Biochemical markers of cartilage metabolism are associated with walking biomechanics 6-months following anterior cruciate ligament reconstruction.
The purpose of our study was to determine the association between biomechanical outcomes of walking gait (peak vertical ground reaction force [vGRF], vGRF loading rate [vGRF-LR], and knee adduction moment [KAM]) 6 months following anterior cruciate ligament reconstruction (ACLR) and biochemical markers of serum type-II collagen turnover (collagen type-II cleavage product to collagen type-II C-propeptide [C2C:CPII]), plasma degenerative enzymes (matrix metalloproteinase-3 [MMP-3]), and a pro-inflammatory cytokine (interleukin-6 [IL-6]). Biochemical markers were evaluated within the first 2 weeks (6.5 ± 3.8 days) following ACL injury and again 6 months following ACLR in eighteen participants. All peak biomechanical outcomes were extracted from the first 50% of the stance phase of walking gait during a 6-month follow-up exam. Limb symmetry indices (LSI) were used to normalize the biomechanical outcomes in the ACLR limb to that of the contralateral limb (ACLR/contralateral). Bivariate correlations were used to assess associations between biomechanical and biochemical outcomes. Greater plasma MMP-3 concentrations after ACL injury and at the 6-month follow-up exam were associated with lesser KAM LSI. Lesser KAM was associated with greater plasma IL-6 at the 6-month follow-up exam. Similarly, lesser vGRF-LR LSI was associated with greater plasma MMP-3 concentrations at the 6-month follow-up exam. Lesser peak vGRF LSI was associated with higher C2C:CPII after ACL injury, yet this association was not significant after accounting for walking speed. Therefore, lesser biomechanical loading in the ACLR limb, compared to the contralateral limb, 6 months following ACLR may be related to deleterious joint tissue metabolism that could influence future cartilage breakdown. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2288-2297, 2017.
Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Brian
B
Pietrosimone
Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Richard F
RF
Loeser
Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
J Troy
JT
Blackburn
Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.|Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Darin A
DA
Padua
Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Matthew S
MS
Harkey
Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Laura E
LE
Stanley
Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Brittney A
BA
Luc-Harkey
Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Veronica
V
Ulici
Injury Prevention Research Center, University of North Carolina at Chapel Hill, North Carolina.
Stephen W
SW
Marshall
Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Joanne M
JM
Jordan
Department of Orthopaedics, School of Medicine, University of North Carolina at Chapel Hill, North Carolina.
Jeffery T
JT
Spang
D000293:Adolescent; D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction; D015415:Biomarkers / Q000097:blood*; D001696:Biomechanical Phenomena; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D016138:Walking / Q000502:physiology*; D016474:Weight-Bearing; D055815:Young Adult
D015415:Biomarkers
collagen; interleukin; knee adduction moment; matrix metalloproteinase-3; osteoarthritis