Ceramic femoral heads generated less linear polyethylene cup wear over 20 years

German researchers concluded after two decades of investigation that ceramic femoral heads create less linear polyethylene cup wear over time compared with metal heads.

While the cobalt-chromium-molybdenum (CoCrMo) group showed a mean 0.190 mm/year wear rate in the long-term study – which examined long-term wear analysis of femoral heads over a 20-year period – the ceramic head group had a 0.107 mm/year wear rate, which caused “significantly less osteolysis and revisions of either component,” the authors wrote in the abstract. The paper was published in Seminars in Arthroscopy.

In 80 patients, surgeons performed 93 consecutive uncemented hip arthroplasties using a titanium-coated cup and cementless stem. Eighty ceramic and 13 CoCrMo 32-mm diameter femoral heads were used. On average, patients followed up for 19.3 years and no patient was lost during follow-up, according to the abstract.

At AAOS 2012: Biomet Debuts Personalized Approach for Partial Knee Replacements

At AAOS in San Francisco, Biomet Orthopedics launched its Signature personalized patient care system designed for use with its Oxford partial knee system. The Signature custom positioning guides enable orthopedic surgeons to create custom femoral and tibial surgical positioning guides to facilitate precise joint implant positioning.

The Oxford partial knee procedure is designed to enable roughly 75% less bone and cartilage to be removed than total knee replacements. The patient-specific positioning guides are created using MRI data.

—Brian Buntz

Melting down hips and knees: The afterlife of implants

As people live longer and medical technology improves, more and more of us will have a surgical implant before we die. We are also getting cremated in larger numbers - and so there is often some expensive metal left among the ashes. Where does it go?

"You tell people what you do, and they think... well, that's a bit strange," says Ruud Verberne above the din of giant sorting machines twirling and clanking.

Verberne is co-founder of OrthoMetals, which recycles metal implants from cremated human bodies. That's everything from steel pins to titanium hips and cobalt-chrome knees.

These are the knees that we have to recover," he says. "Some metals can be sorted by magnets. And the remaining have to be sorted by hand."

Zimmer introduces Chondrofix Osteochondral Allograft

Zimmer Holdings Inc. released its Chondrofix Osteochondral Allograft to repair osteochondral lesions in diarthrodial joints in a single-stage procedure.

“Chondrofix technology offers an innovative new option for early intervention treatment of cartilage lesions through either an open or arthroscopic surgical procedure,” Cheryl R. Blanchard, PhD, senior vice president and chief scientific officer at Zimmer, stated in a company press release.

According to the release, the allograft is designed for patients with osteochondral legions who are considered too young for a total joint replacement or need to reduce the amount of rehabilitation time. It is minimally manipulated using a proprietary process which results in viral inactivation and terminal sterilization. The product also has a 2-year shelf life, and retains the mechanical properties of the pre-processed tissue, including the capacity for immediate load-bearing.

Surgeons Using Metal-Alloy Allergy Tests to Screen Patient Candidates for Total Hip or Knee

Preoperative skin patch testing for metal allergy influenced treatment planning in two-thirds of a small cohort of patients scheduled to receive metal-containing prosthetic devices, a retrospective chart review showed.

All 21 patients with positive tests received allergen-free prostheses and had no complications associated with hypersensitivity.
Post-implantation patch testing led to prosthesis removal in 10 additional patients, and six had resolution of hypersensitivity-associated symptoms.
“The findings of this study support a role for patch testing in patients with a clinical history of metal hypersensitivity before prosthetic device implantation,” Natasha Atanaskova Mesinkovska, MD, PhD, of the Cleveland Clinic, and co-authors wrote in an article published online in Archives of Dermatology.

SI-BONE Awarded Significant "Across Bones" Patent Allowance

SI-BONE, Inc. (San Jose, California), a medical device company that is pioneering the use of a minimally invasive surgical (MIS) device to treat the sacroiliac (SI) joint announced today that it has received a Notice of Allowance from the U.S. Patent and Trademark Office (USPTO) for broad method claims related to the iFuse Implant System. SI-BONE currently markets the iFuse in the United States and European Union under the iFuse name.

Of considerable significance for SI-BONE, was the breadth of the method claims. These claims include placing an elongated device across a joint from one bone to another, using a guide wire to place the implant, using a device that is rectilinear in cross-section, and a device having an exterior surface to provide bony in-growth. "Because the market for minimally invasive surgical treatment of the SI joint is potentially so significant, this allowance provides SI-BONE with a strong competitive barrier. Additionally, the Company has three dependent claims that further claim square, rectangular, and triangular cross-sections," according to Scott Yerby, Ph.D., Chief Technology Officer, SI-BONE.

Additional Patents For Spinal Implant Technologies Acquired

Titan Spine, a medical device surface technology company focused on the development of innovative spinal interbody fusion implants, announced today that it has acquired two patents related to its current and future surface modification techniques. The first patent protects the company's existing manufacturing process that has been shown to produce superior bone-forming activity when compared to standard PEEK and titanium implant materials during in-vitro cellular studies and has been commercially available in the United States since 2006. The second patent protects Titan Spine's next-generation surface technology that further refines its nano features, which the company expects to produce an even more robust osteogenic response.

AAOS 2012: Novel Lighting Technology Helps Orthopaedic Surgeons See What They Are Doing

Invuity is a rare breed of company. It faces “little to no regulatory barriers,” explains the company’s CEO, Philip Sawyer, at AAOS 2012. “And that enables use to develop multiple products and to react quickly and iterate them.”

Founded seven years ago, its lighting technology was initially developed by an optics expert partnering with an orthopaedic surgeon and researcher. The surgeon was working to develop a less-invasive hip for Zimmer and he realized that lighting problems were holding him back. After about five years, the two men had readied their first product: a sophisticated injection-molded optics device the enables orthopedic surgeons to see into small incisions.

The company has been approached by big orthopaedic companies that report they have spent years in vain trying to develop new lighting technologies similar to the firm’s products. “They come to us and say ‘we quit. We need your help.’” Invuity is now “about three weeks from shipping to one of the biggest spinal players,” explains Sawyer.

The company also markets products for breast surgery (through its own sales force) and for spinal surgery (with its sales force working with distributors). Its products are used in less invasive surgeries, where OR surgeons rely on overhead lights or head lamps and it is very difficult to see as you are operating through smaller and smaller incisions.

It developed a core Eigr technology, which uses injected-molded optics and creates a cool glare and shadow-free light. It is integrated in a clever way with access devices, whether those are retractors or whether it is a coupled to a suction device. And the technology creates a nice pattern of light on the tissue. “It looks more straightforward than it is,” Sawyer says. The technology turns the light and in an optimally efficienty way, transmits it, and it is deflected in a pattern. The light is guided through an advanced polymer and extracted via hundreds of micron-sized parallel structures.

“Each of these [structures] has a unique curve so that there is this redundancy," says Sawyer. That way, if anything enters the stream of light--if it is blocked, there is still a strong pattern of light on the tissue. --Brian Buntz

Smith & Nephew Settles Greek Bribery Charges

Smith & Nephew has agreed to pay the U.S. government more than $22 million to settle charges that the company bribed Greek public doctors over more than a decade.

The government had charged Smith & Nephew's U.S. subsidiary under the Foreign Corrupt Practices Act. The government alleged that the company used a distributor to create a "slush fund" to forward payments to doctors working at government hospitals in Greece in order to win business.

This won't come as a shock to readers of Michael Lewis's book, Boomerang. In the book Lewis claims that Greece has a well known culture of cheating on taxes, bribing public officials and cooking the public books.

The company has committed to pay $22,226,799 in fines and profit disgorgement, maintain an enhanced compliance program, and appoint an independent monitor for at least 18 months to review and report on its compliance program.

Value Pricing Leader IFS Now Marketing Subtalar Implants

Internal Fixation Systems, a Miami, Florida, company founded in 2006, has received 510(k) clearance from the FDA to market its subtalar implants. Made of stainless steel, with a cylindrical shape and tapering on one or both ends, the devices are designed to preserve motion at the ankle joint and deal with arthritis as well as whatever trauma the patient has experienced.

IFS’s CEO, Stephen Dresnick, M.D., says that his firm also currently offers a full line of mini-cannulated screws for small bone fixation as well as a Modular Locking Small Fragment System for treatment of bone fractures and osteotomies.

In describing IFS, Dresnick said that the company takes products that have been around for a long time and made by various companies, such as subtalar implants, and figures out how to make them better. He presents the established designs to his panel of recognized surgeons for analysis and modification and the addition of doctor—recommended enhancements. Dresnick then manufactures and sells the devices for 40% to 60% less than the competition.

“We are a value-priced company,” Dresnick told OTW. “We try to build our products inexpensively. They presently cost too much. Medicare is no longer willing or able to pay separately for implants.” IFS customers include ambulatory surgery centers, hospitals and orthopedic surgeons.