Artificial Hips:
Replacing the Replacements

Consumers are all too familiar with recalls of defective automobiles, tires, toys and infant carriers, but imagine the anguish when the defective part being recalled has been surgically implanted inside your body, at great expense and pain.

Thousands of patients who have had hip replacement surgery in recent years are experiencing just that.  For many, the artificial hips that were meant to restore their ability to walk without pain and to enjoy even the simple things of life instead are causing what they describe as “excruciating” pain and, in come cases, further bone loss.  Their only remedy is to subject themselves to yet another painful operation and even longer rehabilitation.

The 'Inter-Op Acetabular Shell'

Producing artificial hips is a lucrative and growing enterprise.  Each year some 310,000 Americans undergo partial or full hip replacement surgery, typically to alleviate the effects of arthritis. Each surgery costs between $20,000 and $50,000, depending on the patient’s age and the length of hospital stay required.  As the population ages, the number of such surgeries is expected to rise.

An artificial hip consists of two parts intended to replace the hip’s normal ball-and-socket structure.  A metal “ball” is mounted on a stem that fits into the femur (thigh bone); the “socket” (acetabulum), a titanium shell lined with polyethylene, is designed to snap into place against the pelvic bone.  The titanium is porous to allow fusing with the bone.

Last year, numerous patient complaints that their “recovery” from hip surgery was causing escalating pain prompted the maker of one of the most popular brands of artificial hips to launch an investigation.  After eight weeks of study, Sulzer Orthopedics, of Austin, Texas, announced on December 8, 2000, that it was recalling 17,500 Inter-Op acetabular shells, 90 percent of them implanted in U.S. patients.  The shells had been manufactured by Sulzer in batches beginning in 1997, when it  began moving production “in-house” from its Pennsylvania contractor.  Most were made beginning in 1999, when the move was completed.  Sulzer controls about 11 percent of the hip-replacement market.

(Not all Sulzer hip replacements are implicated:  in some cases the shell is cemented to the pelvic bone, a process typically reserved for the oldest patients.  These are not included in the recall.) 

The Defect The problem was traced to lubricants, any of four mineral-based oils produced by Mobil Oil Co. that Sulzer used in the manufacturing process.  None of the oils was intended to be ingested or placed inside the body.  Leaking oil had been seeping into the titanium’s pores.  After implant, the oil’s interaction with the patient prevented the necessary bonding between shell and pelvic bone, causing “loosening” of the shell, a build-up of scar tissue and, in some cases, permanent further bone loss.  Typically, within six months of the surgery, patients experienced: Pain in the groin and inner thigh. Pain when rising from a seated position. Weight-bearing pain, notably in the buttocks.

Rhonda Silva, 48, Oakland, CA – Immobilized for seven months by her defective artificial hip, Silva had the replacement itself replaced in October 2000, only to learn in December that her new hip was also defective.  “To get out of bed is the most excruciating” part of her day, she said.  “I feel like I have an alien living in my body.  I just want my life back.”

Helen Simon, of San Francisco – A hearing and speech scientist, Simon said that learning her hip was on the recall list made her feel like a “human Firestone tire.”  She had received her artificial hip on October 16, 2000, while Sulzer was "studying” the problem.

Barry Moore, 61, Belmont, CA – His hip was replaced June 13, 2000, while he was looking forward to leading his daughter up the aisle in her September wedding.  He had to walk the aisle limping with a cane and “halfway through the father-daughter dance, I had to quit.”

Gretel Quick, 55, Blythe, CA – Her April 2000 hip surgery left her in so much pain, she said, she could hardly climb out of bed.  “It’s been sheer hell.  I can’t work, walk, or function normally, and emotionally I’m a mess.” 

The problem had not been unanticipated: In 2000, a National Institutes of Health panel urged that more study be given to what happens to medical devices after they’ve been implanted in patients, in order to improve artificial joints, pacemakers and other such devices.

A Brief History of the Hip Recall

October 1999 – Hip replacement failures begin to be recorded at approximately the same time that Sulzer completes shifting component production “in-house.” 

July 2000 – Dr. Lawrence Dorr, a Los Angeles surgeon who helped Sulzer design some of its products, notifies the manufacturer of problems with the hip implant.  “He was stunned by what he considered to be an unusually high failure rate,” the Austin (TX) Statesman-American later reported.  “He thought the liner was the problem but later became convinced something toxic was on the outer shell.  He urged Sulzer to fix the problem fast.”

September 27, 2000 – Sulzer sends a representative to meet with Dorr and begins an investigation.

November 2000 – Sulzer notifies the U.S. Food and Drug Administration of its investigation.

December 8, 2000 – Sulzer announces it is recalling 17,500 implanted shells.  “It was ultimately the fault of one of our products and we’re taking full responsibility for that,” Sulzer General Manager Steven Whitlock tells the news media.

February 13, 2001 – A federal class action lawsuit is filed against Sulzer Medica, Sulzer’s parent company in Switzerland, on behalf of all patients who received the recalled implants, whether they have experienced problems or not.  The suit asks that Sulzer set up a fund to cover costs of testing, observation and monitoring of all affected patients.

March 2001 – Despite its earlier admission, Sulzer denies in court filings that it has any responsibility for the artificial hip failures and says the injuries were caused instead by unidentified third parties, by patient negligence, and by the product being altered or used incorrectly by others.  Sulzer also said patients contributed to their own losses by not acting to minimize their damages. 

June 1, 2001 – A Sulzer spokesperson concedes that what was initially minimized publicly as “trace amounts” of lubricant found on the hip shells was in fact “an abundance of mineral oil.”

June 13, 2001 – The number of artificial hips reported to have been surgically replaced rises to 1,850, more than 10 percent of those on the recall list.

As one observer noted about the disconnect between earlier admissions by Sulzer and more recent disclosures:  “They’ve got a legal problem, and they’ve got a public relations problem, and they’re dealing with them on separate tracks.”

A Painful ‘Remedy’

Unlike recalling a toy or automobile component, the recall of a surgically implanted device requires yet more surgery, in this case a procedure that is more complicated than the original operation and takes twice as long.  Not only must the artificial hip shell be removed and replaced, but built-up scar tissue must be cut away and the bone scraped clean to assure no oil remains to complicate bonding with the new shell.  This is then followed by a minimum of three months of painful recovery.

Inadequate Concessions 

After repeatedly declining to cover any but the direct medical costs of replacing the defective artificial hips, Sulzer has now agreed to give victims at least some compensation for pain and suffering.  The concession falls short in several respects:

• No standards are specified for evaluating claims.
• Minimum compensation to be paid all defective hip recipients is unspecified.
• The claims process is not subject to judicial review or any guarantee that similar claims will be treated similarly.  Instead, the company plans to base payments on what insurers will reimburse.
• No public offer has been made to cover future medical care, physical therapy, wage loss, or non-medical expenses.
• No fund has been established for ongoing medical care and monitoring those who have the recalled hip implants but do not yet require replacement surgery.

From Hips to Knees

Sulzer’s replacement problems may extend to more than hips.  On March 11, 2001, as the number of lawsuits the company faces over its artificial hips soared,  a Tulsa, Oklahoma, man filed suit over a knee-implant.  Sulzer, which at first insisted its other products were manufactured differently from the hip replacement parts, conceded in May that the knee implant – a stemmed tibia baseplate – had gone through the same process as the flawed hip part and may have the same oil-contamination defect.

A Sulzer spokesman said the company first received reports in January about problems with knee implants, but by then had corrected the manufacturing process.

The company publicly announced the potential knee problem on May 21, and on May 30 it dispatched a “special alert” to surgeons asking them to return for study any knee implants they remove.  Sulzer also asked physicians to monitor their knee surgery patients, but a spokesman said the company has no plans to recall knee implants. 

(07/23/01)