Emerging Techniques to Improve Outcomes with Charcot Reconstruction

Enabling patients with Charcot arthropathy to walk with a plantigrade foot can increase their quality of life and decrease morbidity. Sharing insights from the literature as well as surgical experience, these authors discuss key considerations with various fixation methods including plating, beaming, external fixation and superconstructs.

The treatment of Charcot arthropathy has evolved significantly since the first description of this debilitating condition in 1868.¹ While researchers originally concluded Charcot arthropathy was due to tertiary syphilis, today we consider diabetes to be the most common cause of Charcot.²

Charcot neuropathy occurs in 7.5 percent of patients with diabetes with the highest prevalence in the fifth and sixth decades of life.³ There is an obvious decrease in quality of life that occurs with significant Charcot deformity as well as an increase in morbidity. There is a reported 28 percent incidence of amputation for patients who present with Charcot arthropathy and secondary ulceration.⁴ The most common locations for Charcot deformity are the midfoot (50 percent), hindfoot (28 percent), ankle (19 percent) and forefoot (3 percent).³

The recognition and diagnosis of Charcot arthropathy are of utmost importance for presenting patients. Eichenholtz first classified Charcot in 1966, describing development (I), coalescence (II) and reconstruction/restitution (III) stages.² Stage I is characterized by osteopenia, fragmentation, ligamentous laxity, swelling, erythema and joint subluxation/dislocation. Protected weightbearing, serial radiographs and close follow-up are the mainstay treatments for stage 0 and stage I Charcot. Decreased warmth and erythema with radiographic absorption and bone fragment fusion arise in stage II Charcot. Once warmth, swelling and erythema are absent along with consolidation of the osseous and/or joint deformity, the patient is in stage III. While one may treat stage II and III with offloading and bracing, podiatrists can consider surgical reconstruction at these stages.^2–16 Surgical treatment may help create a plantigrade foot, leaving limited osseous prominences prone to ulceration.

Shibata and coworkers later expanded this Charcot classification to a stage 0 or prodromal stage in 1990.⁴ The prodromal stage entails redness, swelling and pain that precede radiographic changes.

Accordingly, let us review the traditional and emerging surgical techniques for the treatment of Charcot arthropathy.

Comparing The Plating Options For The Charcot Foot

The application of plates for fixation following midfoot Charcot arthropathy deformity correction is not a new concept but rather one that has evolved from standard AO techniques into a technique known as bridge plating. Bridge plating is a concept in which the surgeon extends fixation both proximally and distally to the deformity site using less affected osseous segments to achieve better screw fixation. A corrective arthrodesis extends to include adjacent joints beyond the zone of injury to improve fixation and deformity correction while attempting to prevent further collapse.

The use of locking plate constructs has shown biomechanical superiority in load to failure rates in comparison with traditional plating methods.⁸ These devices create a fixed-angle device by rigidly attaching the screw to the plate. Plating devices have the advantage of significantly improving fixation in osteoporotic bone. The fixed-angle device overcomes some of the difficulties of applying the plate plantarly. In theory, the locked plate has equivalent fixation to the plantar construct without necessitating the extensile plantar exposure needed for the latter.¹⁷ That being said, the location of plating is still a heavily debated topic with Charcot reconstruction.

Medial and dorsomedial plating constructs have been popular choices for Charcot midfoot deformity reconstructions due to anatomic considerations and technical ease of placement. Medial plating techniques in the presence of a severe abduction deformity would be of greatest benefit as those techniques can provide stability to multiple transverse joints of the midfoot.¹⁸ Plate fixation in this manner is on the tension side of the deformity. Plate fixation along the medial column also allows screw placement to cross multiple cortices of the tarsal and metatarsal bones, which improves the screw purchase and overall construct stability.¹⁸ Construct strength with medial plating of the medial column is always a concern when deciding whether to plate medially or plantarly.

In a 2017 study by Simons and colleagues, the authors examined the biomechanical strength of a midfoot fusion using a dorsomedial locking plate and plantar locking plate in eight matched pairs of cadaveric feet.¹⁹ The study revealed no significant difference between the two plating systems with regard to stiffness and cycles to failure.

Schon and colleagues popularized the concept of plantar plating in 1998 as a way to improve the strength of the midfoot construct, and showed successful stabilization using this technique in 34 of 37 patients who had severe midfoot Charcot arthropathy, and had failed conservative and other surgical measures.²⁰ Authors have described plantar plating for the correction of midfoot Charcot deformities as a technique that provides superior strength by placing the plate along the tension side of the deforming forces exerted at the arthrodesis site.^7,17,18,20 Employing plantar plating, Garchar and colleagues demonstrated reliable and reproducible arthrodesis results with a 96 percent union rate among patients who had reconstruction of their Lisfranc joint due to Charcot arthropathy.²¹

We would encourage plantar plating in the presence of a rocker-bottom Charcot midfoot deformity in almost all cases because it does an exceptional job addressing sagittal plane deformities at the naviculocuneiform metatarsal joints. It is important to note, though, that extending the arthrodesis to include the talonavicular joint and the remaining tarsal joints with this technique can be quite challenging. In cases in which the surgeon must cross the talonavicular joint, it can be difficult to apply any plate plantarly due to the sustentaculum tali of the calcaneus. Thus, in this situation, one could use a medial or dorsomedial plate to help achieve excellent fixation in the talar neck.

In a 2017 study, Simons and colleagues examined the biomechanical strength of a midfoot fusion using a dorsomedial locking plate or plantar locking plate in eight matched pairs of cadaveric feet.¹⁹ The study revealed no significant difference between the two plating systems with regard to stiffness and cycles to failure. It should be noted that this study did have a number of limitations, which include a small sample size, and inability to reproduce bony unions at the intended arthrodesis sites, and as the authors stated, “The current test setup was a gross simplification of in-vivo conditions.” This was the first study of its kind to compare the biomechanics of the two plating techniques and further clinical studies would be necessary before reaching a definitive recommendation for dorsomedial or plantar plating techniques.

Despite these findings, the plantar plating approach for stabilization and fixation is still favored in almost all situations when it is possible to use.¹⁹ Favoring the plantar approach is based on our personal experience, biomechanical advantages and from witnessing long-term unsuccessful results in patients when using medial/dorsomedial plating techniques to correct deformities.

What You Should Know About Beaming In The Charcot Foot

In the last two decades, beaming for Charcot arthropathy has become a very common surgical procedure of choice. The first data published was from Rooney and colleagues, who reported on the use of axial screw fixation for Charcot arthropathy in 2002.²² This study has just three cases of midfoot Charcot arthrodesis and overall showed that only six of 43 patients had a loss of correction although it remains unclear how the patients in the three midfoot cases performed postoperatively. Grant and coworkers shared the results of adjunctive beaming with external fixation in a 2009 study showing promise with excellent results in diabetic Charcot limb salvage and patient functional scores.⁶

Commonly presented as an alternative to traditional plating, beaming currently provides another approach for patients with severely deformed foot structure and a poor soft tissue envelope. As with any midfoot Charcot reconstruction, plantigrade realignment with proper stabilization of the arch and the ability to ambulate are ideal outcomes.^6,7

When considering a Charcot reconstruction procedure, one must take into account the apex of the deformity and the concurrent procedures that will be involved. Although beaming is intended to be an alternative for difficult soft tissue coverage, the surgeon typically creates an incision over the plate position for reduction or osteotomy placement.^7,9 Therefore, patients who require minimal to no midtarsal reduction make for excellent candidates.

Another potential complication that may arise involves the need for removal of the beams. In the senior author’s experience, beams have a tendency to antegrade or retrograde. Authors have reported specific cases of retrograding beams through the first metatarsal causing recurrent ulcerations.⁶ Removal of the beam results in a large osseous void, which increases the difficulty in obtaining a stable construct and also increases the likelihood of amputation. In 2017, Ford and colleagues reported on 24 patients who had midfoot Charcot reconstruction with intramedullary beaming, and found that 60 percent required reoperation and 16 percent resulted in amputation.²³

One must also consider the strength of beaming in comparison to traditional plating. A recent study by Simonik and colleagues evaluated non-locking plantar plate fixation versus intramedullary beaming in cadaveric bone.²⁴ The authors discovered that beaming was able to withstand a greater load before failure, which the authors attributed to the more robust design of beaming. A few years earlier, Pope and coworkers found no difference in the load to failure and, in fact, a plantar plate had a tendency to be a more rigid construct.¹⁴ After early reports of hardware failure in beaming reconstruction, Wiewiorski and colleagues examined the use of solid bolt screws rather than a cannulated system in patients.²⁵ This study followed eight patients with midfoot Charcot for 27 months and found only one hardware complication, which the researchers further attributed to loosening rather than hardware failure.

Weighing The Pros And Cons Of External Fixation In Charcot

Surgeons have historically had remarkable success with external fixation in deformity correction and bone healing of limbs that would have otherwise been left with a debilitating deformity or been amputated. Given this success, there is no doubt how external fixation found its way into the treatment of Charcot neuroarthropathy.

In 1996, Sticha and colleagues first described the use of external fixation for the Charcot foot, reporting on the use of Kirschner wires and three Pennig Minifixator (Orthofix) unilateral external fixators for midfoot arthrodesis in patients with chronic Charcot deformity.²⁶ It was in the early 2000s that physicians began investigating the use of static, hybrid and Ilizarov external fixation devices for the dislocation and deformities associated with Charcot. Many of these researchers summarized that this minimally invasive technique had the added surgical benefits of preserving the length of the foot, limiting neuromuscular compromise and allowing for partial weightbearing.¹⁰

In general, documented indications for use of external fixation include non-unions, malunions, large soft tissue or osseous defects, wound healing complications, osteomyelitis, internal fixation failure, and unstable and/or non-braceable Charcot deformities.¹⁵ More recently, researchers have reported that external fixation alone can be a viable treatment option for patients in the acute phase of Charcot neuroarthropathy. In Eichenholtz stage 1 Charcot midfoot deformities, Panagakos and colleagues recommend the use of external fixation until confirming the coalescence of bony structures clinically and radiographically. During the acute phase, osseous structures become hyperemic and soft, making it difficult to achieve adequate fixation with internal fixation.¹³  

Surgeons can also perform arthrodesis with external fixation. External fixation allows for micromotion to occur through the desired fusion site. Some researchers have reported this micromotion can be beneficial in fixating patients with Charcot but few of these cases are documented in the literature.^13,27 In our experience, the use of external fixation alone risks excess micromotion. The excess micromotion at the fusion site ultimately leads to an increased incidence of nonunion, malunion and ultimately failure.
External fixation comes with additional patient risks such as pin site infection, half-pin loosening, wire breakage and lack of patient acceptance with the external frame. The most common complication associated with external fixation is pin tract infection, which is reportedly as high as 60 percent.^28,29 Therefore, appropriate care of external fixation pin sites and close repetitive follow-up are crucial in post-op management.¹⁶ Many researchers have also reported depression and destructive behaviors such as “cage rage” to be associated with external fixation use.¹⁶

In the primary author’s opinion, given the high complication rates and long-term risks of failure, procedural selection for Charcot neuroarthropathy deformities is critical. We only recommend the use of external fixation alone in the very select patient population in the early acute phase or if/when the patient is not a candidate for internal fixation. When considering treatment options of chronic deformity, the surgeon should consider the additional supplementation of internal fixation with external fixation to enhance osseous stability, creating a superconstruct.

Key Pearls On The Effective Use Of Superconstructs

The acceptance and indoctrination of the superconstruct principles have led to the abandonment of conventional non-locking plate fixation and isolated external fixation for Charcot midfoot deformities.30 In 2009, Sammarco introduced the concept of the “superconstruct” and provided four basic principles to reconstruction.¹⁷

1) Fusion must extend beyond the point of destruction to obtain adequate fixation.
2) Bony resection may be required to shorten and reduce deformity.
3) Use the strongest fixation technique or techniques.
4) Apply the fixation device in such a manner to maximize its function.^16,30  

With improvement in hardware and techniques, this concept has become an appealing approach to the Charcot foot. While outcomes-based research is lacking in the area of superconstructs, the principles are promising. In the senior author’s experience, when one applies plantar plating with the superconstruct principles, it provides the most enduring fixation in the case of midfoot Charcot arthropathy. With that said, additional external fixation and/or beaming does have its applications in certain patient populations.

Pertinent Case Studies In Charcot Reconstruction

Case study 1. A 65-year-old woman presented for a second opinion for painful left midfoot Charcot. She had a past medical history of type 2 diabetes, acid reflux, asthma, fibromyalgia, hypertension, neuropathy, stroke and hypothyroidism.

The patient had a gastrocnemius recession followed by open reduction and internal fixation with a six-hole plantar plate and a combination of 3.5 mm and 4.5 mm screws. We corrected the rocker bottom deformity and at 15 months post-op, the patient was ambulating in an Arizona brace with a stable plantigrade foot.                                                                                                                        

Case study 2. A 60-year-old woman presented with a painful left midfoot ulceration secondary to Charcot arthropathy. She had a past medical history of type 1 diabetes, acid reflux, asthma, bronchitis, gout, heart disease, hypertension, kidney disease, neuropathy and hypothyroidism.

To reduce the patient’s deformity, we performed a gastrocnemius recession and reduced the naviculocuneiform joint. By recreating Meary’s angle, we were able to reduce the rocker bottom deformity and achieve a plantigrade foot. We subsequently fixated the foot with a plantarly located plate, 3.5 mm screws, a single 6.5-mm cannulated axial screw and a static circular external fixator. We removed the external fixator 10 weeks later and the patient had a stable plantigrade foot. At her 10-month follow-up, she was ambulating in an Arizona brace.   

In Conclusion

All the aforementioned fixation techniques have published success and failures as failure is an inherent risk to the diabetic/neuropathic population. Through both research and personal experience, we have made the following conclusions:

1) The most severe deformities require a superconstruct fixation.
2) Plantar plating is the most stable and effective long-term internal fixation for this patient population.
3) The threshold for surgical reconstruction of these patients should be lower.

The quality of life for patients with non-plantigrade Charcot arthropathy is low and the morbidity is high. In failure, the quality of life is not decreased but by attempting reconstruction, the patient has a chance for improved quality of life by being able to walk with a plantigrade, non-ulcerating foot.

Dr. Grady is the Director of Podiatric Residencies at Advocate Christ Medical Center and Advocate Children’s Hospital in Illinois. He is an Adjunct Professor of Biomechanics and Surgery at the Dr. William M. Scholl College of Podiatric Medicine at Rosalind Franklin University. Dr. Grady is the Director of the Foot and Ankle Institute of Illinois, and the Director of the Foot and Ankle Institute for Research (FAIR).

Dr. Burdi is a first-year podiatric surgical resident at Advocate Christ Medical Center and Advocate Children’s Hospital in Illinois.

Dr. Kunz is a first-year podiatric surgery resident at Advocate Christ Medical Center in Illinois.

Dr. Schumann is a first-year podiatric surgical resident at Advocate Christ Medical Center and Advocate Children’s Hospital in Illinois.

Dr. Smolinski is a first-year podiatric surgery resident at Advocate Christ Medical Center in Illinois.

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