title: Gait mechanics 2 years after anterior cruciate ligament reconstruction are associated with longer-term changes in patient-reported outcomes.
abstract: This study tested the hypothesis that side-to-side differences in knee gait mechanics 2 years after anterior cruciate ligament (ACL) reconstruction are associated with long-term (∼8 years post-reconstruction) changes in patient-reported outcome scores. Sixteen subjects (5 males; age: 29.1 ± 7.1 years) with primary unilateral ACL reconstruction were gait tested at baseline (2.2 ± 0.3 years post-ACL reconstruction) and filled out KOOS and Lysholm surveys. At long-term follow-up (7.7 ± 0.7 years post-ACL reconstruction), the same subjects completed KOOS and Lysholm surveys. Pearson correlation coefficients assessed relationships between side-to-side differences in kinematics and kinetics at baseline and changes in Lysholm and KOOS Pain/QOL scores from 2 to 8 years post-ACL reconstruction. Significant associations were seen between greater average varus rotation (Lysholm: R = -0.654, p = 0.006) and less anterior femoral displacement (Lysholm: R = 0.578, p = 0.019) during stance of the ACL reconstructed knee versus the contralateral knee at baseline and worse follow-up outcome scores. Significant associations were seen between greater peak knee flexion moment (KOOS Pain: R = -0.572, p = 0.026; KOOS QOL: R = -0.636, p = 0.011), peak knee adduction moment (Lysholm: R = -0.582, p = 0.018; KOOS Pain: R = -0.742, p = 0.002; KOOS QOL: R = -0.551, p = 0.033), and peak internal rotation moment (Lysholm: R = 0.525, p = 0.037; KOOS Pain: R = 0.815, p < 0.001; KOOS QOL: R = 0.777, p = 0.001) in the ACL reconstructed knee at baseline with worse follow-up outcomes. The results of this study support the hypotheses that early changes in gait mechanics following ACL reconstruction are associated with longer-term clinical changes in patient-reported outcomes, suggesting that biomechanical markers obtained as early as 2 years after ACL reconstruction may be useful to understand clinical outcomes in this population. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:634-640, 2017.
authors.affiliation: Department of Orthopaedic Surgery, Stanford University Medical Center, Stanford, California.|Department of Mechanical Engineering, Stanford University, Stanford, California.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Erhart-Hledik
authors.affiliation: Department of Orthopaedic Surgery, Stanford University Medical Center, Stanford, California.|Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Constance R
authors.initials: CR
authors.lastname: Chu
authors.affiliation: Department of Mechanical Engineering, Stanford University, Stanford, California.|Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Asay
authors.affiliation: Department of Orthopaedic Surgery, Stanford University Medical Center, Stanford, California.|Department of Mechanical Engineering, Stanford University, Stanford, California.|Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Andriacchi
mesh_terms: D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology* / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction; D001696:Biomechanical Phenomena; D005260:Female; D005500:Follow-Up Studies; D005684:Gait; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D000071066:Patient Reported Outcome Measures; D055815:Young Adult
keywords: ACL; gait analysis; knee; patient-reported outcome; reconstruction