The Charcot foot as a complication of diabetic neuropathy

Risk factors for Charcot foot development in individuals with diabetes mellitus

AIMS/HYPOTHESIS

Charcot foot is a complication of diabetes mellitus that has potentially disastrous consequences. Although it was first described in 1868 and found to be associated with diabetes in 1936, there is still uncertainty about the risk factors affecting the development of the condition. Here, we aim to identify risk factors for Charcot foot in a nationwide cohort study.

METHODS

A retrospective register-based cohort study was performed for the period 2001-2016, using nationwide registries. Individuals with diabetes and Charcot foot were identified and matched by diabetes type and with similar diabetes duration with individuals with diabetes but not Charcot foot. Logistic regression analyses were used to identify risk factors.

RESULTS

A total of 3397 participants with diabetes mellitus and Charcot foot and 27,662 control participants with diabetes but without Charcot foot were included. HbA1c, duration of diabetes, micro- and macroalbuminuria, retinopathy and atherosclerosis (general and peripheral) were identified as risk factors for Charcot foot in participants with type 1 diabetes and participants with type 2 diabetes.

CONCLUSIONS/INTERPRETATION

In the most extensive study on Charcot foot to date, we identified distinctive and common risk factors associated with the development of Charcot foot in individuals with type 1 diabetes and type 2 diabetes.

Charcot Neuro-Osteoarthropathy With Superimposed Osteomyelitis in a Nondiabetic Patient, as a Consequence of Cancer Chemotherapy: A MR-Monitored Case Report

Charcot neuro-osteoarthropathy (CNO) is a manifestation of peripheral neuropathy as a chronic complication of diabetes mellitus but, less frequently, can be associated to other conditions such as alcoholism or neurotoxic therapies. An increasingly emerging cause of CNO is the use of oncological drugs which can cause neuropathic damage. The use of these therapies dramatically increased in recent years. CNO leads to a progressive degeneration of the foot's joints and to bone destruction and resorption which ends in deformities. These alterations in the foot's anatomy determine a high risk of ulceration, infection, and osteomyelitis. The superimposition of osteomyelitis on CNO increases the risk of major amputation, already high in patients suffering either from only CNO or osteomyelitis alone. We report the case of a 61-year old nondiabetic woman affected by CNO as a consequence of antiblastic therapy for breast cancer and the subsequent overlap of osteomyelitis, confirmed by magnetic resonance imaging. This case underlines how it is necessary to consider CNO as a possible complication of antiblastic therapy in the view of the severe consequences of missing its diagnosis.

Screening for diabetic peripheral neuropathy in resource-limited settings

BACKGROUND

Diabetic neuropathy is the most common microvascular complication of diabetes mellitus and a major risk factor for diabetes-related lower-extremity complications. Diffuse neuropathy is the most frequently encountered pattern of neurological dysfunction and presents clinically as distal symmetrical sensorimotor polyneuropathy. Due to the increasing public health significance of diabetes mellitus and its complications, screening for diabetic peripheral neuropathy is essential. Consequently, a review of the principles that guide screening practices, especially in resource-limited clinical settings, is urgently needed.

MAIN BODY

Numerous evidence-based assessments are used to detect diabetic peripheral neuropathy. In accordance with current guideline recommendations from the American Diabetes Association, International Diabetes Federation, International Working Group on the Diabetic Foot, and National Institute for Health and Care Excellence, a screening algorithm for diabetic peripheral neuropathy based on multiphasic clinical assessment, stratification according to risk of developing diabetic foot syndrome, individualized treatment, and scheduled follow-up is suggested for use in resource-limited settings.

CONCLUSIONS

Screening for diabetic peripheral neuropathy in resource-limited settings requires a practical and comprehensive approach in order to promptly identify affected individuals. The principles of screening for diabetic peripheral neuropathy are: multiphasic approach, risk stratification, individualized treatment, and scheduled follow-up. Regular screening for diabetes-related foot disease using simple clinical assessments may improve patient outcomes.

Impact of Sulfated Hyaluronan on Bone Metabolism in Diabetic Charcot Neuroarthropathy and Degenerative Arthritis

Bone in diabetes mellitus is characterized by an altered microarchitecture caused by abnormal metabolism of bone cells. Together with diabetic neuropathy, this is associated with serious complications including impaired bone healing culminating in complicated fractures and dislocations, especially in the lower extremities, so-called Charcot neuroarthropathy (CN). The underlying mechanisms are not yet fully understood, and treatment of CN is challenging. Several in vitro and in vivo investigations have suggested positive effects on bone regeneration by modifying biomaterials with sulfated glycosaminoglycans (sGAG). Recent findings described a beneficial effect of sGAG for bone healing in diabetic animal models compared to healthy animals. We therefore aimed at studying the effects of low- and high-sulfated hyaluronan derivatives on osteoclast markers as well as gene expression patterns of osteoclasts and osteoblasts from patients with diabetic CN compared to non-diabetic patients with arthritis at the foot and ankle. Exposure to sulfated hyaluronan (sHA) derivatives reduced the exaggerated calcium phosphate resorption as well as the expression of genes associated with bone resorption in both groups, but more pronounced in patients with CN. Moreover, sHA derivatives reduced the release of pro-inflammatory cytokines in osteoclasts of patients with CN. The effects of sHA on osteoblasts differed only marginally between patients with CN and non-diabetic patients with arthritis. These results suggest balancing effects of sHA on osteoclastic bone resorption parameters in diabetes.

Inappropriate antibiotic administration in the setting of Charcot arthropathy: A case series and literature review

AIMS

Differentiating Charcot neuropathic osteoarthropathy (CN) from infection is challenging. The diagnosis of CN is often missed or delayed, resulting in inappropriate and delayed treatment. We hypothesized that the misdiagnosis of CN results in inappropriate antibiotic prescriptions and explore the sequelae of unnecessary antibiotic use.

METHODS

A retrospective review of patient electronic medical records from January 2010 to December 2017 was conducted for those diagnosed with CN after being referred to an orthopaedic foot and ankle specialist.

RESULTS

Our review showed 58 of 103 (56%) patients received antibiotics on the date, or within the next 7 days, of referral to foot and ankle orthopaedic specialist. The antibiotic of choice given on referral were as follows: Sulfamethoxazole/Trimethoprim 18 of 58 (31%), doxycycline 13 of 58 (22%), clindamycin 13 of 58 (22%), cephalexin 9 of 58 (16%), minocycline 5 of 58 (9%).

CONCLUSION

Missed diagnoses for CN are common and result in complications stemming from inappropriate treatment, delays in appropriate therapy, and may accelerate antibiotic resistance. Misdiagnosis of CN contributes to the inappropriate use of prescription antibiotics.

[The role of glycation end products in the development and progression of diabetic neuroarthropathy]

Diabetic neuroarthropathy (DNOAP, Charcot's foot) is a serious complication of diabetes mellitus, the genesis of which is not fully understood. In most cases, this pathology is diagnosed late, which leads to the development of severe deformities of the foot, up to the loss of support ability of the limb. There is no single hypothesis for the formation of Charcot's foot, but there are factors predisposing to its development, as well as a few likely provoking events. Excessive formation and accumulation of end products of glycation may play an important role in the pathogenesis of this complication of diabetes. End products of glycation (AGE) are a variety of compounds formed as a result of a non-enzymatic reaction between carbohydrates and free amino groups of proteins, lipids and nucleic acids. There are various factors that lead to the accumulation of AGE in the human body. Allocate endogenous and exogenous factors. The former include certain diseases, such as diabetes mellitus, renal failure, which accelerate glycation processes. Exogenous factors leading to the formation of lipo-oxidation and glyco-oxidation products include tobacco smoke and prolonged heat treatment of food.This review provides information on the role of glycation end products in the development and progression of complications in patients with diabetes mellitus.

Bilateral Charcot Neuroarthropathy in Pregnancy: A Case Report and Review of the Influence of Pregnancy Hormones on Ligament Laxity

OBJECTIVE

To describe the case of a woman with long-standing poorly controlled type 1 diabetes mellitus who developed bilateral Charcot foot while pregnant. To the best of our knowledge, this is the first reported case of this condition in pregnancy.

METHODS

We performed a retrospective review of physical paper medical records; electronically held laboratory results, including glycated hemoglobin; and imaging reports, including plain radiographs and magnetic resonance imaging.

RESULTS

The Charcot feet were treated by standard offloading in total-contact casts or below-knee removable walking boots. As 1 side resolved, the patient was stepped down into normal footwear on one side and a below-knee walking boot on the other. A review of the literature suggests that the increase in ligamentous laxity associated with a rise in circulating hormones, such as relaxin, increases the risk of developing Charcot neuroarthropathy.

CONCLUSION

Bilateral concurrent Charcot neuroarthropathic foot is uncommon, and to our knowledge, this is the first reported case in pregnancy. We present a possible explanation for why there is an increased risk for the development of Charcot neuroarthropathy in pregnancy.

Novel FEMASK-score, a histopathologic assessment for destructive Charcot neuropathic arthropathy, reveals intraneural vasculopathy and correlates with progression and best treatment

BACKGROUND

Charcot neuropathic arthropathy is a debilitating, rapidly destructive degenerative joint disease that occurs in diabetic, neuropathic midfoot. Clinicoradiologic assessment for Charcot neuropathic arthropathy previously relied on Eichenholtz stage. There is limited histopathologic data on this entity. We wanted to independently develop a histopathologic scoring system for Charcot neuropathic arthropathy.

DESIGN

Retrieval of surgical pathology midfoot specimens from Charcot patients (2012-2019) were analyzed to evaluate joint soft tissue and bone. Considering progression from large (≥half 40× hpf) to small (<half 40× hpf) periarticular bone fragments to resolution, we devised and applied a Charcot neuropathic arthropathy novel FEMASK-score (named after coauthors: Fanburg-Smith, Frauenhoffer, Flemming, Fritsche, Elfar, Murie, Aynardi, Stauch, Smith, King, and Klein): 0 (initial) = the observed intraneural arteriolosclerosis in all diabetic neuropathic patient specimens (not observed in other diabetic nerves); and finally scored with the most destruction observed: 1 = large bone fragments without host histiocytic response; 2 = mixed bone fragments with host histiocytic response; 3 = small minute bone spicules resorption to fibrosis. Eichenholtz stage and outcome were then compared.

RESULTS

Forty-eight cases of Charcot neuropathic arthropathy included 34 males and 14 females, mean age 60.3 and age range 28-83 years, with clinical diabetes mellitus (predominantly Type II) and longstanding neuropathy. Elevated HbA1C, Eichenholtz stage, American Society of Anesthesia score, and Charlson comorbidity index indicated initial clinical amputation. Pathologic specimens varied from fixation tissue to amputation. In addition to neurotraumatic, neurovascular and inflammatory findings, a distinctive intraneural hyalinized arteriolosclerosis was observed. FEMASK-scores: 1 = 10%, 2 = 58%, and 3 = 32%. Score comparisons were 98% accurate compared with Eichenholtz and 98% reproducible among pathologists. FEMASK 2 and 3 correlate with clinical need for amputation.

CONCLUSIONS

Our novel Charcot neuropathic arthropathy FEMASK-score classification, derived from the largest cohort of diabetic neuropathic specimens, is reproducible, explains pathophysiologic progression of destructive phase of Charcot, correlates with Eichenholtz, and predicts progression to or clinical need for amputation. The unique intraneural vasculopathy observed contributes to Charcot neuropathic arthropathy etiology.

Microscopic study of chronic charcot arthropathy foot bones contributes to understanding pathogenesis - A preliminary report

INTRODUCTION

Charcot arthropathy (CA) is non-infective, chronic destructive condition affecting the pes architecture of long standing diabetic patients with neuropathy. Even though several theories have emerged to disclose its pathogenesis, inflammatory cytokine induced osteoclastogenesis stands as the chief culprit. Studies on micro-architecture of foot bones of acute stage CA patients, describes mainly destructive phase of bone remodelling. Increased osteoclast cell activity is reported in all studies communicated. No study has to the best of our knowledge detailed the microscopic structure of chronic stage CA foot bones.

AIM

To study the microscopic structure of foot bones in patients with chronic CA.

MATERIALS AND METHODS

Foot bones were collected from the feet of chronic CA patients (six in number) who underwent corrective foot surgery in the Department of Podiatric Surgery of a tertiary care hospital. Control samples were collected from the feet of age matched non-diabetic controls (2 in number). The samples were fixed in formalin, decalcified in 10% nitric acid, processed, sectioned and stained with haematoxylin and eosin. Histopathology and histomorphometry analysis were performed by two different pathologists.

RESULTS

Trabeculae of chronic CA foot bones exhibited mainly a lamellar architecture, with reduced number of osteocytes and plenty of empty lacunae. Trabecular connectivity was lost and trabeculae showed considerable thinning. Trabecular osteoids lined by active osteoblast cells was a remarkable observation. Bone area was also considerably reduced in chronic CA foot bones.

CONCLUSION

Chronic stage CA foot bones presented features of both healing and fragile bone. The compromised bone quality may be due to thin and fragmented trabecular structure and reduced cellularity.

Charcot arthropathy of the diabetic foot in a sub-Saharan tertiary hospital: a cross-sectional study

Background

Charcot foot arthropathy is a potentially limb-threatening condition that leads to progressive destruction of the bones and joints in the neuropathic foot. One of its main causes is diabetes mellitus whose prevalence is steadily increasing. The acute phase is often misdiagnosed thus leading to foot deformity, ulceration and increased risk of amputation. There is a paucity of literature on this condition from sub-Saharan Africa. This study aimed at determining the extent of Charcot foot arthropathy, the radiological patterns of Charcot foot arthropathy and patient’s factors associated with Charcot foot arthropathy among adult patients with longstanding diabetes in an African setting.

Methods

This was a cross-sectional study that was carried at a national referral and university teaching hospital in Kampala, Uganda. One hundred patients with longstanding diabetes mellitus were consecutively recruited. Patients with a history of having diabetes mellitus for at least seven years since diagnosis were considered to have a longstanding disease. Clinical assessment of both feet was done. Weight-bearing radiographs of the selected foot were taken and evaluated using the Sanders and Frykberg and modified Eichenholtz classifications. A blood sample was taken for glycosylated haemoglobin (HbA1c). Data were summarized using descriptive statistics and student t-test.

Results

The proportion of Charcot foot arthropathy among patients with longstanding diabetes was 12% of which one-third (4 out of 12) were acute cases. Fifty percent of the lesions were in the forefoot and 50% in the midfoot. Seventeen percent of lesions were at the inflammatory stage of the modified Eichenholtz classification, 50% at the developmental stage, 25% at the healing stage, and 8% at the remodelling stage. An abnormal foot radiograph was significantly associated with Charcot foot arthropathy among patients with longstanding diabetes.

Conclusion

Charcot foot arthropathy is fairly common in patients with longstanding diabetes mellitus in these settings with one third of patients presenting in the early acute phase. An abnormal weight-bearing radiograph was an associated factor of Charcot foot arthropathy among this specific group of patients. To reduce on the morbidity and limb threatening sequelae of this condition, clinicians are therefore advised to routinely examine the feet of patients with diabetes and send those with suspicious signs and symptoms for radiographic assessment.

Excess Cost and Healthcare Resources Associated With Delayed Diagnosis of Charcot Foot

The purpose of the present study was to demonstrate the effect of a delayed diagnosis of Charcot foot on acute care cost and usage. We used International Classification of Disease, Ninth Revision, Clinical Modification codes, and the California Office for Statewide Health Planning and Development 2009 to 2012 public patient discharge files to identify patients with type 2 diabetes mellitus and Charcot foot. The costs and length of stay were compared for those with a diagnosis of Charcot foot on admission compared with those who received a delayed diagnosis of Charcot foot before discharge. Patient demographic data, diagnoses often mistaken for Charcot foot, and procedures often performed for Charcot foot were assessed to determine the potential effect on costs and length of stay in Charcot foot subjects. A delayed Charcot foot diagnosis was associated with 10.8% greater inpatient costs and 12.1% longer length of stay. These patients required greater resource usage owing to the significantly greater number of procedures performed. A significantly greater number of patients underwent lower extremity amputation when the diagnosis was delayed, resulting in a 30.4% increase in costs and 31.6% longer length of stay. A greater rate of diabetic foot ulcers, foot infections, and osteomyelitis was also observed; however, the cost was only affected by osteomyelitis, and the length of stay was not significantly affected. A delayed diagnosis of Charcot foot at admission resulted in significantly increased acute care costs and longer lengths of stay.

Role of bisphosphonates in the management of acute Charcot foot

Diabetes mellitus is the most common cause of Charcot neuropathy affecting foot and ankle. Acute Charcot foot (CF) presents with a red and swollen foot in contrast to the painless deformed one of chronic CF. Enhanced osteoclastogenesis plays a central role in the pathogenesis of acute CF. Many studies have shown elevated levels of bone turnover markers in patients with acute CF confirming it. These findings have led clinicians to use anti-resorptive agents [bisphosphonates (BP), calcitonin, and denosumab] along with immobilization and offloading in acute CF patients. The maximum evidence among all anti-resorptive agents is available for BPs, although its quality is low. Pamidronate has been shown to reduce the markers of activity of CF like raised skin temperature, pain, edema, and bone turnover markers in the majority of studies. Intravenous BPs are known to cause acute phase reactions leading to flu-like illness following their first infusion, which can be ameliorated by oral acetaminophen. Alendronate is the only oral BP used in these patients. It needs to be taken on an empty stomach with a full glass of water to avoid esophagitis. The side-effects and contraindications to BPs should be kept in mind while treating acute CF patients with them.

Circulating microparticles in acute diabetic Charcot foot exhibit a high content of inflammatory cytokines, and support monocyte-to-osteoclast cell induction

Circulating microparticles (MPs) are major mediators in cardiovascular complications of type 2 diabetes (T2D); however, their contribution to Charcot foot (CF) disease is not known. Here, we purified and assessed the origin, concentration and content of circulating MPs from 33 individuals: 11 with T2D and acute CF, 11 T2D patients with equivalent neuropathy and 11 non-diabetic controls. First, we demonstrated that there were no differences in the distribution of MPs of endothelial, platelet origin among the 3 groups. However, MPs from leukocytes and monocytes origin were increased in CF patients. Moreover, we demonstrated that monocytes-derived MPs originated more frequently from intermediate and non-classical monocytes in CF patients. Five cytokines (G-CSF, GM-CSF, IL-1-ra, IL-2 and IL-16) were significantly increased in MPs from acute CF patients. Applying ingenuity pathways analysis, we found that those cytokines interacted well and induced the activation of pathways that are involved in osteoclast formation. Further, we treated THP-1 monocytes and monocytes sorted from healthy patients with CF-derived MPs during their differentiation into osteoclasts, which increased their differentiation into multinucleated osteoclast-like cells. Altogether, our study suggests that circulating MPs in CF disease have a high content of inflammatory cytokines and could increase osteoclast differentiation in vitro.

Pathogenesis and potential relative risk factors of diabetic neuropathic osteoarthropathy

Diabetic neuropathic osteoarthropathy (DNOAP) is an uncommon, but with considerable morbidity and mortality rates, complication of diabetes. The real pathogenesis is still unclear. The two popular theories are the neuro-vascular theory and neuro-traumatic theory. Most theories and pathways focused on the uncontrolled inflammations that resulted in the final common pathway, receptor activator of nuclear factor κβ ligand (RANKL)/osteoprotegerin (OPG) axis, for the decreased bone density in DNOAP with an osteoclast and osteoblast imbalance. However, the RANKL/OPG pathway does not explain all the changes, other pathways and factors also play roles. A lot of DNOAP potential relative risk factors were evaluated and reported in the literature, including age, gender, weight, duration and type of diabetes, bone mineral density, peripheral neuropathy and arterial disease, trauma history, and some others. However, most of them are still in debates. Future studies focus on the pathogenesis of DNOAP are still needed, especially for the genetic factors. And, the relationship between DNOAP and those potential relative risk factors are still need to further clarify.