Consequences of Failed All-Metal Hip Implants

Since the recall of the DePuy ASR, there has been extensive discussion surrounding the alarmingly high failure rates of all metal hip implants.

The all-metal prostheses had grown in popularity since the early 2000s, as they were perceived to have greater advantages and fewer limitations than the conventional polyethylene-on-metal hip implants. In particular, those advantages included bone conservation, restoration of normal joint mechanics and superior wear properties.

As a result, approximately 500,000 individual are estimated to have an all-metal hip prosthesis, with 40,000 being performed between 2005 and 2006. As many of you will already know, the DePuy ASR was introduced to the U.S. market in 2005.

Medical literature and recent data show a significant number of all-metal prostheses have been failing due to accelerated wear of the articular surface, i.e., the all-metal ball and socket. This accelerated wear causes metal debris to release into the soft tissue surrounding the hip joint. A study from the Netherlands, where 614 all-metal hip implant patients participated, found that 33% of patients suffered from some adverse tissue reaction. Adverse reactions from this metal debris often lead to revision surgeries.

In addition to the need for a revision surgery, new research suggests that this exposure to metal debris can cause long term health consequences in some patients, even after revision surgery to replace the all-metal hip implant. This is particularly true for those patients who have revision surgery because of a pseudotumor.

Pseudotumors are tumor-like masses that represent an inflammatory reaction to metal debris. They are often destructive, causing tissue death and marked necrosis around the hip joint. One study found that 70% of patients presenting with an inflammatory pseudotumor would have a revision; nearly half of those patients would encounter major complications post-revision, with nearly a third requiring additional surgery. In addition to revision, major complications included dislocations, palsy of the femoral nerve, and early loosening of the acetabular component.

Symptoms of hip implant failure include groin and hip pain, swelling and walking with a limp.

Any person who has had a hip replacement should contact his or her orthopedic surgeon to determine whether the received a DePuy ASR or Pinnacle metal-on-metal hip implant.

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