A prospective randomised study of anatomical single-bundle versus double-bundle anterior cruciate ligament reconstruction: quantitative evaluation using an electromagnetic measurement system

Abstract

We conducted a prospective randomised study of anatomical single-bundle (A-SB group) versus double-bundle (A-DB group) anterior cruciate ligament (ACL) reconstruction using the hamstrings tendons. Twenty patients with unilateral ACL deficiency were randomised into two groups. We created the bone tunnels at the position of the original insertion of the anteromedial bundle footprint and posterolateral bundle footprint in the A-DB group and at the central position between these two bundles in the A-SB group. All of the patients were tested before ACL reconstruction and one year after surgery. The KT-1000 measurements, isokinetic muscle peak torque and heel-height difference were evaluated and the general knee condition was assessed by Lysholm score. For pre- and postoperative stability assessment, we used the six-degrees-of-freedom of knee kinematic measurement system using an electromagnetic device (the EMS) for quantitative assessment during the Lachman test and the pivot shift test. There were no significant differences in the KT-1000 measurements, isokinetic muscle peak torque, heel-height difference, and Lysholm score at one-year follow-up between these two groups. The EMS data showed there were significant differences in the acceleration of the pivot shift test between the operated knee and the contralateral normal knees in the A-SB group. In conclusion, clinical outcomes were equally good in both groups. However, the EMS data showed the anatomical double-bundle ACL reconstruction tended to be biomechanically superior to the single-bundle reconstruction.

Fig. 1

(A-1) Femoral tunnel placement in anatomical double-bundle reconstruction. (A-2) Tibial tunnel placement in anatomic double-bundle reconstruction. (B-1) Femoral tunnel placement in anatomical single-bundle reconstruction. (B-2) Tibial tunnel placement in anatomical single-bundle reconstruction

Fig. 2

a Configuration of the newly-developed electromagnetic measurement system. b Two of the receivers were attached to a plastic brace by a circumferential Velcro strap placed on the thigh and on the lower leg. A third receiver was attached to a specially-made stylus. c The stylus was used for digitising anatomical landmarks before the six-degrees-of-freedom of knee kinematics measurement was performed

Fig. 3

Side-to-side difference of KT-1000 measurements. There were no statistical differences between the two groups at the pre- and postoperative evaluations. The significance level was 5%

Fig. 4

Quantitative evaluation of the Lachman test using the electromagnetic measurement system. There were no significant differences between the two groups at the pre- and postoperative evaluation. The significant level was 5%

Fig. 5

Quantitative evaluation of the pivot shift test using the electromagnetic measurement system. There was significant difference between the operated knees and the contralateral intact knees in the anatomical single-bundle (A-SB) group. However, in the anatomical double-bundle (A-DB) group, no significant difference was found between the operated knees and the contralateral intact knees. The significance level was 5%