Clinical and laboratory data are both essential to assess the locomotor patterns at 4 months post-total knee arthroplasty

Abstract

A recent randomized clinical trial, comparing the clinical effectiveness of a rehabilitation program delivered at home using videoconference technology or face-to-face visits, has revealed equivalent outcomes at 4 months after total-knee arthroplasty (TKA). Here we present the results of the laboratory analysis and the relationships with clinical outcomes for a subgroup of participants. The aim of this subgroup analysis (43% of the whole cohort) was to determine whether the clinical outcomes obtained from a physical assessment are sufficient to predict asymmetry during locomotor patterns at 4 months post-TKA. Eighty-four individuals (mean age and standard deviation: 66 (7.5) years) who had received 8 weeks of physiotherapy were assessed 4 months after TKA. In addition to clinical assessment (pain, ROM and strength, 6MWT and comorbidity, global function of the lower limb with WOMAC), the locomotor patterns during two tasks, sit-to-stand (three foot conditions) and walking at two speeds, were evaluated in the laboratory. Statistical analyses assessed the relationships between clinical outcomes and biomechanical data, more specifically locomotor asymmetry of performance. Participants had moderate pain, and ROM and strength at the knee were inferior on the operated side. Mean values in the WOMAC, 6MWT and stair capacity were 84.7 (14.4), 411.4 m (93.9) and 19.2 (23.5), respectively. They performed the STS with an asymmetrical use of the operated knee although they could perform more symmetrically when imposed. They were more asymmetrical at fast than normal speed during walking. The knee angles, moments, powers and force asymmetries correlated weakly with clinical outcomes except for the knee extensor strength asymmetry with STS. The clinical outcomes explained only a small part of the variance in the locomotor asymmetry. These results bring more evidence that laboratory assessment is essential to characterize the locomotor patterns post-TKA and that it provides useful information to the clinicians.