For many patients who needed a hip replacement device, the Zimmer Kinectiv Prosthesis may have seemed like an attractive option. Rather than insert a one-size-fits-all device, Zimmer’s M/L Taper with Kinectiv Technology offered a wide range of head, stem, and neck sizes, allowing each patient to be custom fitted with a device that closely matches his or her natural hip joint. However, many patients who received these implants suffered debilitating injuries, leading to a nationwide medical device lawsuit against Zimmer.
Reported Problems and Side Effects of the Zimmer M/L Taper Prosthesis With Kinectiv Technology
The Zimmer M/L Taper is composed of three parts: the modular neck, the femoral stem, and the femoral head. Each of the pieces comes in a variety of sizes, which was marketed by the company as offering a more secure fit for both male and female patients. The device was also supposed to offer greater conservation of the bone tissue surrounding the implant and lower the risk of dislocation, as the custom-fit device would ideally move in the joint similar to the patient’s natural hip.
Unfortunately, the device failed to deliver on its promises for many hip replacement patients. Shortly after its release, the FDA received reports of injury due to corrosion between the metal neck and femoral stem. Much like the corrosion that is common in metal-on-metal hip implants, the Zimmer’s M/L Taper components can release debris and metal particles into the body, causing a number of harmful effects, including:
- Pain and inflammation. Patients may suffer swelling, redness, and irritation at the implant site, which may develop into infection of the bone and tissues surrounding the implant. If infection cannot be controlled with antibiotics, the device may have to be removed.
- Metallosis. Tiny particles of metal are released into the body as the pieces of the implant grind together, resulting in metal poisoning (metallosis). As these particles enter the bloodstream, they can cause serious complications throughout the body, including bone degeneration and damage to the nervous system.
- Fractures. The breakdown of bone tissues due to metallosis greatly increases the risk of fractures, both in the hip joint and elsewhere in the body. These fractures can cause the device to dislocate, and can make implantation of a replacement device much more difficult. Risk of fracture is even higher for post-menopausal women, potentially affecting these patients’ mobility for the rest of their lives.
- Allergic reactions. In 2015, the FDA alerted consumers and hospitals about reports of industrial residues left on the Zimmer M/L Taper during the manufacturing process. The company’s failure to monitor its product caused some patients to suffer allergic responses, including pain and irritation due to metal poisoning, and led to a Class I recall of the affected devices.
- Revision surgeries. Metallosis, allergic reaction, loosening of the device, and severe infection can all increase the likelihood of revision surgery to remove and replace the device. Revision surgeries are typically more dangerous than the original hip replacement procedure as they carry greater risk to the patient and are less likely to succeed than the first implantation—potentially causing permanent loss of range of motion and disability in some patients.