Kindsfater K, Barrett WP, Dowd JE, Southworth CB and Cassell MJ. "99.9% Midterm Survival of the Pinnacle Multi-Liner Acetabular Cup in a Prospective Multi-Center Study." Poster Presentation #P077, AAOS, San Diego, CA. February 14-18, 2007.
Notice this reference was to the Depuy Pinnacle multi-liner acetabular cup. Unfortunately, no one can produce this study as it was just a poster at the American Orthopedic Association conference in 2007. I presume it was NOT peer reviewed?
"Pinnacle Hip Solutions were designed to help provide a more fluid range of natural motion. DePuy Orthopaedics remains the leader in metal-on-metal technology, offering several advantages, including larger diameter bearings that can improve hip range of motion and stability. In fact, one study conducted since the device was approved in 2002 observed that an estimated 99.9 percent* of Pinnacle Hip components remain in use. Only Pinnacle Hip Solutions feature TrueGlide™ technology, allowing the body to create a thin film of lubrication between surfaces. The result is a smooth, more fluid range of natural motion."
Gee, its interesting because multi district litigation has begun with the Pinnacle metal on metal hip. While they haven't been recalled, the law suits are piling up.
I just don't know what to make of this study in light of what seems to be some very strong ties with Depuy. I don't know for sure of course but do you know of any other medical professional publishing new data on the great performance of metal on metal hips? Well, here is one! This would have had to be peer reviewed to get into this journal. If I find other studies promoting the use of these hips, I will let you know.
Also note the dates of both sides of this argument:
The Kindsfeter article appeared before print on `14 March 2012
The British Lancet article appeared before print on 12 March 2012.
Is this just a mere coincidence?
Kindsfeter's compiled findings of other studies are quite positive vs the Lancet findings which are completely negative.
Large-Diameter Modular Metal-on-Metal Total Hip Arthroplasty: Incidence of Revision for Adverse Reaction to Metallic Debris.
SourceValley Orthopedic Associates, Proliance Surgeons, Joint Center at Valley Medical Center, Renton, Washington.
AbstractLarge-diameter modular metal-on-metal (MOM) total hip arthroplasty (THA) may offer reduction in wear debris and improved stability. Four studies are summarized here that used a large-diameter modular MOM system. A total of 1076 THAs were performed. This article presents data from 779 of these THAs with minimum 2-year follow-up (mean, 4.2 years) or revision since index THA (21 hips, with 1 more pending). Overall survivorship at 2 years was 98.6%; at 5 years, it was 97.0%. Seven revisions for an adverse reaction to metallic debris (ARMED), and 1 additional pending revision for ARMED, showed marked variability in presenting symptoms and intraoperative and postoperative findings. Data show good clinical performance of the modular MOM system, but suggest that surgeons must be diligent in monitoring MOM THA patients and aggressive in diagnosing and revising patients with a potential ARMED
How do we reconcile these studies with the new recommendations comming out from the British folks recently? Fodder for the lawyers? see the following posts:
At last week's British Hip Society Annual Conference, in Manchester England: "... large diameter MoM primary hip replacements should no longer be performed.... http://www.mydepuyhiprecall.com/2012/03/at-last-weeks-british-hip-society.html