Hip implants aren’t meant to last forever. However, they are expected to function well for several years after implantation, then be replaced.

Some implants, however, fail within just a few years of being implanted, possibly due to defective design. A badly designed implant may be unstable if it does not seat properly on the bone.

Metal-on-metal hip implants create a particular risk of shedding metal particles into the body, causing a toxic reaction known as metallosis. This condition can cause pain and inflammation, and it can kill some of the tissue surrounding the implant.

In some cases, the failed implant needs to be surgically replaced using a procedure known as revision surgery. While hip replacement revision surgery is similar to primary hip replacement surgery, it’s more complicated and takes more time. With those differences comes a greater risk of complications.

The details of revision surgery vary on a case-by-case basis, but generally it consists of removing the failed implant and replacing it with a new one. Depending on the nature of the failure, the surgeon may remove only part of the implant or may instead remove the entire mechanism.

Then the remaining bone must be prepared to receive the new implant, either by cutting away more bone or by affixing a bone graft where more bone is needed. Finally, the new hip implant is put in place.

Things can get even more complicated than that in surgeries with an infected metal hip implant. It has to be done in two stages: the first stage involves removing the original implant and treating the infection, before a second stage to implant the new prosthesis.

Recovery from revision surgery is also longer and more involved than recovery from primary surgery. Usually the patient cannot put weight on the new hip for six to eight weeks. Rehabilitation supervised by a physical therapist may also be necessary for two to four months.

If revision metal hip replacement surgery is successful, it should reduce or eliminate the pain and improper hip function that resulted from the older implant. However, there are many ways that hip revision surgery can go awry.

Patients undergo this surgery at the risk of infection, excessive bleeding, nerve palsy, unequal leg length, blood clots that can lead to pulmonary embolism, and even heart attack or stroke. It’s also possible that the new metal hip implant can fail by loosening or dislocation.

Most hip implants tend to last only 10 to 15 years, so it’s expected that the recipient will need to undergo hip revision surgery when they wear out, but revision surgery may be necessary much sooner than that if the metal hip implant fails due to defective design or manufacture, subjecting the patient to a risk of surgical complications that could have been avoided.

Metal-on-Metal Hip Implant Lawsuits

The need for hip revision surgery associated with some particular metal hip implants has given rise to thousands of hip implant lawsuits, some of which have together resulted in billion dollar settlements.

In November 2013, Johnson & Johnson offered $4 billion to resolve claims over the DePuy ASR metal hip implant. Stryker Corporation settled a group of claims over its Rejuvenate and ABG II implants for over $1.4 billion. Many other hip implants have been subject to manufacturers’ recalls.