Grooved Surface Of RFS Pin May Facilitate Improved Internal Fixation
- Volume 21 - Issue 3 - March 2008
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For podiatric surgeons who are looking for new additions to their internal fixation armamentarium, the NexFix RFS (Resorbable Fixation System) Pin may be a viable option.
The NexFix RFS Fin offers a combination of self-locking technology and a patented grooved surface design. Tornier, the manufacturer of the product, says the RFS Pin provides enhanced rotational stability, improved flexibility to accommodate different drill hole sizes and channels for potential vascularization.
Charles Zelen, DPM, notes he has had success using the NexFix RFS Pin for various osteotomies.
“The RFS Pins have provided reliable fixation for forefoot osteotomies, pediatric osteotomies and the fixation of bone grafts (Evans osteotomies) in my practice,” explains Dr. Zelen, an Assistant Clinical Professor in the Department of Internal Medicine at the University of Virginia.
Gary Lepow, DPM, who has more than 20 years of experience in utilizing resorbable fixation implants, has also had a positive experience with the RFS Pin. Dr. Lepow, a Fellow and Past President of the American College of Foot and Ankle Surgeons, says he has used the RFS Pins in a variety of procedures including Austin and Chevron bunionectomies, lesser distal osteotomies and Akin osteotomies, and has had no complications to date.
The RFS Pin offers several strengths, including the grooves in the pin, easy application and the fact that it is non-reactive, according to Dr. Lepow, a Clinical Associate Professor at the Baylor College of Medicine in Houston and the University of Texas Medical School in Houston.
RFS Pin Offers Improved Bioresorption
Tornier notes that each RFS Pin is composed of oriented bioresorbable polymer poly (L-lactide-co-glycolide, 85L/15G). In the past, surgeons have observed mild foreign body reactions with the use of polylactide- or polyglycolide-based polymers in bone fixation devices. However, Tornier emphasizes that the polymers used in the RFS Pin degrade in vivo by hydrolysis into alpha hydroxyl acids that are metabolized by the body.
As the osteotomy or fracture heals, the RFS Pin gradually loses its strength. Tornier says the pin will retain its intended function for at least eight weeks with full bioresorption occurring within two years. The grooved design of the pin and its mixture of PLLA and PGA create a unique option for the podiatric surgeon, notes Dr. Zelen.
“(The pins) offer a tight fit in the bone with solid initial strength and reliable absorption,” maintains Dr. Zelen, the Vice President of the Virginia Podiatric Medical Association.
The only weakness Dr. Zelen has observed regarding the RFS Pin is that it does not allow for true interfragmentary compression. A screw is necessary for this and Tornier will reportedly be releasing a RFS screw with compression in the near future.
“The textured nature of the RFS Pins provides added stability that is not available with any other pins I have used. I have been very impressed by their ability to fixate osteotomies of the foot,” states Dr. Zelen.
Dr. Lepow concurs. “I am very impressed with the results.”
Ms. Garthwait is a freelance writer who lives in Downingtown, Pa.