Proximal fibular osteotomy as a treatment for degenerative meniscal extrusion

Abstract

Meniscal extrusion treatment is a key focus area for research and clinical study of degenerative knee pathology. The contact forces between the meniscus and the bones cause external displacements of the meniscus that are resisted by the circumferential fibres. The main risk factors for the excessive deformation of the meniscus are meniscal root tears, disruption of the circumferential fibres, knee malalignment and high body mass index. Prior research has shown meniscal extrusion to be a crucial determinant of successful procedures in knee osteoarthritis treatment. The characteristics of medial knee osteoarthritis are an increase in varus malalignment and the load transferred through the medial compartment. This is associated with greatest reduction of the joint space width over the medial meniscus body and an increase in contact forces acting on the meniscus, which results in increased extrusion of the medial meniscal body. Relocating the meniscus in its anatomic position restores the correct distribution of contact force across the knee joint, and prevents destruction of the cartilage. Thus, clinical and biomechanical research focus on improving surgical techniques that allow for diminished meniscal extrusion. Proximal fibula osteotomy is a relatively new technique which involves the removal of a 10 mm piece of fibula, 4–10 cm from the fibular head. This technique has been shown to reduce the knee-lever arm, load transferred through the medial compartment and increase the medial joint space width. We hypothesise that proximal fibular osteotomy could be an effective, simple, and minimally invasive treatment for degenerative meniscal extrusion.