The OMNI artificial hip system, called the K2 or the Apex K2, is a modular artificial hip system designed to allow surgeons to individualize components for each patient. This leads to a better fit, and it is hoped, a more durable artificial hip. The K2 hip system, like many other artificial hips, is made of metal components and includes a stem that attaches to the femur, a neck, and a socket.
The titanium K2 hip system is more advanced than many artificial hips, and is designed to be durable and to last. Unfortunately for some patients this isn’t always the case. The metal rubbing against metal can cause serious problems, like metal poisoning, and the K2 has been found to fail sooner and more often than expected. Many patients have needed revision surgeries to correct problems with the Apex K2 hip system.
Hip Replacement Surgery
Hip replacement surgery is a procedure that replaces either the entire hip or just the damaged parts. The hip joint is a simple ball and socket, with the ball on the end of the femur, or thigh bone, and the socket on the pelvis. When diseases like arthritis, cancer, or even injuries, cause damage to the joint it can lead to pain and a lack of mobility. Replacing the joint, or parts of it, with artificial components restores movement and flexibility, and reduces pain.
Traditionally, hip replacement has been reserved for older patients who it was assumed would not need the new hip to last for decades or to withstand a lot of activity. Companies like OMNI, though, have developed newer and sturdier hip systems that are supposed to be more durable for younger patients. In some cases, this has turned out to be a false promise.
The OMNI Apex K2 Hip System
OMNI is a medical device company that started in 1999 as Apex Surgical, LLC. Apex was bought by OMNIlife science, Inc. in 2004 and eventually changed its name to just OMNI. That same year OMNI debuted its K2 hip system and it became available for surgeons to use for hip replacement patients.
The K2 Apex hip system is a titanium modular artificial hip. This means that the three main components, the stem, neck, and head, can be changed out for parts of different sizes. This helps surgeons to create the perfectly-sized hip system for each individual patient. OMNI claims to have 96 different possible combinations with the K2 system.
The U.S. Food and Drug Administration (FDA) approved the use of the K2 hip system in 2004. It is indicted for use in hip replacement surgeries for the treatment of inflammatory degenerative joint diseases like arthritis and avascular necrosis, congenital hip dislocation, functional deformities, fractures of the femoral neck, and for the use in revision surgeries to correct or replace broken or failed artificial hips.
Risks of Hip Surgery
All surgeries come with risks, including bad reactions to anesthesia, infections, excessive bleeding, and the formation of blood clots. Hip surgery in particular carries the risk of developing a deep joint infection, nerve damage, different lengths of the legs, and bone fractures. After surgery there are risks which include the failure or dislocation of the joint, which can lead to infections, pain, inflammation, and revision surgeries.
Metal-on-Metal Hip Implants
While the Apex K2 system is an advanced, durable hip, it has problems too. It is a metal-on-metal hip system, which means that all components are made of metal. This is supposed to make it more durable and suitable for younger and more active patients. Unfortunately there have been proven risks with metal hip implants. When the metal components rub against each other, for instance, small pieces can break off and cause metal poisoning.
Metal hips have also been shown to cause bone fractures near the hip, dislocations in the joint, and loosening or shifting of the joint once it is implanted. These problems can be very painful and damaging and nearly always require revision surgery to correct. The K2 hip system in particular has been found to have some of these failure problems.
Metal poisoning, or metallosis is a risk with any metal-on-metal hip system, including OMNI’s K2. When metal rubs against metal, pieces wear off and enter the blood stream. The FDA has warned that any metal hip system carries certain risks because of metallosis. These include kidney damage, a reaction and inflammation at the site of the joint, neurological damage, cardiomyopathy, skin rashes, thyroid problems, and mood or cognitive impairment.
Although metal-on-metal hips are supposed to be more durable, they have been proven to be prone to breakage. The K2 system in particular has been seen to break more often than others. One problem is that it was approved through the FDA’s 510(k) system. This approval process does not require rigorous testing for a new device because similar devices are already on the market. Since the K2 was not tested, these problems with breakages were not discovered until many people were already fitted with the hip system.
K2 hips are especially prone to break at the neck, the connection between the stem that attaches to the femur and the socket that attaches to the pelvic bone. One study found that corrosion at the neck may be responsible for the higher rate of breakages as compared to other hip systems. Why they are corroding more than other hips is not known, but when the breakage occurs, patients require another surgery to get a new hip or component.
Banned in Australia
The Apex K2 hip system is still in use in the U.S. despite these problems, but in Australia, the organization equivalent to the FDA here, has pulled the system from the market. Data collected there indicated that patients who used the K2 hip system required more revision surgeries than others due to breakages. More than nine percent of patients with the K2 needed revision surgery within three years of the initial surgery.
The high revision rates and the rates of breakages in K2 hips may lead to a number of lawsuits. If you have been harmed by a K2 hip, consult with a lawyer to find out what your legal options are for recovering monetary damages.