Controversies in diagnosing and managing osteomyelitis of the foot in diabetes

Magnetic Resonance Imaging and 99Tc WBC-SPECT/CT Scanning in Differential Diagnosis between Osteomyelitis and Charcot Neuroarthropathy: A Case Series

BACKGROUND

Distinguishing between Charcot Neuroarthropathy (CN), osteomyelitis (OM), and CN complicated with superimposed OM in diabetic patients is crucial for the treatment choice. Given that current diagnostic methods lack specificity, advanced techniques, e.g., magnetic resonance imaging (MRI) and 99mTc-HMPAO-WBC Single Photon Emission Computed Tomography (SPECT/CT), are needed. This study addresses the challenges in distinguishing OM and CN.

METHODS

We included diabetic patients with CN and soft tissue ulceration. MRI and 99mTc-HMPAO-WBC SPECT/CT were used for the diagnosis. The patients were classified into three probability levels for OM (i.e., Definite, Probable, and Unlikely) according to the Consensus Criteria for Diabetic Foot Osteomyelitis (CC-DFO).

RESULTS

Eight patients met the eligibility criteria. MRI, supported by SPECT-CT and CC-DFO, showed consistency with the OM diagnosis in three cases. The key diagnostic features included the location of signal abnormalities and secondary features such as skin ulcers, sinus tracts, and abscesses. Notably, cases with inconclusive MRI were clarified by SPECT/CT, emphasizing its efficacy in challenging scenarios.

CONCLUSIONS

The primary objective of this study was to compare the results of MRI and 99mTc-HMPAO-WBC SPECT/CT with the CC-DFO score in the diabetic foot with CN and suspected OM. Advanced imaging offers a complementary approach to distinguish between CN and OM. This can help delineate the limits of the disease for presurgical planning. While MRI is valuable, 99mTc-HMPAO-WBC SPECT/CT provides additional clarity, especially in challenging cases or when metallic implants affect MRI accuracy.

Neutrophil Extracellular Traps (NETs) Are Associated with Type 2 Diabetes and Diabetic Foot Ulcer Related Amputation: A Prospective Cohort Study

INTRODUCTION

The prevalence of diabetes mellitus and its sequelae has been on the rise, and diabetic foot ulcer (DFU) is the leading cause of non-traumatic lower limb amputation globally. The rising occurrence and financial burden associated with DFU necessitate improved clinical assessment and treatment. Diabetes has been found to enhance the formation of neutrophil extracellular traps (NETs) by neutrophils, and excessive NETs have been implicated in tissue damage and impaired wound healing. However, there is as yet insufficient evidence to clarify the value of NETs in assessing and predicting outcomes of DFU.

METHODS

We designed this prospective study with three cohorts formed from type 2 diabetes mellitus (T2DM) patients with DFU (n = 200), newly diagnosed T2DM patients (n = 42), and healthy donors (n = 38). Serum levels of NETs were detected for all groups, and the prognostic value for DFU-related amputation was analyzed.

RESULTS

The results showed that serum NET levels of the DFU group were significantly higher than in the T2DM group (P < 0.05), which also had significantly elevated serum NET levels compared to healthy donors (P < 0.05). Multivariate Cox regression showed that serum NET levels, diabetic foot surgical history, and Wagner grade were the risk factors for amputation (P < 0.05), and these three variables also exhibited the highest coefficient values in additional Lasso Cox regression. For patients with DFU, Kaplan-Meier curves showed that high serum NET levels associated with higher amputation probability (HR = 0.19, P < 0.01) and ROC curve based on NET value showed good validity for amputation (AUC: 0.727, CI 0.651-0.803).

CONCLUSION

Elevated serum NET levels serve as an easily accessible serological prognostic marker for assessing the risk of DFU-related amputation, thereby offering evaluation metrics for healthcare providers. Further investigations are necessary to understand the mechanisms driving this relationship.

Diagnostic criteria and core outcome set development for necrotising otitis externa: the COSNOE Delphi consensus study

OBJECTIVE

Evidence for necrotising otitis externa (NOE) diagnosis and management is limited, and outcome reporting is heterogeneous. International best practice guidelines were used to develop consensus diagnostic criteria and a core outcome set (COS).

METHODS

The study was pre-registered on the Core Outcome Measures in Effectiveness Trials (COMET) database. Systematic literature review identified candidate items. Patient-centred items were identified via a qualitative study. Items and their definitions were refined by multidisciplinary stakeholders in a two-round Delphi exercise and subsequent consensus meeting.

RESULTS

The final COS incorporates 36 items within 12 themes: Signs and symptoms; Pain; Advanced Disease Indicators; Complications; Survival; Antibiotic regimes and side effects; Patient comorbidities; Non-antibiotic treatments; Patient compliance; Duration and cessation of treatment; Relapse and readmission; Multidisciplinary team management.Consensus diagnostic criteria include 12 items within 6 themes: Signs and symptoms (oedema, otorrhoea, granulation); Pain (otalgia, nocturnal otalgia); Investigations (microbiology [does not have to be positive], histology [malignancy excluded], positive CT and MRI); Persistent symptoms despite local and/or systemic treatment for at least two weeks; At least one risk factor for impaired immune response; Indicators of advanced disease (not obligatory but mut be reported when present at diagnosis). Stakeholders were unanimous that there is no role for secondary, graded, or optional diagnostic items. The consensus meeting identified themes for future research.

CONCLUSION

The adoption of consensus-defined diagnostic criteria and COS facilitates standardised research reporting and robust data synthesis. Inclusion of patient and professional perspectives ensures best practice stakeholder engagement.

The Differentiation Between Infection and Acute Charcot

The differentiation between acute Charcot neuroarthropathy and infection in the foot and ankle should be supported by multiple criteria. A detailed history and physical examination should always be completed. Plain radiographs should be performed, though advanced imaging, currently MRI, is more helpful in diagnosis. Scintigraphy and PET may become the standard imaging modalities once they are more clinically available due to their reported increased accuracy. Laboratory analysis can also act as a helpful diagnostic tool. Histopathology with culturing should be performed if osteomyelitis is suspected. The prompt diagnosis and initiation of treatment is vital to reducing patient morbidity and mortality.

A systematic review of antimicrobial treatment regimens and their outcomes in necrotising otitis externa

BACKGROUND

Necrotising otitis externa is a serious infection with minimal evidence underpinning its management. This review aims to synthesise published evidence of antimicrobial therapies and their outcomes in necrotising otitis externa.

METHODS

The review was PROSPERO registered (CRD42022353244) and conducted according to Preferred Reporting Items for Systematic Review and Meta-Analyses ('PRISMA') guidelines. A robust search strategy filtered 28 manuscripts into the final review. Antimicrobial therapy and clinical outcome data were extracted and analysed.

RESULTS

Published studies are heterogeneous, with high risk of bias and low certainty. Reporting of outcomes is poor and extremely variable. First-line therapy is most commonly in-patient (95 per cent) empiric fluoroquinolone (68 per cent) delivered intravenously (82 per cent). The lack of granular data and poor outcome reporting mean it is impossible to correlate treatment strategies with clinical outcomes.

CONCLUSION

Robust, consistent outcome reporting with reference to treatments administered is mandatory, to inform clinical management and optimise future research. Optimal antimicrobial choices and treatment strategies require clarification through prospective clinical trials.

Comorbid status in patients with osteomyelitis is associated with long-term incidence of extremity amputation

INTRODUCTION

Osteomyelitis is associated with significant morbidity, including amputation. There are limited data on long-term amputation rates following an osteomyelitis diagnosis. We sought to determine the incidence of amputation in patients with osteomyelitis over 2 years.

RESEARCH DESIGN AND METHODS

Observational cohort study of 1186 inpatients with osteomyelitis between 2004 and 2015 and stratified by osteomyelitis location status to evaluate the impact on amputation, mortality rates, readmission data, and inpatient days.

RESULTS

Persons with diabetes had 3.65 times greater probability of lower extremity amputation (p<0.001), readmission (p<0.001), and longer inpatient stay (p<0.001) and had higher 2-year mortality (relative risk (RR) 1.23, p=0.0027), adjusting for risk factors. Male gender (RR 1.57, p<0.001), black race (RR 1.41, p<0.05), former smoking status (RR 1.38, p<0.01), myocardial infarction (RR 1.72, p<0.001), congestive heart failure (RR 1.56, p<0.001), peripheral vascular disease (RR 2.25, p<0.001) and renal disease (RR 1.756, p<0.001) were independently associated with amputation. Male gender (RR 1.39, p<0.01), black race (RR 1.27, p<0.05), diabetes (RR 2.77, p<0.001) and peripheral vascular disease (RR 1.59, p<0.001) had increased risk of lower, not upper, extremity amputation.

CONCLUSIONS

Patients with osteomyelitis have higher rates of amputation and hospitalization. Clinicians must incorporate demographic and comorbid risk factors to protect against amputation.

Evaluating Predictive Value of Surgical Resected Proximal Bone Margins in Diabetic Foot Osteomyelitis With Clinical Outcomes at 1 Year

Background

Osteomyelitis of the diabetic foot remains a significant complication that may result in the need for amputation. Proximal surgical margin histopathology after limb-sparing amputation could be used to guide antimicrobial duration and prognostic management but remains debatable. Here we evaluate if negative proximal bone margins predict outcomes of diabetic foot osteomyelitis at 1 year.

Methods

A retrospective study assessed adults with diabetes undergoing limb-sparing foot amputations from September 2016 to September 2019. Patients required histopathology confirmation of osteomyelitis, proximal margin histopathology report, and documented electronic medical record follow-up through 12 months. The primary outcome evaluated if no further amputation at the same site was required in the following 12 months.

Results

Of 92 patients, 57 (61.9%) had pathology-confirmed negative margins for osteomyelitis. Patients with negative margins required less frequent subsequent amputations at the same site within 12 months compared to positive margins (86.0% vs 65.7%; P = .003). Antibiotic duration was shorter in patients with negative margins (mean, 18 vs 30 days; P = .001). Negative-margin patients also noted lower rates of readmission at 12 months (26.3% vs 51.4%; P = .015) for site-specific complications. Staphylococcus aureus was more predominant in patients with positive versus negative margins (57.1% vs 29.8%; P = .017).

Conclusions

Negative proximal bone margin by histopathology was associated with lower frequency of further amputations at the index surgical site within 12 months. This group also received shorter courses of antibiotic therapy. It was also associated with lower rates of readmission at 12 months for surgical-site complications. Proximal margin histopathology results potentially can be integrated to guide antimicrobial duration and decrease the frequency of further amputation at the original site.

The internal pedal amputation as a salvage procedure in diabetic and ischemic foot infection. A meta-analysis

BACKGROUND

Osteomyelitis of the diabetic foot is a very challenging condition and amputation is often indicated. In some cases where the infection is localized and the surrounding soft tissue is mildly involved, an internal pedal amputation (IPA) based on resection and limited excision of the infected bone have been suggested as a viable option. This systematic review aims to look for the effectiveness of this technique in treating selected cases of diabetic foot osteomyelitis.

METHODS

A systematic literature search was conducted using multiple electronic databases from inception. Eight studies met the inclusion criteria; one retrospective comparative study, six retrospective observational studies and one prospective observational study.

RESULTS

Based on a pooled sample of 545 patients followed over a mean period of 27.7 ± 15.2 months, the weighted results were as follows: (a) healing rate was 87.7% (95% CI = 0.757-0.959), (b) time for healing was 7.1 ± 2.9 weeks, (c) wound infection rate was 5.6% (95% CI = 0.030-0.089), (d) wound dehiscence rate was 8% (95% CI = 0.010-0.204), (e) ulcer recurrence rate was of 10% (95% CI = 0.037-0.188), and (f) amputation rate was 2.8% (95% CI = 0.001-0.085) whilst all were minor amputations.

CONCLUSION

The findings support the selection of toe/ray sparing surgery via IPA as a viable surgical option for selected cases of focal osteomyelitis secondary to diabetic foot infection. The results would indicate that when the ulcer size could be adequately reduced, removing the infected bone while preserving the soft tissue envelope could yield high chance of success with few serious complications.

Amputation versus Primary Nonoperative Management of Chronic Osteomyelitis Involving a Pedal Digit in Diabetic Patients

BACKGROUND

The preferred primary treatment of toe osteomyelitis in diabetic patients is controversial. We compared the outcome of primary nonoperative antibiotic treatment versus digital amputation in patients with diabetes-related chronic digital osteomyelitis.

METHODS

We conducted a retrospective medical record review of patients treated for digital osteomyelitis at a single center. Patients were divided into two groups according to initial treatment: 1) nonoperative treatment with intravenous antibiotics and 2) amputation of the involved toe or ray. Duration of hospitalization, number of rehospitalizations, and rate of below- or above-the-knee major amputations were evaluated.

RESULTS

The nonoperative group comprised 39 patients and the operative group included 21 patients. The mean ± SD total duration of hospitalization was 24.05 ± 15.43 and 20.67 ± 15.97 days, respectively (P = .43). The mean ± SD number of rehospitalizations after infection recurrence was 2.62 ± 1.63 and 1.67 ± 1.24, respectively (P = .02). During follow-up, the involved digit was eventually amputated in 13 of the 39 nonoperatively treated patients (33.3%). The rate of major amputation (above- or below-knee amputation was four of 39 (10.3%) and three of 21 (14.3%), respectively (P = .69).

CONCLUSIONS

Despite a higher rate of rehospitalizations and a high failure rate, in patients with mild and limited digital foot osteomyelitis in the absence of sepsis it may be reasonable to offer a primary nonoperative treatment for digital osteomyelitis of the foot.

Treating Diabetic Foot Osteomyelitis: A Practical State-of-the-Art Update

Background and Objectives: Diabetic foot osteomyelitis (DFO) can be difficult to treat and securing optimal clinical outcomes requires a multidisciplinary approach involving a wide variety of medical, surgical and other health care professionals, as well as the patient. Results of studies conducted in the past few years have allowed experts to formulate guidelines that can improve clinical outcomes. Material and Methods: We conducted a narrative review of the literature on treat- ment of DFO, with an emphasis on studies published in the last two years, especially regarding antimicrobial therapies and surgical approached to treatment of DFO, supplemented by our own extensive clinical and research experience in this field. Results: Major amputations were once com- mon for DFO but, with improved diagnostic and surgical techniques, "conservative" surgery (foot- sparing, resecting only the infected and necrotic bone) is becoming commonplace, especially for forefoot infections. Traditional antibiotic therapy, which has been administered predominantly in- travenously and frequently for several months, can often be replaced by appropriately selected oral antibiotic regimens following only a brief (or even no) parenteral therapy, and given for no more than 6 weeks. Based on ongoing studies, the recommended duration of treatment may soon be even shorter, especially for cases in which a substantial portion of the infected bone has been resected. Using the results of cultures (preferably of bone specimens) and antimicrobial stewardship princi- ples allows clinicians to select evidence-based antibiotic regimens, often of a limited pathogen spec- trum. Intra-osseous antimicrobial and surgical approaches to treatment are also evolving in light of ongoing research. Conclusions: In this narrative, evidenced-based review, taking consideration of principles of antimicrobial stewardship and good surgical practice, we have highlighted the recent literature and offered practical, state-of-the-art advice on the antibiotic and surgical management of DFO.

Microbiological evaluation of resection margins of the infected diabetic foot ulcer

AIM

To evaluate the impact of surgical debridement on the microbiology of resection margins of an infected diabetic foot ulcer and to compare the use of marginal sampling as a guide for antimicrobial therapy.

METHODS

Forty consecutive participants were studied. Tissue samples from infected diabetic foot ulcers were obtained at first contact by podiatrists. After surgical debridement to macroscopically healthy tissue, multiple samples were obtained from the margins of the residuum and also from excised non-viable tissue. Debridement was done by a single surgeon. Bacterial species were classified according to pathogenic potential a priori into Red Group-Definite pathogen causing infection, Yellow Group-Likely to be causing infection if present in more than one specimen and Green Group -Commensals, not causing infection.

RESULTS

There was a relative reduction of 49% (p = 0.002) in bacteria in the most pathogenic (red) group, and 59% (p = 0.002) in the yellow group in podiatry samples compared with resection specimen. Positive cultures from margins of the residuum were observed in 75% of cases. There was a relative reduction of 67% (p = 0.0001) in bacteria in the red and 48% (p = 0.06) in the yellow group in marginal samples from the residuum compared with podiatry samples.

CONCLUSIONS

After surgical debridement to healthy tissue, positive cultures from marginal tissue samples provided vital information on the presence of pathogenic bacteria. This allowed antibiotics to be individualised post-surgical debridement.

Species-Specific Immunoassay Aids Identification of Pathogen and Tracks Infectivity in Foot Infection

BACKGROUND

Conventional bacterial cultures frequently fail to identify the dominant pathogen in polymicrobial foot infections, in which Staphylococcus aureus is the most common infecting pathogen. Previous work has shown that species-specific immunoassays may be able to identify the main pathogen in musculoskeletal infections. We sought to investigate the clinical applicability of a S. aureus immunoassay to accurately identify the infecting pathogen and monitor its infectivity longitudinally in foot infection. We hypothesized that this species-specific immunoassay could aid in the diagnosis of S. aureus and track the therapeutic response in foot infections.

METHODS

From July 2015 to July 2019, 83 infected foot ulcer patients undergoing surgical intervention (debridement or amputation) were recruited and blood was drawn at 0, 4, 8, and 12 weeks. Whole blood was analyzed for S. aureus-specific serum antibodies (mix of historic and new antibodies) and plasmablasts were isolated and cultured to quantify titers of newly synthesized antibodies (NSAs). Anti-S. aureus antibody titers were compared with culture results to assess their concordance in identifying S. aureus as the pathogen. The NSA titer changes at follow-ups were compared with wound healing status to evaluate concordance between evolving host immune response and clinically resolving or relapsing infection.

RESULTS

Analysis of serum for anti-S. aureus antibodies showed significantly increased titers of 3 different anti-S. aureus antibodies, IsdH (P = .037), ClfB (P = .025), and SCIN (P = .005), in S. aureus culture-positive patients compared with culture-negative patients. Comparative analysis of combining antigens for S. aureus infection diagnosis increased the concordance further. During follow-up, changes of NSA titers against a single or combination of S. aureus antigens significantly correlated with clinically resolving or recurring infection represented by wound healing status.

CONCLUSION

In the management of foot infection, the use of S. aureus-specific immunoassay may aid in diagnosis of the dominant pathogen and monitoring of the host immune response against a specific pathogen in response to treatment. Importantly, this immunoassay could detect recurrent foot infection, which may guide a surgeon's decision to intervene.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

The Infected Diabetic Foot: Re-evaluating the Infectious Diseases Society of America Diabetic Foot Infection Classification

BACKGROUND

We provide evidence to revise the Infectious Diseases Society of America (IDSA) diabetic foot infection classification by adding a separate tier for osteomyelitis and evaluating if moderate and severe infection criteria improve the classification's ability to direct therapy and determine outcomes.

METHODS

We retrospectively evaluated 294 patients with moderate and severe infections. Osteomyelitis was confirmed by bone culture or histopathology. Soft tissue infection (STI) was based on negative bone culture, magnetic resonance imaging, or single-photon emission computed tomography. We stratified STI and osteomyelitis using IDSA criteria for moderate and severe infections and compared outcomes and complications.

RESULTS

Osteomyelitis patients had greater antibiotic duration (32.5 ± 46.8 vs 63.8 ± 55.1 days; P < .01), surgery frequency (55.5% vs 99.4%; P < .01), number of surgeries (2.1 ± 1.3 vs 3.3 ± 2.3; P < .01), amputations (26.3% vs 83.4%; P < .01), reinfection (38.0% vs 56.7%; P < .01), and length of stay (14.5 ± 14.9 vs 22.6 ± 19.0 days; P < .01). There were no differences in moderate and severe STI outcomes except for infection readmissions (46.2% vs 25.0%; P = .02), and acute kidney injury (31.2% vs 50.0%; P = .03). There were no differences in moderate and severe osteomyelitis except the number of surgeries (2.8 ± 2.1 vs 4.1 ± 2.5; P < .01) and length of stay (18.6 ± 17.5 vs 28.2 ± 17.7; P < .01).

CONCLUSIONS

The IDSA classification better reflects outcomes if risk categories are stratified by STI or osteomyelitis and moderate and severe infections are not categorized separately.

Chopart Amputation: Questioning the Clinical Efficacy of a Long-standing Surgical Option for Diabetic Foot Infection

BACKGROUND

Diabetic foot ulcers with associated infection and osteomyelitis often lead to partial or complete limb loss. Determination of the appropriate level for amputation based on the patient's baseline physical function, extent of infection, vascular patency, and comorbidities can be challenging. Although Chopart amputation preserves greater limb length than more proximal alternatives such as Syme or below-the-knee amputations (BKA), challenges with wound healing and prosthesis fitting have been reported. We aimed to investigate the functional and clinical outcomes of Chopart amputation combined with tendon transfers.

METHODS

We identified patients who underwent Chopart amputations for diabetic foot infections by an academic orthopaedic group between August 2013 and September 2018. Subjects completed three Patient-Reported Outcomes Measurement Information Systems (PROMIS) instruments. Incidence of postoperative complications and change in patient-reported outcomes before and after surgery were recorded.

RESULTS

Eighteen patients with an average age of 60.8 (range, 44 to 79) years were identified. The mean follow-up was 22.8 months (range, 6.7 to 51.0). Seventeen of the 18 total patients developed postoperative wound complications. These lead to revision amputations in 10 Chopart amputees, consisting of two Syme and eight BKAs. Half of the Chopart patients never received a prosthesis because of delayed wound healing and revision amputation. PROMIS physical function (PF) (31.1 pre-op and 28.6 post-op), pain interference (63.1 pre-op and 59.4 post-op), and depression (53.0 pre-op and 54.8 post-op) did not show significant change (P-values = 0.38, 0.29, 0.72, respectively). Pre- and post-op the PROMIS physical function scores were well below the US average.

DISCUSSION

In our patient cohort, 94% of patients developed postoperative wound complication. Only 44% of patients ever successfully ambulated with a prosthesis after Chopart amputation, and the others (56%) required revision amputations such as a BKA. Even after wound healing, Chopart amputees may struggle with obtaining a prosthesis suitable for ambulation. Surgeons should exercise judicious patient selection before performing Chopart amputation.

LEVEL OF EVIDENCE

IV, Case Series.

Diagnosing Osteomyelitis: A Histology Guide for Pathologists

Histopathologic examination of bone specimens coupled with bone culture is considered the gold standard for the diagnosis of osteomyelitis (OM). Despite this, studies have demonstrated interpathologist agreement in the diagnosis of OM as low as 30%, largely stemming from a lack of specific definitions and diagnostic criteria. Review of the literature has provided insight into the lifecycle of OM, illustrating the histologic progression of OM phases from acute to chronic, and provides support for defining subcategories of OM. Using an algorithmic histopathologic tool consisting of 15 criteria, each with an associated score, we defined 5 categories of OM: (1) acute OM, (2) acute and chronic OM, (3) chronic OM, (4) chronic active OM, and (5) chronic inactive OM. We reviewed 462 microscopic slides from 263 patients with suspected OM, and for each slide, we determined an algorithm-derived diagnosis, which was then used to calculate a total histopathologic load score (Jupiter score). Algorithm-derived diagnoses recapitulated original clinical diagnoses and diagnosed cases as OM that had not been originally diagnoses. These novel cases were more likely to have subsequent clinical complications. Finally, pathologic load scores were assessed for association with the category of OM.

Early Advanced Therapy for Diabetic Foot Ulcers in High Amputation Risk Veterans: A Cohort Study

Veterans with diabetic foot ulcers (DFUs) represent the highest percentage of lower extremity amputations (LEAs) within the Veterans Affairs (VA) population. Many veterans have additional risk factors for amputation. Few studies focus on advanced therapies for this population. This study explores the impact of early application of dehydrated human amniotic membrane allograft (DAMA) with comprehensive care on preventing amputation. This prospective, single-center cohort study (ClinicalTrials.gov Identifier NCT02632929) was conducted through Boise VA Medical Center. Patients with DFUs were objectively stratified for LEA risk. Those with moderate to high amputation risk could participate. Participants received comprehensive care and weekly application of DAMA. Primary endpoint was avoidance of major LEA. Secondary endpoint was wound epithelialization. Monitoring continued 4 months. Between July 2015 and March 2017, 20 patients (mean age 67.2 years) with 24 DFU classified as moderate (12 wounds) to high risk (12 wounds) for amputation were enrolled. Wound volumes ranged from 0.072 cm³ to 56.4 cm³. Risk factors included neuropathy (20 patients), osteomyelitis (16 wounds), exposed tendon/ligament/bone (19 wounds), Charcot (5 patients), and peripheral arterial disease (13 wounds). All subjects avoided amputation within the study period, all 24 wounds achieved re-epithelialization within 4 to 33 weeks; mean healing time 13.2 weeks. Cost for the DAMA tissue ranged from $750 to $38 150. Estimated cost for LEA ranges from $30 000 to $50 000. No treatment-related adverse events during the study period were reported. The results suggest that early and frequent application of DAMA with comprehensive care may help prevent amputation. Additional research will help inform third-party payors and clinicians.

Frequency and Antimicrobial Susceptibility Patterns of Diabetic Foot Infection of Patients from Bandar Abbas District, Southern Iran

Diabetic foot infection is among the most common complications of diabetes mellitus which significantly causes hospitalization and is the most prevalent etiology of nontraumatic amputation worldwide. The current study aimed at assessing the frequency and antimicrobial susceptibility patterns of diabetic foot infection of patients from the Bandar Abbas area, in the south of Iran. In this study, a total of 83 diabetic patients with diabetic infected foot wounds referring to Shahid Mohammadi Hospital, Bandar Abbas, from 2017 to 2018 were assessed. Samples were obtained from wound sites and evaluated by aerobic culture and also an antibiogram test for antibiotic susceptibility. Factors including age, sex, type of diabetes, the medication used for diabetes, previous history of diabetic foot infection, duration of wound incidence, fever, and laboratory indices were recorded for each subject. The most prevalent detected bacteria were Escherichia coli (20.5%), Enterococcus sp. (16.9%), Klebsiella sp. (12%), Staphylococcus aureus (8.4%), Enterobacter sp. (7.2%), and Acinetobacter sp. (6%). The results of antibiogram tests revealed the most and the least antibiotic sensitivity for E. coli sp. as meropenem and ciprofloxacin, for Enterococcus sp. as gentamicin and ciprofloxacin, for Klebsiella sp. as amikacin and cotrimoxazole, and for Enterobacter sp. as cotrimoxazole and both amikacin and ciprofloxacin. Staphylococcus aureus was sensitive to vancomycin and doxycycline, and Acinetobacter sp. was 100% resistant to all antibiotics except amikacin and gentamycin. A significant statistical association was found between the C-reactive protein and the patients' diabetic foot infection organisms (P=0.019). Findings of the study revealed E. coli sp. as the most common bacteria which are infecting the foot lesions in the studied population. The highest antibiotic susceptibility was seen for vancomycin, linezolid, and carbapenem.

Making the equivocal unequivocal: standardization of clean margins in diabetic foot osteomyelitis

Background

The prevalence of diabetes mellitus continues to rise. Diabetic foot ulcers with osteomyelitis are a diabetes-related complication presenting a significant burden to this cohort. A cure to diabetic foot osteomyelitis remains elusive and standard of care has failed to improve outcomes. To advance research and better patient outcomes, the authors offer specific guidance with terminology to enhance operative dictations which may improve surgical practice and guide treatment.

Methods

A consecutive review of podiatric surgical dictations for inpatient diabetic foot osteomyelitis within a tertiary care facility was performed. Surgical descriptors of bone were standardized: density, anatomic structure, vascular thrombosis, color, and draining sinus. Correlations between the five categories and histopathological results were performed after kappa analysis for interrater reliability was performed.

Results

Kappa coefficient demonstrated high inter-reliability of surgical findings. This suggests potential agreement amongst surgeons performing similar procedures. It was also found that specific bone descriptors had moderate to strong correlation with clean histopathologic bone margins when biopsied. This further suggests that the use of standardized terms may help guide definitive therapy.

Conclusions

The authors suggest a standardized approach which includes consistent descriptors of intraoperative bone. With use of standardized terms, vague and blanket descriptors are eliminated. This has potential to improve understanding of changes within bone as a result of infection and diabetes. Early and improved communication of intraoperative findings will enhance the multidisciplinary approach. This could potentially lead to changes in diabetic foot management and may limit hospital waste waiting for final cultures and pathology reports.

Risk factors affecting amputation in diabetic foot

Background

A diabetic foot is the most common cause of non-traumatic lower extremity amputations (LEA). The study seeks to assess the risk factors of amputation in patients with diabetic foot ulcers (DFU).

Methods

The study was conducted on 351 patients with DFUs from January 2010 to December 2018. Their demographic characteristics, disease history, laboratory data, ankle-brachial index, Wagner classification, osteomyelitis, sarcopenia index, and ulcer sizes were considered as variables to predict outcome. A chi-square test and multivariate logistic regression analysis were performed to test the relationship of the data gathered. Additionally, the subjects were divided into two groups based on their amputation surgery.

Results

Out of the 351 subjects, 170 required LEA. The mean age of the subjects was 61 years and the mean duration of diabetes was 15 years; there was no significant difference between the two groups in terms of these averages. Osteomyelitis (hazard ratio [HR], 6.164; 95% confidence interval [CI], 3.561−10.671), lesion on percutaneous transluminal angioplasty (HR, 2.494; 95% CI, 1.087−5.721), estimated glomerular filtration rate (eGFR; HR, 0.99; 95% CI, 0.981−0.999), ulcer size (HR, 1.247; 95% CI, 1.107−1.405), and forefoot ulcer location (HR, 2.475; 95% CI, 0.224−0.73) were associated with risk of amputation.

Conclusion

Osteomyelitis, peripheral artery disease, chronic kidney disease, ulcer size, and forefoot ulcer location were risk factors for amputation in diabetic foot patients. Further investigation would contribute to the establishment of a diabetic foot risk stratification system for Koreans, allowing for optimal individualized treatment.

A novel intraoperative technique seeding morselized bone tissue into pediatric blood culture bottles improves microbiological diagnosis in patients with foot and ankle osteomyelitis

BACKGROUND

Osteomyelitis, particularly cases involving the foot and ankle, is a challenging situation that frequently leads to amputations and major sequelae. Targeted antibiotics treating an identified pathogen are key to a successful outcome; however, traditional culture methods for bone tissue have poor sensitivity. This study prospectively compared a novel method for obtaining and processing infected bone tissue with the standard technique.

METHODS

107 patients presenting with a diagnosis of osteomyelitis of the foot and ankle between 2008 and 2017 were prospectively included. Diagnosis was done according to clinical, laboratory and imaging findings. We obtained paired samples of bone tissue from all patients; they were processed through a usual culture method (UCM), but they were also morselized and seeded into pediatric blood culture bottles (PBCBs). We compared the culture yield and the number of agents detected using both the McNemar and the Mann-Whitney tests, respectively.

RESULTS

We studied 107 patients (63 with diabetic foot infection and 44 with nondiabetic osteomyelitis). The causative agent was identified in 60.7% of cases using the UCM and in 97.2% of cases using PBCBs (p < 0.001). We detected a mean of 1.05 ± 1.03 bacteria using the UCM and 1.67 ± 0.92 bacteria using PBCBs (p < 0.01).

CONCLUSION

Cultures using morselized bone seeded in PBCBs identified the causative agent in a significantly larger percentage than the UCM. Additionally, this method identified a larger number of pathogen agents. A better agent identification method has advantages such as identifying more specific antibiotic treatment in these cases.

Management of diabetic foot infections in the light of recent literature and new international guidelines

Introduction: In May 2019 the International Working Group on the Diabetic Foot (IWGDF) launched their quadrennially updated guidelines on the management of diabetic foot infections (DFIs). Concomitantly, the number of new publications regarding DFI increased.Areas covered: The IWGDF committee developed and addressed key questions and produced evidence-based recommendations related to diagnosing and treating DFIs. This narrative review provides an overview of this new guideline and also of other recently published literature in the field of DFIs.Expert opinion: The 2019 IWGDF guidelines provide an authoritative, international, evidence-based approach to diagnosing and treating DFIs. The 27 recommendations are supported by systematic reviews of both diagnosis and interventions. Our review of this guideline, along with other recent publications in the field, allows us to offer state-of-the-art guidance for caring for these difficult infections. As the evidence base for management of DFIs remains suboptimal, we need further research to improve the management of DFIs.

Feasibility of Percutaneous Bone Biopsy as Part of the Management of Diabetic Foot Osteomyelitis in a 100% Neuropathic, Grade 3 IDSA/IWGDF Population on an Outpatient Basis

The present study aimed to evaluate the feasibility of percutaneous bone biopsy in an ambulatory setting as part of the management of diabetic foot osteomyelitis (DFO) on an outpatient basis. DFO may complicate some cases of apparently nonsevere foot infections in patients with diabetes and greatly increase the risk of a lower extremity amputation. It has been suggested that bone culture-based antibiotic therapy is a predictive factor of success in patients with diabetes treated nonsurgically for osteomyelitis of the foot. It is recommended to identify the causative microorganism(s) by the means of either a surgical or percutaneous bone biopsy taken appropriately to select the proper antibiotic therapy. Percutaneous bone biopsy in patients not requiring surgery is, however, not performed in everyday practice as it should be according to the current recommendations. In the present retrospective study, we report a series of 23 consecutive patients with a suspicion of DFO in whom 28 bone samples were collected by percutaneous biopsy at the bedside in an outpatient setting. The percentage of positive cultures was in accordance with that reported in the literature. The mean number of isolates per specimen was 1.04. After a mean 12-month follow-up, the remission was almost of 78%. No adverse event related to the bone biopsy was noted. After a 1-year follow-up, no recurrence was recorded among the patients in remission. The results of the present study suggest that bedside percutaneous bone biopsy performed in the ambulatory setting is a valuable and safe tool in the management of DFO on an outpatient basis.

Maximally Disfiguring Surgery for Forefoot Osteomyelitis: Time for a Rethink?

The treatment of choice for diabetic foot osteomyelitis is surgical debridement and targeted antibiotics with or without revascularization, depending on vascular status. In our society, debridement is done by either a vascular or orthopedic surgeon, and the common teaching is that generous amputation of bone with the accompanying soft tissue envelope is essential for adequate source control and to prevent recurrence (which remains as high as 30% even with this approach). Most of our patients undergo formal ray amputation through the metatarsal neck, while a few get digital amputations through the interphalangeal joints. Many of the resultant wounds cannot be closed and are left to heal by secondary intention. These amputations invariably alter the biomechanics of the foot and leave large and slow-healing open wounds, which have associated adverse psychosocial impacts. We describe 2 cases of patients who had osteomyelitis in the region of the forefoot who underwent complete bony resections of the osteomyelitis but with sparing of the soft tissue envelopes with good outcomes, and we challenge the dogma that maximal debridement of soft tissue must accompany debridement of necrotic and infected bone.

Percutaneous image-guided bone biopsy of osteomyelitis in the foot and pelvis has a low impact on guiding antibiotics management: a retrospective analysis of 60 bone biopsies

OBJECTIVE

Image-guided percutaneous bone biopsy may be requested by clinicians to guide antibiotics management decisions in patients with extremity osteomyelitis. Much of the clinical literature describes a high rate of bone biopsy culture positivity in patients with osteomyelitis, but anecdotally biopsy is felt to be fairly low yield in many musculoskeletal radiology practices. The objective of the study is to determine the culture positivity rate and clinical utility of bone biopsy in guiding the management of patients with osteomyelitis.

MATERIALS AND METHODS

All image-guided bone biopsy procedures of the pelvis or foot performed at a single institution were identified by a retrospective report search, and only those with a clinical suspicion for infection were included. Cases were included based on convincing imaging findings of osteomyelitis on retrospective review. Microbiology results were reviewed in the clinical chart, as were antibiotics management decisions and response to antibiotics therapy.

RESULTS

A total of 60 bone biopsies met the inclusion criteria, 25 within the foot and 35 biopsies of the pelvis. Overall, 11 out of 60 core biopsies (18%) yielded positive cultures. Antibiotics management was altered in only 27% patients with a positive culture; thus, only 5% of patients with MRI findings of osteomyelitis undergoing biopsy had an impact on management.

CONCLUSION

Percutaneous bone biopsies may have a low rate of culture positivity, and even when positive, frequently do not have an impact on antibiotics choice. These data differ from much of the clinical literature, which describes a very high rate of culture positivity.

Evidence of differential microbiomes in healing versus non-healing diabetic foot ulcers prior to and following foot salvage therapy

Diabetic foot ulcers (DFU) contribute to 80% of lower extremity amputations. Although physicians currently rely on clinical signs along with non-specific biomarkers of infection, such as erythrocyte sedimentation rate and C-reactive protein, to diagnose and monitor DFU, there is no specific and sensitive measure available to monitor or prognosticate the success of foot salvage therapy (FST). To address this we performed a prospective, observational microbiome analysis to test the hypotheses that: (i) the initial microbiomes of healed versus non-healed DFU are distinct; (ii) the microbial load, diversity and presence of pathogenic organism of the DFU change in response to antibiotics treatment; and (iii) the changes in the DFU microbiome during treatment are prognostic of clinical outcome. To test this, microbiome analyses were performed on 23 DFU patients undergoing FST, in which wound samples were collected at zero, four, and eight weeks following wound debridement and antibiotics treatment. Bacterial abundance was determined using quantitative polymerase chain reaction (qPCR). Eleven patients healed their DFU, while FDT failed to heal DFU in the other 12 patients. Microbiome results demonstrated that healing DFUs had a larger abundance Actinomycetales and Staphylococcaceae (p < 0.05), while DFUs that did not heal had a higher abundance of Bacteroidales and Streptococcaceae (p < 0.05). FST marked increases Actinomycetales in DFU, and this increase is significantly greater in patients that healed (p < 0.05). Future studies to confirm the differential microbiomes, and that increasing Actinomycetales is prognostic of successful FST are warranted. Statement of Clinical Significance: Tracking changes in the prevalence of pathogens in diabetic foot ulcers may be a clinical tool for monitoring treatment response to foot salvage therapy and prognosticating the need for further surgical intervention. The initial wound sample microbiome may provide important prognostic information on the eventual clinical outcome of foot salvage therapy. It may serve as an important clinical tool for patient counseling and making surgical decision of pursuing foot salvage versus amputation. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1596-1603, 2019.

Retrospective analysis of diabetic foot osteomyelitis management and outcome at a tertiary care hospital in the UK

Objectives

This study aimed to analyse retrospectively management and outcomes of the diabetic foot osteomyelitis (DFOM) multi-disciplinary team at St Thomas’ Hospital, London.

Methods

Patients admitted during 2015 with diagnosis of DFOM were included. Data were obtained from medical and microbiology records.

Results

275 patients were admitted for DF infection in 2015: 45.1% had OM (75% males). 40% were newly diagnosed with DF ulcer (DFU). 81% patients had X-ray and 28% had MRI. Bone infection was confirmed by MC&S in 53% cases. 930 microbiological isolates were obtained: 63% were Gram-positive microorganisms [S.aureus and MRSA (~40%), CoNS (20%), and E.faecalis (8%)]. All MRSA were vancomycin and linezolid sensitive. 23.2% isolates were vancomycin-resistant enterococci. 24% isolates were Gram-negative organisms: P.aeruginosa (42%), E.coli (13%), and E.cloacae (12%). Meropenem resistance was low; 5.4% P.aeruginosa, 87.5% A.baumanii. 76% patients received co-amoxiclav; 41% received ≥3 antibiotics; 17% received >3 months antibiotics. Hospital mean-length of stay was 26.1 days. Ulcer time-to-heal was >6 months in 25% patients. 22% ulcers healed without surgery, 60% healed after minor amputation, 12% patients had major amputation.

Conclusion

Despite current MDT approach, many patients progress to amputation. DF-OM still represents a challenging clinical condition, requiring further study to develop better management guidelines.

Systematic review of randomized controlled trials on antibiotic treatment for osteomyelitis in diabetes

AIM

To evaluate the efficacy of antibiotic therapy in osteomyelitis treatment among people with diabetes.

METHODS

A systematic search of PubMed, EMBASE, AMED, Web of Science, the WHO trial registry, Cochrane library databases, and ClinicalTrials.gov, in addition to hand-searching, was undertaken in July 2018. Two reviewers independently extracted data. The studies' methodological quality was assessed using the modified Jadad scale. Descriptive analysis was performed.

RESULTS

Seven randomized controlled trials, with 393 participants in total, were included. The antibiotic regimens, treatments and follow-up durations varied among the trials. The total scores showed that the overall methodological quality of the seven studies was high, despite two studies showing some flaws in double-blinding and withdrawals/drop-outs. Of four studies comparing different antibiotic regimens, three implied a similar remission effect, while one implied that ertapenem ± vancomycin treatment showed a higher remission rate than tigecycline treatment; this conclusion was not robust because of low power and small sample size. In the other three studies, which included two different doses of ciprofloxacin, an antibiotics group and a conservative surgical group, and two durations of the same antibiotic strategy, no significant differences in remission were reported between the groups. No difference was observed in the analyses of microbiological outcomes, superinfections and relapse, except adverse events.

CONCLUSIONS

There is no definitive evidence supporting the superiority of any particular antibiotic agent, dose, or administration duration in the treatment of osteomyelitis in diabetes. As the included studies had some flaws and limitations, further research is necessary.

Comparison of microbiological results obtained from per-wound bone biopsies versus transcutaneous bone biopsies in diabetic foot osteomyelitis: a prospective cohort study

Transcutaneous bone biopsy (TCB) is the gold standard for taking microbiological specimens in diabetic foot osteomyelitis (DFO), but this technique is not widely used in diabetic foot care centers. We aimed to evaluate the reliability of per-wound bone biopsy (PWB) cultures by comparing them with concomitant TCB cultures obtained through healthy skin. This is a prospective monocentric study including patients seen in consultation for clinical and radiological diabetic foot osteomyelitis with positive probe-bone tests between April 2015 and May 2018. Two bone biopsies were performed on each consenting patient: TCB through a cutaneous incision in healthy skin, and PWB, after careful debridement of the wound. A total of 46 paired cultures were available from 43 eligible patients. Overall, 16 (42%) of the PWB and TCB pairs had identical culture results, but the TCB cultures were sterile in 8 (17%) cases. For 38 paired cultures with positive TCB, the correlation between PWB results and TCB results was 58.4%. PWB revealed all microorganisms found in the transcutaneous specimen in 26/38 samples (68.5%). In patients with DFO, the culture results of specimens taken by per-wound biopsies did not correlate well with those obtained by TCB. PWB should be reserved for cases where the transcutaneous biopsy is sterile or not feasible.

Prospective Analysis of Surgical Bone Margins After Partial Foot Amputation in Diabetic Patients Admitted With Moderate to Severe Foot Infections

BACKGROUND

Osteomyelitis is common in diabetic foot infections and medical management can lead to poor outcomes. Surgical management involves sending histopathologic and microbiologic specimens which guides future intervention. We examined the effect of obtainment of surgical margins in patients undergoing forefoot amputations to identify patient characteristics associated with outcomes. Secondary aims included evaluating interobserver reliability of histopathologic data at both the distal-to and proximal-to surgical bone margin.

METHODS

Data were prospectively collected on 72 individuals and was pooled for analysis. Standardized method to retrieve intraoperative bone margins was established. A univariate analysis was performed. Negative outcomes, including major lower extremity amputation, wound dehiscence, reulceration, reamputation, or death were recorded.

RESULTS

Viable proximal margins were obtained in 63 out of 72 cases (87.5%). Strong interobserver reliability of histopathology was recorded. Univariate analysis demonstrated preoperative platelets, albumin, probe-to-bone testing, absolute toe pressures, smaller wound surface area were associated with obtaining viable margins. Residual osteomyelitis resulted in readmission 2.6 times more often and more postoperative complications.

CONCLUSIONS

Certain patients were significantly different in the viable margin group versus dirty margin group. High interobserver reliability was demonstrated. Obtainment of viable margins resulted in reduced rates of readmission and negative outcomes.

LEVELS OF EVIDENCE

Prognostic, Level I: Prospective.

Current health and economic burden of chronic diabetic osteomyelitis

INTRODUCTION

Diabetic foot ulcer (DFU) prevalence is as high as 25% and 40-80% of DFUs become infected (DFI). About 20% of infected ulcers will spread to bone causing diabetic foot osteomyelitis (DFO). DFU costs Medicare $9-13 billion/year. The most expensive costs associated with DFU are inpatient costs and hospital admissions. DFO costs are driven mostly by surgical procedures. DFU patients have a 3-year cumulative mortality rate of 28% and rates approaching 50% in amputated patients.

AREAS COVERED

This review will summarize the current health and economic burden of DFO covering management, epidemiology, and copious costs associated with DFO. The review began by searching PubMed and Cochrane databases for various terms including, 'diabetic osteomyelitis costs,' 'diabetic foot infection,' and 'diabetes and antibiotics.' Additionally, references from retrieved publications were reviewed. The global burden of DFU calls for investigating new therapeutic options.

EXPERT OPINION

For DFI, anti-biofilm agents have had success because they directly deliver antimicrobials to the infection site. For DFO, intraosseous (I/O) antibiotic therapy similarly bypasses the issue of vascular disease, will likely have improved therapeutic efficacy, and reduced costs for DFO patients. I/O antibiotic therapy has had clinical success in one case report already, and may significantly improve the lives of those afflicted with DFO.

Culture of Bone Biopsy Specimens Overestimates Rate of Residual Osteomyelitis After Toe or Forefoot Amputation

BACKGROUND

Guidelines recommend both histological analysis and culture for definite diagnosis of osteomyelitis. It is not clear if histological and culture criteria can be used interchangeably in the clinical scenario of toe amputation. We therefore prospectively compared the results of intraoperative culture and those of histological examination in this setting.

METHODS

Consecutive patients requiring toe or forefoot amputation at the University Hospital Basel during a 2-year period were included in the study. Biopsy specimens from the residual bone were cultured according to microbiological standards. Histological analysis was performed using standardized criteria for osteomyelitis. Clinical outcomes were assessed retrospectively via chart review.

RESULTS

Of 51 patients included in the study, 33 (65%) had a positive culture of residual bone and 14 (27%) showed histological signs of osteomyelitis. A negative histological result but a positive culture was found for 21 (41%) of the patients, suggesting that culture has a high false-positive rate if histological analysis is used as the reference to rule out osteomyelitis. The recommended criteria of both positive histological findings and positive culture were fulfilled by 12 (24%) of the 51 patients.

CONCLUSIONS

Positive cultures of residual bone after forefoot or toe amputation overestimate the true rate of osteomyelitis as defined by histological analysis, presumably because of contamination from soft tissue at the time of surgery. Additional studies are needed to evaluate the indications for, and the duration of, antibiotic treatment according to these findings.

CLINICAL RELEVANCE

Our results cast doubt on the strategy of relying solely on culture of bone biopsy specimens when deciding whether antibiotic treatment for osteomyelitis is necessary after toe or forefoot amputation.

The appropriate management algorithm for diabetic foot: A single-center retrospective study over 12 years

BACKGROUND

Diabetic foot management is a challenge for reconstructive surgeons because it combines dramatically decreased circulation and chronic infection. The goal of managing this condition is to maximize viable tissue; however, unsatisfactory results, such as extremity amputation, are unavoidable in some cases. For appropriate management, thorough understanding of diabetic foot and the phased approach to its management is needed. The purpose of this study is to introduce an optimal algorithm for diabetic foot management by analyzing cases >12 years.

METHODS

A total of 274 patients with diabetic foot at Hanyang University Guri Hospital from 2005 to 2017 were reviewed. The management process was divided into 5 steps: patient evaluation, wound preparation, improving vascularity, surgery and dressing, and rehabilitation. Patient evaluation included a microbial culture, evaluation of vascularity, and an osteomyelitis assessment. During wound preparation, debridement and negative-pressure wound therapy were performed. Vascularity was improved by radiological intervention or surgical method. Surgery and dressing were performed depending on the indications. Rehabilitation was started after complete wound healing.

RESULTS

An infection was confirmed in 213 of 263 patients (81.0%). Of 74 cases in which a vascular study was performed, 83.8% showed arterial occlusion. When surgery was performed with complete eradication of the infection in 155 patients, the rate of revision surgery was 20.6%. The revision rate after surgery with a remnant infection of 66 patients was 40.9% (P = .0003). When surgery was performed after successful revascularization for improving blood flow of 47 patients, the rate of revision surgery was 21.3%. In contrast, the revision rate after surgery with unsuccessful or no revascularization of 174 patients was 28.2% (P = .359).

CONCLUSION

Diabetic foot is a debilitating disease arising from multifactorial process. As its management is complex, a comprehensive but accessible treatment algorithm is needed for successful results. For this reason, the appropriate algorithm for diabetic foot management introduced in this study is significant.

Chronic traumatic ankle and foot osteomyelitis: a nationwide case-control study

BACKGROUND

Osteomyelitis (OM) is an atypical consequence of ankle-foot trauma which is associated with long-term mental and physical morbidity and persistent pain. This study aimed to assess the health status of OM patients with war-related ankle-foot injuries.

METHODS

A total of 1129 veterans with ankle-foot injuries participated in a case-control study (2014-2016). Thirty patients with chronic OM of the ankle-foot were compared with 90 non-OM participants as the control group. Quality of life (QOL), life satisfaction and the ability to perform basic and instrumental activities of daily living were measured using the following questionnaires: short-form health survey (SF-36), satisfaction with life scale (SWLS), activity of daily living (ADL) and instrumental activity of daily living (IADL), respectively. OM patients were categorized according to their risk factors as A, B and C hosts using a modified version of the Cierny and Mader classification system. The one sample t-test, 2-independent sample t-test, ANOVA, Pearson correlation coefficient and multiple linear regression analyses were applied to analyze the data.

RESULTS

Ankle-foot pain leading to surgery (P < 0.001) and orthosis usage (P = 0.039) were more common in OM patients. There was no significant difference between the two groups in the prevalence of pulmonary and cardiovascular diseases or kidney failure and other related diseases. OM patients showed a significantly lower level of mental health compared to non-OM respondents (P = 0.025). Approximately, 70.0% of ankle-foot injured veterans were dissatisfied with their life, and there was no difference between the two groups (P > 0.05). Mobility was significantly lower in the OM patients than in the control group (P = 0.023). Life satisfaction (P = 0.001) and the ability to perform daily activities were the determinants for poor physical (P = 0.018) and mental (P = 0.012) health-related quality of life. According to the Cierny and Mader classification system, they were all included in the type C host classification, with one major and/or three or more minor risk factors.

CONCLUSIONS

A low level of quality and satisfaction of life and ability to perform activities of daily living were observed in OM patients with war-related ankle-foot injuries. Surgeries of the ankle and foot due to pain were much more common in OM patients than in non-OM participants. Since all the participants were classified as the C-host, health policy planning seems to be necessary.

Complications during the treatment of diabetic foot osteomyelitis

AIM

To identify complications of medical treatment in patients with diabetic foot osteomyelitis (DFO).

METHODS

We reviewed 143 records of consecutive patients admitted with DFO, confirmed by bone histopathology or culture. Complications monitored included acute kidney injuries (AKI), development of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), gastrointestinal complications, and venous catheter related complications during a 12months follow-up period.

RESULTS

Forty-seven AKI episodes were reported during follow-up; half occurred during the first hospitalization with involvement of antimicrobial therapy in 14 events (29.8%). Patients with AKI were more likely to have recurrent ulcerations (69.2% vs. 45.2%, p=0.02), recurrent infections (38.5% vs. 17.3%, p=0.01), and recurrent hospitalizations (43.6% vs. 28.8%, p=0.02) during follow-up. Only 14 MRSA isolates were found in bone samples at baseline (9.8%). Resistant strains of MRSA and VRE were identified in twenty-one patients (14.7%) during follow-up. Patients re-hospitalized for infection were more likely to have resistant bacterial strains (52.6% vs. 25.8%, p=0.02).

CONCLUSIONS

In this study, the rates of VRE and MRSA in bone biopsies of patients with DFO were lower than in previous reports. Acute kidney injury occurred frequently in our patient population but might not be associated with antibiotic exposure.

Modern management of diabetic foot osteomyelitis. The when, how and why of conservative approaches

INTRODUCTION

Diabetic foot osteomyelitis (DFO) has long been considered a complex infection that is both difficult to diagnose and treat, and is associated with a high rate of relapse and limb loss. Areas covered: DFO can usually be diagnosed by a combination of clinical evaluation, serum inflammatory markers and plain X-ray. When the results of these procedures are negative or contradictory, advanced imaging tests or bone biopsy may be necessary. Staphylococcus aureus remains the most frequent microorganism isolated from bone specimens, but infection is often polymicrobial. Antibiotic therapy, preferably with oral agents guided by results of bone culture, for a duration of no more than six weeks, appears to be as safe and effective as surgery in cases of uncomplicated forefoot DFO. Surgery (which should be limb-sparing when possible) is always required for DFO accompanied by necrotizing fasciitis, deep abscess, gangrene or in cases not responding (either clinically or radiographically) to apparently appropriate antibiotic treatment. Expert commentary: Research in the past decade has improved diagnosis and treatment of DFO, and most cases can now be managed with a 'conservative' approach, defined as treatment either exclusively with antibiotics or with surgery removing as little bone and soft tissue as necessary.

Inpatient Management of Diabetic Foot Infections: A Review of the Guidelines for Hospitalists

Diabetic foot infections (DFIs) are common and represent the leading cause for hospitalization among diabetic complications. Without proper management, DFIs may lead to amputation, which is associated with a decreased quality of life and increased mortality. However, there is currently significant variation in the management of DFIs, and many providers fail to perform critical prevention and assessment measures. In this review, we will provide an overview of the diagnosis, management, and discharge planning of hospitalized patients with DFIs to guide hospitalists in the optimal inpatient care of patients with this condition.

Application of white blood cell SPECT/CT to predict remission after a 6 or 12 week course of antibiotic treatment for diabetic foot osteomyelitis

AIMS/HYPOTHESIS

Diabetic foot osteomyelitis is a major risk factor for amputation. Medical treatment allows remission in 53-82% of cases. However, the optimal duration of antibiotic therapy remains controversial as a validated marker of osteomyelitis remission is lacking. The aim of this cohort study was to assess prospectively the remission rate of diabetic foot osteomyelitis medically treated using white blood cell (WBC)-single-photon emission computed tomography (SPECT)/computed tomography (CT) as a predictive marker of remission.

METHODS

Individuals with diabetic foot osteomyelitis that was non-surgically treated between April 2014 and December 2015 were included. All participants were treated with antibiotics alone. WBC-SPECT/CT was performed at 6 weeks and antibiotic treatment discontinued if the clinical signs of soft-tissue infection had resolved and there was no abnormal uptake of labelled WBCs. Treatment was otherwise continued for a total of 12 weeks and then discontinued. For these individuals, another WBC-SPECT/CT was performed at 12 weeks. Remission was defined as the absence of recurrence of osteomyelitis at the same location at 1 year.

RESULTS

Forty-five individuals were included; overall remission rate was 84% at 1 year. A 6 week course of antibiotics was used in 23 participants, 22 of whom were in remission at 1 year (96%); a 12 week course was used for 22 participants, 16 of whom were in remission at 1 year (73%). Sensitivity of WBC-SPECT/CT at 12 weeks was 100%, specificity 56%, positive predictive value 46% and negative predictive value 100%.

CONCLUSIONS/INTERPRETATION

The study suggests that WBC-SPECT/CT could predict remission at the end of antibiotic treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02927678.

All-cause and cardiovascular mortality in a consecutive series of patients with diabetic foot osteomyelitis

BACKGROUND

Mortality in patients with type 2 diabetes and diabetic foot osteomyelitis (DFO) have been explored in few small studies with a short follow-up. Aim of the present study is to assess all-cause and cardiovascular mortality and predictors of mortality in a consecutive series of patients with DFO.

RESEARCH DESIGN AND METHODS

Patients with a diagnosis of DFO, attending the Diabetic Foot Unit of San Donato Hospital in Arezzo between January 1st, 2012 and December 31st, 2013, were included in this retrospective study. Information on all-cause mortality up to December 1st, 2016, was obtained from the registry of the Local Health Unit of Arezzo, which contains updated records of all persons living in Tuscany.

RESULTS

One hundred ninety-four patients were included in the study. During a mean period of observation of 2.8±1.4years, 73 (37.6%) died, with a yearly rate of 13.2%. Of the 73 deaths, 59 were attributable to cardiovascular causes. After adjusting for possible confounders in a Cox analysis, site of osteomyelitis (hindfoot vs mid/forefoot) was associated with a higher mortality, and surgical treatment with a lower mortality.

CONCLUSIONS

Mortality in patients with DFO appears to be much higher than that reported in clinical series of patients with diabetic foot ulcers, particularly when hindfoot is affected.

Treatment options for diabetic foot osteomyelitis

INTRODUCTION

Diabetic foot osteomyelitis therapeutical options are based on antibiotic therapy and surgical resection of the infected bone(s). Surgical and medical approaches of patients suffering from a diabetic foot osteomyelitis do not oppose but are complementary and need to be discussed as a tailored manner. Areas covered: The aim of the present article is to discuss data issued from the most recent guidelines of the Infectious Diseases Society of America and the International Working Group on the Diabetic Foot on the management of the diabetic foot infection and from a search in the current literature using the terms diabetic foot osteomyelitis and treatment/therapy/therapeutical in both PubMed and Medline, restricted to the last five years. Expert opinion: Surgical removal of the entire infected bone(s) has been considered in the past as the standard treatment but medical approach of these patients has now proven efficacy in selected situations. The current emergence of bacteria, especially among Gram negative rods, resistant to almost all the available antibiotics gradually augments the complexity of the management of these patients and is likely to decrease the place of the medical approach and to worsen the outcome of these infections in the next future.

Charcot Arthropathy Versus Osteomyelitis: Evaluation and Management

Charcot arthropathy of the foot and ankle is a severe complication of peripheral neuropathy and is most commonly seen in the developed world in association with diabetes mellitus. Correct diagnosis and differentiation from osteomyelitis of the foot and ankle are critical to guide treatment. It can exist concomitantly with osteomyelitis, typically in the setting of an advanced midfoot ulcer. Simple plain radiographs and contrasted MRI studies often yield inconclusive or confusing data. Correct use of imaging studies and a clinical algorithm can be effective tools to help make accurate and early diagnoses and guide clinical interventions for these conditions.

The microbiology of diabetic foot infections in patients recently treated with antibiotic therapy: A prospective study from India

AIM

Clinicians often treat clinically infected diabetic foot ulcers without information from cultures of the wound. The results of wound cultures may also be affected by previous antibiotic therapy. Thus, we aimed to study the microbial isolates, and antimicrobial sensitivity of previously treated patients with a clinically infected DFU.

RESEARCH DESIGN AND METHODS

293 consecutive patients with clinically infected DFU on prior antimicrobial treatment within the immediate past few days for a duration greater than one week were evaluated for microbial etiology, antibiotic sensitivity and final outcomes. Appropriate tissue samples i.e. purulent drainage, soft-tissue and/ or bone were obtained for aerobic/anaerobic cultures and antimicrobial sensitivities. 71 patients with missing prior antibiotic data were excluded.

RESULTS

313 tissue samples obtained from 222 patients isolated 317 causative organisms. Most of the culture results from tissue specimens were mono-microbial (93.2%) compared to 37% in our previous cohort of 60 patients. Pseudomonas aeruginosa was the most common organism isolated on culture of bone (26.9%) or soft tissue (23.2%) specimen, respectively. Only 23% and 64% of P. aeruginosa isolates and 5.6% and 44% of Acinetobacter sp. were sensitive to quinolones and cephalosporins, respectively.

CONCLUSIONS

Clinically infected DFU recently treated with antibiotics have predominant monomicrobial and multi drug-resistant infection. Quinolones as an empirical antibiotic choice may not be appropriate in this setting.

Outcomes of Osteomyelitis in Patients Hospitalized With Diabetic Foot Infections

BACKGROUND

This study was conducted to evaluate the outcomes of patients with diabetic foot osteomyelitis (DFO) compared to diabetic foot soft tissue infections (STIs).

METHODS

229 patients who were hospitalized with foot infections were retrospectively reviewed, identifying 155 patients with DFO and 74 patients with STI. Primary outcomes evaluated were the rates of amputations and length of hospital stay. DFO was confirmed by the presence of positive bone culture and/or histopathology.

RESULTS

Patients with DFO had a 5.6 times higher likelihood of overall amputation (P < .0001), a 3.4 times higher likelihood of major amputation (P = .027) and a 4.2 times higher likelihood of minor amputation (P < .0001) compared to patients without DFO. Major amputation was performed in 16.7% patients diagnosed with DFO and 5.3% of patients diagnosed with STI. Patients with DFO complicated by Charcot neuroarthropathy had a 7 times higher likelihood of undergoing major amputation (odds ratio 6.78, 95% confidence interval 2.70-17.01, P < .0001). The mean hospital stay was 7 days in DFO and 6 days in patients with DFI (P = .0082). Patients with DFO had a higher erythrocyte sedimentation rate (85 vs 71, P = .02) than patients with STI, however the differences in C-reactive protein (13.4 vs 11.8, P = .29) were not significantly different.

CONCLUSION

In this study of moderate and severe DFIs, the presence of osteomyelitis resulted in a higher likelihood of amputation and longer hospital stay. Readers should recognize that the findings of this study may not be applicable to less severe cases of DFO that can be effectively managed in an outpatient setting.

LEVEL OF EVIDENCE

Level III, retrospective comparative case series.

Prolonged oral antibiotic suppression in osteomyelitis and associated outcomes in a Veterans population

OBJECTIVE

Prolonged oral antimicrobial suppression has been suggested as an alternative treatment for patients with prosthetic joint infections who are unable or unwilling to undergo surgical intervention; however, little data exists for utilizing this approach in patients with chronic osteomyelitis and no artificial hardware.

METHODS

We retrospectively reviewed the medical records of all patients over a 5-year time frame who were treated with chronic oral antibiotic suppression for osteomyelitis and who had no artificial hardware. Clinical outcomes, risk factors for treatment failure, and adverse drug reactions were evaluated.

RESULTS

A total of 20 patients were included for evaluation, of which 12 (60%) were able to achieve successful suppression of disease for a mean duration of 778 ± 408 days after discontinuation. Diabetic patients were found to be at higher risk for treatment failure (p = 0.0281). We also identified a high rate of adverse events (25%) attributable to suppressive medications. Despite elevated inflammatory markers contributing to the decision to initiate antibiotic suppression in the majority of patients, few were able to achieve normal values throughout suppressive therapy.

CONCLUSION

Further randomized, controlled studies are needed to determine the utility of antibiotic suppression. However, prolonged oral antibiotic suppression may be a reasonable last-line treatment alternative for chronic osteomyelitis, even in the absence of artificial hardware, for patients who are unwilling or unable to undergo optimal surgical intervention.

Optimising the quality and outcomes of treatments for diabetic foot infections

INTRODUCTION

Infection is the commonest foot complication that arises in people with diabetes and may lead to amputation and even death. The emergence of multidrug resistant bacteria, especially in Gram negative rods, may have a negative impact on the chances of cure in these patients.

AREAS COVERED

We searched the Medline and Pubmed databases for studies using the keywords 'diabetic foot infection' and 'diabetic foot osteomyelits' from 1980 to 2016. Expert commentary: Much has been done in the field of diabetic foot infection regarding pathophysiology, diagnosis and treatment. The construction of multidisciplinary teams is probably the most efficient way to improve the patients' outcome. The rational use of antibiotics and surgical skills are essential in these potentially severe infections. Each case of diabetic infection deserves to be discussed in the light of the current guidelines and the local resources. Because of the overal poor outcome of these infections, prevention remains a priority.