Question: In young patients with an anterior cruciate ligament (ACL)-deficient knee at high risk for reinjury, does adding lateral extra-articular tenodesis (LET) to hamstring ACL reconstruction (ACLR) reduce clinical failure rate? Design: Randomized (allocation concealed), blinded (primary outcome assessors), controlled trial with 2 years of follow-up and intention-to-treat analysis. STABILITY study. ClinicalTrials.gov NCT02018354. Setting: 7 centers in Canada and 2 centers in Europe. Patients: 618 patients 14 to 25 years of age (mean age, 19 years; 51% women) who had an ACL-deficient knee with high risk of reinjury (>= 2 of: competitive pivoting-sport participation, pivot-shift grade >= 2, Beighton score >= 4, or genu recurvatum >10 degrees). Exclusion criteria included skeletal immaturity, previous ACLR on either knee, >= 2 ligaments needing surgery, symptomatic articular cartilage defect requiring intervention other than debridement, or asymmetric varus >3 degrees. 95% of patients completed follow-up. Intervention: Patients underwent a standardized, single-bundle, hamstring autograft ACLR using an anatomic transportal femoral tunnel drilling technique. 306 patients were randomized to ACLR plus a modified Lemaire LET using a strip of iliotibial band (ITB); the remaining patients underwent ACLR alone (n = 312). Main outcome measures: The primary outcome was ACLR clinical failure, defined as either graft rupture, confirmed with magnetic resonance imagingor arthroscopic examination, or persistent rotatory laxity (mild asymmetricpivot shift [grade 1]at >= 2 visits ormoderate/severe asymmetric pivot shift [grade 2 or 3] at any visit). Secondary outcomes included patientreported measures: P4 pain scale, ACL Quality of Life Questionnaire, International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Marx Activity Rating Scale. Main results: ACLR 1 LET reduced clinical failure and graft rupture at 2 years compared with ACLR alone (Table I). Pain was less in the ACLR-alone group vs. ACLR 1 LET at 3 months (p = 0.003). ACLR alone had a greater improvement vs. ACLR 1 LET for IKDC and KOOS domain scores at 3 and 6 months (p < 0.05). Groups did not differ for any patient-reported outcomes, including the Marx Activity Rating Scale, at 2 years (p > 0.10). Conclusion: In young patients with an ACL-deficient knee at high risk for reinjury, adding a modified Lemaire LET to single-bundle hamstring autograft ACLR reduced clinical failure rate at 2 years.
