Zimmer Inc., headquartered in Warsaw Indiana, specializes in musculoskeletal health care. It is one of the largest medical company in the world, with 8500 employees serving all over the globe for more than 80 years. Zimmer’s 2016 sales were approximately $4.5 billion.
Zimmer Femoral Components
Include stem, neck and femoral head. They are fixed with the superior part of femur and is designed to produce movements at the hip joint. Zimmer is manufacturing following femoral components:
• M/L Taper Hip Prosthesis: It is available in 14 different sizes.
Companies using modular-neck technology
The modular-neck technology is employed by many companies and marketed under different names as follows:
• Zimmer M/L Taper Prosthesis with Kinectiv Modular Neck
Zimmer Kinectiv Modular-Neck Technology
This technique allows the surgeon to address length, version and offset independently. The M/L Taper with Kinectiv Technology is dotted and porous with different necks that can meet the anatomical variations of the patients. The wide range of neck sizes enables the surgeon options to deal with the anatomical differences between male and female patients. Proper offset and leg-length restoration improve the total hip replacement function and lower the risk of dislocation.
The Modular Neck
Enables the surgeon to do a minimally invasive surgery. The modular neck requires less retraction of the muscles and it easily fits into the space. Different sizes are easily available. Moreover, the ante version and retroversion of the neck is necessary is some patients with a different anatomy.
The Femoral Stem
With Kinectiv Technology is shorter than conventional stems, providing greater bone conservation compared to other hip replacement systems.
The Femoral Heads
Of +0 sizes can be used because Kinectiv technology allows the surgeon to correct the length independent of the size of the femur head. This helps in proper stabilization of the femoral head and normal movements of the hip joint.
Problems with modular-neck technology
The corrosion is more at the location where the modular metal neck snaps into the body of the femoral stem. Similar to metal-on-metal hip implants, the modular-neck hip implants can corrode, slough off debris into the body and produce the following complications:
Pain:
It is very common complication and is usually associated with signs of inflammation i.e. redness, tenderness, swelling, warmth etc.
Metallosis:
Increased levels of metal debris and plasma concentration of metals due to metal on metal friction. There is an increased risk for metallosis the longer the implant has been in use. Metallosis can cause serious complications including sever pain, inflammation, grey discoloration surrounding the implant site and nervous system issues.
Dislocation or Loosing:
Premature wearing of the articular surfaces results in the loosening of the implant. This can potentially lead to joint dislocation and other issues.
Fractures:
In older ages, the bone becomes too weak to support the metal implant and fractures. This complication is more common in post-menopausal females.
Revision surgery After Device Failure:
There are multiple problems than can lead to a revision surgery. Mechanical failure, infection and recurrent hip dislocation all can prompt a doctor to consider a revision surgery. Often the revision surgery is more dangerous than the initial surgery and can further damage the area of the implant.
Zimmer M/L Taper Kinectiv Stem cases:
Lawsuits have been consolidated into multidistrict litigation and are in the early stages of litigation. This includes lawsuits related to the Zimmer M/L Taper Hip Prosthesis and Zimmer M/L Taper Hip Prosthesis with Kinectiv Technology.
The FDA issued a recall for the Zimmer M/L Taper with Kinectiv Technology Femoral Stems and Necks hip implants on June 19, 2015. Patients are at an increased risk for allergic reactions such as metallosis, pain, infections, or death related to high level of manufacturing residue on these implant components. The FDA has opined that revision surgery to replace the defective implants may be necessary for some patients.
The Kinectiv devices were designed to match a wide range of male and female anatomies without compromise through a broad spectrum of modular neck components.
Judith Harms, a Minnesota resident, filed a product liability lawsuit against the manufacturer of Zimmer Kinectiv Hip Replacement System in the U.S. District Court for the District of Minnesota on May 19. Plaintiff Harms filed the suit over the development of metallosis, a form of metal blood poisoning due to the defectively designed Hip Replacement System implanted in September 2008 for which she had to undergo a revision surgery in October 2015. In her complaint Harms stated that the head-neck taper junction of the Zimmer Kinectiv corroded and crumbled, leaving metallic debris in the body.
The revision surgery revealed the presence of pericapsular necrotic tissue, thickened capsule, and a brown metallic stained fluid in the area of the hip device. Zimmer’s metal head had dislocated from the Zimmer neck, leaving a black smudge.
“Diagnosis of the metallosis was delayed due to Plaintiff’s surgeon having been left uninformed of the potential for this risk and complication when using the Kinective Hip System,” the lawsuit states. “The October 2015 revision surgery revealed pericapsular necrotic tissue, thickened capsule and a brown metallic stained fluid in the area of the hip device. Black sludge was identified where the Zimmer metal head was disimpacted from the Zimmer neck.”
Harms’ lawsuit comes a little more than a year after Zimmer was ordered to pay $2 million to a man who also suffered metallosis due to similar problems with a Zimmer Kinectiv hip. Hip Replacement System recalls have spiked in recent years due to the complications arising from its metal-on-metal design. Zimmer is also facing allegations that their Knee Implant System has caused complications for which cases are consolidated as a part of MDL No. 2272 (in re: Zimmer NexGen Knee Implant Products Liability Litigation) in the U.S. District for New Jersey under Judge Susan D. Wigenton.
