Variability of gait parameters in patients with total knee arthroplasty.

PURPOSE: Gait analysis has provided important information about the variability of gait for patients prior to and after total knee arthroplasty (TKA). The objective of this research was to clarify how the different surgical techniques influence gait variability.
METHODS: Gait analysis was performed at 0.8, 1.0, and 1.2 m/s in three groups of patients (operated on using the conventional technique, conventional technique combined with computer-assisted navigation, and the minimally invasive technique combined with computer-assisted navigation; n = 15 each) and a control group (n = 15; healthy, age, body mass, and body height matched). Gait analysis was performed preoperatively and 6 and 12 months after the surgery. Gait parameter variability was characterized by the coefficient of variance of spatio-temporal parameters and by the mean coefficient of variance of angular parameters.
RESULTS: One year after surgery, the variability of spatio-temporal parameters recovered to normal in patients operated on using the conventional technique; however, the variability of articular motion of the affected side decreased and the variability of articular motion of the non-affected side and pelvis increased compared to the control group. In patients operated on using the minimally invasive technique, the variability of spatio-temporal and angular parameters was similar to that of the control group.
CONCLUSION: The type of surgical technique significantly influences the variability and stability of gait. Difference in the variability of angular parameters predicts gait instability and increased risk of falling after TKA with the conventional surgical technique. The minimally invasive technique ensures a recovery of gait variability and stability. Thus, particular attention must be paid to improving gait stability during postoperative rehabilitation. LEVEL OF EVIDENCE: II.