Hip replacements, often recommended for people between the ages of 50 and 80, may be used to treat injury, arthritis, or bone disease. In 2015, the Journal of Bone & Joint Surgery reported an estimated 4.7 million Americans were living with hip implants.
Hip implants are artificial devices made of metal, plastic, or ceramic materials that must be flexible enough for everyday activity, but strong enough to withstand the body’s weight and pressure. Hip replacements can last anywhere from 10 to 30 years, but because of a high complication rate, revision surgeries are often required.
Ten different manufacturers market hip replacements, the largest being DePuy Orthopedics, a subsidiary of Johnson & Johnson. Other major manufacturers are Wright Medical Group and Stryker Orthopedics.
Physicians may recommend a total hip replacement, partial hip replacement, or hip resurfacing, depending on the condition or injury. Regardless of the implant type, hip replacements may fail and cause patients to develop serious side effects.
"About 755,000 Americans have undergone joint replacement with all-metal hips," according to Consumer Reports. “Not every one of those implants was made by J&J, but all of them are susceptible to the same basic problems, experts say.”
Studies + Science
Hip implants are artificial medical devices, recommended to patients with limited mobility. Hip replacements are also used to treat bone disorders and provide relief from arthritic pain and inflammation. Some conditions that may require hip replacement surgery include:
- Femoroacetabular impingement (FAI) - a disorder in which bone overgrowth—called spurs—damages the soft tissues of the hip during movement.
- Dysplasia - a condition in which the hip socket is abnormally shallow. This puts more stress on the labrum to keep the femoral head within the socket, and makes the labrum more susceptible to tearing.
- Synovitis - inflammation of tissue around the joint.
Hip replacements are made from a variety of materials. Metal-on-metal hip replacements have become less prevalent, after resulting in perilous levels of cobalt, chromium and other metal ions in patients’ blood samples. In 2016 the FDA removed all meta-on-metal hip replacements from market use and followed up in 2019 that “To date, there are no FDA-approved metal-on-metal total hip replacement devices marketed for use in the US.” Ceramic replacements may fracture, or squeak. And plastic wear can cause debris and bone loss.
Hip implants may loosen, fracture, dislocate or disintegrate, but metal-on-metal hip replacements have been associated with the most complications. Adverse reactions to hip replacements may occur during or immediately after the surgery. Some side effects may not develop for three months or longer.
Metal-on-metal hip implants may cause tissue damage before symptoms are present. Common side effects of hip replacements may include:
- Metallosis and infection
- General hypersensitivity reaction (skin rash)
- Neurological changes including sensory changes (auditory, or visual impairments)
- Psychological status change (including depression or cognitive impairment)
- Renal function impairment
- Thyroid dysfunction (including neck discomfort, fatigue, weight gain or feeling cold
- Heterotopic ossification (soft tissue becoming calcified)
- Avascular necrosis (bone death)
There are more serious, even cellular, side effects of hip replacement surgery. A 2004 study found a direct correlation between metal concentrations in hip replacements and chromosomal damage.
In 2015, a three-year study of 626 patients revealed large, solid masses of irritated tissues, or pseudotumors, in one-third of the group. These pseudotumors were a result of heightened sensitivity to metal components of their implants.
Hip replacements, approved by the FDA in the 1960s, are sent to market through the agency’s 510(k) clearance program. The approval process allows companies to demonstrate their device is “substantially equivalent” to existing devices.
Approved in 2011, metal-on-metal hip replacements were initially believed to be an advancement. Today, the FDA has removed all metal-on-metal hip replacements from U.S. markets and only approved two metal-on-metal hip resurfacing devices. Metal-on-metal hip replacements have been associated with high rates of failure and complications, causing manufacturers to recall faulty devices.
Hip Implant Manufacturers
DePuy Orthopedics Inc.
Wright Medical Group
Recalling a product is an expensive process for the FDA, which is why companies often voluntarily recall their own products after a high number of complaints. Manufacturers have recalled a number of hip replacement brands, including:
- ASR Hip Resurfacing System
- ASR XL Acetabular Hip System
- Biomet Mallory-Head
- Exatech Metal liner of R3 Acetabular System
- Exactech Opteon
- Smith and Nephew R3 Acetabular metal liner
- Stryker Orthopaedics
- Stryker Rejuvenate and ABG modular-neck hip stems
- Stryker Orthopaedics Omnifit
- Stryker Orthopaedics Sulzer Inter-Op acetabular shell
- Wright Medical Technology Conserve Plus and Profemur Z Hip Stem
- Zimmer Holdings Durom Acetabular Component
Though there have been some recalls, some are more common than others. In August 2010, DePuy Orthopedics recalled more than 10,000 ASR XL hip implant devices. The British Medical Journal called it “one of the biggest disasters in orthopedic history.”
The most recent recall took place in Nov. 2016 against Smith & Nephew’s SMF and Modular Readapt models. Smith & Nephew previously faced a recall of their R3 Acetabular model in 2012.
In May 2011, the FDA required postmarket surveillance studies from 21 manufacturers of metal-on-metal hip replacements. In 2013, the FDA issued safety communication informing patients and physicians that “metal-on-metal hip implants have unique risks in addition to the general risks of all hip implants.” In 2016, the FDA pulled all metal-on-metal hip replacements from the U.S. market.
The Next Steps
While hip replacements may be necessary to treat rheumatoid arthritis, osteonecrosis or bone tumors, it’s important to consider the potential side effects. Though there are associated risks, approximately 324,000 surgeries were performed in the U.S. in 2015, and the number continues to rise, particularly for those under the age of 50.
Hip Replacement Investigations
According to the U.S. Food and Drug Administration (FDA), doctors will utilize three different tests to better understand the cause of complications:
- Using a needle to remove fluid from around the joint (joint aspiration)
- Soft tissue imaging
- Blood tests, including checking levels of metal ions in the blood
In addition to launching the International Consortium of Orthopaedic Registries (ICOR) and the Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee, the agency will review ongoing studies, adverse event reports, and data from orthopedic device registries.
Hip Replacement Lawsuits
More than 8,000 patients have filed lawsuits after experiencing complications from faulty hip replacements. One lawsuit, filed by a Chicago woman, targeted Johnson & Johnson’s DePuy Orthopedics for selling an allegedly defective hip implant that caused her to develop an infection.
After the 2010 recall, DePuy Orthopedics paid $2.5 million to more than 7,000 patients injured by the ASR XL. In a more recent lawsuit against Johnson & Johnson, a jury awarded $1 billion to six injured patients. An additional lawsuit involving ten injured patients is pending in New York.