The Cadisc-L disc disaster illustrates the need for rigorous clinical trials |

The Cadisc-L disc disaster illustrates the need for rigorous clinical trials



The Cadisc-L from Ranier Technology is a polyurethane-polycarbonate graduated modulus spinal disc implant with physiological, progressive bending stiffness. The implant has a mobile center of rotation for load sharing biomechanics and is well seen on MRI or x-ray.

The surface of the implant has a macro- and micro-texture with a CaPO4 coating for osseointegration.

Report: Folded Ranier Tech’s spinal implants cleared in EU after tiny trial, found to dissolve in patients (MassDevice)

Plastic spinal implants from now-defunct Ranier Technology are allegedly moving and dissolving in patients, calling into question the validity of the short, low-powered trial that won the device’s approval, according to a Guardian report.

The device in question, known as the Cadisc-L, won CE Mark approval in the European Union based on results from a six-month, 30-patient study, according to the report. The device underwent an investigation by researchers from October 2009 until June 2010, winning approval in August.

Now, the devices are at the center of legal action from a number of patients who have undergone explant procedures to remove the disks, some of which have “completely disintegrated,” according to The Guardian.

Nearly 50% of patients implanted with the Cadisc-L have had to undergo follow-up surgeries, and scientific evidence seems to indicate that similar issues were noted during development, according to the report.

The discs were also implanted into nine baboons in an earlier animal trial, according to The Guardian. Data from a 2009 review of animals in the trial indicated that “overall six months is a relatively short time to follow and implant up,” and that there were “worrying changes between the implant and the bone in all but one subject.”

Details from the human trial were not published, according to the report.

Asked to respond to the accusations, former Ranier Tech CEO Dr. Geoffrey Andrews told The Guardian that the devices used in the baboons were custom-made and dissimilar to the devices that eventually made it to the market.

Andrews defended the devices, stating that “Ranier spent over eight years and more than £20 million in the design, development, and testing of Cadisc-L,” according to the report.

He went on to state that the company’s decision to pull the devices from the market in March 2014 was based on the conditions of four patients who had to undergo follow-up surgeries related to the implants, according to The Guardian.

The paper’s data comes from the recently released ICIJ’s “Implant Files,” released earlier this week. The report raised a number of questions about the quality of the regulatory bodies that approve medical devices.

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