Before DePuy Orthopaedics, Inc. recalled the ASR model artificial hip in August 2010, Dr. Thomas P. Schmalzried of the Joint Replacement Institute in Los Angeles, the self-proclaimed "lead surgeon designer" of the heavily-marketed metal-on-metal device, extolled the ASR as superior to other artificial hips and he encouraged fellow orthopedic surgeons to implant the ASR in their younger, active patients.
Recently, however, Dr. Schmalzried announced at a national meeting that all ASR patients are at increased risk for complications, including those who are "pain free." He recommends that they be assessed and monitored for as long as the device remains in their bodies. He made these comments in February 2012 at the annual conference of the American Academy of Orthopedic Surgeons (AAOS) in San Francisco.
During a talk, entitled "Metal-Metal Bearings: Risk Factors for Failure and Timing of Intervention," Dr. Schmalzried said that some ASR patients, especially "small females," develop "Adverse Local Tissue Reaction" ("ALTR"). He said that in other patients, the ASR fails to "osseointegrate" - meaning that the cup of the device never becomes fixed to the patient's pelvic bone and comes loose.
Patients suffering from either complication may need a second operation to remove the defective ASR device and implant new hardware. This is called a revision surgery. Because ALTR may cause irreversible harm or death to bone, muscle and tendons around the affected hip joint, Dr. Schmalzried warned the doctors in attendance "not to delay" the revision surgery when the requisite symptoms were present. He also cautioned the gathering that some patients with a failing ASR device do not feel any pain. This is a stark reversal from the advice he gave in a March 2010 letter, published on a popular website, which said that asymptomatic ASR patients had little to worry about.
The ASR is made of a cobalt and chromium alloy. A failing ASR device may shed metal debris around the hip joint, which can then enter the blood stream. Elevated levels of cobalt or chromium ions in the patient's blood are strongly correlated with failing devices. Some health organizations have announced the threshold for concern is an ion level at or above 7 parts per billion (ppb). But Dr. Schmalzried told the AAOS that this standard is "not stringent enough," and that any measurement above 2 ppb is cause for concern. He also said that in his experience, any patient with ion levels of 10 ppb or greater was also probably experiencing ALTR.
Dr. Schmalzried's PowerPoint presentation to the AAOS can be viewed here.
The Walkup law firm has filed individual lawsuits on behalf of more than 175 ASR patients. Walkup partners Michael A. Kelly and Matthew D. Davis have taken the depositions DePuy's key executives, and are preparing the first cases for trial. If you were implanted with the DePuy ASR device and you would like to know more about your legal rights, then call Mike or Matt at 415-981-7210, or email them at email@example.com.