Total knee arthroplasty with computer-assisted navigation more closely replicates normal knee biomechanics than conventional surgery.

BACKGROUND: Computer-assisted navigation in total knee arthroplasty (TKA) reduces variability and may improve accuracy in the postoperative static alignment. The effect of navigation on alignment and biomechanics during more dynamic movements has not been investigated.

METHODS: This study compared knee biomechanics during level walking of 121 participants: 39 with conventional TKA, 42 with computer-assisted navigation TKA and 40 unimpaired control participants.

RESULTS: Standing lower-limb alignment was significantly closer to ideal in participants with navigation TKA. During gait, when differences in walking speed were accounted for, participants with conventional TKA had less knee flexion during stance and swing than controls (P<0.01), but there were no differences between participants with navigation TKA and controls for the same variables. Both groups of participants with TKA had lower knee adduction moments than controls (P<0.01).

CONCLUSIONS: In summary, there were fewer differences in the biomechanics of computer-assisted navigation TKA patients compared to controls than for patients with conventional TKA. Computer-assisted navigation TKA may restore biomechanics during walking that are closer to normal than conventional TKA.