X-alt Polyethelene

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hip products

press fit stems

• CLP Hip Stem
• Foundation Total Hip System
• Revelation Hip System
• Keystone Revision Hip System
• Linear Total Hip System
• R120PC Modular Stem
• ALFA II Modular Stem

cemented stems

• Foundation Total Hip System
• R120 Modular Stem

modular stems

• Keystone Revision Hip System
• ALFA II Modular Stem
• R120 Modular Stem

revision stems

• Keystone Revision Hip System
• ALFA II Modular Stem

acetabular systems

• Keramos Ceramic Hip
• FMP Acetabular System
• MIS Instruments
• X-alt HXL Poly

bearing options

• Keramos Ceramic hip
• Metal/Metal CoCr
• FMP Acetabular System
• X-alt HXL Poly

technology

• 3DMatrix
• X-alt HXL Poly

Maintaining Material Integrity

Lever-Out of Liner from Shell

This test simulates an extreme case of the stem impinging on the liner edge, causing the liner to be peeled from the cup. The X-alt™/FMP assembly outperformed all of the following competitive components in a study of highly crosslinked polyethylene liners. ^{9 10}

Mechanical Properties of X-alt Highly Crosslinked Polyethylene Compared to ASTM Requirement

The data have been normalized, dividing the values by the standard. In all areas, X-alt highly crosslinked polyethylene surpasses the requirement. ²⁴

Stability Against Oxidation

After crosslinking, or gamma sterilization, free radicals remain in the material. Over time, oxygen binds to these sites, causing degradation, embrittlement, possible brittle implant failures, and increased wear rates.

The melt-annealing step in the X-alt manufacturing process eliminates free radicals, providing stability against oxidation and aging.

X-alt highly crosslinked polyethylene was examined for oxidation after accelerated aging by an independent lab using Fourier Transform Infrared Spectroscopy (FTIR). No oxidation was detected.¹¹

All X-alt wear, device, and material testing was conducted after accelerated aging. Accelerated aging models the material’s condition after extended service by exposing the implants to an oxygen-rich atmosphere at an elevated temperature.

Above-Melt versus Below-Melt Anneal

Polyethylene has areas of crystalline and amorphous material. Upon heating, the chains in the amorphous areas are able to slide past one another, allowing neighboring free radicals to connect and creating crosslinks. Above melt temperature, the crystalline regions become amorphous and mobile, as well, and free radicals combine throughout the entire bulk of the material. This is called “melt-annealing.” Only above melt are all free radicals removed.