Biochemical markers of cartilage metabolism are associated with walking biomechanics 6‐months following anterior cruciate ligament reconstruction

Abstract

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]) six 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 two weeks (6.5±3.8 days) following ACL injury and again six 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 six-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 six-month follow-up exam were associated with lesser KAM LSI. Lesser KAM was associated with greater plasma IL-6 at the six-month follow-up exam. Similarly, lesser vGRF-LR LSI was associated with greater plasma MMP-3 concentrations at the six-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, six months following ACLR may be related to deleterious joint tissue metabolism that could influence future cartilage breakdown.

Associations Between Slower Walking Speed and T1ρ Magnetic Resonance Imaging of Femoral Cartilage Following Anterior Cruciate Ligament Reconstruction

“…(20, 24) Trajectories form the anterior superior iliac spine and sacral cluster markers were low-pass filtered at 10 Hz using a 4th order recurrent Butterworth filter and used to estimate the pelvic center of mass. (26) To more accurately determine habitual walking speed for data analysis, we located the point of initial ground contact for the injured limb striking the force plate during each gait trial and measured the velocity of the pelvis center of mass during a 1-meter distance that began 0.5 meter prior to initial ground contact and ended 0.5 meter after initial ground contact. (20)…”

“…During data collection, participants performed 5 gait trials for which they were required to do the following: individually strike an individual force plate with each foot; maintain walking speed within AE5% of the average speed during the practice trials; and not undergo any visible alterations to gait during the trial (e.g., trip or stutter step) (20,24). Trajectories from the anterior superior iliac spine and sacral cluster markers were low-pass filtered at 10 Hz using a fourth-order recurrent Butterworth filter and used to estimate the pelvic center of mass (27). To more accurately determine habitual walking speed for data analysis, we located the point of initial ground contact for the injured extremity striking the force plate during each gait trial and measured the velocity of the pelvis center of mass during a 1-meter distance that began 0.5 meter prior to initial ground contact and ended 0.5 meter after initial ground contact (20).…”

Walking gait asymmetries 6 months following anterior cruciate ligament reconstruction predict 12‐month patient‐reported outcomes

“…All participants were outfitted with 25 retroreflective markers and a ridged cluster of three additional markers secured over the sacrum . Marker positions were collected using a 10–camera three‐dimensional motion capture system (Vicon Nexus) and post‐processed with Vicon Nexus v1.4.1 motion capture software (Vicon Motion Systems, Oxford, UK).…”

Slower Walking Speed Is Related to Early Femoral Trochlear Cartilage Degradation After ACL Reconstruction

“…One potentially modifiable factor that may be related to post‐traumatic OA development is aberrant walking mechanics . Most studies investigating the association between walking mechanics and post‐traumatic OA, however, have examined the tibiofemoral joint, rather than the patellofemoral joint.…”

“…Most studies investigating the association between walking mechanics and post‐traumatic OA, however, have examined the tibiofemoral joint, rather than the patellofemoral joint. These studies have found that unloading the tibiofemoral joint, especially its medial compartment, early after ACLR is associated with future tibiofemoral OA . One study by Culvenor et al found that those with established, radiographic patellofemoral OA approximately 9 years after ACLR walked with altered mechanics at that time.…”