Intramedullary foot fixation for midfoot Charcot neuroarthropathy

Midfoot Charcot collapse commonly occurs through the tarsometatarsal and/or midtarsal joints, which creates the characteristic "rocker bottom" deformity. Intramedullary metatarsal fixation spanning the tarsus into the talus and/or calcaneus is a recently developed method for addressing unstable midfoot Charcot deformity. The intramedullary foot fixation technique has various advantages when addressing midfoot Charcot deformity in the neuropathic patient. These advantages include anatomical realignment, minimally invasive fixation technique, formal multiple joint fusion, adjacent joint fixation beyond the level of Charcot collapse, rigid interosseus fixation, and preservation of foot length. The goals of the intramedullary foot fixation procedure are to create a stable, plantigrade, and ulcer-free foot, which allows the patient to ambulate with custom-molded orthotics and shoes.     

External fixation of Charcot arthropathy

Deformity, instability, and ulceration are present in a high percentage of patients who have Charcot arthropathy. Traditional treatment of these conditions has consisted of debridement, antibiotics, and immobilization with limited weight bearing. These measures are followed by long-term use of various foot and ankle bracing devices, such as the CROW walker, double metal upright, and the lined clam shell AFO with accommodative footwear either incorporated or attached. Sometimes these conservative measures fail and surgery is indicated for foot and ankle deformities with: (1) unbraceable deformity; (2) recurrent ulceration secondary to deformity, instability, or both; and (3) Charcot arthropathy with pain that is unresponsive to conservative measures. Certain acute traumatic situations with impending deformity also may benefit from early surgical stabilization. High deep infection rates (25%) have been reported in surgical reconstruction of feet that have a history of ulceration. The high rates of infection with internal fixation techniques and improved external fixation devices have led surgeons to consider external fixation as a viable alternative for: (1) singlestage correction of a limb with recent or current ulceration; (2) revision or salvage of previously reconstructed limbs; and (3) acute treatment of insufficiency type fractures (impending Charcot arthropathy) in the diabetic who has severe peripheral neuropathy with or without adjuvant internal fixation.     

Charcot neuroarthropathy in patients with Charcot Marie Tooth Disease

Charcot Marie Tooth disease (CMT) is the most common inherited neuropathy and is also called Hereditary Motor Sensory Neuropathy (HMSN). Whilst both motor and sensory deficits are present, motor deficits tend to predominate over sensory deficits. Charcot neuroarthropathic joints occur in conditions, most commonly diabetes nowadays, where joints are destroyed in association with reduced protective sensation, pain in particular.Three cases of development of Charcot joint disorders in patients with CMT are discussed and the literature is reviewed.Orthopaedic surgeons should be aware that Charcot joints can occur in CMT and surgery can be complicated by Charcot joints.     

Bisphosphonates for the treatment of Charcot neuroarthropathy

Excess osteoclastic activity is believed to be responsible for the destruction in Charcot neuropathic joint disease. By intervening early in the destructive process, it may be possible to halt the progression toward the devastating bone and joint deformity responsible for morbidity in Charcot feet. This retrospective study evaluated the effects of the bisphosphonate pamidronate on associated signs of Charcot. The 13 study patients (14 infusions) administered pamidronate were compared with 10 control patients who were treated with traditional immobilization methods. Limb temperature and alkaline phosphatase levels were measured as markers of the Charcot process. After pamidronate infusion, limb temperature decreased a mean 2.8 degrees F by 48 hours and 7.4 degrees F by 2 weeks. The alkaline phosphatase levels also decreased an average 53% 2 weeks after infusion. The control group showed no reduction in limb temperature at 48 hours, and had an average limb temperature reduction of 2.3 degrees F at 2 to 3 weeks. This was significantly less than the temperature reduction in the treated group ( P = .008 at 48 hours and P = .001 at 2 weeks). Mean alkaline phosphatase levels declined only 9% in the control group, a significantly smaller decline than in the pamidronate-infusion group ( P = .001). These results suggest that pamidronate may be useful in halting the acute phase of Charcot neuroarthropathy.     

A Surgeon's guide to advances in the pharmacological management of acute Charcot neuroarthropathy

Acute Charcot neuroarthropathy is a devastating condition and, its incidence is increasing. Currently, treatment consists of immobilisation and off-loading of the involved extremity. Outcomes are frequently poor and novel treatments are being sought urgently. This review aims to outline advances in the pharmacological treatment of this, condition.PubMed and the Cochrane Database of systematic reviews were searched. Relevant papers were cross referenced.Eleven original studies were identified. The limited data available suggest pamidronate, alendronate and calcitonin provide some clinical and biochemical improvements while zoledronic acid is deleterious and, increases off-loading times. However, the data is not robust enough to convincingly demonstrate clinically meaningful effects. The studies were predominantly low quality and heterogeneous. They differed markedly in study type, pharmacological agent used, dosing regimen, disease, aetiology/stage/location, concurrent off-loading regimen, outcomes and, follow-up. Few were rigorous in controlling for associated confounding variables and none investigated long term outcomes.The routine use of pharmacological treatment modalities for this condition is not recommended in the United States by the Food and Drug Administration or in the United Kingdom by the National Institute for Health and Clinical Excellence. Given the evidence available this is justified and further higher quality research is required.     

Single stage correction with external fixation of the ulcerated foot in individuals with Charcot neuroarthropathy

The ulcerated foot in individuals with Charcot neuroarthropathy presents a complex problem when correction of the deformity is necessary but the presence of infection precludes the use of internal fixation. We reviewed 11 patients with midfoot Charcot neuroarthropathy, collapse, and ulceration who were at risk for amputation. These patients underwent operative debridement, corrective osteotomy, external skeletal fixation and culture-directed antibiotic therapy as a limb salvage procedure. Patients were transitioned from the external fixator (average 57 days) to total contact casting (average 131 days) and all subsequently progressed to therapeutic footwear in 12 to 49 months of follow-up (average 24 months), except one patient whose medical decline resulted in bedrest. We believe that when performed in properly selected patients, this procedure presents an alternative to amputation and, via corrective osteotomy, results in a shoe-able, functional foot that is potentially less prone to ulceration.     

Current topics review: Charcot neuroarthropathy of the foot and ankle

Charcot arthropathy is a destructive process, most commonly affecting joints of the foot and ankle in diabetics with peripheral neuropathy. Affected individuals present with swelling, warmth, and erythema, often without history of trauma. Bony fragmentation, fracture, and dislocation progress to foot deformity, bony prominence, and instability. This often causes ulceration and deep infection that may necessitate amputation. Instability or deformity may limit the ability to use standard footwear. Treatment is focused on providing a stable and plantigrade foot for functional ambulation with accommodative footwear and orthoses. Historically, treatment had included nonweightbearing immobilization for the acute phase, and surgery had been reserved only for infection, unresolved skin ulceration, or deformity that precluded the use of therapeutic footwear. Current controversies include weightbearing in the acute or reparative phases and early surgical stabilization. Foot-specific patient education and continued periodic monitoring may reduce the morbidity and associated expense of treating the complications of this disorder and may improve the quality of life in this complex patient population.     

HIV neuropathy induced Charcot neuroarthropathy: A case discussion

Charcot neuroarthropathy is a devastating joint condition that affects persons with neuropathy. With HIV/AIDS treatments prolonging the lives of these persons, it is likely that long-term sequelae of the disease will become more evident in the near future. Patients with this disease frequently develop peripheral neuropathy. A high index of suspicion must be raised in any patient with peripheral neuropathy of any cause and a red, hot, swollen, painful foot for Charcot neuroarthropathy to give these patients proper treatment to help prevent the devastating effects of Charcot neuropathy with its potential consequences including foot ulceration and amputation. We present a case of an individual with HIV peripheral neuropathy and Charcot neuroarthropathy.     

Orthotic management of Charcot feet after external fixation surgery

The authors use a total contact cast (TCC), Charcot restraint orthotic walker (CROW), or prefabricated diabetic walker (DW) for the treatment of neuroarthropathy, depending on the medical, social, and economic circumstances. There is not one single orthosis for the treatment of Charcot feet, but there are several models with advantages and disadvantages the physician should be aware of. In a retrospective study of 200 Charcot feet, the ankle foot orthosis (AFO) built in the authors' workshop turned out to be an efficient and comfortable appliance for orthotic treatment after reconstructive surgery. They prefer this type of orthosis because of its versatility and its safe application in a compliant patient.     

Charcot neuroarthropathy: an unusual case and a review of the literature

Charcot neuroarthropathy is a devastating consequence of diabetes, requiring early identification and immediate management. A differentiation should be made from osteomyelitis and other pathologies. The authors describe a case of Charcot foot with radiological findings of complete fragmentation of the calcaneum. Further investigation with magnetic resonance and white cell-labeled imaging revealed osteomyelitis. Below-knee amputation was the only therapeutic option in this hindfoot collapse complicated with osteomyelitis.     

Staging of Charcot neuroarthropathy along the medial column of the foot in the diabetic patient.

Diabetes mellitus is the leading cause of Charcot neuroarthropathy. The most common location is along the medial column of the foot. Over a 2-year period, the process can result in a severely deformed foot, which is highly prone to ulcers, infection, and subsequent amputation. To help identify the early stages of the disease process, the histories, physical examinations, and radiographs of 40 patients with 51 neuropathic feet were evaluated. We were able to identify five stages of Charcot deformities. Stage 0 is a clinical stage in which the patient presents with a locally swollen, warm, and often painful foot. Radiographs are negative and technetium 99 bone scan is markedly positive. Indium and gallium scans are normal. Stage 1, in addition to the clinical findings, demonstrates periarticular cysts, erosions, localized osteopenia, and sometimes diastases. Stage 2 is marked by joint subluxations, usually starting between the second cuneiform and the base of the second metatarsal and spreading laterally. Stage 3 is identified by joint dislocation and arch collapse. Stage 4 is the healed and stable end result of the process. Clinically, there is no temperature gradient between the two feet. Radiographically, there is bony trabeculation across joint spaces indicative of mature fusion. Treatment of stage 0 consists of limited weightbearing and close observation while the diagnosis becomes clear. Stage 1 is treated with casting followed by a University of California Biomechanics Lab orthosis (UCBL), to maintain the arch while allowing limited weightbearing. In stage 2, a partial weightbearing total contact cast followed by a Charcot restraint orthotic walker (CROW) is used. Surgery may be needed at this stage, while the joints are still reducible. Arthrodesis with rigid fixation is recommended. Stage 3 is treated with casting for the acute phase, then with a patellar-tendon-bearing ankle-foot orthosis, CROW, or caliper orthosis. If ulcers are present, they are treated with weekly local debridement, antibiotics, and total contact casting. Occasionally decompressive ostectomy is required. Stage 4 may need surgical removal of the bony prominences causing the nonhealing ulcers. Extra-depth shoes and pressure-relieving orthoses are also used. Twenty-five percent of our patients diagnosed and treated in the early stages (stages 0, 1 and 2) did not develop deformity. Surgery to prevent deformity is recommended early, before the destructive stage (stage 3). Close follow-up, especially in a noncompliant population is necessary.     

The management of acute Charcot fracture-dislocations with the Taylor's spatial external fixation system

The surgical repair of acute diabetic neuropathic osteoarthropathy of the midfoot remains a challenge with little guidance available in the medical literature. The authors present a review of the diabetic Charcot neuropathic osteoarthropathy process and proposed surgical intervention techniques with a special emphasis on the available data regarding the use of external fixation. A detailed, step-by-step, guide through the foot-specific Taylor spatial external fixation system is provided. Finally, the authors' preferred technique for these difficult limb salvage cases is presented in detail.     

Charcot neuroarthropathy patient education among podiatrists in Scotland: a modified Delphi approach

Background

This evaluation sought to determine current Charcot neuroarthropathy (CN) diabetes patient education practices among Scottish National Health Service (NHS) and academic podiatrists and evaluate novel visual tools and develop expert consensus for future practice.

Methods

Questionnaires collected mixed qualitative and quantitative responses, analysed concurrently within a convergence coding matrix. Delphi methodology permitted member-checking and agreement of consensus over two rounds.

Results

Fourteen participants (16.28%) completed a Round One questionnaire, leading to the generation of four themes; Experience; Person-Centred Care and the Content and Context of CN patient education. Seven consensus statements were subsequently developed and six achieved over 80% agreement among 16 participants (18.60%) with a Round Two questionnaire. Respondents agreed CN patient education should be considered for all ‘At-risk’ individuals with diabetic peripheral neuropathy (DPN). Verbal metaphors, including the ‘rocker-bottom’ foot, soft or brittle bones, collapsing, walking on honeycomb and a shattering lightbulb were frequently employed. Visual tools, including visual metaphors and The Charcot Foot Thermometer, were positively evaluated and made available online.

Conclusions

Key findings included respondent’s belief that CN education should be considered for all individuals with DPN and the frequent use of simile, analogy and metaphor in CN education. The concept of ‘remission’ proved controversial due to its potential for misinterpretation.

     

Impact of Charcot neuroarthropathy on metatarsal bone mineral density and geometric strength indices

Charcot neuroarthropathy (CN), an inflammatory condition characterized by rapid and progressive destruction of pedal bones and joints, often leads to deformity and ulceration in individuals with diabetes mellitus (DM) and peripheral neuropathy (PN). Repetitive, unperceived joint trauma may trigger initial CN damage, causing a proinflammatory cascade that can result in osteolysis and contribute to subsequent neuropathic fracture. We aimed to characterize osteolytic changes related to development and progression of CN by measuring bone mineral density (BMD) and geometric strength indices using volumetric quantitative computed tomography. Twenty individuals with DM + PN were compared to twenty age-, sex-, and race-matched individuals with DM + PN and acute CN. We hypothesized that individuals with acute CN would have decreased BMD and decreased total area, cortical area, minimum section modulus, and cortical thickness in the diaphysis of the second and fifth metatarsals. Results showed BMD was lower in both involved and uninvolved feet of CN participants compared to DM + PN participants, with greater reductions in involved CN feet compared to uninvolved CN feet. There was a non-significant increase in total area and cortical area in the CN metatarsals, which helps explain the finding of similar minimum section modulus in DM + PN and CN subjects despite the CN group's significantly lower BMD. Larger cortical area and section modulus are typically considered signs of greater bone strength due to higher resistance to compressive and bending loads, respectively. In CN metatarsals, however, these findings may reflect periosteal woven bone apposition, i.e., a hypertrophic response to injury rather than increased fracture resistance. Future research using these techniques will aid further understanding of the inflammation-mediated bony changes associated with development and progression of CN and other diseases.     

Physical management of the Charcot foot

Charcot arthropathy places individuals at risk of developing diabetic foot ulcers and potentially subsequent limb amputation by means of altering the anatomy of the foot and ankle. Physical trauma is an important component to the etiology of the condition. The physical management of the Charcot foot is concerned with minimizing the stress applied to the affected foot and ankle skeletal structure. The most appropriate device is temporally dependent on the progression of the disease. At the initiation of Charcot arthropathy, care by total contact cast is recommended. As the affected bones begin to heal, use of a removable cast walker may be implemented. When the bones reach a fixed state, appropriate footwear is dictated by the degree of deformity.     

Use of a retrograde nail for ankle arthrodesis in Charcot neuroarthropathy: a limb salvage procedure

BACKGROUND: Charcot neuroarthropathy is a serious complication associated with diabetic neuropathy. This complication probably is most serious when the ankle is involved because of the instability and progressive deformity, which often leads to ulceration, osteomyelitis, and amputation. Arthrodesis before the ulcerated lesion appears is considered a limb salvage treatment. One of the most effective techniques for an unstable ankle in Charcot neuroarthropathy is retrograde transcalcaneal nailing. METHODS: Eighteen diabetic patients, without a history of ulceration, were treated from July, 2003, to November, 2005, with panarthrodesis of the ankle using intramedullary retrograde transcalcaneal nailing. The average follow up was 14 +/- 10.1 months. All patients completed the unloaded postoperative period with a fiberglass cast (3 months nonweightbearing and 3 months partial weightbearing) and commenced walking in shoes with a stiff rocker sole and a molded insole. RESULTS: During the followup period there were no major complications. In three patients, removal of one of the proximal screws used for anchoring the nail to the tibia was done because of protrusion causing skin breakdown. Fourteen patients had a stable fusion and four patients had fibrous union. The percentage of limb salvage was 100% in the followup period. CONCLUSIONS: Our study confirms that this operative technique is effective and safe.     

The RANKL/RANK/OPG signaling pathway mediates medial arterial calcification in diabetic Charcot neuroarthropathy

OBJECTIVE

The receptor activator of nuclear factor-κB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) signaling pathway (RANKL/RANK/OPG signaling) is implicated in the osteolysis associated with diabetic Charcot neuroarthropathy (CN); however, the links with medial arterial calcification (MAC) seen in people with CN are unclear. This study aimed to investigate the role of RANKL/OPG in MAC in patients with CN.

RESEARCH DESIGN AND METHODS

Enzyme-linked immunosorbent assay and Bio-plex multiarray technology were used to quantify a range of cytokines, including RANKL and OPG in sera from 10 patients with diabetes, 12 patients with CN, and 5 healthy volunteers. Human tibial artery segments were immunohistochemically stained with Alizarin red and human RANKL antibody. Human vascular smooth muscle cells (VSMCs) were also explanted from arterial segments for in vitro studies.

RESULTS

We demonstrate colocalization and upregulation of RANKL expression in areas displaying MAC. Systemic levels of RANKL, OPG, and inflammatory cytokines (interleukin-8, granulocyte colony–stimulating factor) were elevated in those with CN compared with diabetic patients and healthy control subjects. Human VSMCs cultured in CN serum showed accelerated osteoblastic differentiation (alkaline phosphatase activity) and mineralization (alizarin red staining) compared with cells treated with diabetic or control serum (P < 0.05). Coincubation with OPG, the decoy receptor for RANKL, attenuated osteogenic differentiation of VSMCs and was independent of a high calcium-phosphate milieu. The accelerated mineralization induced by RANKL and CN serum correlated with nuclear translocation of nuclear factor-κB, a process abrogated by OPG.

CONCLUSIONS

Our data provide direct evidence that RANKL/RANK/OPG signaling is modulated in patients with CN and plays a role in vascular calcification. This study highlights this pathway as a potential target for intervention.Vascular calcification is a strong independent predictor of cardiovascular mortality (1). In people with diabetes, medial arterial calcification (MAC) has emerged as a strong predictor of lower limb amputation and cardiovascular mortality (2,3). This may be to the result of an increase in arterial stiffness, pulse wave velocity, and systolic blood pressure, ultimately leading to reduced coronary perfusion and ventricular hypertrophy (4). MAC in people with diabetes is more common in those with peripheral neuropathy, who also display increased bone resorption (osteolysis) (5–7), typically seen in Charcot neuroarthropathy (CN). The signaling pathway of the receptor activator of nuclear factor-κB (RANK), RANK ligand (RANKL), and its decoy receptor osteoprotegerin (OPG) has been suggested as the link between vascular and bone metabolism (8,9). In fact, RANKL has been shown to mediate osteolysis in CN by stimulating osteoclastic differentiation of monocytes/macrophages, an effect that is attenuated by OPG, the decoy receptor (10). This has led to nascent theories implicating RANKL/OPG signaling as the potential pathogenetic basis for CN.RANKL exists in two biologically active soluble forms secreted by T cells, endothelial cells, or osteoblasts or proteolytically cleaved from cell surfaces. RANKL binds to its target receptor RANK on cell surfaces (including vascular smooth muscle cells [VSMCs]) to generate multiple intracellular signals that regulate cell differentiation, function, and survival (8,11,12). In the vasculature, RANKL is expressed and upregulated in calcifying vascular cells (13) and enhances the recruitment and infiltration of cells that have been shown to stimulate VSMC mineralization (14).Most of the evidence for a direct role of RANKL/OPG signaling in vascular calcification is derived from animal studies with limited human data. For instance, with the use of VSMCs from rat aorta, RANKL has been shown to increase VSMC calcification via activation of the alternate nuclear factor-κB (NF-κB) pathway (15). However, to enhance translational applications, we extend these data to human VSMCs and use of patient serum.In diabetic CN, there is osteolysis and simultaneous vascular calcification, potentially leading to amputation (16,17). Therefore, the aim of this study was to determine the role of RANKL/OPG signaling in MAC in diabetic CN by using an in vitro model of vascular calcification.