Diagnostic value of procalcitonin, erythrocyte sedimentation rate (ESR), quantitative C-reactive protein (CRP) and clinical findings associated with osteomyelitis in patients with diabetic foot

Comparison of Procalcitonin Levels in Diabetic Foot Ulcer Infection and Osteomyelitis: A Systematic Review and Meta-Analysis

BackgroundFoot ulcers represent a major complication in patients with diabetes and are often challenging for clinicians. Distinguishing between infected and non-infected diabetes foot ulcers (DFUs) can prevent many irreversible injuries such as inappropriate antibiotic therapy, amputation, and even death. Procalcitonin (PCT) has been proposed in the diagnosis of infection and osteomyelitis in diabetes foot ulcers. The present study aimed to compare PCT levels between patients with and without infected diabetes foot ulcer (IDFU).MethodThis review searched three databases including PubMed, Web of Science, and Scopus to identify all articles reporting PCT levels in two groups of infected diabetes foot ulcer (IDFU) and non-infected diabetes foot ulcer (NIDFU). Quality has been assessed using the NIH tool. The pooled mean difference (MD) of PCT level between groups was estimated by random effect meta-analysis. In addition, The PRISMA 2020 statement has been used to update guidelines for reporting present systematic reviews.ResultTwenty-three studies were eligible for meta-analysis, of which data from 2412 people was extracted. Pooled estimation of PCT level was significantly higher in IDFU patients compared with NIDFU patients (MD = 0.25 ng/l, 95% CI: 0.14-0.37). According to the meta-analysis results, PCT level was not significantly higher in patients with Osteomyelitis compared with those without Osteomyelitis (MD = 0.59 ng/l, 95% CI: -0.19, 1.38, I2 = 98.5%).ConclusionSince the results of the present study showed higher PCT levels in patients with IDFU compared to those without, it can be suggested that procalcitonin might be applied as an additional biomarker for the differentiation of NIDFU from IDFU. It needs more evidence to conclude about the role of PCT in terms of osteomyelitis and amputation.

Lower extremity infections: Essential anatomy and multimodality imaging findings

In modern practice, imaging plays an integral role in the diagnosis, evaluation of extent, and treatment planning for lower extremity infections. This review will illustrate the relevant compartment anatomy of the lower extremities and highlight the role of plain radiographs, CT, US, MRI, and nuclear medicine in the diagnostic workup. The imaging features of cellulitis, abscess and phlegmon, necrotizing soft tissue infection, pyomyositis, infectious tenosynovitis, septic arthritis, and osteomyelitis are reviewed. Differentiating features from noninfectious causes of swelling and edema are discussed.

Update of biomarkers to diagnose diabetic foot osteomyelitis: A meta-analysis and systematic review

The aim of this study was to evaluate the diagnostic characteristics of biomarker for diabetic foot osteomyelitis (DFO). We searched PubMed, Scopus, Embase and Medline for studies who report serological markers and DFO before December 2022. Studies must include at least one of the following diagnostic parameters for biomarkers: area under the curve, sensitivities, specificities, positive predictive value, negative predictive value. Two authors evaluated quality using the Quality Assessment of Diagnostic Accuracy Studies tool. We included 19 papers. In this systematic review, there were 2854 subjects with 2134 (74.8%) of those patients being included in the meta-analysis. The most common biomarkers were erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and procalcitonin (PCT). A meta-analysis was then performed where data were evaluated with Forrest plots and receiver operating characteristic curves. The pooled sensitivity and specificity were 0.72 and 0.75 for PCT, 0.72 and 0.76 for CRP and 0.70 and 0.77 for ESR. Pooled area under the curves for ESR, CRP and PCT were 0.83, 0.77 and 0.71, respectfully. Average diagnostic odds ratios were 16.1 (range 3.6-55.4), 14.3 (range 2.7-48.7) and 6.7 (range 3.6-10.4) for ESR, CRP and PCT, respectfully. None of the biomarkers we evaluated could be rated as 'outstanding' to diagnose osteomyelitis. Based on the areas under the curve, ESR is an 'excellent' biomarker to detect osteomyelitis, and CRP and PCT are 'acceptable' biomarkers to diagnose osteomyelitis. Diagnostic odds ratios indicate that ESR, CRP and PCT are 'good' or 'very good' tools to identify osteomyelitis.

Diagnostic Performance of Atherogenic Index of Plasma for Predicting Diabetic Foot Osteomyelitis with Peripheral Artery Disease

Background: This study aims to assess the atherogenic index of plasma (AIP) diagnostic value in detecting diabetic foot osteomyelitis (DFO) among patients with diabetic foot ulcers (DFUs). Methods: A prospective cohort study was conducted on 80 patients with DFUs and suspected DFO between January 2022 and December 2023. The primary outcome measures included the diagnosis of DFO, determined by positive microbiological analysis results from bone samples and its correlation with the AIP. Receiver operating characteristic (ROC) curves were utilized to select the optimal diagnostic cut-off points for AIP and post hoc analysis was performed to evaluate the difference in the AIP for diagnosing DFO in patients with and without peripheral arterial disease (PAD). Results: The diagnostic potential for DFO in PAD patients of AIP-1 (Log TC/HDL) showed an AUC of 0.914 (p < 0.001 [0.832-0.996]), leading to a sensitivity of 83% and a specificity of 85%. By contrast, AIP-2 (Log TG/HDL) demonstrated a slightly lower AUC of 0.841 (p < 0.001 [0.716-0.967]), leading to a sensitivity of 76% and a specificity of 74%. Conclusions: The AIP tool, with its ideal blend of sensitivity and specificity, aids in predicting DFO effectively. Therefore, clinicians should consider using AIP for patients suffering from PAD and associated DFO.

The infected diabetic foot: Modulation of traditional biomarkers for osteomyelitis diagnosis in the setting of diabetic foot infection and renal impairment

The objective of this paper was to investigate erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP) in diagnosing pedal osteomyelitis (OM) in patients with and without diabetes, and with and without severe renal impairment (SRI). This was a retrospective cohort study of patients with moderate and severe foot infections. We evaluated three groups: Subjects without diabetes (NDM), subjects with diabetes and without severe renal insufficiency (DM-NSRI), and patients with diabetes and SRI (DM-SRI). SRI was defined as eGFR <30. We evaluated area under the curve (AUC), cutoff point, sensitivity and specificity to characterize the accuracy of ESR and CRP to diagnose OM. A total of 408 patients were included in the analysis. ROC analysis in the NDM group revealed the AUC for ESR was 0.62, with a cutoff value of 46 mm/h (sensitivity, 49.0%; specificity, 76.0%). DM-NSRI subjects showed the AUC for ESR was 0.70 with the cutoff value of 61 mm/h (sensitivity, 68.9%; specificity 61.8%). In DM-SRI, the AUC for ESR was 0.67, with a cutoff value of 119 mm/h (sensitivity, 46.4%; specificity, 82.40%). In the NDM group, the AUC for CRP was 0.55, with a cutoff value of 6.4 mg/dL (sensitivity, 31.3%; specificity, 84.0%). For DM-NSRI, the AUC for CRP was 0.70, with a cutoff value of 8 mg/dL (sensitivity, 49.2%; specificity, 80.6%). In DM-SRI, the AUC for CRP was 0.62, with a cutoff value of 7 mg/dL (sensitivity, 57.1%; specificity, 67.7%). While CRP demonstrated relatively consistent utility, ESR's diagnostic cutoff points diverged significantly. These results highlight the necessity of considering patient-specific factors when interpreting ESR results in the context of OM diagnosis.

Investigation and management of diabetic foot osteomyelitis: An update for the foot and ankle orthopaedic surgeon

Diabetic foot osteomyelitis (DFO) poses a significant challenge in the management of diabetic patients, often leading to severe complications and increased morbidity. Effective management of DFO requires a multidisciplinary approach, involving endocrinologists, infectious disease specialists, vascular surgeons, orthopaedic surgeons, and wound care experts. Early diagnosis is paramount, facilitated by advanced imaging techniques such as magnetic resonance imaging (MRI) and bone scintigraphy. Once diagnosed, the treatment strategy hinges on a combination of medical and surgical interventions. Antibiotic therapy, guided by culture results, plays a central role in managing DFO. Tailored regimens targeting the specific pathogens involved are administered, often for prolonged durations. Surgical intervention becomes necessary when conservative measures fall short. Surgical approaches range from minimally invasive procedures, like percutaneous drainage, to more extensive interventions like debridement and bone resection. Prevention of DFO recurrence is equally vital, emphasising glycemic control, meticulous foot care, patient education, monitoring of at-risk signs, revascularization and early intervention when indicated. The management of diabetic foot osteomyelitis mandates a comprehensive strategy that addresses both the infectious and surgical aspects of the condition. A collaborative, interdisciplinary approach ensures timely diagnosis, tailored treatment, and holistic care. Further research into novel therapeutic modalities and long-term outcomes remains essential in refining the management of this complex and debilitating complication of diabetes.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

A New Inflammatory Marker of Clinical and Diagnostic Importance in Diabetic Foot Infection: Systemic Immune-Inflammation Index

Diabetes and associated complications still pose an important public health problem. Osteomyelitis as especially seen in patients with diabetes is associated with increased rates of morbidity and mortality. The present study aimed to investigate the clinical and diagnostic significance of inflammatory markers, including the systemic immune-inflammation index (SII) and erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and procalcitonin (PCT) to differentiate osteomyelitis and cellulitis. The present study included 96 patients with osteomyelitis (Group 1) and 151 patients with cellulitis (Group 2). Inflammatory markers were significantly elevated in Group 1 compared to Group 2 patients (p < 0.05). Furthermore, the correlation coefficients (rho) between SII and ESR, CRP, and PCT were 0.466 (p < 0.001), 0.627 (p < 0.001), and 0.501 (p < 0.001), respectively, as a result of Spearman's Rho analysis. Accordingly, a moderately positive relationship was found between the variables. The area under the curve (AUC) values for SII, ESR, CRP, and PCT in diabetic foot infection patients with osteomyelitis were 0.687, 0.722, 0.692, and 0.641, respectively. As a result of the Likelhood Ratio (LR) test, the cut-off values were 2.182 for SII (sensitivity: 39.8% and specificity: 79.8%), 76.5 mm/h for ESR (sensitivity: 59.1% and specificity: 73.1%), 109.5 mg/mL for CRP (sensitivity: 40.9% and specificity: 79.8%), and 0.44 ng/mL for PCT (sensitivity: 26.1% and specificity: 88.2%). In conclusion, given that the patients with osteomyelitis had much higher ESR, CRP, PCT, and SII levels combined with the fact that SII is a low-cost and easy-to-measure index, suggests that the same may serve as an effective and novel marker alternative to other inflammatory markers for predicting diabetic foot osteomyelitis.

Extra-pulmonary applications of procalcitonin: an updated literature review

INTRODUCTION

: Procalcitonin (PCT) is a biomarker with established performance in the differentiation between bacterial and viral infections, predominantly in pulmonary infections, as well as the diagnosis and prognosis of bacterial sepsis. However, the role of PCT in extra-pulmonary infections is not well described.

AREAS COVERED

: We reviewed the role of PCT in commonly experienced extra-pulmonary infections including meningitis, diabetic foot infection, prosthetic joint infection, osteomyelitis, and skin and soft tissue infection. PubMed and Medline online libraries were searched, from 2013 till 2022, for relevant articles.

EXPERT OPINION

: For meningitis, PCT could distinguish bacterial from viral meningitis. PCT distinguished septic arthritis from different types of arthritis but had variable performance in discriminating septic arthritis from crystal arthropathy. For periprosthetic joint infections, results were inconclusive. PCT had a potential role in diagnosis of more complex infections such as osteomyelitis and diabetic foot infections, but further studies are needed for a definitive cutoff. In skin and soft tissue infections, PCT performance was more variable requiring further investigation to define cutoff for the discrimination of cellulitis from necrotizing fasciitis. We find that PCT performed best for meningitis and helps in the reduction of unnecessary antibiotic treatment, but has variable outcomes with other extra-pulmonary infections.

Surgical Treatment of Diabetic Foot and Ankle Osteomyelitis

A review of the literature regarding the evaluation and management of osteomyelitis and discussion on clinical, radiographic, laboratory, and pathologic findings with both acute and chronic cases is presented. Cases illustrate the complexities that can typically present at an academic setting, which often require a stepwise approach and interdisciplinary collaboration. Surgical pearls and ancillary treatment of osteomyelitis highlight the technical challenges and surgeons' preferences.