Alterations in Static Plantar Pressure Before and After Total Knee Arthroplasty in Individuals with Knee Osteoarthritis

Background/Objectives: Knee osteoarthritis (OA) alters lower limb biomechanics, often leading to an asymmetric plantar pressure distribution. Total knee arthroplasty (TKA) aims to restore joint function and may normalize plantar loading, but evidence from instrumented static pressure analysis is limited. The objective of this study was to compare static plantar pressure distributions before and after TKA in individuals with knee OA and in age- and sex-matched healthy controls. Methods: A pre-post study was conducted on 77 individuals with severe knee OA (Kellgren–Lawrence grade 4) who underwent TKA and 77 matched healthy controls. The plantar pressure area, average pressure, and maximal pressure were assessed preoperatively and at 6 and 12 months postoperatively using a Win-Track force platform. Standard postoperative rehabilitation was followed. Statistical analyses included independent t-tests and repeated-measures ANOVA (p ≤ 0.05). Results: Compared with controls, pre-TKA patients presented significantly lower plantar pressure area, average pressure, and maximal pressure than controls (p < 0.001). At 6 and 12 months post-TKA, the plantar pressure area (p < 0.001) and average pressure (p = 0.001) improved significantly, with more balanced bilateral loading and increased forefoot weight transfer. At 12 months, no significant differences in any plantar pressure parameters remained between the TKA and control groups. Conclusions: Severe knee OA is associated with altered static plantar pressure patterns, characterized by reduced loading and asymmetry. TKA effectively restores plantar pressure distribution, achieving normalization within 12 months. The incorporation of plantar pressure assessment into pre- and postoperative care may guide targeted rehabilitation and enhance functional recovery.