Point-Counterpoint: Locking Plates Or Staples: What Is The Best Fixation For First MPJ Arthrodesis?

Locking plates.

Acknowledging that researchers have yet to come to a consensus on the most effective fixation on first MPJ arthrodesis, this author touts the benefits of locking plates.  

By Patrick A. DeHeer, DPM, FACFAS

Arthrodesis of the first metatarsophalangeal joint (MPJ) is well-documented in the literature to be a reliable procedure for first MPJ pathologies such as hallux rigidus, hallux abducto valgus, rheumatoid arthritis and hallux varus.^1-13 The principles of the procedure have essentially remained the same since Broca first described it in 1852 and Clutton subsequently described arthrodesis in 1894.^14,15 The outcomes for first MPJ arthrodesis show good to excellent outcomes in 77 to 100 percent of cases.^4,16-22

The procedure technique has been refined over the past 165 years, particularly when it comes to methods of arthrodesis fixation. Fixation methods for first MPJ arthrodesis have included K-wires, memory stapes, plates and screws.^23-33 Although the success rates for all types of fixation average approximately 90 percent, the literature does not paint a clear picture for one type of fixation providing a higher fusion rate than other types of fixation.^{23,25-31,33-35} The literature does provide information on which type of fixation is strongest for first MPJ arthrodesis.³⁶

What The Literature Says About First MPJ Fixation

Examination of the best method of fixation for first MPJ arthrodesis begins with a couple of questions in which evidence-based medicine provides some insight. The initial question for consideration is plate versus screw fixation as these two types of fixation dominate the literature, especially for construct stiffness.

Denning and van Erve compared fusion rates for four types of fixation in 72 patients having first MPJ arthrodesis.³⁶ The results from the study are as follows: a 71 percent fusion rate for 24 patients who had single screw fixation; a 90 percent fusion rate for 21 patients who had cross-screw fixation; a 100 percent fusion rate for 13 patients who had dorsal plate fixation; and a 93 percent fusion rate for 14 patients who had a dorsal plate and plantar lag screw. The fusion rates at six weeks and three months showed no statistically significant differences. However, non-union rates were statistically significant with authors showing lower non-union rates for dorsal plate fixation in comparison to single screw fixation.

Wassink and van der Oever’s findings contradicted this study, showing fusion rates for single screw fixation to be 95.4 percent.³³ Sharma and colleagues demonstrated similar findings with fusion rates of 100 percent for single screw fixation and 94 percent for dorsal plate and lag screw fixation.³⁴

Curtis and coworkers revealed single screw fixation to be more stable than a dorsal plate in a study examining four constructs (planar resection with crossed K-wires, dorsal plate, or a single lag compression screw; and conical reaming with crossed-screws).³⁷ Hyer and colleagues found similar results to Denning and van Erve, comparing crossed screw fixation (92.9 percent fusion rate) and dorsal plate fixation (90.3 percent fusion rate) with no significant difference in time to fusion between the two constructs.³⁰ Sharma and colleagues confirmed this lack of statistically significant difference in time to fusion.³⁴

Neufeld and colleagues not only compared crossed screw fixation to plate fixation but also examined staple fixation.³⁸ All constructs had supplementation with a 0.062-inch K-wire to prevent rotation. Their findings showed the cross-screw and plate constructs to be statistically superior to compression staples.³⁴

Reviewing five constructs for first MPJ arthrodesis, Politi and coworkers assessed conical reaming with four different forms of fixation including a 3.5 mm cortical lag screw; a 3.5 mm cortical lag screw with a four-hole dorsal plate using 3.5 mm cortical screws; crossed 0.062-inch K-wires; and a four-hole dorsal plate with 3.5 mm cortical screws and no lag screw. They also evaluated planar surface excision and fixation with a single 3.5 mm cortical lag screw.³⁹ The study authors found that conical reaming and the combination of an oblique lag screw and dorsal plate provided the most stability. They noted that this fixation combination “should lead to higher rates of arthrodesis.” The weakest constructs were the 0.062 crossed K-wires and the use of the dorsal plate alone for fixation.

Buranosky and colleagues also showed that plate with compression screw fixation is more stable than crossed screw fixation.⁴⁰ In 2009, Bennett and Sabetta performed one of the larger and more standardized studies looking at fixation for first MPJ arthrodesis.⁴¹ The study consisted of one surgeon using the same intraoperative, postoperative and fixation construct (dorsal plate and compression lag screw) for all 233 patients. The fusion rate for the study was 98.7 percent.

Other Pertinent Considerations With Locking Plates

The next consideration in fixation constructs for first MPJ arthrodesis fixation is locked versus non-locked plating. Hyer and coworkers analyzed four constructs (static plate, static plate with lag screw, locked plate and locked plate with lag screw) and found no statistical difference between groups for fusion rates or time to heal.⁴² The average radiographic healing rate in the study was 93 percent. Hunt and coworkers examined the stiffness and strength of locked vs. non-locked plating with both being supplemented with a compression screw.⁴³ The locked plate construct had significantly less plantar gapping in endurance testing and greater stiffness in load to failure testing.

A more relevant question that requires examination is whether locking plates are too stiff to allow interfragmentary motion, possibly resulting in suppression of bone healing. Bottlang and coworkers answered this question by stating that “postoperative interfragmentary motion provided by locked plates may therefore be too small to promote callus formation, especially at the near cortex.”⁴⁴ The authors noted that locked plating can lead to inconsistent and asymmetric callus formation. Surgeons can mitigate this stiffness inhibition of adequate callus formation with the use of far cortical construct locking screws. This type of fixation promotes secondary bone healing by “promoting secondary bone healing with locking plates: stiffness reduction, parallel interfragmentary motion and progressive stiffening.”

The result is symmetric callus formation and stronger osseous union. Conversely, standard lock plating can result in partial non-unions due to high construct stiffness and asymmetric gap closure.
Hunt and colleagues confirmed the Bottlang study’s hypothesis, comparing locked and non-locked plating for first MPJ arthrodesis, and revealing a higher non-union rate in the locked plating group.⁴⁵ Jastifer similarly stated that “Constructs that are too stiff can result in nonunion from lack of micromotion at the site of healing.”⁴⁶

To date, there has been no published literature on the next generation of fixation for first MPJ arthrodesis: locked plating with the use of an external compression device. Surgeons may combine this type of fixation with a compression screw or a compression slot with an eccentrically drilled, non-locking bicortical screw. This type of fixation combines the best of internal and external fixation, providing a robust form of fixation. However, this construct may be too rigid based on the locking plate literature, potentially leading to incomplete bony union.

Final Thoughts

The debate of locked plating versus intramedullary nails/staples has little, if no direct, comparative literature. While there are a couple of articles for intramedullary and staple fixation in the literature, this pales in comparison to the literature on plate/screw fixation for first MPJ arthrodesis. There is insufficient evidence to make any argument on behalf of intramedullary nails or staples.

Arthrodesis of the first MPJ is one of the most predictable and documented foot/ankle procedures. The procedure has become commonplace in foot and ankle surgery as a result. Despite robust research, fixation remains the sole technique variability for first MPJ arthrodesis. One should consider several factors when choosing a method of fixation. These factors include implant cost, evidence-based outcomes and surgeon preference. While there are several options that provide excellent outcomes, the literature has yet to provide an ultimate answer to the best fixation construct for first MPJ arthrodesis.

Dr. DeHeer is a Fellow of the American College of Foot and Ankle Surgeons, and a Diplomate of the American Board of Podiatric Surgery. He is also a team podiatrist for the Indiana Pacers and the Indiana Fever. Dr. DeHeer is in private practice with various offices in Indianapolis and is the founder of Step by Step Haiti.

References

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5. DeSandis B, Pino A, Levine DS, et al. Functional outcomes following first metatarsophalangeal arthrodesis. Foot Ankle Int. 2016; 37(7):715-721.
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8. Dayton P, Feilmeier M, Hunziker B, et al. Reduction of the intermetatarsal angle after first metatarsal phalangeal joint arthrodesis: a systematic review. J Foot Ankle Surg. 2014; 53(5):620-623.
9. Sung W, Kluesner AJ, Irrgang J, et al. Radiographic outcomes following primary arthrodesis of the first metatarsophalangeal joint in hallux abductovalgus deformity. J Foot Ankle Surg. 2010; 49(5):446-451.
10. Kim PJ, Hatch D, DiDomenico LA, et al. A multicenter retrospective review of outcomes for arthrodesis, hemi-metallic joint implant, and resectional arthroplasty in the surgical treatment of end-stage hallux rigidus. J Foot Ankle Surg. 2012; 51(1):50-56.
11. Wood EV, Walker CR, Hennessy MS. First metatarsophalangeal arthrodesis for hallux valgus. Foot Ankle Clin. 2014; 19(2):245-258.
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13. Little JB. First metatarsophalangeal joint arthrodesis in the treatment of hallux valgus. Clin Podiatr Med Surg. 2014; 31(2):281-289.
14. Broca P. Des difformités de la partie anterieure du pied produite par faction de la chaussure. Bull Soc Anat. 1852; 27:60-67.
15. Clutton HH. The treatment of hallux valgus. St Thomas Rep. 1894; 22:1-12.
16. Raikin SM, Ahmad J, Pour AE, Abidi N. Comparison of arthrodesis and metallic hemiarthroplasty of the hallux metatarsophalangeal joint. J Bone Joint Surg Am. 2007; 89(9):1979-1985.
17. Womack JW, Ishikawa SN. First metatarsophalangeal arthrodesis. Foot Ankle Clin. 2009; 14(1):43-50.
18. Doty J, Coughlin M, Hirose C, Kemp T. Hallux metatarsophalangeal joint arthrodesis with a hybrid locking plate and a plantar neutralization screw: a prospective study. Foot Ankle Int. 2013; 34(11):1535-1540.
19. Fitzgerald JAW. A review of long-term results of arthrodesis of the first metatarsophalangeal joint. J Bone Joint Surg Br. 1969; 51(3):488-493.
20. Goucher NR, Coughlin MJ. Hallux metatarsophalangeal joint arthrodesis using dome-shaped reamers and dorsal plate fixation: a prospective study. Foot Ankle Int. 2006; 27(11):869-876.
21. Mann RA, Oates JC. Arthrodesis of the first metatarsophalangeal joint. Foot Ankle Int. 1980; 1(3):159-166.
22. Mann RA, Thompson FM. Arthrodesis of the first metatarsophalangeal joint for hallux valgus in rheumatoid arthritis. J Bone Joint Surg. 1984; 66(5):687-692.
23. Choudhary RK. Theruvil B, Taylor GR. First metatarsophalangeal joint arthrodesis: a new technique of internal fixation by using memory compression staples. J Bone Joint Surg. 2004; 43(5):312-317.
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25. Ivory JP, Gregg PJ. The management of the painful first metatarsophalangeal joint in the older patient: a 5-year review. Foot. 1992; 2(3):162-165.
26. Santini AJA, Walker CR. First metatarsophalangeal joint fusion: a low profile plate technique. Foot Ankle Surg. 2001; 7(1):15-21.
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28. Coughlin MJ, Abdo RV. Arthrodesis of the first metatarsophalangeal joint with Vitallium plate fixation. Foot Ankle Int. 1994; 15(1):18-28.
29. Flavin R, Stephens MM. Arthrodesis of the first metatarsophalangeal joint using a dorsal titanium contoured plate. Foot Ankle Int. 2004; 25(11):783-787.
30. Hyer CF, Glover JP, Berlet GC, Lee TH. Cost comparison of crossed screws versus dorsal plate construct for first metatarsophalangeal joint arthrodesis. J Foot Ankle Surg. 2008; 47(1):13-18.
31. Sage RA, Lam AT, Taylor DT. Retrospective analysis of first metatarsal phalangeal arthrodesis. J Foot Ankle Surg. 1997; 36(6):425-429.
32. Grondal L, Broström E, Wretenberg P, Stark A. Arthrodesis versus Mayo resection: The management of the first metatarsophalangeal joint in reconstruction of the rheumatoid forefoot. J Bone Joint Surg Br. 2006; 88(7):914–919.
33. Wassink S, van den Oever M. Arthrodesis of the first metatarsophalangeal joint using a single screw: retrospective analysis of 109 feet. J Foot Ankle Surg. 2009; 48(6):653-661.
34. Sharma H, Bhagat S, Deleeuw J, Denolf F. In vivo comparison of screw versus plate and screw fixation for first metatarsophalangeal arthrodesis: does augmentation of internal compression screw fixation using a semi-tubular plate shorten time to clinical and radiologic fusion of the first metatarsophalangeal joint (MTPJ)? J Foot Ankle Surg. 2008; 47(1):2-7.
35. Kumar S, Pradhan R, Rosenfeld PF. First metatarsophalangeal arthrodesis using a dorsal plate and a compression screw. Foot Ankle Int. 2010; 31(9):797-801.
36. Dening J, van Erve RH. Arthrodesis of the first metatarsophalangeal joint: a retrospective analysis of plate versus screw fixation. J Foot Ankle Surg. 2012; 51(2):172-175.
37. Curtis MJ, Myerson M, Jinnah RH, et al. Arthrodesis of the first metatarsophalangeal joint: a biomechanical study of internal fixation techniques. Foot Ankle. 1993; 14(7):395-399.
38. Neufeld SK, Parks BG, Naseef GF, et al. Arthrodesis of the first metatarsophalangeal joint: a biomechanical study comparing memory compression staples, cannulated screws, and a dorsal plate. Foot Ankle Int. 2002; 23(2):97-101.
39. Politi J, John H, Njus G, et al. First metatarsal-phalangeal joint arthrodesis: a biomechanical assessment of stability. Foot Ankle Int. 2003; 24(4):332-337.
40. Buranosky DJ, Taylor DT, Sage RA, et al. First metatarsophalangeal joint arthrodesis: quantitative mechanical testing of six-hole dorsal plate versus crossed screw fixation in cadaveric specimens. J Foot Ankle Surg. 2001; 40(4):208-213.
41. Bennett GL, Sabetta J. First metatarsalphalangeal joint arthrodesis: evaluation of plate and screw fixation. Foot Ankle Int. 2009; 30(8):752-757.
42. Hyer CF, Scott RT, Swiatek M. A retrospective comparison of four plate constructs for first metatarsophalangeal joint fusion: static plate, static plate with lag screw, locked plate, and locked plate with lag screw. J Foot Ankle Surg. 2012; 51(3):285-287.
43. Hunt KJ, Barr CR, Lindsey DP, Chou LB. Locked versus nonlocked plate fixation for first metatarsophalangeal arthrodesis: a biomechanical investigation. Foot Ankle Int. 2012; 33(11):984-990.
44. Bottlang M, Doomink J, Lujan TJ, et al. Effects of construct stiffness on healing of fractures stabilized with locking plates. J Bone Joint Surg Am. 2010; 92(Suppl 2):12-22.
45. Hunt KJ, Ellington JK, Anderson RB, et al. Locked versus nonlocked plate fixation for hallux MTP arthrodesis. Foot Ankle Int. 2011; 32(7):704-709.
46. Jastifer JR. Topical review locking plate technology in foot and ankle surgery. Foot Ankle Int. 2014; 35(5):512–18.

Nitinol staples.

Noting that he does not use the same fixation method for every patient, this author discusses the advantages of nitinol staples, including continuous compression and bone-to-bone contact.

By William Fishco, DPM, FACFAS

The first metatarsophalangeal joint (MPJ) fusion is a common procedure that surgeons perform for a variety of foot pathologies. The most common indication for the surgery in my practice is for end-stage arthrosis. Less common indications include severe hallux valgus, rigid hallux varus, iatrogenic deformities and rheumatoid foot reconstruction.

I have been asked to comment on what is the best fixation method for the first MPJ fusion. I must preface my answer by saying “nothing works for everybody all of the time.” That is my standard line that I use daily in my practice when I am discussing with patients treatments for warts, heel pain or even surgical procedures. My preferred fixation technique for straightforward fusions of the great toe joint is nitinol compression staples. Certainly, there are better fixation choices for patients with osteoporosis, patients needing interpositional bone grafts, obese patients and/or patients with the inability to remain non-weightbearing for a period of time.

There are a number of reasons that nitinol compression staples are my preferred method of fixation. The insertion of the staples is technically simple and takes very little time and instrumentation. A drill bit is really all you need. Saving 15 minutes in the operating room is a win-win situation for the surgeon, the patient and the facility. There is nothing more aggravating than having to move the C-arm in and out 10 times when using other fixation methods.

Moreover, a scrub tech who does not have a lot of orthopedic experience will struggle with a large tray of drill bits, screws, plates, etc. If there is not a rep in the room, I will have to stop what I am doing and sort everything out for the scrub tech.

Another attractive benefit with staples is the extra-articular fixation so there is no metal in the fusion site. If you run two crossing 4.0 mm screws across the joint, then there is a loss of 8 mm of bone to bone contact. We are dealing with a very small amount of bone surface area. Moreover, the staple legs purchase the far cortex so you have bicortical compression.

Finally, the most compelling reason that I use nitinol staples is that you get continuous compression forever. We know that the first phase of bone healing will be hyperemia with subsequent resorption of bone. With screw fixation, the screw is only as tight as the last twist of the screwdriver. Then as time goes on, there will be loss of compression. Now we can probably argue all day about how much compression we really need but I think we can all agree that stability is the most important aspect of fixation, and compression helps.

One of the problems with screw fixation is that when it fails, it fails miserably. As there is a loss of compression, now the screw threads will maintain the gap between the bone margins. I never have to worry about this phenomenon with compression staples.

A Closer Look At The Author’s Fixation Technique

My preferred technique for preparation of the joint for fusion is to keep a flat joint flat and a round joint round. Accordingly, when it comes to a jumbo bunion deformity or rigid hallux varus deformity, I will generally use hand instrumentation augmented with a rotary burr to maintain the ball and socket configuration. That way, I don’t over-shorten the first ray. For flat joints, like one would encounter with hallux rigidus and arthritic conditions, I will tabletop the fusion, using the saw to resect both ends of the the joint and leaving two flat surfaces for apposition (which is more stable). I will typically keep it simple by passing the saw blade a few times and use a curette and rongeur to finish the preparation. The surgeon can use a small drill bit to fenestrate the subchondral bone if necessary.

For the insertion of fixation, I tend to use a single K-wire down the middle of the toe (just like in hammertoe surgery). This is my positioning of the K-wire before performing further fixation. Loading the foot is important to simulate weightbearing. No one can ensure that the toe position is clinically perfect in all three planes. I will also use fluoroscopy to confirm the position and apposition of the bone margins. Next, I will typically use an 18 mm nitinol staple dorsally right in the middle and then a second staple, staggering the staple legs so they don’t bump into each other (or you can use a 15 mm or 20 mm staple). This will be a delta configuration, which is the most stable construct for staples. You can leave the K-wire in for four to six weeks if you want or need an additional point of fixation. If you would rather have only internal fixation, then you can remove the K-wire.

I am still conservative with weightbearing after a first MPJ fusion, even though published studies have stated that it is perfectly acceptable to allow protected weightbearing.¹ I generally will have patients non-weightbearing for three to four weeks with subsequent transition into walking in a fracture boot. I can’t say I have had any more non-unions with this technique than with any other technique.

Over the years, I have had good success with crossing K-wires, crossing screws, non-compression plates, compression plates, anatomic plates and various combinations. We know they all work. I think there is a lot to be said for minimal metal, maximum stability and compression. That is where I believe compression staples really shine.

What makes a great surgeon is knowing when to operate, on whom to operate and how to make adjustments in technique, fixation and postoperative management. Do I use compression staples on all first metatarsophalangeal joint fusions? No. If I have a patient with osteoporosis, I would rather use three K-wires (internally crossing the joint and one percutaneous axial wire). A patient with a bone graft will need a plate with a screw through the graft for added stability.  

What The Literature Reveals On Nitinol Staples

In a retrospective study by Shah and colleagues in 2012, the authors compared nitinol staples to a single lag screw and a lag screw with cerclage wire for clinical and radiographical outcomes of the first metatarsophalangeal joint fusion.² Forty-six patients had the surgery and the same surgeon performed all operations. The mean time to radiographical union was the fastest with compression staples at 7.6 weeks followed by 8.0 weeks for lag screw and 8.1 weeks for lag screw and cerclage wire. The nitinol staples had the lowest incidence of non-union (one out of 15) versus four out of 15 in the single lag screw fixation group and three out of 16 in the lag screw and cerclage fixation group.  

A prospective study by Choudhary and colleagues evaluated first MPJ fusions with delta configuration of nitinol staples.³ Twenty-seven patients had surgery. Postoperatively, patients immediately bore weight in a rigid surgical shoe. The average time to fusion was 8.2 weeks with one non-union. There were no other significant postoperative complications.

In Conclusion

I prefer nitinol compression staples for fixation of straightforward first metatarsophalangeal joint fusions for four reasons: less operating room time, simplicity of instrumentation, the ability to have continuous dynamic compression and the allowance for maximum bone to bone contact by not having any fixation through the fusion site (extra-articular fixation).

Dr. Fishco is board-certified in foot surgery and reconstructive rearfoot and ankle surgery by the American Board of Podiatric Surgery. He is a Fellow of the American College of Foot and Ankle Surgeons, and a faculty member of the Podiatry Institute. Dr. Fishco is in private practice in Phoenix.

References

1. Campbell B, Schimoler P, Belagaje S, et al. Weight-bearing recommendations after first metatarsophalangeal joint arthrodesis fixation: a biomechanical comparison. J Orthop Surg Res. 2017; 12(1):23.
2. Shah K, Augustine A, Carter R, McFadyen A. Arthrodesis of the first metatarsophalangeal joint: comparison of three techniques. J Am Podiatr Med Assoc. 2012;102(1):13-7.
3. Choudhary RK, Theruvil B, Taylor GR. First metatarsophalangeal joint arthrodesis: a new technique of internal fixation by using memory compression staples. J Foot Ankle Surg. 2004;43(5):312-7.