Texas lawyers representing thousands of plaintiffs in Dallas federal court in what’s known as the Pinnacle System hip-replacement cases expect pre-trial battles to heat up at a scheduled Sept. 10 conference before U.S. District Judge Ed Kinkeade.

In the past 18 months, plaintiffs have filed more than 4,000 complaints related to the Pinnacle hip-replacement system in the U.S. District Court in the Northern District of Texas. That massive wave of complaints follows a U.S. Judicial Panel on Multidistrict Litigation decision in 2011 to assign Kinkeade, who is in the Northern District, to preside over designated MDL proceedings for the Pinnacle System cases.

“It’s a monstrous process,” says Mark Lanier, founder of the Lanier Law Firm in Houston, who along with Larry Boyd, a partner in Fisher Boyd & Huguenard, also in Houston, serves as co-chair of the executive committee of the Pinnacle System MDL proceedings plaintiffs’ steering committee.

Plaintiffs continue to file new Pinnacle System cases in the Northern District. On Aug. 23, 49 additional complaints were filed naming the manufacturers of the Pinnacle System hip replacement product, DePuy Orthopaedics Inc., and its parent company, Johnson & Johnson Services, Inc. as defendants. And Aug. 23 doesn’t even stand out as an unusually busy one for the DePuy defendants in the Northern District. So far this year, plaintiffs have filed 1504 cases in the Northern District against DePuy, and, in the previous year, 2660 cases.

At the scheduled Sept. 10 conference for all of the participants the Pinnacle System MDL litigation before Kinkeade, the judge will ask the plaintiff and defense representatives to determine which cases should serve as bellwether ones, according to Lanier, Boyd and Mindy Tinsley, a spokeswoman for Johnson & Johnson.

In advance of that conference, plaintiff and defendant representatives have each selected four cases, for a total of eight, as possible bellwether candidates, Lanier says.

“It’s a toss-up,” he says about the outcome of which ones of those eight and how many will get chosen for trials. The plaintiffs would like to try four cases at a time because doing so would give them more “data” about the litigation and also be more efficient and economic, Lanier says. He says the defendants, however, want to try one case at a time.

About the decisions related to which and how many cases will be tried first, Tinsley writes in an email: “The Court and the parties continue to work toward selecting the cases to be tried as bellwether trials. No decisions have been made on the number of bellwether cases to be tried.”

Once designated, the bellwether cases are currently scheduled to be tried in September 2014.

Representing the defendants are Michael Powell, a partner in Locke Lord in Dallas, and Seth Roberts, an associate at the same firm and office (who previously clerked for Kinkeade). Also representing the defendants are John Beisner and Steven Harburg, partners in the Washington, D.C. office Skadden, Arps, Slate, Meagher & Flom. Powell did not return a call for comment.

Reports of problems with the Pinnacle System hip-replacements have increased in recent years. In a complaint filed in Kathleen Herlihy-Paoli vs. DePuy Orthopaedic, Inc., et al. in July 2012, was one of the cases identified as a bellwether candidate. The plaintiff alleges in that case that “[d]efendants have known, or should have known, that the Pinnacle device was not safe or durable and presented a considerable risk of injury to those implanted with it.” Herlihy-Paoli also alleges that, “Defendants knew, or should have known, of reports that metal-on-metal implants, such as the Pinnacle, generated unusually high amounts of metal debris over time due to unusual, premature or increased wear and tear. This debris can spread throughout the surrounding bone and tissue and cause serious complications and damage.” The plaintiff alleges among other causes of action negligence and breach of express and implied warranties.

The DePuy defendants have not yet filed an answer in Herlihy-Paoli. But Johnson & Johnson spokesperson Tinsley writes in an email: “DePuy is vigorously defending itself against the claims made in the PINNACLE Cup System litigation. For more than 10 years, the PINNACLE Cup System has been a widely used and clinically successful modular acetabular cup system for hip replacement. The PINNACLE Cup System has a strong track record of helping to reduce pain and restore mobility for patients suffering from chronic pain. You should also know that lawsuits in the MDL primarily involve allegations related to the metal-on-metal option with the PINNACLE Cup System, called ULTAMET. ULTAMET has performed well in thousands of patients and is backed by clinical data showing a track record of safety and effectiveness for patients who are candidates for hip replacement.”

Kinkeade appointed James M. Stanton of the Stanton Law Firm in Addison as special master on the case. Stanton declines to comment on the pending cases.

Lanier says he estimates the defendants face $4 to $5 billion in liabilities in the Pinnacle Systems MDL proceedings overall. Neither side has discussed settlements, Lanier says. He expects after the bellwether cases are tried, the plaintiffs will try to dissolve the MDL proceedings and transfer the cases to federal courts nationwide.