Cartiva SCI - Technology

Cartiva SCI is an organic polymer-based biomaterial comprised of 40% polyvinyl alcohol (PVA). PVA is a synthetic polymer derived from polyvinyl acetate through partial or full hydroxylation. Depending on the degree of polymerization and hydrolysis, the physical characteristics, chemical properties and mechanical properties of PVA can be customized to defined functional requirements.

The properties of PVA can be further modified by crosslinking, a process whereby individual polymer chains are connected to yield a tough and physically stable matrix. Crosslinking of PVA produces a material that is inert, viscoelastic and lubricious attractive properties for medical device applications. A crosslinked PVA matrix is no longer water soluble, but can be swollen to produce a hydrogel, a gel where the swelling agent is water. PVA hydrogels and membranes have been developed for biomedical applications such as contact lenses, artificial pancreases, hemodialysis and synthetic vitreous humor. It is an attractive material for these applications because of its biocompatibility and low protein adsorption properties resulting in low cell adhesion compared with other hydrogels. PVA’s properties also make it a good biomaterial for simulating natural tissues inside the body, such as cartilage replacement. Cartilage, typically comprised of 60-80% water with a mass balance primarily of collagen, is the prototypical, biologic hydrogel.

With a high water content similar to surrounding healthy cartilage and its elastic and compressive mechanical properties, the physical properties of Cartiva SCI make it an excellent replacement for damaged articular cartilage. The material has been shown to resist compression and shear with exceptional wear characteristics. Stringent control of the PVA composition and a proprietary manufacturing process results in compressive properties (aggregate modulus and creep) and wear resistance similar to native cartilage. The manufacturing process results in a viscoelastic implant engineered to withstand the repetitive loading associated with the physiologic conditions of the knee and the first metatarsophalangeal joint.

Property Articular Cartilage Cartiva SCI
Water Content 60-80% 60%
Compressive Modulus 0.3-0.8 MPa 2.5-3.2 MPa
Coefficient of Friction <0.01-0.05 0.04-0.07

The finished device is cylindrical in shape and is for use during a single surgical procedure, where its placement allows for addressing focal articular defects. Due to the similar osmotic, physical, and frictional properties of Cartiva SCI to native cartilage, joint resurfacing repairs using this implant does not require replacement of the opposing articular surface. Consequently, joint resurfacing with Cartiva SCI is simple, does not require significant removal of healthy tissue or its replacement with a durable bearing surface, and thus typically results in nominal surgical trauma and rapid recovery.

Cartiva Feature Benefit
Synthetic No risk of viral bacterial transmission associated with human or animal derived materials
Biocompatible Composed of saline and an organic polymer.
No systemic irritation in 10+ years of clinical use
Biostable Does not degrade
Durable Mechanical and physical properties similar to native cartilage.
Capable of withstanding repetitive loading typical of MTP, knee, talus and other joints
Compliant Suppleness and flexibility allows for ease of handling and implantation
Slippery Low coefficient of friction aids joint articulation and mobility