Exploring Prognostic Implications of Race and Ethnicity in Patients With Peripheral Arterial Disease

INTRODUCTION

Significant health inequalities in major adverse limb events exist. Ethnically minoritized groups are more prone to have a major adverse event following peripheral vascular interventions. This systematic review and meta-analysis aimed to describe the postoperative implications of racial and ethnic status on clinical outcomes following vascular interventions for claudication and chronic limb-threatening ischemia.

METHODS

Searches were conducted across seven databases from inception to June 2021 and were updated in October 2022 to identify studies reporting claudication or chronic limb-threatening ischemia in patients who underwent open, endovascular, or hybrid procedures. Studies with documented racial and ethnic status and associated clinical outcomes were selected. Extracted data included demographic and clinical characteristics, vascular interventions, and measured outcomes associated with race or ethnicity. Meta-analyses were performed using random-effect models to report pooled odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Seventeen studies evaluating the impact of Black versus White patients undergoing amputation as a primary intervention were combined in a meta-analysis, revealing that Black patients had a higher incidence of amputations as a primary intervention than White patients (OR: 1.91, 95% CI: 1.61-2.27). Another meta-analysis demonstrated that Black patients had significantly higher rates of amputation after revascularization (OR: 1.56, 95% CI: 1.28-1.89). Furthermore, multiple trends were demonstrated in the secondary outcomes evaluated.

CONCLUSIONS

Our findings suggest that Black patients undergo primary major amputation at a significantly higher rate than White patients, with similar trends seen among Hispanic and First Nations patients. Black patients are also significantly more likely to be subjected to amputation following attempts at revascularization when compared to White patients.

Effectiveness of Global Leadership Initiative on Malnutrition and Subjective Global Assessment for diagnosing malnutrition and predicting wound healing in patients with diabetic foot ulcers

Malnutrition significantly hampers wound healing processes. This study aimed to compare the effectiveness of the Global Leadership Initiative on Malnutrition (GLIM) and Subjective Global Assessment (SGA) in diagnosing malnutrition and predicting wound healing in patients with diabetic foot ulcers (DFU). GLIM criteria were evaluated for sensitivity (SE), specificity (SP), positive predictive value, negative predictive value and kappa (κ) against SGA as the reference. Modified Poisson regression model and the DeLong test investigated the association between malnutrition and non-healing ulcers over 6 months. This retrospective cohort study included 398 patients with DFU, with a mean age of 66·3 ± 11·9 years. According to SGA and GLIM criteria, malnutrition rates were 50·8 % and 42·7 %, respectively. GLIM criteria showed a SE of 67·3 % (95 % CI 60·4 %, 73·7 %) and SP of 82·7 % (95 % CI 76·6 %, 87·7 %) in identifying malnutrition, with a positive predictive value of 80·0 % and a negative predictive value of 71·1 % (κ = 0·50) compared with SGA. Multivariate analysis demonstrated that malnutrition, as assessed by SGA, was an independent risk factor for non-healing (relative risk (RR) 1·84, 95 % CI 1·45, 2·34), whereas GLIM criteria were associated with poorer ulcer healing in patients with estimated glomerular filtration rate ≥ 60 ml/min/1·73m2 (RR: 1·46, 95 % CI 1·10, 1·94). SGA demonstrated a superior area under the receiver's operating characteristic curve for predicting non-healing compared with GLIM criteria (0·70 (0·65-0·75) v. 0·63 (0·58-0·65), P < 0·01). These findings suggest that both nutritional assessment tools effectively identify patients with DFU at increased risk, with SGA showing superior performance in predicting non-healing ulcers.

Controversial Issues Regarding Positive Bone Margins in Surgery for Diabetic Foot Osteomyelitis: A Pilot Study

Obtaining clean margins in patients who undergo surgical treatment for diabetic foot osteomyelitis (DFO) is recommended. We hypothesize that the rate of recurrence of the infection is not associated with positive margins, even when using a short-term duration of postoperative antibiotic treatment. We conducted a retrospective pilot study of patients who underwent surgery for DFO confirmed by histopathological analysis of the resected bone from August 1, 2020, to December 1, 2020. Bone samples were taken from the proximal margins to be studied by microbiology and histopathology. Twenty-five (89.3%) patients underwent conservative surgery, and 3 (10.7%) patients underwent a minor amputation. After surgery, the antibiotics were stopped in 19 (67.9%) patients and continued in 9 (32.1%) patients for a median period of 4 days. The microbiology of the bone margins was positive in 20 (71.4%) cases, but the histopathology of the bone margins was positive in just 7 (25%) cases. Recurrence of the infection was detected in 3 (10.7%) patients. Seventeen (68%) patients with microbiological-positive margins did not have a recurrence of infection, while 3 (100%) patients had a recurrence of infection (P = .53). Six (24%) patients among those with histopathological-positive margins did not have a recurrence of infection, and1 (33.3%) patient had a recurrence of infection (P = 1). The recurrence of infection was low and always detected in soft tissues, including the cases with a histopathological-positive bone margin. Postoperative antibiotics were administered for a short period of time and not based on the analysis of bone margins.

Evaluation of routine proximal bone analysis for microbiology and histopathology in diabetes-related foot infections and osteomyelitis

PURPOSE

The value of proximal bone analysis for surgical clearance of infection remains debated. Real-world practice traditionally utilized proximal bone microbiology rather than histopathology to diagnose residual diabetes-related osteomyelitis of the foot (DFO) post-amputation. We assessed the concordance between proximal bone microbiology and histopathology in determining residual infection and their predictability for revision operation in DFO and diabetes-related foot infection (DFI).

METHODOLOGY

A single-centre retrospective study was conducted between June and December 2020 at a tertiary institution. We recruited patients with diabetes mellitus who had minor amputations for DFO and DFI and analyzed their proximal bone microbiology, histopathology and outcomes at 6 months.

RESULTS

Eighty-four patients were recruited; 64 (76.2%) were male. The mean age was 69.3 years. The mean HbA1c was 8.6%. Seventy-seven operations were performed for DFO and 17 for DFI. Negative microbiology showed complete concordance with histopathology; and none had revision operation (P = 0.99). Positive microbiology had 9.8% concordance with histopathology (P = 0.99). Positive histopathology was associated with a higher rate of revision operation (80% vs. 12.5%; P = 0.01). High preoperative C-reactive protein was associated with residual DFO (P = 0.02) and revision operation (P = 0.01).

CONCLUSION

Positive histopathology was more reliable for determining significant residual DFO and predicting revision operation. Positive microbiology was valuable for guiding antibiotic selection. We suggest routine proximal bone analysis for both histopathology and microbiology to optimize the treatment of DFO and DFI.

Clinical practice recommendations for infectious disease management of diabetic foot infection (DFI) - 2023 SPILF

In march 2020, the International Working Group on the Diabetic Foot (IWGDF) published an update of the 2015 guidelines on the diagnosis and management of diabetic foot infection (DFI). While we (the French ID society, SPILF) endorsed some of these recommendations, we wanted to update our own 2006 guidelines and specifically provide informative elements on modalities of microbiological diagnosis and antibiotic treatment (especially first- and second-line regiments, oral switch and duration). The recommendations put forward in the present guidelines are addressed to healthcare professionals managing patients with DFI and more specifically focused on infectious disease management of this type of infection, which clearly needs a multidisciplinary approach. Staging of the severity of the infection is mandatory using the classification drawn up by the IWGDF. Microbiological samples should be taken only in the event of clinical signs suggesting infection in accordance with a strict preliminarily established protocol. Empirical antibiotic therapy should be chosen according to the IWGDF grade of infection and duration of the wound, but must always cover methicillin-sensitive Staphylococcus aureus. Early reevaluation of the patient is a fundamental step, and duration of antibiotic therapy can be shortened in many situations. When osteomyelitis is suspected, standard foot radiograph is the first-line imagery examination and a bone biopsy should be performed for microbiological documentation. Histological analysis of the bone sample is no longer recommended. High dosages of antibiotics are recommended in cases of confirmed osteomyelitis.

Concordance of bone culture and deep tissue culture during the operation of diabetic foot osteomyelitis and clinical characteristics of patients

PURPOSE

To retrospectively analyze the concordance of bacterial culture between bone tissue and deep soft tissue in diabetic foot osteomyelitis (DFO) patients and clinical characteristics of patients.

METHODS

This study collected samples from 155 patients with suspected DFO (who required amputation after clinical evaluation). Bacterial culture and drug susceptibility tests were performed on the patients' deep soft tissue and bone tissue, and the consistency between the two was compared. In addition, the differences among DFO patients with different degrees of infection were compared classified by the PEDIS classifications.

RESULTS

Among the 155 patients diagnosed with DFO, the positive rate of bone culture was 78.7% (122/155). This study cultured 162 strains, including 73 Gram-positive bacteria, 83 Gram-negative bacteria, and 6 fungi. Staphylococcus aureus (33 strains) was the most common bacteria. The overall agreement between bone culture and tissue culture was 42.8%, with Staphylococcus aureus and Enterobacteria having the best (64.3%) and least agreements (27.3%), respectively. The drug sensitivity results in bone culture showed that Staphylococcus aureus was the main Gram-positive bacteria. The bacteria were sensitive to linezolid and vancomycin. Proteus mirabilis was the main Gram-negative bacteria. These were more sensitive than biapenem and piperacillin/tazobactam. Fungi were more sensitive to voriconazole and itraconazole.

CONCLUSION

The culture results of deep soft tissues near the bone cannot accurately represent the true pathogen of DFO. For DFO patients, bone culture should be taken as much as possible, and appropriate antibiotics should be selected according to the drug susceptibility results.

Residual osteomyelitis at the resection margin after conservative surgery is not associated with the recurrence of diabetic foot infection and may successfully be treated without postoperative antibiotic therapy

AIMS

We hypothesize that microbiology- and pathology-confirmed positive bone margins after the resection of diabetes-related foot osteomyelitis are associated with worse outcomes.

METHODS

We conducted a prospective study consisting of a cohort of 93 patients with diabetes-related foot osteomyelitis (histopathology confirmed) who underwent bone resection and where an additional bone biopsy was taken at the resection margin. The primary outcome was the recurrence of the infection.

RESULTS

Pathology-confirmed positive margins were detected in 62 cases (66.7%), microbiology-confirmed positive margins were detected in 75 cases (80.6%) and recurrence was detected in 19 patients (20.4%). Chi-squared test failed to show the presence of an association between the recurrence of the infection with pathology-confirmed positive margins (p = 0.82), with microbiology-confirmed positive margins, (p = 0.34) and with the use of postoperative antibiotics (p = 0.70). Healing in patients with pathology-confirmed positive margins was achieved in a median of 12 weeks (95% CI 9.2-18) and those with pathology-confirmed negative margins in 14.9 weeks (95% CI 10.2-21.9), Log-rank test, p = 0.74. Thirty-four patients out of 61 available for follow-up (55.7%) with pathology-confirmed positive margins were treated without postoperative antibiotics. In that group, Chi-squared test failed to show the presence of an association between the recurrence of the infection with the use of postoperative antibiotics (p = 0.47).

CONCLUSIONS

A positive margin was neither associated with the recurrence of the infection nor with the time to healing. More than half of patients with pathology-confirmed positive margins were treated without postoperative antibiotics and this approach was not associated with the recurrence of the infection.

Secondary amputation after lower extremity free-flap reconstruction

BACKGROUND

Microsurgical free-tissue transfer is often the definitive reconstructive option for lower extremity limb salvage. Despite an initial successful free-flap reconstruction, some patients ultimately undergo lower extremity amputation. The indications for secondary amputation include non- or malunion, infection, hardware failure, or chronic pain. This study aimed to identify the etiology and outcome of secondary amputation after lower extremity free-flap reconstruction.

METHODS

A retrospective cohort study was performed including patients who underwent lower extremity free-flap reconstruction from January 2002 to December 2020. Patients who underwent secondary amputation were identified. A survey based on the PROMIS® Pain Interference Scale and activities of daily living (ADLs) was then conducted to assess patient-reported outcomes. Fifteen (52%) patients who underwent amputation responded to the survey, with a median follow-up time of 4.4 years.

RESULTS

Of 410 patients who underwent lower extremity free-flap reconstruction, 40 (9.8%) patients underwent subsequent amputation. Of these, 10 patients had failed free-flap reconstruction and 30 patients had secondary amputation after an initially successful soft tissue coverage. The most common etiology for secondary amputation was infection (68%, n = 27). Eighty percent (n = 12) of survey respondents were able to use a prosthetic limb and ambulate.

CONCLUSIONS

The most common etiology of secondary amputation was infection. Most patients who ultimately underwent amputation were able to ambulate with a prosthetic, but the majority of patients reported chronic pain. This study could be used to guide potential free-flap candidates regarding the risks and outcomes of lower extremity free-flap reconstruction.

Handgrip Strength But Not Malnutrition According to Global Leadership Initiative on Malnutrition Criteria Is a Risk Factor for Mortality in Hospitalized Patients with Ischemic Diabetic Foot Ulcers

Objective: This study aimed to test the hypothesis that patients with malnutrition and impaired muscle function determined by hand grip strength (HGS) will have adverse outcomes. Approach: We conducted a prospective observational study of 77 patients admitted for ischemic diabetic foot ulcers (IDFU). Global Leadership Initiative on Malnutrition (GLIM) criteria were used to diagnose malnutrition. Values obtained with a dynamometer were dichotomized into values < and ≥ mean according to the values obtained in both sexes. The Cox proportional hazards model and the Kaplan-Meier method were applied. STROBE guidelines for cohorts were met in the present study. Results: In total, 55 patients (71.4%) were malnourished. Malnutrition according to GLIM criteria was not associated with adverse outcomes. HGS < mean was associated with patient age, duration of diabetes mellitus, body mass index, brachial circumference, plasma albumin, prealbumin, hemoglobin, transferrin, and HbA_1c levels. Predictive variables of mortality after applying multivariate Cox model were age >69years (hazard ratio [HR] 4.0, 95% confidence interval [CI] 1.3-12.0, p = 0.01), and HGS < mean (HR 3.7, 95% CI 1.2-11.3, p = 0.01). Survival time in patients with HGS < mean was shorter than in those with HGS ≥ mean, p < 0.01. Innovation: HGS is an easy and useful tool associated with nutritional parameters and with prognosis in patients admitted for IDFU. Conclusions: Neither malnutrition nor muscle function impairment were associated with limb loss or a need for readmission. Patients with HGS < mean presented shorter survival times. As HGS is a simple and cost-effective tool, it should be implemented as part of the nutritional admission evaluation.

Clinical Features, Inflammatory Markers, and Limb Salvage in Older Adults with Diabetes-Related Foot Infections

Little information exists about diabetic foot infections (DFIs) in older patients. We hypothesize that older patients with DFIs have different clinical features and worse outcomes than younger patients. We conducted a prospective observational study consisting of a cohort of patients with diabetes and moderate to severe DFIs. Patients included in the cohort were dichotomized into two groups using percentile 75 (P75) of age as the cut-off value. Patients aged > P75 presented with more comorbidities and foot-related complications, a higher rate of peripheral arterial disease (PAD), worse renal function (higher values of blood urea nitrogen and creatinine, and lower values of estimated glomerular filtration rate), and lower values of HbA1c compared with younger patients. Infection severity, microbiological features, and inflammatory markers were similar in both groups. In the multivariate analysis, minor amputations were associated with age > P75 (OR = 2.8, 95% CI 1.3-5.9, p <0.01), necrosis (OR = 4.2, 95% CI 1.8-10.1, p < 0.01), and CRP values (OR = 1.045, 95% CI 1.018-1.073, p < 0.01). Major amputations were associated with a history of amputation (OR = 4.7, 95% CI 1.3-16.7, p = 0.01), PAD (OR = 4.3, 95% CI 1.2-14.6, p = 0.01), and albumin values (OR = 0.344, 95% CI 0.130-0.913, p = 0.03). In conclusion, limb salvage can be achieved in older patients with diabetes-related foot infections at the same rate as in younger patients, despite the fact that they have more comorbidities and foot-related complications, a higher rate of PAD, and worse renal function.

A Novel Classification for Diabetic Foot Ulcers of the First Ray

OBJECTIVE

Diabetic foot ulcers of the first ray result from several distinct biomechanical mechanisms related to anatomical deformities, which must be addressed if surgical offloading is contemplated. The objective of this study was to create a classification of the anatomical deformities of first-ray ulcers that could lead to better standardization of treatment and reporting.

METHODS

The authors performed a file review of patients with diabetic neuropathy diagnosed with first-ray ulcers over a period of 3 years in an outpatient setting. Anatomical deformities were diagnosed clinically and reported with ulcer location. The primary classification was the metatarsophalangeal joint, the interphalangeal joint, and the distal phalanx.

RESULTS

Records for 59 patients (mean age, 62 years) with University of Texas A1 and A2 ulcers were reviewed. Mean ulcer duration was 2 months. The more common deformities were hallux valgus (41%), hallux valgus interphalangeus (14%), and hallux malleus (20%), and these were primarily associated with metatarsophalangeal, interphalangeal joint, and tip-of-toe ulcers, respectively (P < .0001).

CONCLUSIONS

By classifying ulcer locations, the relevant corrective surgery may be chosen. Although some prophylactic procedures may be safe and effective, prophylactic hallux valgus correction in the diabetic foot requires further study.

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.

Decreasing Osteomyelitis Occurrence in Remaining Bone After Partially Resected Infected Bone

BACKGROUND

After partial bone resection for osteomyelitis there is a high rate of osteomyelitis occurrence in the remaining bone due to adherent bacterial biofilm, dysvascular infected spongiosum bone, and absence of a surgical technique that can prevent osteomyelitis developing in the remaining bone.

METHODS

Presented is a surgical procedure using a dicalcium phosphate bone void filler putty with antibiotics placed into the remaining bone to prevent the development of osteomyelitis, therefore preventing amputation.

RESULTS

This procedure has an osteomyelitis eradication rate of 94.8% and also decreases the rate of lower-extremity amputations.

CONCLUSIONS

This procedure provides a single stage surgical technique for infected open bone defects decreasing the previously reported high osteomyelitis reoccurrence rate of 57.1% to 5.2%.

Polymicrobial Foot Infection Patterns Are Common and Associated With Treatment Failure

BACKGROUND

That foot infections are predominately polymicrobial has long been recognized, but it is not clear if the various species co-occur randomly or in patterns. We sought nonrandom species co-occurrence patterns that might help better predict prognosis or guide antimicrobial selection.

METHODS

We analyzed tissue (bone, skin, and other soft tissue), fluid, and swab specimens collected from initial foot infection episodes during a 10-year period using a hospital registry. Nonrandom co-occurrence of microbial species was identified using simple pairwise co-occurrence rates adjusted for multiple comparisons, Markov and conditional random fields, and factor analysis. A historical cohort was used to validate pattern occurrence and identify clinical significance.

RESULTS

In total, 156 unique species were identified among the 727 specimens obtained from initial foot infection episodes in 694 patients. Multiple analyses suggested that Staphylococcus aureus is negatively associated with other staphylococci. Another pattern noted was the co-occurrence of alpha-hemolytic Streptococcus, Enterococcus fecalis, Klebsiella, Proteus, Enterobacter, or Escherichia coli, and absence of both Bacteroides and Corynebacterium. Patients in a historical cohort with this latter pattern had significantly higher risk-adjusted rates of treatment failure.

CONCLUSIONS

Several nonrandom microbial co-occurrence patterns are frequently seen in foot infection specimens. One particular pattern with many Proteobacteria species may denote a higher risk for treatment failure. Staphylococcus aureus rarely co-occurs with other staphylococci.

Surgical Care of Patients Experiencing Homelessness: A Scoping Review Using a Phases of Care Conceptual Framework

Homelessness is a growing concern across the world, particularly as individuals experiencing homelessness age and face an increasing burden of chronic health conditions. Although substantial research has focused on the medical and psychiatric care of patients experiencing homelessness, literature about the surgical care of these patients is sparse. Our objective was to review the literature to identify areas of concern unique to patients experiencing homelessness with surgical disease. A scoping review was conducted using a comprehensive database for studies from 1990 to September 1, 2020. Studies that included patients who were unhoused and discussed surgical care were included. The inclusion criteria were designed to identify evidence that directly affected surgical care, systems management, and policy making. Findings were organized within a Phases of Surgical Care framework: preoperative care, intraoperative care, postoperative care, and global use. Our search strategy yielded 553 unique studies, of which 23 met inclusion criteria. Most studies were performed at public and/or safety-net hospitals or via administrative datasets, and surgical specialties that were represented included orthopedic, cardiac, plastic surgery trauma, and vascular surgery. Using the Surgical Phases of Care framework, we identified studies that described the impact of housing status in pre- and postoperative phases as well as global use. There was limited identification of barriers to surgical and anesthetic best practices in the intraoperative phase. More than half of studies (52.2%) lacked a clear definition of homelessness. Thus, there is a marked gap in the surgical literature regarding the impact of housing status on optimal surgical care, with the largest area for improvement in the intraoperative phase of surgical and anesthetic decision making. Consistent use of clear definitions of homelessness is lacking. To promote improved care, a standardized approach to recording housing status is needed, and studies must explore vulnerabilities in surgical care unique to this population.

Bacteriophage Therapy for Staphylococcus Aureus Infections: A Review of Animal Models, Treatments, and Clinical Trials

Staphylococcus aureus (S. aureus) is a common and virulent human pathogen causing several serious illnesses including skin abscesses, wound infections, endocarditis, osteomyelitis, pneumonia, and toxic shock syndrome. Antibiotics were first introduced in the 1940s, leading to the belief that bacterial illnesses would be eradicated. However, microorganisms, including S. aureus, began to develop antibiotic resistance from the increased use and abuse of antibiotics. Antibiotic resistance is now one of the most serious threats to global public health. Bacteria like methicillin-resistant Staphylococcus aureus (MRSA) remain a major problem despite several efforts to find new antibiotics. New treatment approaches are required, with bacteriophage treatment, a non-antibiotic strategy to treat bacterial infections, showing particular promise. The ability of S. aureus to resist a wide range of antibiotics makes it an ideal candidate for phage therapy studies. Bacteriophages have a relatively restricted range of action, enabling them to target pathogenic bacteria. Their usage, usually in the form of a cocktail of bacteriophages, allows for more focused treatment while also overcoming the emergence of resistance. However, many obstacles remain, particularly in terms of their effects in vivo, necessitating the development of animal models to assess the bacteriophage efficiency. Here, we provide a review of the animal models, the various clinical case treatments, and clinical trials for S. aureus phage therapy.

Impact of wound microbiology on limb preservation in patients with diabetic foot infection

AIMS/INTRODUCTION

To investigate the association between specific bacterial pathogens and treatment outcome in patients with limb-threatening diabetic foot infection (LT-DFI).

MATERIALS AND METHODS

Consecutive patients treated for LT-DFI in a major diabetic foot center in Taiwan were analyzed between the years 2014 and 2017. Patients with positive wound culture results at first aid were enrolled. Clinical factors, laboratory data, and wound culture results were compared. Lower-extremity amputations and in-hospital mortality were defined as a poor outcome.

RESULTS

Among the 558 patients, 272 (48.7%) patients had lower extremity amputation and 22 (3.9%) patients had in-hospital mortality. Gram-negative bacterial (GNB) infection was the independent factor following factors adjustment. When all the 31 microorganisms were analyzed, only E. coli (adjusted odds ratio [aOR], 3.01; 95% CI, 1.60-5.65), Proteus spp. (aOR, 2.99; 95% CI, 1.69-5.29), and Pseudomonas aeruginosa (aOR, 2.00; 95% CI 1.20-3.32) were associated with poor outcome. The analysis of specific GNB species in association with major- or minor- amputation have been reported. No specific pathogen was associated with cause of death in patients with mortality within 30 days. The antimicrobial-resistant strains were not associated with a poor treatment outcome.

CONCLUSIONS

The presence of GNB was associated with limb amputations. This study provides insight into more timely and appropriate management of the diabetic foot infection.

The Joint-Specific BACH classification: A predictor of outcome in prosthetic joint infection

BACKGROUND

There is currently no commonly accepted method of stratifying complexity of prosthetic joint infection (PJI). This study assesses a new classification, the Joint-Specific, Bone involvement, Anti-microbial options, Coverage of the soft tissues, Host status (JS-BACH) classification, for predicting clinical and patient reported outcomes in PJI.

METHODS

Patients who received surgery for PJI at two centres in the UK between 2010 and 2015 were classified using JS-BACH as 'uncomplicated', 'complex' or 'limited treatment options'. Patient reported outcomes were recorded at 365-days following the index operation and included the EuroQol EQ-5D-3L index score and the EQ-visual analogue score (VAS). Clinical outcome data were obtained from the most recent follow-up appointment.

FINDINGS

220 patients met the inclusion criteria. At 365-days following the index operation, patients with 'uncomplicated' PJI reported similar EQ-index scores (0.730, SD:0.326) and EQ-VAS (79.4, SD:20.9) compared to the age-matched population. Scores for 'uncomplicated' PJI were significantly higher than patients classified as having 'complex' (EQ-index:0.515 SD:0.323, p = 0.012; EQ-VAS:68.4 SD:19.4, p = 0.042) and 'limited treatment options' PJI (EQ-index:0.333 SD:0.383, p < 0.001; EQ-VAS:60.2, SD:23.1, p = 0.005). The median time to final follow-up was 4.7 years (inter-quartile range 2.7-6.7 years) where there were 74 cases (33.6%) of confirmed recurrence. Using death as a competing risk, the Cox proportional-hazards ratio of recurrence for 'complex' versus 'uncomplicated' PJI was 23.7 (95% CI:3.23-174.0, p = 0.002) and having 'limited options' verses 'uncomplicated' PJI was 57.7 (95% CI:7.66-433.9, p < 0.001).

INTERPRETATION

The JS-BACH classification can help predict likelihood of recurrence and quality of life following surgery for PJI. This will aid clinicians in sharing prognostic information with patients and help guide referral for specialist management of PJI.

A systematic review of phage therapy applied to bone and joint infections: an analysis of success rates, treatment modalities and safety

Bone and joint infections are difficult to treat, and increasing antibiotic resistance has only made them more challenging. This has led to renewed interest in phage therapy (PT). The aim of this systematic review was to determine success rate, current treatment modalities and safety of PT in bone and joint infections.A systematic search of PubMed, EMBASE and Cochrane databases as well as the journal PHAGE for literature published between January 2000 and April 2021 was conducted according to PRISMA guidelines to identify all human studies assessing bacteriophages as therapy for bone and joint infections. All study designs and patient populations were eligible. The review's primary outcome was success rate.Twenty records describing a total of 51 patients and 52 treatment episodes were included. No randomized controlled studies were identified. The overall success rate was 71% (n = 37/52). Topical administration alone was the most frequent administration route (85%, n = 44/52). Antibiotics were administered concomitantly with PT in the majority of treatments (79%, n = 41/52), and surgery was performed for 87% (n = 45/52) of treatment episodes. Four minor adverse events related to PT were reported, representing 8% (n = 4/52) of treatment episodes.PT for bone and joint infections has not been evaluated in any randomized controlled clinical study, and current administration modalities are highly variable between case reports and case series. While publications included here show potential benefit and few adverse effects, clinical trials are warranted to assess the efficacy of PT for bone and joint infections and determine optimal treatment modalities. Cite this article: EFORT Open Rev 2021;6:1148-1156. DOI: 10.1302/2058-5241.6.210073.

Clinical, microbiological and inflammatory markers of severe diabetic foot infections

AIMS

In addition to systemic inflammatory response syndrome (SIRS), various clinical signs, microbiological findings and inflammatory markers could be associated with severe diabetic foot infections (DFI).

METHODS

This study included a retrospective cohort of 245 patients with DFI treated at San Juan de Dios Hospital in San José de Costa Rica. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), CRP/albumin ratio, peripheral blood leucocyte ratios and the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) scoring system were evaluated. Univariate analysis was carried out between moderate and severe infections. ROC curves were plotted. Cut-off value of inflammatory markers for diagnosing severe infections was established and then dichotomized to be included in a logistic regression model. A score was designed based on its results.

RESULTS

Skin necrosis (p < 0.01, OR = 8.5, 95% CI = 3.5-20.9), ESR > 94 mm/h (p < 0.01, OR = 2.5, 95% CI = 1.2-5.1), albumin < 2.8 g/dl (p = 0.04, OR = 2.0, 95% CI = 1.0-4.1) and neutrophil-to-lymphocyte ratio (NLR) > 4.52 (p < 0.01, OR = 3.3, 95% CI = 1.6-6.5) were found to be predictive of severe infections. Score >5 had a good diagnosis performance for classifying severe infections. Moderate infections with a score >5 had a worse prognosis than moderate ones.

CONCLUSIONS

We found an association of necrosis, serum albumin, ESR and NLR values with severe DFI. The presence of these predictive factors of severity in cases of moderate infections was significantly associated with a higher rate of amputations and recurrences, longer duration of antibiotic treatment and longer hospital stays. DFI could be classified as mild, moderate, severe without SIRS and severe.

Systematic review of risk prediction studies in bone and joint infection: are modifiable prognostic factors useful in predicting recurrence?

Background: Classification systems for orthopaedic infection include patient health status, but there is no consensus about which comorbidities affect prognosis. Modifiable factors including substance use, glycaemic control, malnutrition and obesity may predict post-operative recovery from infection. Aim: This systematic review aimed (1) to critically appraise clinical prediction models for individual prognosis following surgical treatment for orthopaedic infection where an implant is not retained; (2) to understand the usefulness of modifiable prognostic factors for predicting treatment success. Methods: EMBASE and MEDLINE databases were searched for clinical prediction and prognostic studies in adults with orthopaedic infections. Infection recurrence or re-infection after at least 6 months was the primary outcome. The estimated odds ratios for the primary outcome in participants with modifiable prognostic factors were extracted and the direction of the effect reported. Results: Thirty-five retrospective prognostic cohort studies of 92 693 patients were included, of which two reported clinical prediction models. No studies were at low risk of bias, and no externally validated prediction models were identified. Most focused on prosthetic joint infection. A positive association was reported between body mass index and infection recurrence in 19 of 22 studies, similarly in 8 of 14 studies reporting smoking history and 3 of 4 studies reporting alcohol intake. Glycaemic control and malnutrition were rarely considered. Conclusion: Modifiable aspects of patient health appear to predict outcomes after surgery for orthopaedic infection. There is a need to understand which factors may have a causal effect. Development and validation of clinical prediction models that include participant health status will facilitate treatment decisions for orthopaedic infections.

Is Reconstruction of Unstable Midfoot Charcot Neuroarthropathy Cost Effective from a US Payer's Perspective?

BACKGROUND

Charcot neuroarthropathy is a morbid and expensive complication of diabetes that can lead to lower extremity amputation. Current treatment of unstable midfoot deformity includes lifetime limb bracing, primary transtibial amputation, or surgical reconstruction of the deformity. In the absence of a widely adopted treatment algorithm, the decision to pursue more costly attempts at reconstruction in the United States continues to be driven by surgeon preference.

QUESTIONS/PURPOSES

To examine the cost effectiveness (defined by lifetime costs, quality-adjusted life-years [QALYs] and incremental cost-effectiveness ratio [ICER]) of surgical reconstruction and its alternatives (primary transtibial amputation and lifetime bracing) for adults with diabetes and unstable midfoot Charcot neuroarthropathy using previously published cost data.

METHODS

A Markov model was used to compare Charcot reconstruction and its alternatives in three progressively worsening clinical scenarios: no foot ulcer, uncomplicated (or uninfected) ulcer, and infected ulcer. Our base case scenario was a 50-year-old adult with diabetes and unstable midfoot deformity. Patients were placed into health states based on their disease stage. Transitions between health states occurred annually using probabilities estimated from the evidence obtained after systematic review. The time horizon was 50 cycles. Data regarding costs were obtained from a systematic review. Costs were converted to 2019 USD using the Consumer Price Index. The primary outcomes included the long-term costs and QALYs, which were combined to form ICERs. Willingness-to-pay was set at USD 100,000/QALY. Multiple sensitivity analyses and probabilistic analyses were performed to measure model uncertainty.

RESULTS

The most effective strategy for patients without foot ulcers was Charcot reconstruction, which resulted in an additional 1.63 QALYs gained and an ICER of USD 14,340 per QALY gained compared with lifetime bracing. Reconstruction was also the most effective strategy for patients with uninfected foot ulcers, resulting in an additional 1.04 QALYs gained, and an ICER of USD 26,220 per QALY gained compared with bracing. On the other hand, bracing was cost effective in all scenarios and was the only cost-effective strategy for patents with infected foot ulcers; it resulted in 6.32 QALYs gained and an ICER of USD 15,010 per QALY gained compared with transtibial amputation. As unstable midfoot Charcot neuroarthropathy progressed to deep infection, reconstruction lost its value (ICER USD 193,240 per QALY gained) compared with bracing. This was driven by the increasing costs associated with staged surgeries, combined with a higher frequency of complications and shorter patient life expectancies in the infected ulcer cohort. The findings in the no ulcer and uncomplicated ulcer cohorts were both unchanged after multiple sensitivity analyses; however, threshold effects were identified in the infected ulcer cohort during the sensitivity analysis. When the cost of surgery dropped below USD 40,000 or the frequency of postoperative complications dropped below 50%, surgical reconstruction became cost effective.

CONCLUSIONS

Surgeons aiming to offer both clinically effective and cost-effective care would do well to discuss surgical reconstruction early with patients who have unstable midfoot Charcot neuroarthropathy, and they should favor lifetime bracing only after deep infection develops. Future clinical studies should focus on methods of minimizing surgical complications and/or reducing operative costs in patients with infected foot ulcers.

LEVEL OF EVIDENCE

Level II, economic and decision analysis.

Risk Factors Associated with 30-Day Readmission in Patients with Diabetic Foot Infections

BACKGROUND

Diabetic foot infections (DFIs) are the most common cause of hospitalization for patients with diabetes. Studies have shown diabetic patients have high readmission rates. It is important to identify variables that contribute to readmission. This study aimed to investigate clinical variables associated with 30-day hospital readmission in patients with DFI.

METHODS

We conducted a retrospective study of adults admitted to the hospital for DFI between July 1, 2012, and July 1, 2015. We identified patients by International Classification of Diseases, Ninth Revision codes and randomly selected 35% of medical records for review. Patients were excluded if they did not have a DFI by review, were pregnant, or were incarcerated. The primary outcome was 30-day readmission. Data collected included baseline demographics, medical comorbidities, substance abuse, homelessness, tobacco use, and laboratory and surgical pathology data. Univariate and multivariate logistic regression models were used to identify independent predictors.

RESULTS

Of 140 included patients, 106 (76%) were male. Median age was 55 years and length of stay (LOS) was 7 days. In univariate analysis, 31 patients (22%) were readmitted in the 30 days after the index hospitalization. Factors associated with readmission included treatment failure, elevated C-reactive protein level, and hospital LOS (P < .05). In multivariate analyses, LOS and treatment failure were independent predictors of readmission.

CONCLUSIONS

The 30-day readmission rate for patients with DFI is high. Treatment failure, C-reactive protein, and LOS are independently associated with readmission. More work is needed to determine reasons for readmission so that appropriate measures can be taken before discharge.

Predicting osteomyelitis in patients whose initial MRI demonstrated bone marrow edema without corresponding T1 signal marrow replacement

PURPOSE

We endeavored to determine which characteristics of diabetic ulcers portend the strongest risk for osteomyelitis in patients whose initial T1-weighted imaging was normal. By determining which features have a greater risk for osteomyelitis, clinicians can treat patients more aggressively to reduce the sequela of inadequately treated osteomyelitis.

MATERIALS AND METHODS

We performed a retrospective analysis of MR imaging from 60 pedal ulcers with suspected osteomyelitis. Ulcer dimensions and depth were measured. Ratios of marrow ROI/joint fluid ROI on T2/STIR sequences were obtained. Progression to osteomyelitis on subsequent MRI was characterized by loss of normal marrow signal on T1-weighted images. Statistical analysis was performed with a two-sample t test and Cox proportional hazard model. A p value < 0.05 was used as the threshold for statistical significance.

RESULTS

Sixty MR exams were identified. Thirty-four progressed to osteomyelitis. Marrow ROI/joint fluid ratios averaged 65% in the osteomyelitis group, and 45% in the non-osteomyelitis group, p < 0.001. ROI ratios > 53% had a 6.5-fold increased risk of osteomyelitis, p < 0.001. Proximity to bone averaged 6 mm in the osteomyelitis group and 9 mm in the non-osteomyelitis group, p = 0.02. Ulcer size averaged 4 cm² in the osteomyelitis group versus 2.4 cm² in the non-osteomyelitis group, p = 0.07. Ulcers greater than 3 cm² has a 2-fold increase in the risk of osteomyelitis, p = 0.04.

CONCLUSION

Increasing bone marrow ROI signal/joint fluid ratios on T2/STIR images were the strongest risk factors for developing osteomyelitis, while ulcer size and depth are weaker predictors.

Surgical techniques for Bone Biopsy in Diabetic Foot Infection, and association between results and treatment duration

Surgery is an important part of the management of patients diagnosed with DFO. It consists in some selected patients, to remove all or part of the infected bone(s) or even to amputate all or part of the foot. Despite the use of sophisticated imaging techniques, it is however difficult to remove all the infected tissue while respecting the principles of an economical surgery. Bone biopsy performed at the margins of the resection permits to identify residual osteomyelitis and to adjust the post-surgical antibiotic treatment. Some recent studies have reported the way to perform bone margin biopsies and have assessed the impact of the bone results on the patient's outcome. However, the real impact of a residual osteomyelitis on the risk of recurrent DFO is still debated and questions regarding the interpretation of the results remain to be solved. Similarly, the consequences in terms of choice and duration of the antimicrobial treatment to use in case of positive bone margin are not clearly established.

Renal Function as a Predictor of Early Transmetatarsal Amputation Failure

Chronic kidney disease (CKD) is a major concern in patients with foot disease because it is associated with high rates of neuropathy, peripheral vascular disease, and poor wound healing. The purpose of this study was to evaluate renal dysfunction as a risk factor for reamputation after initial transmetatarsal amputation (TMA). Patients who underwent a TMA were retrospectively identified in the American College of Surgeons National Surgical Quality Improvement Program database. Of 2018 patients, reamputation after TMA occurred in 4.4%. End-stage renal disease (ESRD) was associated with 100% increased odds of TMA failure (adjusted odds ratio [OR] = 2.00; 95% CI = 1.10, 3.52), 128% increased odds of major amputation (adjusted OR = 2.28; 95% CI = 1.27, 3.96), and 182% increased odds of 30-day mortality (adjusted OR = 2.82; 95% CI = 1.69, 4.64). In addition, white blood cell count >10 000/mm³ and deep infection at the time of surgery were independently associated with TMA failure. In conclusion, severe renal dysfunction is associated with TMA failure in the short-term, perioperative period. There was no incremental increase in risk of TMA failure with worsening level of renal function before ESRD. A multidisciplinary approach should be implemented in patients with CKD to prevent foot-related pathologies that may necessitate lower-extremity amputation. Levels of Evidence: Level III: Retrospective cohort study.

Outcomes of Limb-Sparing Surgery for Osteomyelitis in the Diabetic Foot: Importance of the Histopathologic Margin

Background

Diabetes mellitus affects up to 14% of Americans. Infection of the diabetic foot is a common complication, which may lead to amputation. If infection extends to involve bone, the risk of amputation is increased 4-fold. Presence of osteomyelitis at the histopathologic margin of resection portends a poor prognosis in osteomyelitis outside the setting of the diabetic foot. We aimed to assess the association of a positive histopathologic margin with the outcome of osteomyelitis in the diabetic foot.

Methods

Medical records were reviewed for all patients who underwent below-ankle amputation for osteomyelitis of the diabetic foot. Patients who had at least 1 year of follow-up, a histopathologic diagnosis of osteomyelitis, and a comment on whether the margin was involved were included.

Results

Thirty-nine of 66 (59%) cases had remission of osteomyelitis at 12 months. When comparing cases with remission with those who experienced recurrence in the 12 months of follow-up, there were no statistically significant differences in age, glycosylated hemoglobin, duration of antimicrobial therapy, Infectious Diseases Society of America class, or presence of osteomyelitis at the histopathologic margin. Among cases with a negative histopathologic margin, 29/48 (60.4%) were free of disease at 1 year, compared with 10/18 (55.6%) cases with a positive histopathologic margin (P = .72). Remission was significantly more frequent in cases undergoing amputation at the digit level (66.7%) compared with amputation at the metatarsal level (40.7%) (P = .045).

Conclusions

Osteomyelitis of the diabetic foot at the histopathologic margin of resection was not associated with increased risk of treatment failure. Resection at the level of the digit was associated with a lower risk of failure than at the metatarsal level.

Hospital admission and readmission among homeless patients with neurologic disease

OBJECTIVE

To characterize the most common neurologic diagnoses leading to hospitalization for homeless compared to housed individuals and to assess whether homelessness is an independent risk factor for 30-day readmission after an admission for a neurologic illness.

METHODS

We performed a retrospective serial cross-sectional study using data from the Healthcare Cost and Utilization Project California State Inpatient Database from 2006 to 2011. Adult patients with a primary neurologic discharge diagnosis were included. The primary outcome was 30-day readmission. We used multilevel logistic regression to examine the association between homelessness and readmission after adjustment for patient factors.

RESULTS

We identified 1,082,347 patients with a neurologic primary diagnosis. The rate of homelessness was 0.37%. The most common indications for hospitalization among homeless patients were seizure and traumatic brain injury, both of which were more common in the homeless compared to housed population (19.3% vs 8.1% and 31.9% vs 9.2%, respectively, p < 0.001). A multilevel mixed-effects model controlling for patient age, sex, race, insurance type, comorbid conditions, and clustering on the hospital level found that homelessness was associated with increased 30-day readmission (odds ratio 1.5, 95% confidence interval 1.4-1.6, p < 0.001). This association persisted after this analysis was repeated within specific diagnoses (patients with epilepsy, trauma, encephalopathy, and neuromuscular disease).

CONCLUSION

The most common neurologic reasons for admission among homeless patients are seizure and traumatic brain injury; these patients are at high risk for readmission. Future interventions should target the drivers of readmissions in this vulnerable population.

Advances in the Management of Peripheral Artery Disease

PURPOSE OF REVIEW

This paper provides a concise update on the management of peripheral artery disease (PAD).

RECENT FINDINGS

PAD continues to denote a population at high risk for mortality but represents a threat for limb loss only when associated with foot ulcers, gangrene, or infections. Performing either angiogram or non-invasive testing for all patients with foot ulcers, gangrene, or foot infections will help increase the detection of PAD, and refined revascularization strategies may help optimize wound healing in this patient group. Structured exercise programs are becoming available to more patients with claudication as methods to improve adherence to community-based exercise programs will improve. Finally, ensuring more patients with PAD receive aspirin therapy and statins may improve long-term survival, while further research will help determine if adding newer antiplatelet or anticoagulant medications may reduce leg amputations in selected patients. Clinicians should have a low threshold to obtain an angiogram and to pursue revascularization in patients with foot ulcers, gangrene, or foot infections. In patients with claudication, clinicians should maximize the benefits derived from exercise therapy and medical management before offering percutaneous or surgical revascularization.

Diabetes Care for Patients Experiencing Homelessness: Beyond Metformin and Sulfonylureas

On any given night in the United States, an estimated 553,742 people are homeless. Applying a broader definition of homelessness that includes unstably housed people, an estimated 1.5% of Americans experience homelessness in a given year. Rates of diabetes are increasing among individuals experiencing homelessness. The social, psychological, and physical challenges of homelessness not only contribute to the rate of diabetes, but also complicate management. Unstable housing, limited medical resources, food insecurity, and competing priorities are barriers to diabetes care among patients experiencing homelessness. Homeless patients with diabetes more frequently develop specific comorbidities that require special attention, such as cardiovascular disease, substance abuse, depression, and foot wounds. The Affordable Care Act gave states the option to expand Medicaid to those earning up to 138% of the federal poverty level. This addressed a gap in coverage for low-income individuals not eligible for Medicaid or employer-sponsored insurance. With increased insurance coverage, this has increased the variety of medications available to treat hyperglycemia from type 2 diabetes beyond metformin, sulfonylureas, and insulin. Several of the newer classes of medications have advantages for patients experiencing homelessness, but also have special considerations in this vulnerable patient population. This narrative review will provide a review of dipeptidyl peptidase-4 inhibitors, glucagon-like peptide agonists, sodium glucose cotransporter-2 inhibitors, and thiazolidinediones in individuals experiencing homelessness.

Discordant isolates in bone specimens from patients with recurrent foot osteomyelitis

We compared paired operative bone cultures (initial operation and reoperation) for 35 patients who experienced foot osteomyelitis treatment failure at a single hospital. Concordance was poor (kappa = 0.180). Staphylococcus aureus, gram negatives, and anaerobes were the most common discordant bacteria seen at reoperation, while Enterococcus was the most persistent.

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.