One year after Johnson & Johnson pulled 93,000 metal hip implants from the market, the company internally estimated that 37 percent of the devices would fail within 4.6 years, according to newly unsealed court records.

J&J faces 10,000 lawsuits over its ASR hips, which it pulled in August 2010 after citing U.K. joint registry data showing that more than 12 percent failed within five years. The estimate of triple the failure rate publicly cited by J&J came in documents unsealed Jan. 18 in the lawsuit of Loren Kransky in state court in Los Angeles.

Jurors are scheduled to hear opening statements Friday in Kransky’s case, the first to go to trial against J&J, the world’s biggest seller of health-care products.

J&J offered to pay more than $200,000 a case to settle most of the 10,000 lawsuits, according to five people familiar with the matter. The deal’s cost could exceed $2 billion if most plaintiffs accept the terms. Lawyers for hip recipients have so far rejected the offer, the people said.

The failure-rate estimate came in pretrial testimony of Paul Voorhorst, a biostatistician for J&J’s Warsaw-based DePuy unit which made the hips.

Lorie Gawreluk, a DePuy spokeswoman, said that the company was “looking out for patient interests by analyzing data” on the ASR hip system.

She said the analysis cited by Voorhorst “was based on a small, limited set of data that could not be used to generalize the revision rate for ASR, unlike published data from national joint registries that include large numbers of patients and detailed revision information.”

Source: David Voreacos and Jef Feeley | Bloomberg News