Partial hemiarthroplasty for the treatment of osteonecrosis of the femoral head

Abstract

he use of a composite osteochondral device for simulating partial hemiarthroplasty was examined. The device was composed of a polyvinyl alcohol hydrogel and a titanium fibre mesh, acting as artificial cartilage and as porous artificial bone, respectively. The titanium fibre mesh was designed to act as an interface material, allowing firm attachment to both the polyvinyl alcohol gel (through injection moulding) and the femoral joint surface (through bony ingrowth). We implanted 22 of these devices into canine femoral heads. Histological findings from the acetabular cartilage and synovial membrane, as well as the attachment of the prosthesis to bone, were examined up until one year after operation.No marked pathological changes were found and firm attachment of the device to the underlying bone was confirmed. The main potential application for this device is for partial surface replacement of the femoral head after osteonecrosis. Other applications could include articular resurfacing and the replacement of intervertebral discs. J Bone Joint Surg [Br] 2003;85-B:922-30.

Biological and functional evaluation of a novel pyrolytic carbon implant for the treatment of focal osteochondral defects in the medial femoral condyle: assessment in a canine model

“…Focal hemiarthroplasty devices using pyrolytic carbon [15], metal alloys [15, 16], polymer composites [17], and ceramic composites [18] have been investigated for a number of anatomical locations with varying results. Several previous studies have shown that even when the shape and design of the implant closely match the surface, the implant material properties may be detrimental to the opposing articular cartilage in the long-term due to differences in elastic modulus [15, 19, 20].…”

Poro-viscoelastic constitutive modeling of unconfined creep of hydrogels using finite element analysis with integrated optimization method

“…Femoral heads in dogs (Kobayashi et al, 2003b;Ushio et al, 2003), femoral condyles in rabbits (Gu et al, 1999;Kobayashi et al, 2003b), and intervertebral discs (Bao and Higham, 1991) have all been reported. Meniscus plugs were fabricated, mounted into bone holes, and secured by nylon thread (Oka et al, 2000).…”

Hydrophilic–hydrophobic hydrogels for cartilage replacement

“…Frictional behaviors of hydrogels do not exhibit Coulomb friction, which states that the friction force is proportional to normal force (normal means perpendicular to the surfaces). The friction coefficient of the hydrogels may show unique load dependencies: for example, as load increases, friction coefficient decreases (Ushio et al, 2003b). It is postulated that as the hydrogel deforms under the applied load, part of the water is squeezed out from the bulk gel and serves as a lubricator leading to boundary lubrication or hydrodynamic lubrication.…”