Questions And Answers On The Suture And Button Technique For Plantar Plate Stabilization

I recently presented the suture and button technique as a preliminary report of my personal experience with second metatarsophalangeal joint (MPJ) instability and predislocation syndrome (see https://bit.ly/e6mD4d ). This method has been developed for those patients who have failed conservative efforts to stabilize the digit and accommodate the forefoot. This procedure is unique and is not published in the literature to date.

I want to make it infinitely clear that I am not suggesting others pursue this technique at this point. I do not have follow-up beyond eight months post-op. To date, I have performed this technique on three patients and seven digits. The thought and development of this technique comes from mentoring that I have received over the years and the thought process that is fundamental to this technique is not my own.1

I recently presented this technique at the 11th Annual Scientific Seminar of the North West Ohio Academy of Podiatric Medicine in Sandusky, Ohio. I fielded a number of questions regarding the technique and I present those to you as another point of reference for understanding this concept.

Q: Why do you choose this technique over arthrodesis of the digit? Doesn't that force the hammertoe into the proper alignment and eliminate the forefoot pain?

A: The patients on whom I perform this procedure do not have a hammertoe per se. What I am treating is predislocation syndrome, which is associated with plantar plate dysfunction in association with weakness of the long flexor tendon, second dorsal interossei and the first lumbricale of the affected digit. This combination of structural and functional abnormalities results in destabilization at the level of the plantar plate, elevation at the MPJ and transverse plane luxation (often medially), most commonly seen in the second digit.

Hammertoe, in contrast, is associated with overpowering by the flexor digitorum longus, which prompts retrograde buckling at the MPJ level and often high angulation flexion at the proximal interphalangeal joint (PIPJ) level. The apex of deformity for the hammertoe is at the PIPJ and in longstanding cases affects the MPJ secondarily. Predislocation is associated with an apex of deformity at the MPJ and, secondarily, subtle and flexible contracture occurs within the distal digit.

Q: Doesn't pinning the MPJ freeze the MPJ in place and stabilize the toe?

A: Pinning across the MPJ is a procedure that I had previously used to stabilize the toe after a sequential reduction and internal fixation. I have learned over time that running a pin, often 1.25 mm in diameter, through the metatarsal head produces articular damage that may or may not cause degenerative change within the MPJ.

When this does occur, collapse of the metatarsal head and the risk of symptomatic osteoarthritis or even avascular necrosis is possible. That aside, after three to four weeks when the K-wires are typically removed, patients may have a difficult time returning to more normal weightbearing function due to stiffness at this level. The resulting imbalance and overloading at this joint level often cause a transfer of weight to the lesser metatarsals, and may prompt fatigue fracture or painful intramedullary edema in those regions.

Sherman and colleagues published an article on the Keller procedure in which they demonstrated the ill effect of pinning across the hallux interphalangeal joint, showing degenerative and long-lasting change in this region.2 Two of their most significant findings in these cases were the stiffness and degenerative changes documented at this level one year after surgery. They related concern about the long-term impact this would have.

On that note, it would seem that pinning across the MPJ is an invasive technique that causes at minimum (depending on the technique) a singular osteochondral defect that may not be necessary to achieve digital stabilization.

The more important consideration is determining what condition one is treating. This will determine what it will take to reduce deformity and restore balance across the MPJ. Where is the apex of deformity? What structures are involved? Where is the target of tenderness?

In summary, if the answers to these questions fit with instability at the MPJ level, then decompressing the joint and stabilizing the plantar plate will be required. This, in my opinion, does not require pinning across the MPJ.

Q: How exactly are you stabilizing the plate with the suture and button technique?

A: I do not suggest that others perform this procedure. I present this preliminary information as a basis for discussion and debate. To date, I have performed this procedure in only a few patients in whom I have stabilized seven digits. The associated structural and functional considerations in each of these cases are unique and I will discuss them in detail at a later date.

The technique has been refined and now includes simply using straight Keith needles and 3-0 Vicryl suture. Run the suture over the anatomic neck of the metatarsal and the proximal metaphyseal-diaphyseal junction of the proximal phalanx. Run the suture along the medial and lateral aspects of the metatarsal head and phalangeal base, and then run the suture out the plantar fat pad. Then these free suture ends are secured through a sterile button and secure the button with a strand of multiple hand ties. Finally, it is important to interpose drain sponges between the button and the skin.

The buttons remain intact until they either fall off or are removed in four to six weeks. The patient is allowed to heel weight bear in an OrthoWedge shoe immediately after surgery. Return to full weightbearing is determined by consolidation of the associated second metatarsal osteotomy.

In Summary

To date, in my own experience, I have achieved the goals of re-establishing position and alignment of the second MPJ. Elimination of forefoot pain and subjective satisfaction has been excellent in this very short-term follow-up.

Patients have been appreciative of the fact that this procedure does not require external pins and the risk of infection associated with those devices is obviously eliminated. The surgeon’s satisfaction with the procedure comes as much from the patient's return to function and overall well-being as it does the radiographic findings.

Thank you to all of the readers who have been pondering this discussion and given it careful consideration. I invite your questions or concerns, and am happy to entertain further discussion and debate.

References

1. Personal communications with Luke Cicchinelli, DPM, and the late Gerard V. Yu, DPM, the originator of the term predislocation syndrome

2. Sherman KP, Douglas DL, Benson MK. Keller’s arthroplasty: is distraction useful? A prospective trial. J Bone Joint Surg Br. 1984; 66(5):765-9.