by Jerome A. Slavitt, DPM, FACFAS

If one is in practice long enough, surgical procedures, fixative devices, implants, tend to be cyclic in nature. In the past, stainless steel 28 or 30 gauge monofilament wire was a primary choice for fixation along with standard screws, non-compression staples, and various forms of hemi implants and composites. With the development of the cannulated screw, standard screws have seen somewhat of a decline. Hemi implants were used extensively in the eighties followed by a lull only to rebound again over the last 10 years due to better designs and materials. Staples have improved with the creation of compression staples. Years of patient experience, improved surgical techniques along with product development have all played a role in the podiatric surgeons' efforts to obtain the best possible results. This review will primarily be concerned with the next generation of fixative devices, compression staples.

Staples for bone fixations have increased in popularity with the advent of compression staples. Certain factors have played a role in this resurgence. These include: ease of surgical implantation, greater flexibility when less then ideal bone stock is present, and the ability to maintain positive compression along the osteotomy site. Are there possible concerns with staple use? The answer is an individual one, as it applies to each surgeon. The staple is usually a permanent implantable device which may be of some concern to those surgeons who prefer to remove devices after the osteotomy site has healed. Additionally, staples are slightly elevated above the bone and based on placement may cause some soft tissue irritation. I've never found this to be the case though.

Staples can be used for all types of fixation including forefoot, midfoot and rear foot procedures. This includes Akin osteotomies, first MTP arthrodesis, hallux IP arthrodesis, Lapidus, Dwyer osteotomies, and triple arthrodesis to name a few. The chief chemical components of compression staples are nickel and titanium (Nitinol). The trabecular response in regards to bone healing is significantly better with Nitinol as compared to stainless steel.

The staples are shape memory implantable devices which possess transition temperatures ranging from 25°C to 50°C or 77°F to 125.6°F. There are varying activation temperatures based on the staple manufacturer. With the exception of temperature variations, all compression staples have the same physical shape characteristics. As an example, three popular staples have specific temperature requirements for compression, OssStaple, 130°F, Memodyne, 109°F, and the new BioPro Memory Staple at 98°F.

Biopro Memory Compression Staple

Do not rely on compression staples to approximate the osteotomy site, but rather to maintain the coaptated positions of the bones with the staple's compression force. A key factor with varying temperature regulated devices is the resting temperature compression. All staples have a direct relationship to increased temperature applications yielding increased compression forces. However, noting that some staples require activation temperatures in the 130 degree range, the initial force "dialed in" on the surgical table will not be the same compression force after closure when the staple reaches normal body temperature.

How does one choose which staple manufacturer to use, taking product reps out of the equation? Your choice should be based on several points. These include the possibility of charges incurred for Bio-Med testing of actuator devices, sterilization of actuator cords, charges for disposable cautery devices, temperature variation changes after implantation resulting in a reduction of compression force, and cost.

Since the BioPro compression staples use normal body temperature of 98°F for compression, this eliminates the need for additional pieces of equipment, Bio Med testing, extra sterilization processing, and cautery devices. What you see is what you get, several seconds after implantation. There is no concern for compression loss since the staple legs are position maintained at body temperature. All these items make it very cost effective for the hospital or surgery center.

Today's podiatric surgeon is faced with so many similar product manufacturers vying for your business. Be prudent and scientific in your choices. What will work best for the patient yielding the highest surgical success is a company that will provide that personal touch, commitment, integrity and geared to the podiatric surgeons needs.

For further information visit Biopro at www.bioproimplants.com

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