The causes of the Charcot syndrome

Minor and Major Amputation Rates Following Midfoot Charcot Reconstructive Surgery

Charcot neuroarthropathy (CNA) is a progressive disease that affects the bones and joints of the foot. To prevent collapse and loss of stability within the pedal architecture, CNA should be diagnosed and managed early. The objective of this retrospective study was to review patients who underwent midfoot CNA reconstructive surgery and evaluate subsequent rates of minor and major amputations. Secondary objectives include identifying patients that underwent midfoot CAN with and without a subtalar joint (STJ) arthrodesis. Out of the 72 patients, 4 (5.6%) underwent minor (digital, ray) amputation, 2 (2.8%) underwent proximal amputations (either below or above the knee), and none underwent midfoot amputation (transmetatarsal, Lisfranc, Chopart). A Fisher's exact test was employed to compare the outcomes of minor and major amputation rates in our CNA cohort with those who underwent midfoot CNA reconstruction with STJ arthrodesis and found no statistical significance (p = .15). Overall, a total progression to amputation was 8.4% following midfoot CNA reconstruction, with 2.8% of patients undergoing major amputation (below knee or above knee). Despite no statistical significance, we recommend surgeons to consider including an STJ arthrodesis in addition to midfoot CNA reconstruction to establish a stable and plantigrade foot.

Management of Midfoot Charcot: Minimally Invasive Techniques and Improved Fixation

The objective of this article is to review the etiology and pathophysiology of Charcot neuroarthropathy as it contributes to the breakdown of the midfoot. The article will also discuss the emerging techniques in minimally invasive surgery and how this is applied to Charcot reconstructive surgery as well as reflect on a newer thought processes to surgical intervention.

Progression to Hindfoot Charcot Neuroarthropathy After Midfoot Charcot Correction in Patients With and Without Subtalar Joint Arthrodesis

Charcot neuroarthropathy (CNA) is a disabling and progressive disease that affects the bones and joints of the foot. Successful Charcot reconstruction focuses on restoring anatomic alignment, obtaining multiple joint arthrodesis, selecting stable fixation, preserving foot length, and creating a foot suitable for community ambulation in supportive shoegear. Intramedullary fixation arthrodesis of the medial and lateral columns has been previously reported to produce improvement in midfoot Charcot reconstruction. More recently, a growing trend of stabilization of the subtalar joint (STJ) has been incorporated alongside the medial and lateral column fusion. Our objectives were to retrospectively review patients who underwent midfoot Charcot reconstructive surgery, whether with or without accompanying STJ arthrodesis, and establish which patients progressed to ankle CNA. Of the 72 patients who underwent midfoot Charcot reconstruction, 28 (38.9%) underwent STJ arthrodesis, and 22 converted to ankle CNA (30.6%). Fourteen (63.6%) of 22 ankle CNA cases had not undergone STJ arthrodesis; 8 patients (36.4%) had it. A Fisher exact test was performed to identify the relationship between those without STJ arthrodesis and those progressing to ankle CNA; it revealed statistical significance (P = 0.001). Performing an STJ arthrodesis with midfoot Charcot reconstructive surgery may be beneficial to aiding in hindfoot stability, establishing a plantigrade foot, and providing further insight into the management of midfoot Charcot. LEVEL OF CLINICAL EVIDENCE: III.

Managing Acute Fore- and Midfoot Fractures in Patients with Diabetes

Few is investigated about the management of acute fore- and midfoot injuries in diabetics. With well controlled diabetes, indications and techniques are similar to non-diabetics. With poorly controlled diabetes, medical optimization should be exercised. Stable internal fixation in case of surgical treatment and prolonged offloading independent of the choice of treatment are advised. With manifest Charcot neuroarthropathy, the goal is to achieve a plantigrade, stable foot that is infection- and ulcer-free and ambulant with orthopaedic shoes. If operative treatment is chosen, the concept of superconstructs in combination with prolonged protection in a well-padded total contact cast is applied.

Nonoperative Treatment of Charcot Neuro-osteoarthropathy

Conservative treatment of Charcot neuro-osteoarthropathy (CN) aims to retain a stable, plantigrade, and ulcer-free foot, or to prevent progression of an already existing deformity. CN is treated with offloading in a total contact cast as long as CN activity is present. Transition to inactive CN is monitored by the resolution of clinical activity signs and by resolution of bony edema in MRI. Fitting of orthopedic depth insoles, orthopedic shoes, or ankle-foot orthosis should follow immediately after offloading has ended to prevent CN reactivation or ulcer development.

An Approach to Managing Midfoot Charcot Deformities

We present an approach to managing complex deformities in Charcot neuroarthropathy that typically present around the midfoot. This approach follows a stepwise progression from prevention, early detection, nonoperative through to operative management. It centers on multidisciplinary care with input from diabetologists, orthotists, plaster technicians, physiotherapists, orthopedic, vascular, and/or plastic surgeons. We discuss the timing of surgery with regard to Eichenholtz stage of disease and trends toward early surgical intervention. We review traditional and new surgical concepts. We evaluate the role of limited interventions. We aim to provide a template for deciding where future research priorities should be directed.

Charcot Reconstruction: Understanding and Treating the Deformed Charcot Neuropathic Arthropathic Foot

With worsening diet and increasing prevalence of diabetes, patient encounters with Charcot neuropathic arthropathy (CNA) are expected to increase. Without intervention, the pathology progresses with further subluxation/dislocation and fracture, placing soft tissues at risk of preulceration or formal ulceration, infection, and potentially major amputation. The need to avoid amputation is of paramount importance. Although a formal single eradicating tool for CNA is lacking, there is capacity to intervene in ways that may curtail the pace of destruction. This article reviews understanding of the disease process and provides guidance to surgical reconstruction of the deformity.

An atypical and bilateral presentation of Charcot foot disease

BACKGROUND

Charcot neuropathic osteoarthropathy (CNO) is one of the most devastating complications of neuropathy in patients with diabetes. Establishing diagnosis of CNO is difficult, due to the lack of clear clinical and radiological diagnostic criteria. Diagnosis is even more difficult when there is atypical and bilateral clinical presentation. Since CNO may lead to foot deformity, lower-extremity amputation and significant decrements in quality of life, it must be detected and treated without delay. Treatment focuses mainly on interruption of the inflammatory process and relief from pain using feet offloading devices. In more severe cases, surgical intervention may be needed. Additionally, the use of custom-made insoles and custom-made orthopaedic shoes is mandatory.

CASE PRESENTATION

We report a case of a young diabetic patient who presented to our clinic with bilateral and atypical presentation of Charcot foot disease. Patient was treated successfully upon diagnosis with bilateral aircast offloading. Unfortunately, due to depression and non-compliance, the disease progressed to severe and permanent lesions later on.

CONCLUSION

Despite the rareness of this disease, clinicians must include CNO into differential diagnosis of diabetic foot oedema, inflammation and deformity.

Development of Charcot Neuroarthropathy in Diabetic Patients who Received Kidney or Kidney-Pancreas Transplants

Only a small percentage of the general diabetic population develops Charcot neuroarthropathy. Charcot arthropathy greatly increases the risk of foot complications. At our academic institution, there appeared to be an increased incidence of Charcot arthropathy in transplant patients. We hypothesized that Charcot neuroarthropathy incidence is higher in the diabetic patients who had received kidney or kidney-pancreas transplants. The charts of 1000 patients were reviewed from January 2000 to January 2011. Four hundred and eighty-seven patients were included in the study. Of these diabetic patients, 249 had received a kidney transplant and 238 a kidney-pancreas transplant. The data were analyzed for the incidence of Charcot in each group. Other risk factors and sequelae were also evaluated and analyzed. The incidence of Charcot development in the diabetic patients who had a kidney-pancreas transplant was 18.4%, 44 of 238 patients. This was significantly higher than the incidence in kidney transplant patients, which was 11.2%, 28 of 249 patients (p < .05). Peripheral arterial disease was a statistically significant independent risk factor for developing ulceration, osteomyelitis, and subsequent amputation. Type 1 diabetic patients developed Charcot at a higher rate that was also statistically significant compared with type 2 diabetic patients. In our study, diabetic patients who had undergone kidney-pancreas transplants were associated with higher risk for development of Charcot neuroarthropathy than kidney transplants alone. The incidence of Charcot development in both these transplant groups was also much higher than in the general diabetic population. This is of particular interest to clinicians and surgeons as both transplant groups were found to be high risk for subsequent foot ulceration, infection, and amputation.

Nutritional and Pharmacological Effects on Oxidative Stress in Soft Tissue and Bone Remodeling

Oxidative damage is the causal link to a multitude of pathologies, such as diabetes, arthritis, neuropathy, heart disease, and asthma. These conditions affect hundreds of millions of people nationwide, and billions worldwide. Even in otherwise healthy individuals, oxidative stress is a natural byproduct of metabolism that is augmented in "healthy" activities such as athletics. In many disease states, the pharmacological agents used to treat these conditions can induce oxidative damage and vitamin depletion. It is underappreciated by many that many of the most common medications prescribed result in oxidative stress. Therefore, physicians need to carefully scrutinize which medications their patients are on before surgery and treatment and during the recovery stage to obtain optimal healing results. We provide a review of the current literature of how oxidative damage and inflammation are linked to bone damage, Charcot neuroarthropathy, delayed wound healing, diabetic complications, and delayed flap consolidation. Where available, antioxidant intervention literature is offered to offset these conditions.

Risk factors of diabetic foot Charcot arthropathy: a case-control study at a Malaysian tertiary care centre

INTRODUCTION

This study aimed to determine the risk factors of diabetic Charcot arthropathy of the foot among diabetic patients with and without foot problems.

METHODS

This was a case-control study involving diabetic patients attending the Diabetic Foot Care and Wound Management Clinic at University Malaya Medical Centre, Kuala Lumpur, Malaysia, from June 2010 to June 2011. Data on sociodemographic profiles, foot factors and diabetes characteristics was collected and analysed.

RESULTS

A total of 48 diabetic patients with Charcot arthropathy of the foot were identified. Data from these 48 patients was compared with those of 52 diabetic patients without foot problems. Up to 83.3% of patients with diabetic Charcot arthropathy presented with unilateral Charcot foot, most commonly located at the midfoot (45.8%). Patients with a history of foot problems, including foot ulcer, amputation, surgery or a combination of problems, had the highest (26-time) likelihood of developing Charcot arthropathy (odds ratio 26.4; 95% confidence interval 6.4-109.6). Other significant risk factors included age below 60 years, more than ten years' duration of diabetes mellitus and the presence of nephropathy.

CONCLUSION

A history of prior diabetic foot problems is the greatest risk factor for developing diabetic Charcot arthropathy, compared with other risk factors such as diabetes characteristics and sociodemographic profiles. Preventive management of diabetic foot problems in the primary care setting and multidisciplinary care are of paramount importance, especially among chronic diabetic patients.

Charcot arthropathy in ultrasound examination - a case report

This article presents a patient with a long history of type 1 diabetes mellitus complicated with neuropathy and Charcot disease. The most common cause of neuropathic osteoarthropathy, called Charcot osteoarthropathy, is poorly controlled diabetes. The clinical picture is characterized by considerable edema, redness and increased skin temperature with relatively slight pain due to injury to nerve fibers responsible for pain sensation. The differential diagnosis should include bacterial or autoimmune arthritis, arthritis associated with gout as well as venous thrombosis and injury. The contribution of a local inflammatory reaction and abnormal bone turnover with excessive osteoclast activity might play a role in the etiopathogenesis of this disease. As a result, osseous and articular destruction progresses rapidly leading to irreversible deformity of the foot. Avoiding weight-bearing and resting the foot in a specially selected plaster cast is the most important part of treatment. Patients with the aforementioned complaints are referred to radiologists for imaging examinations. An ultrasonographer should pay attention to changes typical of Charcot arthropathy, such as: inflammatory and destructive changes in joints of the foot, uneven contour of bones with thickening and periosteal hyperemia as well as soft tissue swelling.

Neuropathic osteoarthropathy with and without superimposed osteomyelitis in patients with a diabetic foot

Soft tissue and bone infection involving the foot is one of the most common long-term complications of diabetes mellitus, implying a serious impairment in quality of life for patients in the advanced stages of the disease. Neuropathic osteoarthropathy often coexists and differentiating between these two entities is commonly challenging, but crucial, as the management may differ substantially. The importance of correct diagnosis cannot be understated and effective management requires a multidisciplinary approach owing to the complicated nature of therapy in such patients. A missed diagnosis has a high likelihood of major morbidity for the patient, including limb amputation, and over-diagnosis results in a great socioeconomic challenge for healthcare systems, the over-utilization of healthcare resources, and the unwise use of antibiotics. Diagnosis is largely based on clinical signs supplemented by various imaging modalities such as radiography, MR imaging, and hybrid imaging techniques such as F-18 fluorodeoxyglucose-positron emission tomography. In the interests of the management of diabetic foot complications, this review article is aimed on the one hand at providing radiologists with important clinical knowledge, and on the other hand to equip clinicians with relevant radiological semiotics.

Risk factors for Charcot foot

OBJECTIVE

Diabetes mellitus is the main cause of Charcot neuroarthropathy and is clinically classified as follows: Charcot foot, acute Charcot foot (ACF) when there is inflammation, and inactive Charcot foot when inflammatory signs are absent. The aim of this study was to identify the risk factors for ACF in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

A matched case-control study was conducted to assess the factors associated with acute Charcot foot from February 2000 until September 2012. Four controls for each case were selected 47 cases of ACF and 188 controls without ACF were included. Cases and controls were matched by year of initialization of treatment. Conditional logistic regression was used to estimate matched odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

In multivariate analysis, patients having less than 55 years of age (adjusted OR = 4.10, 95% CI = 1.69 - 9.94), literate education age (adjusted OR = 3.73, 95% CI = 1.40 - 9.92), living alone (adjusted OR = 5.84, 95% CI = 1.49 - 22.86), previous ulceration (adjusted OR = 4.84, 95% CI = 1.62 - 14.51) were at increased risk of ACF. However, peripheral arterial disease (adjusted OR = 0.16, 95% CI = 0.05 - 0.52) of 6.25 (1.92 - 20.0) was a protective factor.

DISCUSSION

The results suggest that PCA in type 2 diabetes primarily affects patients under 55 who live alone, are literate, and have a prior history of ulcers, and that peripheral arterial disease is a protective factor.

Role of Wnt/β-catenin and RANKL/OPG in bone healing of diabetic Charcot arthropathy patients

BACKGROUND AND PURPOSE

Charcot neuropathy is characterized by bone destruction in a foot leading to deformity, instability, and risk of amputation. Little is known about the pathogenic mechanisms. We hypothesized that the bone-regulating Wnt/β-catenin and RANKL/OPG pathways have a role in Charcot arthropathy.

PATIENTS AND METHODS

24 consecutive Charcot patients were treated by off-loading, and monitored for 2 years by repeated foot radiography, MRI, and circulating levels of sclerostin, dickkopf-1, Wnt inhibitory factor-1, Wnt ligand-1, OPG, and RANKL. 20 neuropathic diabetic controls and 20 healthy controls served as the reference.

RESULTS

Levels of sclerostin, Dkk-1 and Wnt-1, but not of Wif-1, were significantly lower in Charcot patients than in the diabetic controls at inclusion. Dkk-1 and Wnt-1 levels responded to off-loading by increasing. Sclerostin levels were significantly higher in the diabetic controls than in the other groups whereas Wif-1 levels were significantly higher in the healthy controls than in the other groups. OPG and RANKL levels were significantly higher in the Charcot patients than in the other groups at inclusion, but decreased to the levels in healthy controls at 2 years. OPG/RANKL ratio was balanced in all groups at inclusion, and it remained balanced in Charcot patients on repeated measurement throughout the study.

INTERPRETATION

High plasma RANKL and OPG levels at diagnosis of Charcot suggest that there is high bone remodeling activity before gradually normalizing after off-loading treatment. The consistently balanced OPG/RANKL ratio in Charcot patients suggests that there is low-key net bone building activity by this pathway following diagnosis and treatment. Inter-group differences at diagnosis and changes in Wnt signaling following off-loading treatment were sufficiently large to be reflected by systemic levels, indicating that this pathway has a role in bone remodeling and bone repair activity in Charcot patients. This is of particular clinical relevance considering the recent emergence of promising drugs that target this system.

Lower limb complications of diabetes mellitus: a comprehensive review with clinicopathological insights from a dedicated high-risk diabetic foot multidisciplinary team

Diabetic complications in the lower extremity are associated with significant morbidity and mortality, and impact heavily upon the public health system. Early and accurate recognition of these abnormalities is crucial, enabling the early initiation of treatments and thus avoiding or minimizing deformity, dysfunction and amputation. Following careful clinical assessment, radiological imaging is central to the diagnostic and follow-up process. We aim to provide a comprehensive review of diabetic lower limb complications designed to assist radiologists and to contribute to better outcomes for these patients.

The management of Charcot midfoot deformities in diabetic patients

Charcot foot neuropathic osteoarthropathy is a disorder affecting the soft tissues, joints, and bones of the foot and ankle. The disease is triggered in a susceptible individual through a process of uncontrolled inflammation leading to osteolysis, progressive fractures and articular malpositioning due to joint subluxations and dislocations. The progression of the chronic deformity with a collapsed plantar arch leads to plantar ulcerations because of increased pressure on the plantar osseous prominences and decreased plantar sensation. Subsequent deep soft tissue infection and osteomyelitis may result in amputation. The Charcot foot in diabetes represents an important diagnostic and therapeutic challenge in clinical practice. Conservative treatment remains the standard of the care for most patients with neuropathic disorder. Offloading the foot and immobilization based on individual merit are essential and are the most important recommendations in the active acute stage of the Charcot foot. Surgical realignment with stabilization is recommended in severe progressive neuropathic deformities consisting of a collapsed plantar arch with a rocker-bottom foot deformity.

Charcot neuroarthropathy of the foot and ankle: diagnosis and management strategies

This article reviews current literature discussing the etiology, pathophysiology, diagnosis and imaging, and conservative and surgical treatment of Charcot osteoarthropathy. The treatment of Charcot osteoarthropathy with concurrent osteomyelitis is also discussed.

Radiographic and functional results in the treatment of early stages of Charcot neuroarthropathy with a walker boot and immediate weight bearing

Background

One of the most common gold standards for the treatment of Charcot neuroarthropathy (CN) in the early Eichenholtz stages I and II is immobilization with the total contact casting and lower limb offloading. However, the total amount of offloading is still debatable.

Objectives

This study evaluates the clinical and radiographic findings in the treatment of early stages of CN (Eichenholtz stages I and II) with a walker boot and immediate total weight-bearing status.

Methods

Twenty-two patients with type 2 diabetes mellitus (DM) and CN of Eichenholtz stages I and II were selected for non-operative treatment. All patients were educated about their condition, and full weight bearing was allowed as tolerated. Patients were monitored on a fortnightly basis in the earlier stages, with clinical examination, temperature measurement, and standardized weight-bearing radiographs. Their American Orthopedic Foot and Ankle Society (AOFAS) scores were determined before and after the treatment protocol.

Results

No cutaneous ulcerations or infections were observed in the evaluated cases. The mean measured angles at the beginning and end of the study, although showing relative increase, did not present a statistically significant difference (p > 0.05). Mean AOFAS scores showed a statistically significant improvement by the end of the study (p < 0.005).

Conclusion

The treatment of early stages of CN (Eichenholtz stages I and II) with emphasis on walker boot and immediate weight bearing has shown a good functional outcome, non-progressive deformity on radiographic assessment, and promising results as a safe treatment option.

Charcot neuroarthropathy of the foot and ankle: a review

Charcot neuroarthropathy is a limb-threatening, destructive process that occurs in patients with neuropathy associated with medical diseases such as diabetes mellitus. Clinicians' treating diabetic patients should be vigilant in recognizing the early signs of acute Charcot neuroarthropathy, such as pain, warmth, edema, or pathologic fracture in a neuropathic foot. Early detection and prompt treatment can prevent joint and bone destruction, which, if untreated, can lead to morbidity and high-level amputation. A high degree of suspicion is necessary. Once the early signs have been detected, prompt immobilization and offloading are important. Treatment should be determined on an individual basis, and it must be determined whether a patient can be treated conservatively or will require surgical intervention when entering the chronic phase. If diagnosed early, medical and conservative measures only will be required. Surgery is indicated for patients with severe or unstable deformities that, if untreated, will result in major amputations. A team approach that includes a foot and ankle surgeon, a diabetologist, a physiotherapist, a medical social councilor, and, most importantly, the patient and immediate family members is vital for successful management of this serious condition.

An overview of the Charcot foot pathophysiology

Charcot arthropathy of the foot is a rare but devastating complication of diabetes that remains to be a challenging issue for the foot and ankle surgeons. Charcot foot fails to be an obvious diagnostic option that comes to mind, even in a pathognomonic clinical appearance. The rarity of the disorder, more common pathologies that mimic the condition, and the self-limiting prognosis deviate the clinician from the right diagnosis. The clinical challenges in the diagnosis of Charcot foot require in-depth investigations of its enigmatic nature to establish useful guidelines. Yet, this goal seems to be beyond reach, without a holistic view of the immense literature concerning the pathophysiology of the disorder. The primary objective of this article is to put together and review the recent advancements about the etiology and intrinsic mechanisms of diabetic Charcot foot.

Etiology, pathophysiology and classifications of the diabetic Charcot foot

In people with diabetes mellitus, the Charcot foot is a specific manifestation of peripheral neuropathy that may involve autonomic neuropathy with high blood flow to the foot, leading to increased bone resorption. It may also involve peripheral somatic polyneuropathy with loss of protective sensation and high risk of unrecognized acute or chronic minor trauma. In both cases, there is excess local inflammatory response to foot injury, resulting in local osteoporosis. In the Charcot foot, the acute and chronic phases have been described. The former is characterized by local erythema, edema, and marked temperature elevation, while pain is not a prominent symptom. In the latter, signs of inflammation gradually recede and deformities may develop, increasing the risk of foot ulceration. The most common anatomical classification describes five patterns, according to the localization of bone and joint pathology. This review article aims to provide a brief overview of the diabetic Charcot foot in terms of etiology, pathophysiology, and classification.

Plantar Temperature Response to Walking in Diabetes with and without Acute Charcot: The Charcot Activity Response Test

Objective. Asymmetric plantar temperature differences secondary to inflammation is a hallmark for the diagnosis and treatment response of Charcot foot syndrome. However, little attention has been given to temperature response to activity. We examined dynamic changes in plantar temperature (PT) as a function of graduated walking activity to quantify thermal responses during the first 200 steps. Methods. Fifteen individuals with Acute Charcot neuroarthropathy (CN) and 17 non-CN participants with type 2 diabetes and peripheral neuropathy were recruited. All participants walked for two predefined paths of 50 and 150 steps. A thermal image was acquired at baseline after acclimatization and immediately after each walking trial. The PT response as a function of number of steps was examined using a validated wearable sensor technology. The hot spot temperature was identified by the 95th percentile of measured temperature at each anatomical region (hind/mid/forefoot). Results. During initial activity, the PT was reduced in all participants, but the temperature drop for the nonaffected foot was 1.9 times greater than the affected side in CN group (P = 0.04). Interestingly, the PT in CN was sharply increased after 50 steps for both feet, while no difference was observed in non-CN between 50 and 200 steps. Conclusions. The variability in thermal response to the graduated walking activity between Charcot and non-Charcot feet warrants future investigation to provide further insight into the correlation between thermal response and ulcer/Charcot development. This stress test may be helpful to differentiate CN and its response to treatment earlier in its course.

The Charcot foot in diabetes

The diabetic Charcot foot syndrome is a serious and potentially limb-threatening lower-extremity complication of diabetes. First described in 1883, this enigmatic condition continues to challenge even the most experienced practitioners. Now considered an inflammatory syndrome, the diabetic Charcot foot is characterized by varying degrees of bone and joint disorganization secondary to underlying neuropathy, trauma, and perturbations of bone metabolism. An international task force of experts was convened by the American Diabetes Association and the American Podiatric Medical Association in January 2011 to summarize available evidence on the pathophysiology, natural history, presentations, and treatment recommendations for this entity.

Salvage arthrodesis for charcot arthropathy

The principles of fusion of a Charcot joint arise from the assertion that successful fusion requires removal of all cartilage, debris, and sclerotic bone. The authors believe that reconstruction can prevent amputation in patients who have unbraceable or unstable deformities, or recurrent ulcerations. The goal with any Charcot reconstruction procedure is to achieve a plantigrade foot free of ulceration, and to prevent any future collapse, deformity, or ulcerations. The authors strongly believe arthrodesis of unstable joints of the Charcot neuropathic foot can lead to limb salvage and better quality of life.

Review: The diabetic bone: a cellular and molecular perspective

With the increasing worldwide prevalence of diabetes the resulting complications, their consequences and treatment will lead to a greater social and financial burden on society. One of the many organs to be affected is bone. Loss of bone is observed in type 1 diabetes, in extreme cases mirroring osteoporosis, thus a greater risk of fracture. In the case of type 2 diabetes, both a loss and an increase of bone has been observed, although in both cases the quality of the bone overall was poorer, again leading to a greater risk of fracture. Once a fracture has occurred, healing is delayed in diabetes, including nonunion. The reasons leading to such changes in the state of the bone and fracture healing in diabetes is under investigation, including at the cellular and the molecular levels. In comparison with our knowledge of events in normal bone homeostasis and fracture healing, that for diabetes is much more limited, particularly in patients. However, progress is being made, especially with the use of animal models for both diabetes types. Identifying the molecular and cellular changes in the bone in diabetes and understanding how they arise will allow for targeted intervention to improve diabetic bone, thus helping to counter conditions such as Charcot foot as well as preventing fracture and accelerating healing when a fracture does occur.

The Charcot foot in diabetes

The diabetic Charcot foot syndrome is a serious and potentially limb-threatening lower-extremity complication of diabetes. First described in 1883, this enigmatic condition continues to challenge even the most experienced practitioners. Now considered an inflammatory syndrome, the diabetic Charcot foot is characterized by varying degrees of bone and joint disorganization secondary to underlying neuropathy, trauma, and perturbations of bone metabolism. An international task force of experts was convened by the American Diabetes Association and the American Podiatric Medical Association in January 2011 to summarize available evidence on the pathophysiology, natural history, presentations, and treatment recommendations for this entity.

Loss of RAGE defense: a cause of Charcot neuroarthropathy?

OBJECTIVE

This study investigated the relationship between circulating soluble receptor for advanced glycation end products (sRAGE) and parameters of bone health in patients with Charcot neuroarthropathy (CNA).

RESEARCH DESIGN AND METHODS

Eighty men (aged 55.3±9.0 years), including 30 healthy control subjects, 30 type 2 diabetic patients without Charcot, and 20 type 2 diabetic patients with stage 2 (nonacute) CNA, underwent evaluations of peripheral and autonomic neuropathy, nerve conduction, markers of bone turnover, bone mineral density, and bone stiffness of the calcaneus.

RESULTS

CNA patients had worse peripheral and autonomic neuropathy and a lower bone stiffness index than diabetic or control individuals (77.1, 103.3, and 105.1, respectively; P<0.05), but no difference in bone mineral density (P>0.05). CNA subjects also had lower sRAGE levels than control (162 vs. 1,140 pg/mL; P<0.01) and diabetic (162 vs. 522 pg/mL; P<0.05) subjects, and higher circulating osteocalcin levels.

CONCLUSIONS

CNA patients had significantly lower circulating sRAGE, with an accompanying increase in serum markers of bone turnover, and reduced bone stiffness in the calcaneus not accompanied by reductions in bone mineral density. These data suggest a failure of RAGE defense mechanisms against oxidative stress in diabetes. Future studies should determine if medications that increase sRAGE activity could be useful in mitigating progression to CNA.

Charcot arthropathy of the knee. A case-based review

The diagnosis of Charcot arthropathy in the knee is rare. However, there is an increasing number of diabetic patients, and they are living longer due to improvements in treatment. Because neuropathic arthropathy is a late effect of peripheral neuropathy, we can expect an increasing incidence of neuropathic arthropathy. Total knee arthroplasty is the preferred choice of treatment by patients, although it may also be associated with a high incidence of serious complications. This case report presents a young female with diabetes mellitus and Charcot arthropathy of the knee managed by total knee arthroplasty and a literature review. The report encompasses a 5-year follow-up of the patient, from the first contact after knee distortion through diagnosis of Charcot arthropathy and the performance of total knee arthroplasty with outpatient controls. The diagnosis was established on the basis of the rapid destruction of the medial tibial condyle after knee distortion in a patient with neuropathy. Neuropathic arthropathy was confirmed by histology. The patient refused knee fusion and total knee arthroplasty was performed. The patient quickly achieved a painless, stable knee with a 130-degree range of motion. However, a radiolucent line appeared under the tibial component due to premature weight-bearing. The patient was ordered to refrain from weight-bearing for the next 3 months, and the knee was healed. While the management of Charcot arthropathy in the knee remains controversial, total knee arthroplasty is not a contraindication. Early diagnosis, appropriate choice of implant and operative technique, and long-term weight protection are essential.