How effective is proximal fibular osteotomy in redistributing joint pressures? Insights from an HTO comparative in-silico study.

BACKGROUND: Knee osteoarthritis (KOA) represents a widespread degenerative condition among adults that significantly affects quality of life. This study aims to elucidate the biomechanical implications of proximal fibular osteotomy (PFO), a proposed cost-effective and straightforward intervention for KOA, comparing its effects against traditional high tibial osteotomy (HTO) through in-silico analysis. METHODS: Using medical imaging and finite element analysis (FEA), this research quantitatively evaluates the biomechanical outcomes of a simulated PFO procedure in patients with severe medial compartment genu-varum, who have undergone surgical correction with HTO. The study focused on evaluating changes in knee joint contact pressures, stress distribution, and anatomical positioning of the center of pressure (CoP). Three models are generated for each of the five patients investigated in this study, a preoperative original condition model, an in-silico PFO based on the same original condition data, and a reversed-engineered HTO in-silico model. RESULTS: The novel contribution of this investigation is the quantitative analysis of the impact of PFO on the biomechanics of the knee joint. The results provide mechanical evidence that PFO can effectively redistribute and homogenize joint stresses, while also repositioning the CoP towards the center of the knee, similar to what is observed post HTO. The findings propose PFO as a potentially viable and simpler alternative to conventional surgical methods for managing severe KOA, specifically in patients with medial compartment genu-varum. CONCLUSION: This research also marks the first application of FEA that may support one of the underlying biomechanical theories of PFO, providing a foundation for future clinical and in-silico studies.

In-silico study of the biomechanical effects of proximal-fibular osteotomy on knee joint contact pressure in varus-valgus misalignment.

The aim of this work is to investigate in-silico the biomechanical effects of a proximal fibular osteotomy (PFO) on a knee joint with different varus/valgus deformities on the progression of knee osteoarthritis (KOA). A finite element analysis (FEA) of a human lower extremity consisting of the femoral, tibial and fibular bones and the cartilage connecting them was designed. The FEA was performed in a static standing primitive position to determine the contact pressure (CP) distribution and the location of the center of pressure (CoP). The analysis examined the relationship between these factors and the degree of deformation of the hip-knee angle in the baseline condition. The results suggested that PFO could be a simple and effective surgical treatment for patients with associated genu varum. This work also reported that a possible CP homogenization and a CoP correction can be achieved for medial varus deformities after PFO. However, it reduced its effectiveness for tibial origin valgus misalignment and worsened in cases of femoral valgus misalignment.