Emerging Concepts With Dynamic Compression Staples In Foot Surgery

Nitinol dynamic compression staples may provide unique benefits in a wide variety of foot surgeries. Accordingly, this author shares his experience with staple fixation in recent cases involving an active duty military population. 

The use of nitinol dynamic compression staples can provide unique benefits in a wide variety of foot surgeries. In my experience, these staples have facilitated a fast return to function without need for hardware removal for five Lapidus arthrodeses, two hallux interphalangeal joint fusions, 17 Austin bunionectomies, four Akin osteotomies, three calcaneal slide osteotomies, one Cotton osteotomy and two first metatarsophalangeal joint (MPJ) fusions (see photos). 

A key intraoperative advantage is that staples are technically easier and faster to apply as fewer steps are required in comparison to an AO-applied screw.¹ If future removal of staples is required, this obviates the hassle of determining the appropriate screwdriver as the process of removal involves simply cutting the bridge of the staple and removing the two remaining fragments. Additionally, there may be a reduced need to re-operate to remove prominent hardware as the bulk and prominence of staples are generally lower in comparison with plates and screws. A related advantage of less bulky hardware is better visualization of the fusion site on postoperative X-ray, allowing for a better assessment of bone healing.

In comparison with a traditional screw, in which the last turn of the screw is the final amount of dynamic compression that occurs, the continuous compression afforded by staples provides a theoretical advantage in maintaining close apposition of bone fragments as indicated by Glissan’s accepted principles of arthrodesis.²  

In comparison to plates, which need to be perfectly contoured to the anatomic shape of the bones one is fusing, staples do not require contouring. Staples reduce the risk of the fusion site being deformed by placement of an ill-fitting plate. This is a critical theoretical advantage, particularly for the Lapidus arthrodesis, which has an established nonunion rate of approximately 10 percent.³ Staples also provide the advantage of not violating the bone fusion surface, preserving critical surface area which is needed for optimal fusion results.  

Key Insights On The Efficient Use Of Staples

Practical pearls of using staples include creating a trough in the bone where the bridge will lie, reducing hardware prominence and soft tissue irritation. When performing a Lapidus arthrodesis, the use of a medially placed staple near the plantar aspect of the fusion site is effective in providing critical compression at the tension side of the fusion site. Also, one can cut the proximal leg of the medially placed Lapidus staple prior to insertion to avoid crossing the intercuneiform joint. 

There are many brands of dynamic compression staples available. I have used the EasyClip (Stryker), which offers the benefit of a proprietary forceps that facilitates intraoperative repositioning. Without this forceps, the staple may have to be cut and discarded in order to reposition. I have had good experience with the Speed Nitinol Memory Implant (BME/DePuy Synthes), which provides enhanced compression strength for Lapidus fusions.  

In Conclusion

Staples can provide effective fixation for a variety of foot surgical procedures with a minimum of hardware bulk and complications in comparison to more frequently used methods of fixation. 

Dr. Harris is an active duty Navy podiatrist.

The views expressed in this article are those of the author and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense or the U.S. government. Dr. Harris has disclosed that he has no financial relationship with Stryker or BME.

References

1. Mereau TM, Ford TC. Nitinol compression staples for bone fixation in foot surgery. J Am Podiatr Med Assoc. 2006; 96(2):102-106.
2. Glissan DJ. The indications for inducing fusion at the ankle by operation with description of two successful techniques. Aust N Z J Surgery. 1949; 19(1):64-71.
3. Sangeorzan FJ, Hansen ST Jr. Modified Lapidus procedure for hallux valgus. Foot Ankle Int. 1989; 9(6):262-266.