Confronting a dramatic situation: the charcot foot complicated by osteomyelitis

Diagnostic imaging of the diabetic foot: an EANM evidence-based guidance

PURPOSE

Consensus on the choice of the most accurate imaging strategy in diabetic foot infective and non-infective complications is still lacking. This document provides evidence-based recommendations, aiming at defining which imaging modality should be preferred in different clinical settings.

METHODS

This working group includes 8 nuclear medicine physicians appointed by the European Association of Nuclear Medicine (EANM), 3 radiologists and 3 clinicians (one diabetologist, one podiatrist and one infectious diseases specialist) selected for their expertise in diabetic foot. The latter members formulated some clinical questions that are not completely covered by current guidelines. These questions were converted into statements and addressed through a systematic analysis of available literature by using the PICO (Population/Problem-Intervention/Indicator-Comparator-Outcome) strategy. Each consensus statement was scored for level of evidence and for recommendation grade, according to the Oxford Centre for Evidence-Based Medicine (OCEBM) criteria.

RESULTS

Nine clinical questions were formulated by clinicians and used to provide 7 evidence-based recommendations: (1) A patient with a positive probe-to-bone test, positive plain X-rays and elevated ESR should be treated for presumptive osteomyelitis (OM). (2) Advanced imaging with MRI and WBC scintigraphy, or [18F]FDG PET/CT, should be considered when it is needed to better evaluate the location, extent or severity of the infection, in order to plan more tailored treatment. (3) In a patient with suspected OM, positive PTB test but negative plain X-rays, advanced imaging with MRI or WBC scintigraphy + SPECT/CT, or with [18F]FDG PET/CT, is needed to accurately assess the extent of the infection. (4) There are no evidence-based data to definitively prefer one imaging modality over the others for detecting OM or STI in fore- mid- and hind-foot. MRI is generally the first advanced imaging modality to be performed. In case of equivocal results, radiolabelled WBC imaging or [18F]FDG PET/CT should be used to detect OM or STI. (5) MRI is the method of choice for diagnosing or excluding Charcot neuro-osteoarthropathy; [18F]FDG PET/CT can be used as an alternative. (6) If assessing whether a patient with a Charcot foot has a superimposed infection, however, WBC scintigraphy may be more accurate than [18F]FDG PET/CT in differentiating OM from Charcot arthropathy. (7) Whenever possible, microbiological or histological assessment should be performed to confirm the diagnosis. (8) Consider appealing to an additional imaging modality in a patient with persisting clinical suspicion of infection, but negative imaging.

CONCLUSION

These practical recommendations highlight, and should assist clinicians in understanding, the role of imaging in the diagnostic workup of diabetic foot complications.

Surgical OFF-LOADING of the diabetic foot

Diabetic foot ulcer treatment is a challenge for the healthcare world. Widespread infection and the presence of critical ischemia (especially with end-stage renal disease) can lead to major amputation rather than amenable to conservative treatment. Surgical strategies of the diabetic foot have been changing over the past 10 years and are now focused on reconstructive treatment and limb salvage. These goals were achieved, thanks to an evolution of distal revascularization techniques and a distinct approach, which integrates various methods focused on limb salvage. Podoplastic techniques of the diabetic foot are focused on infection clearance, the surgical treatment of corrective deformities, soft tissue coverage and limb ischemia correction along with the management of diabetes and the comorbidities that compromise tissue repair processes. The reconstructive techniques used in diabetic foot treatment owe their effectiveness in part to the results of technological improvements such as the circular external fixator as a tool for stabilization and surgical site protection. In the last decade, many studies have shown that circular external fixation should be considered as the most useful method to protect the reconstructive surgical site in limb salvage of the diabetic foot. The objective of this review is to highlight the role of surgical offloading using circular external fixation as an adjunct to the podoplastic diabetic foot reconstruction procedures.

Ocular Manifestations and Neuropathy in Type 2 Diabetes Patients With Charcot Arthropathy

OBJECTIVE

Diabetes can affect the eye in many ways beyond retinopathy. This study sought to evaluate ocular disease and determine any associations with peripheral neuropathy (PN) or cardiac autonomic neuropathy (CAN) in type 2 diabetes (T2D) and Charcot arthropathy (CA) patients.

DESIGN

A total of 60 participants were included, 16 of whom were individuals with T2D/CA, 21 of whom were individuals with T2D who did not have CA, and 23 of whom were healthy controls. Ocular surface evaluations were performed, and cases of dry eye disease (DED) were determined using the Ocular Surface Disease Index (OSDI) questionnaire, ocular surface staining, Schirmer test, and Oculus Keratograph 5M exams. All variables were used to classify DED and ocular surface disorders such as aqueous deficiency, lipid deficiency, inflammation, and ocular surface damage. Pupillary and retinal nerve fiber measurements were added to the protocol in order to broaden the scope of the neurosensory ocular evaluation. PN and CAN were ascertained by clinical examinations involving the Neuropathy Disability Score (for PN) and Ewing's battery (for CAN).

RESULTS

Most ocular variables evaluated herein differed significantly between T2D patients and controls. When the controls were respectively compared to patients with T2D and to patients with both T2D and CA, they differed substantially in terms of visual acuity (0.92 ± 0.11, 0.73 ± 0.27, and 0.47 ± 0.26, p=0.001), retinal nerve fiber layer thickness (96.83 ± 6.91, 89.25 ± 10.44, and 80.37 ± 11.67 µm, p=0.03), pupillometry results (4.10 ± 0.61, 3.48 ± 0.88, and 2.75 ± 0.81 mm, p=0.0001), and dry eye symptoms (9.19 ± 11.71, 19.83 ± 19.08, and 24.82 ± 24.40, p=0.03). DED and ocular surface damage also differed between individuals with and without CA, and were associated with PN and CAN.

CONCLUSION

CA was found to be significantly associated with the severity of ocular findings. DED in cases of CA was also associated with PN and CAN. These findings suggest that intrinsic and complex neurosensory impairment in the eyes, peripheral sensory nerves, and the autonomic nervous system are somehow connected. Thus, a thorough ocular evaluation may be useful to highlight neurological complications and the impact of diabetes on ocular and systemic functions and structures.

Surgical treatment of midfoot Charcot neuroarthropathy with osteomyelitis in patients with diabetes: a systematic review

OBJECTIVE

A wide range of clinical presentations of Charcot neuroarthropathy of the foot with concomitant osteomyelitis in patients with diabetes has been described. Existing literature provides an equally diverse list of treatment options. The purpose of this systematic review was to assess the outcomes specifically for the surgical management of midfoot Charcot neuroarthropathy with osteomyelitis in patients with diabetes.

METHOD

A systematic review was conducted by three independent reviewers using the following databases and search engines: Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Library, EMBASE (Excerpta Medica dataBASE), Google Scholar, Ovid, PubMed and Scopus. Search terms used were: Charcot neuroarthropathy, osteoarthropathy, neuro-osteoarthropathy, neurogenic arthropathy, osteomyelitis, midfoot, foot, ankle, diabetes mellitus, ulceration, wound, infection, surgical offloading, diabetic reconstruction, internal fixation, external fixation. Studies meeting the following criteria were included: English language studies, studies published from 1997-2017, patients with diabetes mellitus surgically treated for Charcot neuroarthropathy of the midfoot (specified location) with concomitant osteomyelitis, with or without internal and/or external fixation, follow-up period of six months or more postoperatively, documentation of healing rates, complications, and need for revisional surgery. Studies which were entirely literature reviews, descriptions of surgical-only technique and/or cadaveric studies, patients without diabetes, studies that did not specify location of osteomyelitis and Charcot neuroarthropathy, and treatment proximal to and including Chopart's/midtarsal joint specifically talonavicular, calcaneocuboid, subtalar, ankle were excluded.

RESULTS

A total of 13 selected studies, with a total of 114 patients with diabetes of which 56 had surgical treatment for midfoot Charcot neuroarthropathy with osteomyelitis, met the above inclusion criteria and were used for data extraction.

CONCLUSION

Surgical intervention for midfoot Charcot neuroarthropathy with osteomyelitis in patients with diabetes demonstrated a relatively high success rate for a range of procedures including debridement with simple exostectomy, arthrodesis with or without internal or external fixation, and advanced soft tissue reconstruction. However, this systematic review emphasises the need for larger, better designed studies to investigate the efficacy and failure rates of surgical treatment in this group of patients.

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.

Treatment of Charcot Neuroarthropathy and osteomyelitis of the same foot: a retrospective cohort study

BACKGROUND

We evaluated treatment of osteomyelitis in the foot in the presence of Charcot neuroarthropathy, a devastating condition with progressive degeneration and joint destruction. We hypothesized that there was a difference in (1) amputation rate, (2) amputation level, (3) duration of antibiotic therapy, and (4) duration of immobilization for treatment of osteomyelitis within versus outside the Charcot zone.

METHODS

Forty patients (43 ft) diagnosed with Charcot neuroarthropathy and osteomyelitis of the same foot were retrospectively analyzed. Some patients were successfully treated for osteomyelitis at different sites on the same foot at different times, thus 60 cases of osteomyelitis were identified in 40 treated patients. Cases were divided according to osteomyelitis localization: Group 1 had osteomyelitis outside the active Charcot region; Group 2 had osteomyelitis within the active Charcot region.

RESULTS

Male patients (n = 29; mean age 58.2, range 40.1 to 77.5 years) were younger than female patients (n = 11; mean age 70.4, range 51.4 to 87.5, p = 0.02 years). Amputation rate was 52% overall (26/40 patients; 26/43 ft): 63% of 30 Group 1 cases and 40% of 30 Group 2 cases (p = 0.09). Amputation level (p = 0.009), duration of antibiotic treatment (p = 0.045) and duration of immobilization (p = 0.01) differed significantly between the groups.

CONCLUSIONS

Osteomyelitis within the Charcot region is associated with a higher level of amputation and longer durations of antibiotic therapy and immobilization. Osteomyelitis outside and within the Charcot affected region should be considered separately. If osteomyelitis occurs outside the active Charcot region, primary amputation may be preferred to internal resection.

LEVEL OF EVIDENCE

Retrospective cohort chart review study.

Neuropathic Minimally Invasive Surgeries (NEMESIS):: Percutaneous Diabetic Foot Surgery and Reconstruction

Patients with peripheral neuropathy associated with ulceration are the nemesis of the orthopedic foot and ankle surgeon. Diabetic foot syndrome is the leading cause of peripheral neuropathy, and its prevalence continues to increase at an alarming rate. Poor wound healing, nonunion, infection, and risk of amputation contribute to the understandable caution toward this patient group. Significant metalwork is required to hold these technically challenging deformities. Neuropathic Minimally Invasive Surgeries is an addition to the toolbox of management of the diabetic foot. It may potentially reduce the risk associated with large wounds and bony correction in this patient group.