Summary

At 6 months postoperative, we found significant differences, in favor of ACLR alone, for hop test limb symmetry index, peak torque, average power quadriceps index, and a subjective functional score. All outcomes were no longer statistically different by 12 months postoperative. The addition of LET may mean a slower rate of recovery with no differences from 12 months onward.

Abstract

Introduction

The addition of a lateral extra-articular tenodesis (LET) to anterior cruciate ligament reconstruction (ACLR) has been proposed to improve rotational stability and reduce failure rates. It is not clear what effect the addition of an LET has to functional recovery.

Purpose

The purpose of this study is to investigate the effect of LET on functional indices within a subset of patients enrolled in the multicenter Stability Study.

Methods

In this multicenter, randomized clinical trial, 624 active patients under the age of 25 years were randomly allocated to either ACLR alone (control) or ACLR with LET then followed for two years postoperatively. Three of the 9 study centres collected functional outcome data. The primary outcome for functional assessment was Limb Symmetry Index (LSI) calculated using a series of four hop tests at 6, 12 and 24 months postoperative. Secondary outcome measures included quadriceps index (QI) and hamstrings index (HTI) measured using an isokinetic dynamometer and Lower Extremity Functional Scale (LEFS).

Results

To date, 229, 247 and 230 patients have completed the hop tests at 6, 12 and 24 months postoperatively. At six months, the ACLR alone group had an LSI of 94.5% ± 0.8 and the ACLR plus LET group had an LSI of 91.5% ± 0.8 (p=0.01). At 12 months, the ACLR alone group had an LSI of 96.1% ± 0.5 and the ACLR plus LET group had an LSI of 95.4% ± 0.5 (p=0.33). Isokinetic strength testing was completed by 176, 160 and 121 patients at 6, 12 and 24 months respectively. At six months, the ACLR alone group had a QI peak torque of 79.3% ± 1.5 and an average power of 81.0% ± 1.5 and the ACLR plus LET group had a QI peak torque of 74.7% ± 1.5 (p=0.04) and an average power of 76.0% ± 1.4 (p=0.01). At 12 months, the ACLR alone group had a QI peak torque of 90.1% ± 1.4 and an average power of 89.9% ± 1.4 and the ACLR plus LET group had a QI peak torque of 86.9% ± 1.4 (p=0.12) and an average power QI of 87.9% ± 1.4 (p=0.32). At six months, the ACLR alone group had a LEFS score of 70.2 ± 0.8 and the ACLR plus LET group had a LEFS score of 68.5 ± 0.8 (p=0.03). At 12 months, the ACLR alone group had a LEFS score of 71.9± 0.9 and the ACLR plus LET group had a LEFS score of 73.4 ± 0.9 (p=0.24). No significant differences exist between the two groups at 12 or 24 months for HTI.

Conclusions

Significant differences were found at six months between the two groups for hop test LSI, peak torque and average power QI and subjective functional score, in favor of the ACLR alone, all of which normalized by 12 months. The addition of LET would suggest a slower rate of recovery with no differences from 12 months onward.