How To Manage The Charcot Midfoot Deformity

Given the challenges of Charcot neuroarthropathy and the lack of guidelines for surgical treatment, this author offers a closer look at Charcot midfoot deformities as well as insights on addressing concomitant soft tissue infection and joint instability.

Charcot neuroarthropathy most commonly affects the foot and ankle, and is unfortunately becoming more prevalent over the last decade as the incidence of diabetes and its related complications continue to rise.1 The scientific literature is limited in regard to treatment protocols and guidelines for the overall surgical management of Charcot foot and ankle deformities.1-3 Some of the reasons for the lack of specific treatment recommendations may be largely due to the presence of the unique clinical scenario that is usually associated with each Charcot of the foot and ankle.

   Accordingly, let us consider pertinent keys to the thorough evaluation of a Charcot midfoot deformity among various presentations and the surgical rationale for addressing the vast majority of Charcot midfoot deformities.

   The initial examination of the Charcot midfoot deformity begins with evaluation of the multiple associated factors that usually determine the patient’s overall treatment. The inherent factors that are often associated with a Charcot midfoot deformity include but are not limited to the following: acute Charcot process; presence of an ulceration; pre-ulcerative lesion with a Charcot bursa formation; concomitant osteomyelitis; Charcot joint instability; and coexistent rearfoot and/or ankle deformity.

   In regard to the overall management of the Charcot midfoot deformity, one must address any of the aforementioned factors in conjunction with a thorough evaluation of the patients’ comorbidities. Since operative intervention may involve multiple complicating issues, a stepwise rational approach with appropriate procedure and patient selection that is based on these inherent factors is essential for the patient’s successful outcome.

   As with any Charcot reconstructive case, a thorough history and physical examination, vascular assessment, review of precipitating events, pertinent radiographs, laboratory testing and medical imaging studies serve as the foundation in surgical preparation or for establishing the criteria of which patients would not be suitable for reconstruction. Careful preoperative evaluation and patient selection are fundamental to reduce the risks associated with reconstructive surgery. Neglecting issues such as patient adherence, overall medical health status, cardiac disease, renal dialysis, uncontrolled blood sugars, smoking, ambulatory ability and lack of social or family support will only lead to further complications regardless of the surgical plan.4 Awareness of patient-related variables that may increase the risks of complications would allow for better preoperative planning and overall management of the patient.

   Surgical consideration for the management of a Charcot midfoot deformity mostly depends on the underlying pathology. The following recommendations emphasize the fact that not every Charcot midfoot deformity or patient presentation is the same, and physicians need to consider many factors prior to surgical intervention for the patient.

Key Considerations With The Acute Charcot Midfoot Deformity

The acute Charcot process associated with erythema, edema and warmth was once considered a contraindication for surgery. Today, this issue of operative intervention for an acute Charcot process is debatable as some surgeons have reported acceptable outcomes with an early intervention.5,6 Charcot midfoot deformities, as opposed to rearfoot and ankle deformities, are often sufficiently managed with non-operative intervention.7 In comparison to ankle and rearfoot deformities, the need for delayed reconstructive surgery in cases of midfoot Charcot deformities is less likely if the physician emphasizes sufficient bracing and appropriate therapeutic shoes to accommodate for any residual deformity.8

   The exception to this would be an acute Charcot joint with gross dislocation(s), which may cause soft tissue compromise. These patients may benefit from stabilization and gradual correction with external fixation until the acute inflammatory stage resolves and to facilitate later reconstruction.6 In those cases, early intervention would also prevent devastating deformities as the patient progresses into the coalescence and reparative stages of the Charcot process.5,7 It is also evident that the presence of an acute infection and an open wound may necessitate surgical intervention at any time during the acute Charcot process.

   If one opts for surgery in the early stages of a Charcot midfoot deformity, the surgeon needs to consider that there is a longer convalescence period following the initial surgery with subsequent staged procedures likely. This approach could potentially increase complication rates.

   It is highly advised that the surgeon delays surgical intervention until the associated erythema and edema subside, skin lines are present and the skin temperature is within normal limits in comparison to the contralateral extremity in order to preserve the integrity of the soft tissues.

   Physicians initially manage most acute Charcot midfoot deformities by emphasizing cast immobilization, total contact casting, bone stimulation and/or strict non-weightbearing status until the acute inflammatory response subsides.9 Then one may progress the patient to a walking cast or a boot, and subsequently transition him or her into therapeutic shoe gear and bracing.10 Physicians should evaluate the foot clinically and compare it to serial radiographs at each transition to ensure no other factors are evident that would preclude continued conservative management of the Charcot midfoot deformity.

When There Is Soft Tissue Infection With A Charcot Midfoot Deformity

The presence of soft tissue compromise with a Charcot midfoot deformity poses great challenges to the treating surgeon. In these cases, an orthoplastic approach is typically required with procedures or modalities that lead to durable wound and osseous healing.
When it comes to the presence of a Charcot midfoot bursa formation, unstable scar and pre-ulcerative lesions, physicians need to emphasize alternative forms of bracing and offloading devices, and close clinical evaluation in order to prevent frank ulceration and infection from occurring. Additionally, when these chronic pre-ulcerative lesions persist despite the use of therapeutic devices, the surgeon needs to evaluate the Charcot midfoot deformity to determine if an ostectomy or corrective arthrodesis procedures would be of clinical benefit to the patient.

   The presence of ulceration with a Charcot midfoot deformity usually signifies the need for surgical intervention even if infection is not present. Studies have demonstrated that the presence of ulceration with Charcot arthropathy leads to a higher risk for lower extremity amputation.11,12 When it comes to Charcot midfoot deformities with associated ulcerations that are not amenable to bracing and local wound care, surgical reconstruction is highly recommended to address the underlying pathology.

   In contrast, the presence of an infected ulceration almost always requires surgical intervention to achieve limb salvage under the guidance of a multidisciplinary team approach specializing in these conditions.13,14 These patients are typically hospitalized and staged procedures are coordinated with the other surgical and medical services.15

   The initial procedure involves ulcer excision and deep intraoperative soft tissue and bone cultures/biopsies if one suspects osteomyelitis and in order to establish an appropriate antibiotic regimen if required.16

   In conjunction with intraoperative assessment of tissue perfusion, one should review noninvasive vascular studies. The surgeon may need to pursue further angiography and/or vascular surgical intervention before the final reconstructive procedure.17 In addition, performing an initial full-thickness ulcer excision allows the surgeon the ability to create an acute wound free of bacterial colonization, which will subsequently facilitate healing of delayed plastic surgery procedures for definitive wound closure. After one has converted the wound to an acute wound with adequate tissue perfusion and no clinical signs of infection, the surgeon subsequently performs staged procedures — according to microbiology and histopathology results — to correct the underlying deformity while simultaneously achieving wound closure if feasible.

   There are multiple plastic surgery procedures to close diabetic foot wounds. The elaboration of each is beyond the scope of this article. However, surgeons commonly utilize local random flaps, muscle flaps or the medial plantar artery flap to obtain definitive soft tissue coverage with the Charcot midfoot deformity.18 A direct plantar approach to osseous reconstruction and joint arthrodesis combined with wound closure is usually recommended for the Charcot midfoot deformity with plantar ulceration.19 This allows direct access to the underlying osseous deformity while preventing inadvertent arterial compromise to the plantar soft tissues and avoids additional incisions.

   When it comes to Charcot midfoot deformities with the presence of an ulceration, it is typically best to manage and stabilize these deformities with external fixation as opposed to internal fixation. The reasons for this include:
• avoidance of retained hardware when infection or soft tissue compromise is present;
• allowance of osseous stabilization, deformity correction and compression across joints that are prepared for arthrodesis;
• provides adequate offloading and stabilization of the soft tissues by preventing unwarranted motion; and
• avoidance of the need for cumbersome splints and casts that would require frequent changes and clinical evaluation of the soft tissue envelope.20,21

What You Should Know About Charcot Midfoot Joint Instability

Determining instability in a Charcot midfoot deformity can be more difficult during physical examination as opposed to rearfoot and ankle deformities that display obvious unstable deformities. In rare cases, one may appreciate frank instability on clinical examination but this is not the common clinical scenario. More often, the patients display a rocker bottom deformity, medial or lateral column collapse, forefoot abduction or adduction that appears clinically rigid and stable. However, subtle joint instability is often apparent, especially when soft tissue compromise is present.

   It is recommended to utilize a combination of serial non-weightbearing radiographs and compare them with weightbearing images to determine the presence of joint subluxation and collapse. In addition, computed tomography is beneficial for determining the presence of osseous consolidation and bone bridging across the Charcot midfoot deformity.22

   Determining the presence of joint instability becomes important when considering surgical intervention, especially if you are considering a simple ostectomy. Often, surgeons perform ostectomy procedures in elderly patients and patients with multiple comorbidities and prominent bony exostoses that are not considered stable for an extensive surgical reconstruction. The problem arises when one performs an ostectomy on an unstable Charcot midfoot deformity or if an ostectomy will compromise joint stability by removing the osseous bridging that developed around the affected fractures and joint subluxations.

   Surgeons should reserve the ostectomy for truly stable Charcot midfoot deformities that do not display further joint subluxation on weightbearing radiographs and those that would not be compromised by an ostectomy.23 When it comes to Charcot midfoot deformities with joint instability, it is best to pursue extended joint arthrodesis procedures in order to prevent later collapse and future complications.20,24

Final Thoughts

The goal for surgical management of a Charcot midfoot deformity is to achieve a stable, functional and plantigrade foot that is not prone to wound breakdown. The utilization of various therapeutic braces and/or custom shoes may be required in conjunction with surgical reconstruction. This is imperative to the patient’s overall successful outcome. Additionally, the treating physician needs to address and coordinate the treatment of all the associated factors that are common with Charcot midfoot deformities. For this reason, a combined medical and surgical team approach is necessary to provide these types of complex procedures in a major healthcare facility.

   Dr. Zgonis is an Associate Professor, Fellowship Director and Chief within the Division of Podiatric Medicine and Surgery in the Department of Orthopaedics at the University of Texas Health Science Center in San Antonio. He is a Fellow of the American College of Foot and Ankle Surgeons and is board certified in foot and rearfoot/ankle surgery by the American Board of Podiatric Surgery.

   Dr. Zgonis is the editor of Surgical Reconstruction of the Diabetic Foot and Ankle (Lippincott, Williams and Wilkins). Dr Zgonis is the Co-Chairman of the yearly International External Fixation Symposium (IEFS) in San Antonio. He can be reached at zgonis@uthscsa.edu.

References:

1. Frykberg RG, Belczyk R. Epidemiology of the Charcot foot. Clin Podiatr Med Surg 2008;25(1):17-28. 2. Frykberg RG, Zgonis T, Armstrong DG, et al. Diabetic foot disorders: a clinical practice guideline. J Foot Ankle Surg 2006;45(Suppl 5):S1-66. 3. Zgonis T, Roukis TS, Lamm BM. Charcot Foot and Ankle Reconstruction: current thinking and surgical approaches. Clin Podiatr Med Surg 2007;24(3):505-517. 4. Roukis TS, Stapleton JJ, Zgonis T. Addressing psychosocial aspects of care for patients with diabetes undergoing limb salvage surgery. Clin Podiatr Med Surg 2007;24(3):601-610. 5. Roukis TS, Zgonis T. The management of acute Charcot fracture-dislocations with the Taylor's spatial external fixation system. Clin Podiatr Med Surg 2006;23(2):467-483. 6. Delhey P, Bürklein D, Kessler S, Volkering C. Closed reposition of an acute midfoot luxation fracture in Charcot arthropathy with the ring fixator. Unfallchirurg 2010; Apr 15. [Epub ahead of print]. 7. Zgonis T, Roukis TS. A systematic approach to diabetic foot infections. Adv Ther 2005;22(3): 244-262. 8. Verity S, Sochocki M, Embil JM, Trepman E. Treatment of Charcot foot and ankle with a prefabricated removable walker brace and custom insole. Foot Ankle Surg 2008;14(1):26-31. 9. Petrova NL, Edmonds ME. Charcot neuro-osteoarthropathy-current standards. Diabetes Metab Res Rev 2008;24 (Suppl 1):S58-61. 10. De Souza LJ. Charcot arthropathy and immobilization in a weight-bearing total contact cast. J Bone Joint Surg Am 2008;90(4):754-759. 11. Sohn MW, Stuck RM, Pinzur M, Lee TA, Budiman-Mak E. Lower-extremity amputation risk after charcot arthropathy and diabetic foot ulcer. Diabetes Care 2010;33(1):98-100. 12. Van Baal J, Hubbard R, Game F, Jeffcoate W. Mortality associated with acute charcot foot and neuropathic foot ulceration. Diabetes Care 2010; 33(5):1086-9. 13. Zgonis T, Stapleton JJ, Girard-Powell VA, Hagino RT. Surgical management of diabetic foot infections and amputations. AORN J 2008;87(5):935-946. 14. Zgonis T, Stapleton JJ, Jeffries LC, Girard-Powell VA, Foster LJ. Surgical treatment of Charcot neuropathy. AORN J 2008;87(5): 971-986. 15. Zgonis T, Stapleton JJ, Roukis TS. Advanced plastic surgery techniques for soft tissue coverage of the diabetic foot. Clin Podiatr Med Surg 2007;24(3):547-568. 16. Byren I, Peters EJ, Hoey C, Berendt A, Lipsky BA. Pharmacotherapy of diabetic foot osteomyelitis. Expert Opin Pharmacother 2009;10(18):3033-3047. 17. Kalish J, Hamdan A. Management of diabetic foot problems. J Vasc Surg 2010;51(2):476-486. 18. Zgonis T, Roukis TS, Stapleton JJ, Cromack DT. Combined lateral column arthrodesis, medial plantar artery flap, and circular external fixation for Charcot midfoot collapse with chronic plantar ulceration. Adv Skin Wound Care 2008;21(11):521-525. 19. Zgonis T, Jolly GP, Blume P. External fixation use in arthrodesis of the foot and ankle. Clin Podiatr Med Surg 2004;21(1):1-15. 20. Stapleton JJ, Belczyk R, Zgonis T. Revisional Charcot foot and ankle surgery. Clin Podiatr Med Surg 2009;26(1):127-139. 21. Dalla Paola L, Brocco E, Ceccacci T, Ninkovic S, Sorgentone S, Marinescu MG, Volpe A. Limb salvage in Charcot foot and ankle osteomyelitis: combined use single stage/double stage of arthrodesis and external fixation. Foot Ankle Int 2009;30(11):1065-1070. 22. Laurinaviciene R, Kirketerp-Moeller K, Holstein PE. Exostectomy for chronic midfoot plantar ulcer in Charcot deformity. J Wound Care 2008 ;17(2):53-55, 57-58. 23. Giza E, Hyer CF, Sella EJ, Zgonis T. Charcot neuroarthropathy. Foot Ankle Spec 2008;1(4): 243-246. 24. Capobianco CM, Ramanujam CL, Zgonis T. Charcot foot reconstruction with combined internal and external fixation: case report. J Orthop Surg Res 2010;5:7.