Preserving Anatomy & Motion
Preserving Anatomy & Motion
Evolution of AxioMed Freedom® Viscoelastic Disc Replacement
From the pioneering AcroFlex disc to today's advanced Freedom® platform—35+ years of innovation in motion preservation
HISTORY
Late 1980s-1990
The Origins of Viscoelastic Disc Replacement: From AcroFlex to the AxioMed Freedom® Disc
The AcroFlex Lumbar Disc Replacement (LDR) was developed in the late 1980s by pioneering spine surgeon Dr. Arthur Steffee and engineering collaborators, later commercialized through DePuy. It was one of the earliest attempts to create a viscoelastic artificial disc designed to replicate the natural biomechanics and shock absorption of the human intervertebral disc.
Initial Clinical Use
1988–1989
(six patients)
Design Innovation
Titanium endplates with hexene-based polyolefin rubber core vulcanized between them
Function
Physiological shock absorption & six degrees of freedom motion, unlike early ball-and-socket designs
Key Clinical Insight from AcroFlex Disc
​Clinical Findings:
Pilot studies initially reported encouraging outcomes. However, later imaging revealed mid-substance elastomer tearing, along with cases of subsidence, osteolysis, and incomplete osseointegration.
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Long-Term Outcomes:
A later follow-up study reported 10-year cumulative survival of 60.7%, with many revisions required due to implant failure, elastomer tearing, and osteolysis.
Outcome:
Due to concerns about material durability, further implantation of the device was discontinued in the late 1990s.
Despite these limitations, the AcroFlex disc demonstrated that viscoelastic disc replacement could replicate the natural function of the human disc, laying the foundation for later technologies such as the AxioMed Freedom® Disc.
The Birth of AxioMed
In 2001, a group of surgeons at Cleveland Clinic and AcroFlex engineers, including individuals who had worked with Dr. Steffee on the AcroFlex technology, founded AxioMed Corporation in Cleveland, Ohio.
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Their goal was to develop a next-generation disc replacement capable of replicating the natural biomechanics of the human disc while lasting for decades inside the body.
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This work led to the development of the Freedom® Disc, a viscoelastic disc replacement designed to restore both motion and shock absorption.
2001
2005 - Present
Clinical Development and Global Use
The Freedom Lumbar Disc was first implanted in patients in Europe in 2005, beginning the clinical history of AxioMed’s viscoelastic technology.
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Unlike mechanical ball-and-socket implants, the Freedom Disc uses a single-piece viscoelastic polymer core permanently bonded between titanium endplates, allowing the implant to compress under load and move in multiple planes — more closely replicating the behavior of a natural disc.
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The proprietary material was engineered to mimic the stiffness and flexibility of the human disc while maintaining long-term durability and biocompatibility. Extensive biomechanical testing has simulated decades of spinal loading.
Today:
More than 800 Freedom Disc implants have been performed worldwide
Patients have been treated across Europe, the United States, Australia, and the Caribbean
Clinical follow-up extends over 13 years in some patients
​The Freedom Lumbar Disc is also notable for being the only viscoelastic lumbar disc replacement to complete a U.S. FDA IDE clinical study.
2014 - Present
Advancing Motion Preservation
In 2014, KIC Ventures, led by orthopedic spine surgeon Dr. Kingsley R. Chin, acquired AxioMed to advance the development of motion-preserving spine technologies.
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The acquisition brought renewed investment and focus to the long-term vision behind viscoelastic disc replacement:
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Restoring the natural biomechanics of the spine by replacing diseased discs while preserving motion and shock absorption.
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Today, AxioMed continues to build upon more than two decades of research in viscoelastic biomaterials and spinal biomechanics, advancing technologies designed to improve outcomes for patients with degenerative disc disease.