&NA; This study evaluates the feasibility of growing tissue‐engineered cartilage in the shape of a human ear using chondrocytes seeded onto a synthetic biodegradable polymer fashioned in the shape of a 3‐year‐old child's auricle. A polymer template was formed in the shape of a human auricle using a nonwoven mesh of polyglycolic acid molded after being immersed in a 1% solution of polylactic acid. Each polyglycolic acid‐polylactic acid template was seeded with chondrocytes isolated from bovine articular cartilage and then implanted into subcutaneous pockets on the dorsa of 10 athymic mice. The three‐dimensional structure was well maintained after removal of an external stent that had been applied for 4 weeks. Specimens harvested 12 weeks after implantation and subjected to gross morphologic and histologic analysis demonstrated new cartilage formation. The overall geometry of the experimental specimens closely resembled the complex structure of the child's auricle. These findings demonstrate that polyglycolic acid‐polylactic acid constructs can be fabricated in a very intricate configuration and seeded with chondrocytes to generate new cartilage that would be useful in plastic and reconstructive surgery. (Plast. Reconstr. Surg. 100: 297, 1997.)

Transplantation of chondrocytes utilizing a polymer-cell construct to produce tissue-engineered cartilage in the shape of a human ear

Mechanical and microstructural properties of polycaprolactone scaffolds with one-dimensional, two-dimensional, and three-dimensional orthogonally oriented porous architectures produced by selective laser sintering.

Muscle as a collagen fiber reinforced composite: a review of force transmission in muscle and whole limb.

As the understanding of interactions between articular cartilage and subchondral bone continues to evolve, increased attention is being directed at treatment options for the entire osteochondral unit, rather than focusing on the articular surface only. It is becoming apparent that without support from an intact subchondral bed, any treatment of the surface chondral lesion is likely to fail. This article reviews issues affecting the entire osteochondral unit, such as subchondral changes after marrow-stimulation techniques and meniscectomy or large osteochondral defects created by prosthetic resurfacing techniques. Also discussed are surgical techniques designed to address these issues, including the use of osteochondral allografts, autologous bone grafting, next generation cell-based implants, as well as strategies after failed subchondral repair and problems specific to the ankle joint. Lastly, since this area remains in constant evolution, the requirements for prospective studies needed to evaluate these emerging technologies will be reviewed.

/pdf/the-subchondral-bone-in-articular-cartilage-repair-current-2g62pxlzoy.pdf

The subchondral bone in articular cartilage repair: current problems in the surgical management

Stresses in the local collagen network of articular cartilage: a poroviscoelastic fibril-reinforced finite element study

A fibril-reinforced poroviscoelastic swelling model for articular cartilage

Pathways of load-induced cartilage damage causing cartilage degeneration in the knee after meniscectomy

http://www.mate.tue.nl/mate/pdfs/4656.pdf

The role of computational models in the search for the mechanical behavior and damage mechanisms of articular cartilage

In numerical simulations of skeletal muscle contractions, geometric information is of major importance. The aim of the present study was to determine whether the diffusion tensor imaging (DTI) technique is suitable to obtain valid input with regard to skeletal muscle fibre direction. The accuracy of the DTI method was therefore studied by comparison of DTI fibre directions in the rat tibialis anterior muscle with fascicle striation patterns visible on high-resolution magnetic resonance imaging (MRI) and with fibre directions in an actual longitudinal section (ALS) through the same muscle. The results showed an excellent qualitative agreement between high-resolution MRI and DTI. Despite less accurate quantitative comparison with ALS, it was concluded that DTI does indeed measure skeletal muscle fibre direction. After the experiment, it was possible to determine an appropriate voxel size (0.9 mm3) that provided enough resolution and acceptable accuracy (5°) to use DTI fibre directions in biomechanical analyses. Muscle deformation during contraction, resulting from a finite element simulation with a mesh that was directly generated from the experimental data, has been presented.

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1469-7580.1999.19410079.x

C.C. van Donkelaar

Papers

Stresses in the local collagen network of articular cartilage: a poroviscoelastic fibril-reinforced finite element study

A fibril-reinforced poroviscoelastic swelling model for articular cartilage

Pathways of load-induced cartilage damage causing cartilage degeneration in the knee after meniscectomy

The role of computational models in the search for the mechanical behavior and damage mechanisms of articular cartilage

Diffusion tensor imaging in biomechanical studies of skeletal muscle function