Johnson and Johnson will pay more than $4 billion to settle thousands of lawsuits over its recalled defective hip implants. The tentative plan, which must win court approval, represents one of the largest payouts for product liability claims involving a medical device.The agreement will include those patients who have already been forced to have the device, known as the Articular Surface Replacement, or A.S.R., removed and replaced with another artificial hip, said the lawyers who spoke about the agreement only on the condition of anonymity.

According to the story in the New York Times, each patient would receive about $350,000 on average in compensation, though that figure will vary depending on factors like a patient’s age and medical condition.The precise value of the settlement is unclear because lawyers for patients are still trying to estimate how many of the 12,000 related lawsuits involve patients who had a replacement. Lawyers believe that number may be 7,000 to 8,000 cases.The final cost of the deal to Johnson and Johnson could rise, depending on how many claimants who received the device undergo replacement operations in the future, the lawyers said. Under the plan, patients who have not had a replacement would not receive compensation, the lawyers said.

The A.S.R. hip was sold by DePuy until mid-2010, when the company recalled it amid sharply rising early failure rates. The device, which had a metal ball and a metal cup, sheds metallic debris as it wears, generating particles that have damaged tissue in some patients or caused crippling injuries. DePuy officials have long insisted that they acted appropriately in recalling the device when they did. However, internal company documents disclosed during the trial of a patient lawsuit this year showed that DePuy officials were long aware that the hip had a flawed design and was failing prematurely at a high rate.

Many artificial hips last 15 years or more before they wear out and need to be replaced. But by 2008, data from orthopedic databases outside the United States also showed that the A.S.R. was failing at high rates in patients after just a few years. Internal DePuy projections estimate that it will fail in 40 percent of those patients in five years, a rate eight times higher than for many other hip devices.

The hip was first sold by DePuy in 2003 outside the United States for use in an alternative hip replacement procedure called resurfacing. Two years later, DePuy started selling another version for use here in standard hip replacements that used the same cup component as the resurfacing device. Only the standard version was sold in the United States; both were sold outside the country.About 93,000 patients received an A.S.R., about one-third of them in the United States.

Problems with the design first came to light in Australia and England just a few years after its marketing began. But DePuy officials insisted for years to surgeons who complained about that device that patient problems reflected their surgical technique rather than the implant’s design.

Last year, The New York Times reported that DePuy executives decided in 2009 to phase out the A.S.R. and sell existing inventories weeks after the Food and Drug Administration asked the company for more safety data about the implant.

There remains some potential for claims administrators to seek credit for recoveries received by claimants who received these defective hip replacements as a result of an admitted industrial injury. However, few claim files reflect the product details of surgical implants used in surgeries. This lack of information poses a significant problem for the task of identifying appropriate claims.