Deep lateral extra-articular tenodesis (LET) is associated with improved tibial internal rotational stability and favourable patient-reported outcomes compared with superficial LET in high-grade pivot-shift male patients undergoing quadrupled hamstring autograft ACL reconstruction

Abstract

Purpose Lateral extra-articular tenodesis (LET) has been shown to improve rotational stability and clinical outcomes and to reduce graft failure rates in selected high-risk patients. However, the comparative effects of deep (beneath-LCL) and superficial (over-LCL) LET techniques on clinical and biomechanical outcomes remain uncertain. This study aimed to compare the functional, kinematic, and strength outcomes of deep and superficial LET performed concomitantly with ACLR in patients with high-grade pivot-shift. It was hypothesised that superficial LET would result in clinical and biomechanical outcomes comparable to those of the deep LET technique. Methods This prospective, randomised, double-blind comparative study included 24 male patients with isolated ACL rupture and pivot-shift grades 2-3. Patients were divided equally into two treatment groups as ACLR with deep LET or superficial LET. All procedures used standardised quadrupled hamstring autografts. Clinical outcomes were assessed using the IKDC, Lysholm, and Tegner scores preoperatively and at 6 and 12 months. Biomechanical assessments included three-dimensional running gait analysis and isokinetic tibial rotation strength testing at 6 months postoperatively. Results All patients completed follow-up with no graft ruptures. Both groups showed significant improvement in IKDC and Lysholm scores at 6 and 12 months (p < 0.05). The deep LET group demonstrated greater improvement in IKDC (86.5 +/- 3.0 vs. 81.3 +/- 6.7, p = 0.022) and Lysholm (90.8 +/- 2.9 vs. 85.8 +/- 7.2, p = 0.037) scores. Running gait analysis revealed reduced stance phase tibial rotation (p = 0.035) and anterior translation (p = 0.01) in the deep LET group, indicating superior dynamic control. Isokinetic torque recovery and Tegner activity levels (6.4 vs. 6.0, p = 0.19) were comparable. Conclusion Concomitant deep and superficial LET techniques effectively restored knee stability and improved clinical outcomes after ACL reconstruction. However, the deep LET technique was associated with improved tibial rotational stability and more favourable patient-reported outcomes in young, athletic male patients with high-grade pivot-shift. Level of Evidence Level 1, randomised controlled trials with adequate statistical power to detect differences (narrow confidence intervals) and follow up >80%.