DePuy Pinnacle Hip Replacement Implant
Failures of DePuy Pinnacle Ultamet Hip Implants under Investigation
The DePuy Pinnacle Ultamet hip implant is a metal on metal hip implant that appears to have a failure problem similar to the recalled Depuy ASR hip implant. The DePuy ASR is a metal on metal implant that was recalled in 2010 as a result of a high failure rate.
The failure rate of the Pinnacle Ultamet is not as high as the ASR and has
not been recalled but reports are building of metallosis toxicity. Metallsosis
is caused by metal ions released from the metal on metal bearing surfaces of
the implant. These metal ions are toxic to the soft tissues in the hip joint and
can lead to loosening and failure of the implant. If radiology films show soft
tissue reactions, fluid collections, or masses such as pseudotumors then most
doctors recommend revision of the implant. Also, if blood tests show high
levels of chromium and cobalt a revision may be recommended. Revision
means removal of the implant and replacement with a different implant.
Not all Depuy Pinnacle hip systems are metal on metal. The Pinnacle
hip implant systems allow for insertion of different types of liners in the
acetabular cup. Only the Ultamet liner has a metal liner that interfaces with
the metal femoral head of the implant prosthesis. Other Pinnacle liners have
bearing surfaces of polymer, polyethylene, or ceramic. Some of the Pinnacle
systems have femoral heads that are ceramic.
The 2010 Australian Hip Implant Registry has demonstrated that the metal
on metal bearing surface has the highest risk of revision compared to all
other bearing surfaces. It also appears that the size of the metal femoral head
is a factor in the failures. It appears that the Pinnacle metal on metal with a
femoral head larger than 32 mm pose a greater risk of revision.
Surgeons removing metal on metal implants have found significant damage
from the metallosis, or metal toxicity, including necrotic soft tissues, cavities
containing cloudy fluid under pressure, avulsed tendons, and denuded
osteonecrotic upper femora. If metallosis causes significant damage to the
tissues and to the upper part of the femur it may be difficult for the patient
to recover the ability to walk because those supporting tissues are necessary
for proper movement of the hip. This type of damage has been found in
revisions of the Depuy ASR and Pinnacle Ultamet as well as those of other
manufacturers of metal on metal hip implants.
The concept of metal on metal implants was intended to address the
needs of younger patients who were active and were likely to wear out
the polyethylene cups that had previously been commonly used. The
polyethylene acetabular cups generally last from 12-15 years before
a replacement was necessary. It had been proposed by the marketing
departments of the manufacturers of the metal on metal hips that these
bearing surfaces would last longer and that patients would not need as many
revisions over a lifetime. However, it now appears that the metallosis risk
is not worth the benefit of the metal on metal design. Surgeons are now
moving away from recommending the metal on metal designs for their
One of the objectives of the many product liability and class action lawsuits
that have been filed involving DePuy ASR will be to find out when Johnson
& Johnson and DePuy knew or should have known that the metal on metal
implant patients were taking a significant risk of metal poisoning from the
implants. It appears that the next wave of lawsuits may be directed at the
DePuy Pinnacle Ultamet and Ultamet XL hip implant systems.