The law firm of Saunders & Walker P.A. in conjunction with attorney Stephen Leshner has filed a lawsuit on behalf of our clients against Wright Medical Technology Inc. (A Delaware Corporation) in relation to personal injuries suffered by our client as a result of a defective Wright Medical ProFemur Hip System that subsequently caused our client to suffer personal injury.
If you or a loved have also experienced injury, pain, or other problems with a defective hip device, please contact us for more information and attorney review of your case.
Wright Medical Technology Changed Material in 2009, but Issued No Warnings or Recalls
PHOENIX- A Phoenix man filed a lawsuit today in U.S. District Court against Wright Medical Technology, Inc. and Wright Medical Group, Inc. after needing emergency surgery following a sudden catastrophic fracture of the titanium modular neck of the Wright ProFemur Total Hip System as he was dressing for work last July.
“One minute I’m standing there getting dressed for work and the next I’m on the ground.”
Attorney Joseph H. Saunders of Saunders & Walker P.A. with Stephen Leshner of Stephen I. Leshner, P.C., filed the complaint against the Tennessee-based company on behalf of Dale Purcell, who had the device implanted in June 2005 during a total left-hip replacement.
The Wright ProFemur Total Hip System is comprised of three separate components which are assembled during surgery: a femoral head, a modular neck and the femoral stem.
“There is a design defect in the femoral implant that causes it to fracture just below the neck,” Leshner said. “When it fractures, you’re on the floor, in extreme pain and you have to have emergency surgery immediately.” The nine-count complaint, which charges negligence, design defect, manufacturing defect, failure to warn and fraudulent misrepresentation, seeks unspecified general, special and punitive damages.
“One minute I’m standing there getting dressed for work and the next I’m on the ground,” Parcell said. “At first I thought there was an earthquake that knocked me down, but then the pain hit and I couldn’t move my leg.”
Purcell, 57, underwent revision surgery at Chandler Regional Medical Center on July 7, 2011, when surgeons had to remove the “fractured fragments of the ProFemur Z titanium modular femoral neck” and noted “some mild corrosion” at the site of the fracture, according to the complaint.
According to the complaint, “The titanium modular neck used in Mr. Parcell fractured and broke very near the femoral stem, leaving a broken portion of the titanium neck wedged inside the stem. The fracture of the modular neck adapter caused failure of the system, requiring corrective surgery, and made it extremely difficult to extract the fragment.”
The complaint points out that “studies have shown that modular neck adapters made from titanium alloy, such as the ProFemur modular neck adapter” “are more likely to suffer fretting corrosion and fatigue fracture than those made from cobalt-chromium.”
A 2009 report by the Australian Orthopaedic Association showed that the Wright ProFemur Z femoral stem had a high failure rate, requiring approximately 11.2 percent of all patients receiving the implant to need revision surgery.
According to the complaint, in 2009, Wright Medical changed the material in the ProFemur Hip System Modular Necks from titanium to cobalt chrome alloy, but the company took “no corrective action in the form of a recall or even an announcement of warning to the medical community or to the public at large concerning its decision to switch from titanium modular neck adapters to cobalt chrome adapters.”
“At all relevant times, Defendants knew, or should have known, that the Device which included a titanium modular femoral neck was more prone to fatigue fracture and failure than a device made with a cobalt chromium modular neck,” according to the complaint.
Leshner said this is the first of several lawsuits he expects to file on behalf of individuals who suffered similar failures of the hip-replacement device.
|12/13/2000||First modular neck Pro Femur 510K cleared (K003016)|
|05/28/2004||First Pro Femur metal on metal 510K cleared (K041114)|
|2004||Australian Registry: 41 ProFemur Z implanted|
|06/28/2005||Parcell implanted with ProFemur Z with Ti modular neck||Conserve Plus Acetabular Shell (no liner), so the metal Conserve Total Femoral Head was directly on the metal cup.|
|2005||Australian Registry: 79 ProFemur Z implanted|
|Fall 2006||Australian Registry: cumulative percent revision of 7.30 at one year|
|2006||Australian Registry: 56 ProFemur Z implanted|
|Fall 2007||Australian Registry: cumulative percent revision of 8.66 at two years||“The risk of revision at this early stage however is over three and half times that of other cementless stems.”|
|2007||Australian Registry: 6 ProFemur Z implanted|
|Fall 2008||Australian Registry: cumulative percent revision of 12.2 at three years|
|2008||Australian Registry: 1 ProFemur Z implanted|
|04/16/2009||510K with modular neck change from Ti to Co/Cr submitted (K091423)|
|08/04/2009||Botha implanted with ProFemur Z with Ti modular neck||Dynasty Shell with a Dynasty CoCr liner, again with the metal Conserve Total Femoral Head, this one against a metal liner|
|08/25/2009||510K with modular neck change from Ti to Co/Cr cleared (K091423)|
|Fall 2009||Australian Registry: cumulative percent revision of 11.2 at three years|
|2009||Australian Registry: 2 ProFemur Z implanted|
|January 2010||Results of Metha Short Hip Stem Prosthesis study of about 5000 devices implanted between 08/2004 and 11/2006. Average time to failure was 2.8 years, with cumulative failure rate at 2.4%.
BMC Musculoskeletal Disorders.
|“Retrieval examinations and biomechnical simulation revealed that primary micromotions initiated fretting within the modular tapered neck connection. A continuous abrasion and repassivation process with a subsequent cold weling at the titanium alloy modular interface. Surface layers of 10-30 um titanium oxide were observed. Surface cracks caused by fretting or fretting corrosion finally lead to fatigue fracture of the titanium alloy modular neck adapters. Neck adapters made of cobalt chrome alloy show significantly reduced micromotions especially case of contaminated cone connection. With a cobalt-chromium neck the micromotions can be reduced by a factor of 3 compared to the titanium neck. The incidence of fretting corrosion was also substantially lower with the cobalt-chromium neck configuration.”|
|June 2010||Forty-nine-year-old man implanted with ProFemur Z hip stem in June 2005. In January 2009, patient slipped on ice and fell, noting a new onset of clicking and squeaking from the hip. Two months later he leaned over to tie his shoes, heard a snap, and was unable to bear weight on the LLE. The modular neck fractured. The Journal of Bone & Joint Surgery||Examination of the distal fragment of the modular neck with use of light microscopy showed marked fretting and corrosion damage and black fretting with corrosion debris. SEM revealed severe corrosion, consisting of scalloping and pitting of the mating surfaces. The fracture surface demonstrated a clear clamshell pattern characteristic of a fatigue fracture radiating from the corroded area on the anterolateral surface of the modular neck. Neither fretting nor corrosion damage was evident at the modular head-neck junction.
Longer implantation times increase the amount of corrosion and fretting. They also reported that the degradation of the neck-stem junction was more significant than at the head-neck junction and was believed to be secondary to the increased lever arm and high mechanical stress. Inflammatory mediators are released as a consequence of the cellular response to the particulate and/or ionic products of fretting and corrosion. This can ultimately result in the need to revise the prosthesis.
|June 2010||Thirty-year-old man, 6’6”, 242 lbs., implanted with ProFemur Z hip stem with long, straight neck and COC articulation. Patient fell April 2008 and the modular neck, approx.. 2 mm below the edge of the stem, fractured. The portion of fractured neck press fit inside stem could not be removed. The Journal of Bone & Joint Surgery||“Evidence of fretting and large pits indicates that micromotion at the modular interface between the neck and the stem led to crevice corrosion. This crevice corrosion process together with normal loading generated a sharp crack that, when the patient fell, resulted in catastrophic fracture of the neck.
“Orthopaedic metal implants mde from Ti6A14V alloy, such as the ProFemur Z, are protected from corrosion in the body’s aggressive environment by a passive oxide layer on the surface. However, fretting at a modular junction can continually wear away the oxide film, requiring constant repassivation. When this repassivation process occurs in a crevice such as the modular neck-stem interface, it depletes the limited oxygen supply and decreases the local pH, which promotes further corrosion and results in pitting and the formation of sharp cracks. Corrosion-induced cracks may result in catastrophic fracture on the application of high stresses, such as those at the neck-stem junction. This process is called stress corrosion cracking and is often associated with tensile stresses such as the bending stress at the fracture initiation site of the retrieved implant in the present report.
“Tensile bending stresses in the neck are highest at the neck-stem junction and are proportional to the load applied and to the length of the neck. In other words, a long neck will be subjected to higher stresses than a short neck. According to the manufacturer’s information on the ProFemur Z device, the long-neck length option is about 25% longer than the standard-neck length, producing roughly 25% higher bending stresses. This analysis suggests that long necks may contribute to a greater risk of fracture.”
|October 2010||Fatigue fracture in modular neck of femoral implant 3.5 years after implantation. The Journal of Arthroplasty, Vol. 25, Issue 7.|
|October 2010||“Three recent case reports of a failure of a modular neck hip stem (ProFemur Z) have increased the attention being given to this potential complication.” The American Journal of Orthopedics||“It should be noted that 2 of these cases involved fairly large patients and traumatic falls, and the third involved failure of neck replaced during a revision surgery. A commonality in these cases is use of long necks, which all the authors postulated as a contributing factor. As noted earlier, fatigue strength performance is influenced by amount of offset, amount of version, and, in the case of modular neck implants, taper design geometry.”|
|Fall 2010||Australian Registry: cumulative percent revision of 10.6 at three years|
|10/22/2010||Albi Qeli, M.D. comment on Orthopaedia: There were 3 case reports of fractures of the modular neck of this stem in JBJS in 2010. I have personally explanted a similarly failed prosthesis. According to the manufacturer, the modular neck used to be made of Ti alloy, but now they use only the stronger Co-Cr. This was explained to the patient, and she wanted to just replace the Ti modular neck with a Co-Cr neck, so as to keep dissection at a minimum. It proved impossible however to replace just the modular neck, and an extended osteotomy had to be performed to replace the entire stem.|
|2010||Australian Registry: 1 ProFemur Z implanted|
|07/27/2011||The combined effects of crevice and fretting corrosion, large-diameter femoral head, long modular neck, metal-on-metal articulation, patient size, and activity level may have all played integral roles in creating an environment susceptible to this classic pattern of fatigue fracture. Journal of Arthoplasty.|
|Fall 2011||Australian Registry: cumulative percent revision of 11.0 at five years|
|11/30/2011||Failure mechanism described in text, Mechanics of Biomaterials.|