Purpose: These aim of the study was to conduct a long-term evaluation of whether total hip replacement permanently affects the dynamic body balance.
Methods: Twenty-five patients after the unilateral total hip replacement (mean age: 69.9 ± 6.2) and 25 subjects without the total hip replacement (mean age: 68.4 ± 4.8) who matched the age and overall health participated in this study. The force platform and functional tests such as Timed Up and Go, 3m walk test, Functional Reach Test, 30s Chair Stand Test, Step Test and Berg Balance Scale were used to assess dynamic balance. The results obtained in individual trials were compared using the Student's t-test for independent variables, the Welch test or the non-parametric Mann-Whitney U-test.
Results: Subjects from the THR group exhibited significantly increased time and distance in the tests performed on the force platform, compared to the control group. We also observed worse balance and functional test scores in the THR group: Timed Up and Go test ( p < 0.001), 3 m walk test ( p < 0.001), Functional Reach Test ( p < 0.001), 30 s Chair Stand Test ( p = 0.001) and Step Test (operated leg: p < 0.001, non-operated leg: p < 0.001). The results obtained in the Berg Balance Scale tests were not significantly different between the groups ( p = 0.218).
Conclusions: We observed significant differences in postural stability and dynamic balance between patients after THR and subjects in the same age without endoprosthesis. Our research shows that total hip replacement permanently impairs patients' dynamic balance and their functionality in certain lower-extremity activities.