Acute Charcot neuro-osteoarthropathy

A Review of Immunomodulatory Reprogramming by Probiotics in Combating Chronic and Acute Diabetic Foot Ulcers (DFUs)

Diabetic foot ulcers (DFUs) are characterized by a lack of angiogenesis and distal limb diabetic neuropathy. This makes it possible for opportunistic pathogens to protect the biofilm-encased micro-communities, causing a delay in wound healing. The acute and chronic phases of DFU-associated infections are distinguished by the differential expression of innate proinflammatory cytokines and tumor necrosis factors (TNF-α and -β). Efforts are being made to reduce the microbial bioburden of wounds by using therapies such as debridement, hyperbaric oxygen therapy, shock wave therapy, and empirical antibiotic treatment. However, the constant evolution of pathogens limits the effectiveness of these therapies. In the wound-healing process, continuous homeostasis and remodeling processes by commensal microbes undoubtedly provide a protective barrier against diverse pathogens. Among commensal microbes, probiotics are beneficial microbes that should be administered orally or topically to regulate gut-skin interaction and to activate inflammation and proinflammatory cytokine production. The goal of this review is to bridge the gap between the role of probiotics in managing the innate immune response and the function of proinflammatory mediators in diabetic wound healing. We also highlight probiotic encapsulation or nanoformulations with prebiotics and extracellular vesicles (EVs) as innovative ways to tackle target DFUs.

Increased synovial expression of calcitonin gene-related peptide and its potential roles in Charcot Neuroarthropathy

OBJECTIVE

Joint destruction in Charcot neuroarthropathy (CNA) is accompanied with abundant hyperplastic synovium. This study aimed to characterize the expression patterns of a group of neuropeptides in the CNA synovium.

METHODS

Synovial specimens were collected during surgery from the CNA (n = 6) and non-CNA joints (n = 14). Tissue samples were processed for protein extraction and western blot for vasoactive intestinal peptide (VIP), galanin, and calcitonin gene-related peptide (CGRP). Immunohistochemistry was performed to localize CGRP in the CNA synovium. Additionally, CGRP was applied to fibroblast-like synoviocytes (FLS) isolated from CNA synovium for its effects on cell proliferation and collagenolysis in vitro.

RESULTS

Western blot detected light bands of VIP in the CNA samples but abundant galanin in both CNA and non-CNA samples. Most of the CNA samples (5/6) increased expression of CGRP, with an average band density about 2 times that in the non-CNA group (p < .05). Immunohistochemistry of CGRP demonstrated intense staining in the intimal layer of the CNA synovium. In tissue culture, adding CGRP (10 nM) in the medium promoted FLS proliferation. In combination with TNF-α, CGRP enhanced FLS-mediated collagenolysis in vitro.

CONCLUSION

This study revealed an increased expression of CGRP in the CNA synovium and demonstrated that CGRP regulates FLS proliferation and collagenolytic activity, suggesting CGRP may contribute to the bone and cartilage destruction in CNA.

Diabetes Mellitus: An Overview in Relationship to Charcot Neuroarthropathy

Diabetes mellitus with the lack of glycemic control increases risks for developing comorbidities affecting organ systems responsible for critical function. The development of diabetic neuropathy predisposes patients to the onset of Charcot neuroarthropathy (CN). There is significant complexity with treatment of diabetic-induced CN, which can have an often delayed or missed diagnosis. Supervision and treatment from trained specialists are required to provide care for this multifaceted disease process. It is essential for patients to partner with glucose control, comorbidity prevention and care, as well as lower extremity management. Ultimately, CN can result in significant lower extremity deformity placing patients at risk of limb and life.

Trends in the relation between hyperglycemia correction and active Charcot neuroarthropathy: results from the EPICHAR study

INTRODUCTION

The pathophysiology of Charcot neuroarthropathy (CN) remains unclear. There are a number of hypotheses but these are not exclusive. In its clinical presentation, this complication intersects with the semiology of diabetic-induced neuropathy, such as peripheral hypervascularization and the appearance of arteriovenous shunt. The EPICHAR study is as yet an unpublished cohort of people living with diabetes complicated by CN (in active or chronic phase). Based on the findings of the EPICHAR study, this study aimed to investigate whether a reduction in the rate of hyperglycemia accompanies the onset of an active phase of CN.

RESEARCH DESIGN AND METHODS

Hemoglobin A1c (HbA1c) levels were assessed 3 months (M3) and 6 months (M6) before the diagnosis of active CN (M0).

RESULTS

103 patients living with diabetes and presenting active CN were included between January and December 2019 from the 31 centers participating in this study (30 in France and 1 in Belgium). The mean age of the participants was 60.2±12.2 years; the vast majority were men (71.8%) living with type 2 diabetes (75.5%). Mean HbA1c levels significantly declined between M6 (median 7.70; Q1, Q3: 7.00, 8.55) and M3 (median 7.65; Q1, Q3: 6.90, 8.50) (p=0.012), as well as between M6 and M0 (median 7.40; Q1, Q3: 6.50, 8.50) (p=0.014). No significant difference was found between M3 and M0 (p=0.072).

CONCLUSIONS

A significant reduction in HbA1c levels seems to accompany the onset of the active phase of CN.

TRIAL REGISTRATION NUMBER

NCM03744039.

Predictive Radiographic Values for Foot Ulceration in Persons with Charcot Foot Divided by Lateral or Medial Midfoot Deformity

Background: To identify differences in radiographic outcomes in weight-bearing lateral X-ray to predict the probability of ulceration in patients with midfoot Charcot neuroarthropathy (CN) differentiated by lateral and medial column deformities. Methods: Thirty-five patients who suffered from CN midfoot deformity participated in this 1 year prospective study in a specialized diabetic foot unit. Lateral talar-first metatarsal angle, calcaneal pitch, and cuboid height were performed by digital radiographs in the weight-bearing lateral view. Patients were followed up for 1 year or until an ulcer ulceration event occurred in the midfoot region. Results: ROC analyses showed that all patients with medial pattern deformity that developed a midfoot ulcer had a lateral talar-first metatarsal angle greater (negative) than −27.5 degrees (°). All patients with lateral pattern deformity that developed a midfoot ulcer had a calcaneal pitch greater (more negative) than −5° and a cuboid height greater (more negative) than −1.5°. Conclusions: Lateral talar-first metatarsal angle was the greatest predictor of midfoot ulceration, with greater than −27.5° measurement correlating with ulceration occurrence in patients with medial deformity. Calcaneal pitch and cuboid height were the greatest predictors of midfoot ulceration with greater than −5 and −1.5°, respectively in patients with CN lateral deformity.

Long-term foot outcomes following differential abatement of inflammation and osteoclastogenesis for active Charcot neuroarthropathy in diabetes mellitus

AIMS

Inflammatory osteolysis is sine-qua-non of active Charcot neuroarthropathy (CN) causing decreased foot bone mineral density (BMD) and fractures. We aimed to explore the effect of anti-inflammatory or anti-resorptive agents for effect on foot bone mineral content (BMC) and consequent long-term outcomes of foot deformities, fractures and amputation.

METHODS

Forty-three patients with active CN (temperature difference >2°C from normal foot) were evaluated. Patients were off-loaded with total contact cast and randomized to receive either methylprednisolone (1gm) (group A), zoledronate (5mg) (group B) or placebo (100ml normal saline) (group C) once monthly infusion for three consecutive months. Change in foot BMC was assessed at 6 months or at remission and followed subsequently up to 4 years for the incidence of new-onset fracture, deformities, or CN recurrence.

RESULTS

Thirty-six participants (24 male, 12 female) were randomized (11 in group A, 12 group B, 13 group C). The mean age was 57.7± 9.9 years, duration of diabetes 12.3± 5.8 years and symptom duration 6.5± 2.8 weeks. BMC increased by 36% with zoledronate (p = 0.02) but reduced by 13% with methylprednisolone (p = 0.03) and 9% (p = 0.09) with placebo at remission. There were no incident foot fractures, however, two patients sustained ulcers, and 3 had new-onset or worsening deformities and none required amputation during 3.36 ± 0.89 years of follow-up.

CONCLUSION

Bisphosphonate for active CN is associated with an increase in foot bone mineral content as compared to decrease with steroids or total contact cast but long-term outcomes of foot deformities, ulceration and amputation are similar.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03289338.

Effect of Recombinant Human Parathyroid Hormone (1-84) on Resolution of Active Charcot Neuro-osteoarthropathy in Diabetes: A Randomized, Double-Blind, Placebo-Controlled Study

OBJECTIVE

Fractures in Charcot neuro-osteoarthropathy (CN) often fail to heal despite prolonged immobilization with below-knee casting. The aim of the study was to assess the efficacy of recombinant human parathyroid hormone (PTH) in reducing time to resolution of CN and healing of fractures.

RESEARCH DESIGN AND METHODS

People with diabetes and acute (active) Charcot foot were randomized (double-blind) to either full-length PTH (1-84) or placebo therapy, both in addition to below-knee casting and calcium and vitamin D3 supplementation. The primary outcome was resolution of CN, defined as a skin foot temperature difference >2°C at two consecutive monthly visits.

RESULTS

Median time to resolution was 5 months (95% CI 4, 12) in intervention and 6 months (95% CI 2, 9) in control. On univariate mixed Cox and logistic regression, there was no significant difference in time to resolution between the groups (P = 0.64) or in the likelihood of resolution (P = 0.66). The hazard ratio of resolution was 0.84 (95% CI 0.41, 1.74; P = 0.64), and the odds ratio of resolution by 12 months was 0.80 (95% CI 0.3, 2.13; P = 0.66) (intervention vs. control). On linear regression analysis, there were no significant differences in the effect of treatment on fracture scores quantitated on MRI scans (coefficient 0.13 [95% CI -0.62, 0.88]; P = 0.73) and on foot and ankle X-rays (coefficient 0.30 [95% CI -0.03, 0.63]; P = 0.07).

CONCLUSIONS

This double-blind placebo-controlled trial did not reduce time to resolution or enhance fracture healing of CN. There was no added benefit of daily intervention with PTH (1-84) to below-knee casting in achieving earlier resolution of CN.

Predictive values of foot plantar pressure assessment in patients with midfoot deformity secondary to Charcot neuroarthropathy

AIMS

The principal aim of this study was to identify a cut-off point along the spectrum of peak plantar midfoot pressure that has an optimum combination of sensitivity and specificity to screen for neuropathic ulceration in patients with Charcot neuroarthropathy (CN).

METHODS

A 1-year outcome study was performed in twenty-five patients with diabetes, affected with chronic CN midfoot deformity. Peak plantar pressure (PPP) and pressure/time Integral (PTI) in the midfoot region were registered. For selecting the optimal diagnostic cut-off points on the scale of pressure measurement, ROC curves were used.

RESULTS

Twelve (48%) patients developed a plantar midfoot ulcer. Baseline PPP (24.04 ± 6.33 Vs. 12.85 ± 3.29 N/cm²) and PTI (11.89 ± 4.60 Vs. 5.42 ± 2.26 N/cm²/s) were significantly higher in the ulcerated group (p < .001 and p < .001, respectively). Using ROC analyses, optimal cut-off point for PPP was 16.45 N/cm², yielding a sensitivity of 92% and a specificity of 85%; and for PTI, optimal cut-off point was 7.2 N/cm²/s, yielding a sensitivity of 92% and a specificity of 77%.

CONCLUSIONS

Patients with CN midfoot deformity with cut-off values for PPP of 16.45 N/cm² and PTI of 7.2 N/cm²/s showed an elevated risk of neuropathic ulceration in the plantar area of the midfoot.

Long-term outcome of persons with diabetic and non-diabetic neuro-osteoarthropathy after foot correction using external fixation

AIM

Diabetic neuro-osteoarthropathy (Charcot foot) is a serious form of diabetic foot syndrome, often leading to severe deformity of the foot and subsequently to ulcers and osteomyelitis. The aim of this retrospective study was to determine the success rate and long-term outcomes for a Charcot foot operation using external fixation in 115 individuals who underwent surgery between July 2008 and December 2012.

METHODS

Some 115 consecutive persons, 78 (68%) men and 37 (32%) women, were enrolled in this study. The eligibility criterion for this retrospective study was reconstructive foot surgery using a Hoffmann II external fixator in diabetic and non-diabetic neuro-osteoarthropathy. The main examination parameters in the follow-up were walking ability, amputation and mortality. Average follow-up was 5.7 (± 3.2) years.

RESULTS

Ninety-seven per cent of people were able to walk after the operation with bespoke shoes or an orthosis. At follow-up, 77% were able to walk and 51% were fully mobile even outside the home. Subsequent amputations were performed in 29 individuals (26%), with 17 (15%) minor and 12 (11%) major amputations. Forty-seven individuals died before follow-up, the majority (53%) from cardiovascular events. Average survival time post surgery was 4.5 (± 2.9) years.

CONCLUSION

Reconstruction surgery using external fixation is a very useful method for maintaining walking ability in the case of conservatively non-treatable diabetic and non-diabetic neuro-osteoarthropathy. Individuals with severe Charcot foot disease had a low rate of major amputations. Osteomyelitis was the main reason for major amputations.

Foot ulcer recurrence, plantar pressure and footwear adherence in people with diabetes and Charcot midfoot deformity: A cohort analysis

AIMS

To investigate people with Charcot midfoot deformity with regard to plantar pressure, footwear adherence and plantar foot ulcer recurrence.

METHODS

Twenty people with diabetes, Charcot midfoot deformity, plantar foot ulcer history and custom-made footwear were assessed with regard to barefoot and in-shoe plantar pressures during walking, footwear adherence (% of daily steps over 7-day period) and plantar foot ulcer recurrence over 18 months. In a cohort design, they were compared to 118 people without Charcot foot (non-Charcot foot group) with custom-made footwear and similar ulcer risk factors.

RESULTS

Median (interquartile range) barefoot midfoot peak pressures were significantly higher in the Charcot foot group than in the non-Charcot foot group [756 (260-1267) vs 146 (100-208) kPa; P<0.001]. In-shoe midfoot peak pressures were not significantly higher in the Charcot foot group [median (interquartile range) 152 (104-201) vs 119 (94-160) kPa] and significantly lower for all other foot regions. Participants in the Charcot foot group were significantly more adherent, especially at home, than participants in the non-Charcot foot group [median (interquartile range) 94.4 (85.4-95.0)% vs. 64.3 (25.4-85.7)%; P=0.001]. Ulcers recurred in 40% of the Charcot foot group and in 47% of the non-Charcot foot group (P=0.63); midfoot ulcers recurred significantly more in the Charcot foot group (4/8) than in the non-Charcot foot group (1/55; P=0.001).

CONCLUSIONS

Effective offloading and very high footwear adherence were found in people with diabetes and Charcot midfoot deformity. While this may help protect against plantar foot ulcer recurrence, a large proportion of such people still experience ulcer recurrence. Further improvements in adherence and custom-made footwear design may be required to improve clinical outcome.

Why the Risk of Developing Neuroarthropathy Is Higher After Simultaneous Kidney and Pancreatic Transplantation Compared to Kidney Transplantation Only: The Role of Euglycemia

Charcot’s neuroarthropathy is a destructive complication of the joint, which is often found in patients living with diabetes. Despite the fact that its description was published almost 100 years ago, its pathophysiology, diagnosis, and treatment remain areas that need to be updated. Its prevalence is low in patients living with diabetes, but this increases in particular situations such as peripheral neuropathy, as well as after simultaneous kidney-pancreas transplantation (SPKT) in patients living with type 1 diabetes. We suggest that the development of neuroarthropathy after SPK in not only due to glucocorticoid therapy, as described, but also to the rapid passage into euglycemia. The reduced prevalence of neuroarthropathy after only kidney transplantation compared to SPK seems to validate our hypothesis.

The Role of Bone Scintigraphy with SPECT/CT in the Characterization and Early Diagnosis of Stage 0 Charcot Neuroarthropathy

We describe the use of Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) in the investigation and diagnosis of Charcot neuroarthropathy (CN) in patients with a hot swollen foot but normal radiographs and clinical suspicion of CN, usually termed Stage 0. This was a retrospective cohort review of 46 diabetes patients who underwent 3 phase bone scintigraphy with “High Resolution” SPECT/CT. The imaging demonstrated that Stage 0 Charcot foot has a distinct bone pathology, which can be classified into three groups: (1) fractures on Computed Tomography (CT) with accompanying focal uptake of tracer on SPECT, (2) bony abnormalities apart from fracture on CT with focal uptake of tracer on SPECT, and (3) normal CT but focal bony uptake of tracer on SPECT. The CT component of SPECT/CT detected bony fractures in 59% of patients. Early treatment with below knee cast and follow-up for 24 months showed only 4 patients who developed Stage 1 Eichenholtz Charcot foot. Our findings support the use of 3 phase bone scintigraphy with SPECT/CT in the characterization and early diagnosis of CN. Stage 0 Charcot foot has a distinct bone pathology which requires urgent treatment to prevent progression to Stage 1 Eichenholtz Charcot foot. If SPECT/CT is unavailable, CT alone will detect bone fracture in 59% patients.

An overview of Charcot's neuroarthropathy

Charcot's neuroarthropathy is a destructive complication of the joints, which is often found in people with diabetes with peripheral neuropathy. Despite the fact that its description was published almost 130 years ago, its pathophysiology, diagnosis, and treatment remain areas that need to be described. Thanks to the use of bone remodelling, new therapeutic classes have emerged, we hope that this review will shed light on the pathology from its discovery through to the current state of knowledge on its classification, diagnosis and treatment methods.

A review of bone metabolism and developments in medical treatment of the diabetic Charcot foot

Charcot foot is a rare but severe, and possibly limb-threatening, complication to neuropathy and diabetes mellitus. The current treatment consists of long-term off-loading, and has a large negative impact on the patient's life. Much research has gone into understanding the condition and its biochemical mechanisms, however, the underlying pathogenesis of a Charcot foot is not yet fully understood. In the recent decades several key advances in our understanding of the Charcot foot have been made, both in regards to the changes in bone metabolism and structure an acute Charcot foot can cause, and to the molecular pathways involved in this. This review summerizes the available research into the bone metabolism around a Charcot foot, with an emphasis on the biochemical profile. The existing data regarding attempts at medical treatment is also reviewed, including novel trials targetting specific inflammatory pathways upregulated in the acute diabetic Charcot foot.

Differentially expressed circulating microRNAs in the development of acute diabetic Charcot foot

Aim:

Charcot foot (CF) is a rare complication of Type 2 diabetes (T2D).

Materials & methods:

We assessed circulating miRNAs in 17 patients with T2D and acute CF (G1), 17 patients with T2D (G2) and equivalent neuropathy and 17 patients with T2D without neuropathy (G3) using the high-throughput miRNA expression profiling.

Results:

51 significantly deregulated miRNAs were identified in G1 versus G2, 37 in G1 versus G3 and 64 in G2 versus G3. Furthermore, we demonstrated that 16 miRNAs differentially expressed between G1 versus G2 could be involved in osteoclastic differentiation. Among them, eight are key factors involved in CF pathophysiology.

Conclusion:

Our data reveal that CF patients exhibit an altered expression profile of circulating miRNAs.

Diagnostic performance of diffusion-weighted MR imaging in differentiation of diabetic osteoarthropathy and osteomyelitis in diabetic foot

PURPOSE

To study the diagnostic performance of diffusion weighted MR imaging in differentiation of diabetic osteoarthropathy and osteomyelitis in diabetic foot.

PATIENTS AND METHODS

This prospective study was carried out on 41 patients with diabetic foot, 22 males and 19 females with mean age of 51 years. They underwent diffusion-weighted MR imaging of the foot. The apparent diffusion coefficient (ADC) values of the bony lesions were calculated by two reviewers and correlated with the surgical findings or biopsy. The kappa statistic (k) was used to estimate the proportion of inter-observer agreement of two reviewers.

RESULTS

The mean ADC of acute diabetic osteoarthropathy was 1.27±0.19×10^-3mm²/s for reviewer 1 and 1.26±0.21×10^-3mm²/s for reviewer 2. The mean ADC value in diabetic osteomyelitis was 0.86±0.11×10^-3mm²/s for reviewer 1 and 0.85±0.12×10^-3mm²/s for reviewer 2. There was excellent inter-observer agreement of ADC value of bony lesions in diabetic foot by both reviewers (K=0.93). There was statistically significant difference in the ADC values of both groups (P=0.001). The cut-off point of ADC value of both reviewers used in differentiating acute diabetic osteoarthropathy and osteomyelitis were 0.98×10^-3mm²/s and 1.04×10^-3mm²/s with an accuracy of 94% and 93% and area under the curve of 0.94 and 0.93 respectively.

CONCLUSION

We conclude that the ADC value is a non-invasive imaging parameter that can help in differentiation of diabetic osteoarthropathy from osteomyelitis with excellent inter-observer agreement.

Novel Semiquantitative Bone Marrow Oedema Score and Fracture Score for the Magnetic Resonance Imaging Assessment of the Active Charcot Foot in Diabetes

There are no accepted methods to grade bone marrow oedema (BMO) and fracture on magnetic resonance imaging (MRI) scans in Charcot osteoarthropathy. The aim was to devise semiquantitative BMO and fracture scores on foot and ankle MRI scans in diabetic patients with active osteoarthropathy and to assess the agreement in using these scores. Three radiologists assessed 45 scans (Siemens Avanto 1.5T, dedicated foot and ankle coil) and scored independently twenty-two bones (proximal phalanges, medial and lateral sesamoids, metatarsals, tarsals, distal tibial plafond, and medial and lateral malleoli) for BMO (0-no oedema, 1-oedema < 50% of bone volume, and 2-oedema > 50% of bone volume) and fracture (0-no fracture, 1-fracture, and 2-collapse/fragmentation). Interobserver agreement and intraobserver agreement were measured using multilevel modelling and intraclass correlation (ICC). The interobserver agreement for the total BMO and fracture scores was very good (ICC = 0.83, 95% confidence intervals (CI) 0.76, 0.91) and good (ICC = 0.62; 95% CI 0.48, 0.76), respectively. The intraobserver agreement for the total BMO and fracture scores was good (ICC = 0.78, 95% CI 0.6, 0.95) and fair to moderate (ICC = 0.44; 95% CI 0.14, 0.74), respectively. The proposed BMO and fracture scores are reliable and can be used to grade the extent of bone damage in the active Charcot foot.

Outcome after protected full weightbearing treatment in an orthopedic device in diabetic neuropathic arthropathy (Charcot arthropathy): a comparison of unilaterally and bilaterally affected patients

Background

Charcot neuropathic arthropathy (CN) is a chronic, progressive, destructive, non-infectious process that most frequently affects the bone architecture of the foot in patients with sensory neuropathy. We evaluated the outcome of protected weightbearing treatment of CN in unilaterally and bilaterally affected patients and secondarily compared outcomes in protected versus unprotected weightbearing treatment.

Methods

Patient records and radiographs from 2002 to 2012 were retrospectively analyzed. Patients with Type 1 or Type 2 diabetes with peripheral neuropathy were included. Exclusion criteria included immunosuppressive or osteoactive medication and the presence of bone tumors. Ninety patients (101 ft), mean age 60.7 ± 10.6 years at first diagnosis of CN, were identified. Protected weightbearing treatment was achieved by total contact cast or custom-made orthosis. Ulcer, infection, CN recurrence, and amputation rates were recorded. Mean follow-up was 48 (range 1–208) months.

Results

Per the Eichenholtz classification, 9 ft were prodromal, 61 in stage 1 (development), 21 in stage 2 (coalescence) and 10 in stage 3 (reconstruction). Duration of protected weightbearing was 20 ± 21 weeks and 22 ± 29 weeks in patients with unilateral and bilateral CN, respectively. In bilaterally affected patients, new ulcers developed in 9/22 (41%) feet. In unilaterally affected patients, new ulcers developed in 5/66 (8%) protected weightbearing feet and 4/13 (31%) unprotected, full weightbearing feet (p = 0.036). The ulceration rate was significantly higher in bilaterally versus unilaterally affected patients with a protected weightbearing regimen (p = 0.004). Soft tissue infection occurred in 1/13 (8%) unprotected weightbearing feet and 1/66 (2%) protected weightbearing feet in unilaterally affected patients, and in 1/22 (4%) protected weightbearing feet of bilaterally affected patients. Recurrence and amputation rates were similar across treatment modalities.

Conclusions

Bilateral CN results in significantly more ulcers than unilateral CN and leads to slightly higher soft tissue infections. Protected weightbearing in an orthopedic device can reduce the risk for complications in acute CN of the foot and ankle.