Gait mechanics in those with/without medial compartment knee osteoarthritis 5 years after anterior cruciate ligament reconstruction.

The objective of the study was to evaluate differences in gait mechanics 5 years after unilateral anterior cruciate ligament reconstruction surgery, for non-osteoarthritic (n = 24) versus osteoarthritic (n = 9) subjects. For the involved knee, the osteoarthritic group demonstrated significantly lower peak knee flexion angles (non-osteoarthritic = 24.3 ± 4.6°, osteoarthritic = 19.1 ± 2.9°, p = 0.01) and peak knee flexion moments (non-osteoarthritic = 5.3 ± 1.2% Body Weight × Height, osteoarthritic = 4.4 ± 1.2% Body Weight × Height, p = 0.05). Differences in peak knee adduction moment approached significance, with a higher magnitude for the osteoarthritic group (non-osteoarthritic = 2.4 ± 0.8% Body Weight × Height, osteoarthritic = 2.9 ± 0.5% Body Weight × Height, p = 0.09). Peak medial compartment joint load was evaluated using electromyography-informed neuromusculoskeletal modeling. Peak medial compartment joint load in the involved knee for the two groups was not different (non-osteoarthritic = 2.4 ± 0.4 Body Weight, osteoarthritic = 2.3 ± 0.6 Body Weight). The results suggest that subjects with dissimilar peak knee moments can have similar peak medial compartment joint load magnitudes. There was no evidence of inter-limb asymmetry for either group. Given the presence of inter-group differences (non-osteoarthritic vs. osteoarthritic) for the involved knee, but an absence of inter-limb asymmetry in either group, it may be necessary to evaluate how symmetry is achieved, over time, and to differentiate between good versus bad inter-limb symmetry, when evaluating knee gait parameters.