Summary

Adding an anterolateral tenodesis in patients with persistent instability after a tras-tibias ACL reconstruction, improve subjective and objective stability

Abstract

Objective

Isolated anterior cruciate ligament reconstruction (ACLR) not always leads to a complete recovery in terms of patient-reported outcomes (PROs), knee kinematics, and return to sports.
Regardless of the technique used for the ACLR, a non-anatomical reconstruction has been shown to lead to a higher failure rate. Adopting the transtibial technique (TT) for ACLR it is more difficult to place the femoral tunnel in the anatomical footprint, probably for this reason it is more frequent to find a postoperative residual instability. The aim of the present study was to determine in vivo if adding an anterolateral tenodesis (ALT) in those patients with a persistent subjective and objective residual instability after a TT ACL, reduced the anteroposterior and rotational laxity. We also wanted to evaluate 2 years follow-up clinical outcomes to analyse whether biomechanical changes have a clinical relevance or not.

Method

During the period from January 2017 to November 2018, all patients presenting with a residual subjective instability after a TT ACLR were proposed to undergo an isolated ALT. 17 patients were prospectively included in the study. All operative procedures were performed by 2 expert surgeons in the same hospital. In all cases a modified Lemaire anterolateral tenodesis have been performed. A quantitative assessment of knee instability was performed using KT1000 arthrometer and KiRA inertial sensor. The first was used preoperatively and during the follow up (FU). KiRA was used preoperatively before and under anaesthesia, postoperatively under anaesthesia and during the FU. Single vertical jump test (SVJT) was evaluated preoperatively and at each FU. FU were carried out at 6 weeks, 4 months, 1 year, 2 years. IKDC and Lysholm scores have been recollected preoperatively and at last follow up.

Results

100% of the patients complained subjective instability preoperatively, in 88,2% of the cases this feeling disappeared at last follow up. 9 patients (52,9%) were unable to perform SVJT before the operation, 12 (70,6%) were able ad 6 weeks postoperatively, 15 (88,2%) at 2-year FU. 2 patients needed ACL revision surgery due to persistent instability and ACL re-rupture. The side-to-side difference in dynamic rotational acceleration of the tibia during pivot shift test measured with KiRA decreased significantly both under anaesthesia (2,1 ± 3,2 preoperatively ; 0,6 ± 1,1 postoperatively; p=0,008) and without the effect of the anaesthesia (1,5 ± 2,8 preoperatively ; 0,3 ± 0,7 last FU; p=0,012). The side-to-side difference in anterior tibial translation measured in millimetres with KiRA decreased significantly only under anaesthesia (3,7 ± 2,1 preoperatively ; 2,4 ± 1,3 postoperatively; p=0,022).
The anterior tibial translation measured both with KiRA without anaesthesia and with KT1000 resulted not significative (p= 0,06 and p= 0,071). Postoperative analysis of knee laxity didn’t show any significative variation from the first to the last FU. While IKDS showed a significant improvement (p=0,018) between pre and postoperative evaluation, for Lysholm no significant improvement has been detected (p=0,057).

Conclusion

in patients with residual instability after ACL TT reconstruction, modified Lemaire ALT can significantly reduce the objective and subjective knee instability.