In spite of recent efforts by DePuy to have a metal-on-metal hip lawsuit thrown out, the lawsuit will go to trial on September 1. The metal-on-metal hip lawsuit is part of a special phase of the mass litigation over metal-on-metal hip replacement surgeries.

Metal-on-metal hip joints are a specific type of artificial hip joint. Artificial hip joints are used to replace hip joints that wear out as a person ages. In most artificial hip joints, the hip surfaces are made out of polymers or ceramic. However, several companies released metal hip implants, where the interfacing surfaces of the hip are made of special metals. However, it has been alleged in thousands of metal hip lawsuits that this type of artificial hip has serious flaws.

Allegedly, metal-on-metal hip joints suffer from several problems not seen in other types of artificial hips. Hip implant lawsuits allege that the metal surfaces of hip joints may grind against each other, shaving off microscopic metal flakes from the implant. In this form, the material of the implant may be more reactive than the material when it is undamaged.

These flakes can reportedly form metallic ions, which can cause pseudotumors and heart and neurological problems. On top of this, it is alleged that metal-on-metal hip joints fail more often than other types of hip implants.

The solution to these situations can be a second, more risky surgery called revision surgery. In this type of procedure, surgeons replace the failed joint with a new hip implant. However, this procedure is more risky than a regular hip replacement, as there is less of the original joint for surgeons to work with and the patient is typically already suffering from health problems related to the damaged joint.

Due to the large number of Depuy metal-on-metal hip implant lawsuits, they have been coordinated into a type of group litigation called a multidistrict litigation or MDL. MDLs are a type of group legal proceeding, wherein a number of individual lawsuits are coordinated together since they are very similar. There are currently a number of metal-on-metal hip lawsuit MDLs, each against a different manufacturer.

Within an MDL, litigation begins with bellwether trials, which are an important part of the process. Bellwether cases are selected to determine key aspects of the MDL, and establish rulings that will eventually apply to all cases in the MDL.

The metal hip replacement lawsuit DePuy tried to have dismissed was a bellwether lawsuit. The judge overseeing the MDL issued a ruling that there was sufficient evidence to move forward with the bellwether trials, and that the case was too complicated to issue a summary ruling.

The DePuy Hip Implant MDL is In re: DePuy Orthopaedics Inc., Pinnacle Hip Implant Products Liability Litigation, MDL No. 2244 in the U.S. District Court for the Northern District of Texas, Dallas Division.