Abstract
Pedobarographic gait analysis is a useful tool for the determination of loading distributions
and alterations on the lower extremity and their reflection on the foot sole after
many orthopaedic surgical applications. To date, there have been no studies evaluating
the relationship between component alignment and changes of pedobarographic gait analysis
in total knee arthroplasty (TKA). We aimed to investigate the effects of TKA and prosthetic
alignment on the distribution of pedobarographic parameters. Quantitative gait patterns
of 47 patients were prospectively evaluated by using pedobarography 1 week before
surgery and at the seventh month, on average, postoperatively. Component positions
were assessed, and all applications were divided into three groups according to tibial
component position as varus, neutral, and valgus. Pedobarographic results were compared
between pre- and postoperative values for all applications and compared among the
groups. Mean postoperative tibiofemoral angle was 5.4 degrees in valgus, and preoperative
knee scores were markedly improved postoperatively. The range of tibial component
alignment changed between 1 and 4 degrees in the varus and valgus groups. Plantar
loading parameters (force and pressure) were significantly decreased in all operated
knees, especially in forefoot and midfoot. In varus tibial components, plantar loading
values decreased in midfoot and hindfoot. However, in the neutral and valgus groups,
similar alterations of plantar loadings were obtained, which included decreasing in
forefoot and midfoot with significant increase in hindfoot. Plantar loading distribution
changed statistically significantly after TKA despite good clinical and radiographic
results. Tibial component alignment was also responsible for plantar loading distribution.
Tibial components in varus position create different foot loading characteristics
compared with neutral and valgus aligned components. Pedobarographic evaluation in
TKA allows clinicians to obtain a proper understanding of abnormal gait caused by
component malposition.
Keywords
pedobarography - gait analysis - total knee arthroplasty - foot loading - component
alignment
