A study from the University of Oxford finds that 24 percent of all hip replacement devices available in the UK have no evidence of clinical effectiveness, and that 8 percent of components used in primary hip replacements in 2011 were implanted without evidence of clinical effectiveness. Researchers also said the current regulation process “seems to be entirely inadequate,” according to a press release by BMJ, the journal in which the study was published.

“This study shows that the need still exists for an improved and more rigorous approach to regulation of devices to avoid devices with no available evidence being used in a widespread and uncontrolled manner,” the study’s authors noted.

Their findings are “of great concern” in light of the injuries caused by defective hip implant devices and the publicity surrounding those safety problems, authors said. Over the last few years, evidence has emerged that a number of defective hip implant devices were released into the market and have subsequently caused patient injuries including pseudo tumors, cobalt and chromium poisoning, tissue necrosis, bone damage, pain, and immobility.

Researchers at Oxford used data from the National Joint Registry of England and Wales to identify hip replacement devices that were rated “unclassified” or “pre-entry” by the Orthopaedic Data Evaluation Panel. A rating of unclassified means the implants had no safety evidence from the manufacturer, while a rating of pre-entry means products had less than three years of evidence.

In the United States, many orthopaedic devices entered the market via a process known as 510(k) clearance. This process allows companies to put a product on the market based on the product’s similarity to a previously-approved device that is already on the market. Products like Johnson and Johnson’s DePuy ASR XL entered the market under the 510(k) clearance.

The ASR device was marketed to younger patients under the guise that the product would be durable and long-lasting. Yet the companies who produced and marketed the ASR and similar hip implant devices were not required to provide clinical evidence for the safety of their products. As a result, Johnson and Johnson and other manufacturers have faced thousands of lawsuits by patients who were injured as a result of being implanted with faulty orthopaedic devices.

Just last month, plaintiffs attorneys in the DePuy ASR multi-district litigation agreed to settle with the company for $2.475 billion. Although the settlement can help provide some financial relief to patients, many have experienced permanent damage and changes to their lifestyles as a result of the defective devices.

“This study is yet another indicator of the need to properly vet orthopedic implants before they enter the market, said Levin, Papantonio attorney Daniel Nigh, who practices in the areas of personal injury and products liability, including the DePuy, Stryker, and Smith and Nephew hip litigation. “Patients who rightly assumed that they were being implanted with safe and effective devices are now finding out that many of these devices may have entered the market without adequate safety testing.”

Alisha is a writer and researcher with Ring of Fire. You can follow her on Twitter @childoftheearth.