Stryker hip lawsuits are continuing to mount over allegations that these metal-on-metal hip implants fail more often than other types of hip implant.

Stryker manufactured a model of metal-on-metal hip implants. These hip implants are different from older hip implants in that the moving surfaces of the joint are matching pieces of metal instead of polymers or ceramics.

According to the metal-on-metal hip implant lawsuits, the metal surfaces allegedly rub against each other and cause microscopic flakes of metal to grind off. In this form, the metal of the implant can dissolve, forming toxic ions allegedly linked to a host of medical problems including pseudotumor growth, neurological problems, and even heart issues.

Additionally, metal-on-metal hip implants, including Stryker’s, allegedly have a higher failure rate than other types of hip implants. Stryker sold roughly 20,000 metal-on-metal hip implants prior to the Stryker hip recall.

When a hip implant fails, a patient may need to undergo hip revision surgery. In hip revision surgery, the original, failed hip implant is removed and replaced with a new hip implant — often a different brand or design.

Revision surgery is typically more complex and dangerous than the original hip implant procedure. First, surgeons have less of the original bone to work with, since hip implants take the place of part of the bone. Additionally, a failed implant can lead to scarring and inflamed tissue, further complicating the surgery. And any surgery carries risks, so any problem that can lead to surgery is not to be taken lightly.

At present, almost 4,000 Stryker metal hip lawsuits have been filed over alleged hip implant failure. The legal system is consolidating these cases in several district courts.

Medical implant lawsuits often take the form of a multidistrict litigation (MDL) or mass tort. MDLs are a kind of group lawsuit created by coordinating tens, hundreds, or, in this case, thousands of individual lawsuits into a single coordinated procedure.

Since drug or medical device lawsuits often hinge on similar evidence, MDLs allow the legal system to streamline the legal process, saving time, money, and other resources by cutting down on duplicated efforts by everyone involved.

If a mass settlement is not reached soon, the first Stryker hip lawsuits could go to trial as early as the summer of 2015.

In MDLs, individual lawsuits retain a degree of autonomy, so these will be individual trials. But within an MDL, the first cases, called bellwether cases, are carefully watched, and used to establish precedents that can apply to thousands of other metal hip lawsuits.

Stryker is currently in court-mediated negations to try and reach a settlement in lieu of going to court.

The Stryker Hip Implant Mass Tort is In re: Stryker Rejuvenate and ABG II Hip Implant Products Liability Litigation, MDL No. 2441, in the U.S. District Court for the District of Minnesota.