- versus a single-bundle technique. Prospective randomised study of short-term clinical results].

PURPOSE OF THE STUDY: The aim of the study is to present a comparison of short-term results of double- versus single-bundle anatomical reconstruction of the anterior cruciate ligament (ACL) using hamstring endons and their fixation with absorbable interference screws.

MATERIAL AND METHODS: A total of 110 patients with an isolated ACL lesion and the healthy contralateral knee who met the indication criteria for ACL double bundle reconstruction (TISL, 14 mm; ICNW, 12 mm) were intra-operatively allocated at random to either double-bundle group (DB, n=55) or single-bundle group (SB, n=55). At 12 months after surgery, 97 patients (DB group, n=49; SB group, n=48), comprising 68 men and 29 women, were evaluated; the average age was 29.1 years and the injury-to-surgery interval was 15.9 weeks. Pre- and post-operative subjective criteria involved the IKDC and Lysholm score. Objectively, the occurrence of graft failure, range of motion deficit, return to pre-injury sports activity, side-to-side difference in anterior laxity of both knees in 20° flexion on a GNRB laximeter at an applied pressure of 124 N and 250 N, and pivot shift phenomenon were assessed.

RESULTS: No statistically significant difference was found in pre-operative values between the two groups. Post-operatively, there were no significant differences in the occurrence of complete graft failure (p=0.0755; DB group, n=0; SB group, n=3), range-of-motion deficit (p=0.2277-0.9788) or return to pre-operative sports activity (p=0.2322). In the DB group, side-to-side anterior tibial shifts at a pressure of 124 N (medians=1.3 mm and 2.1 mm for DB and SB groups, respectively; p=0.0007) and at a pressure of 250 N (DB group =2.1 mm; SB group = 3.1 mm; p<0.0001) were significantly different from the corresponding values in the SB group. Positive results for the pivot shift test (PST) were significantly less frequent in the DB than the SB group (Chi-square test =0.0112). The SB group patients had a 2.9-times (odds ratio, 2.8704) higher risk of positive postoperative PST results than the DB group patients. In both groups, a comparison of pre- and post-operative criteria showed significant improvement in both the subjective and the objective results.

DISCUSSION: The results of this study, in accordance with other authors' conclusions, suggest that the double-bundle technique provides better control over rotational and anterior knee laxity and therefore restores knee biomechanics better. However, other literature data do not confirm any significantly better outcomes of this method. Since only short-term results have been obtained so far, the study will continue because only the long-term results can provide conclusive evidence of an advantage of one technique over the other.

CONCLUSIONS: Our study showed significantly better restoration of knee rotational and anterior laxity in the patients undergoing anatomical reconstruction of the ACL by the double-bundle technique. The other evaluated criteria did not differ in relation to the technique used.