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

BedBiopsy: Diagnostic performance of bedside ultrasound-guided bone biopsies for the management of diabetic foot infection

OBJECTIVE

We aimed to assess the feasibility and diagnostic performance of ultrasound-guided bone biopsies at the bedside of diabetic patients admitted for suspected foot osteitis not requiring surgery.

RESEARCH DESIGN AND METHODS

In this retrospective monocentric study, we compared the performance of ultrasound-guided (n = 29 consecutive patients, Dec.2020-Oct.2022) versus surgical (n = 24 consecutive patients, Jan.2018-Nov.2020) bone biopsies at confirming or ruling out diabetic foot osteitis (primary outcome).

RESULTS

Patient characteristics were similar in the two intervention groups, including arteritis prevalence (62.3 %), SINBAD score, and wound location (phalanges 36 %, metatarsus 43 %, and calcaneus 21 %). However, the ultrasound-guided group was older (67 ± 11 versus 60 ± 13 years respectively, P = 0.047) and had more type 2 diabetes (97 % versus 75 %, P = 0.038). Diagnostic performance (i.e., capacity to confirm or rule out suspected osteitis) was similar for ultrasound-guided (28/29 cases: 25 confirmations, 3 invalidations) and surgical (24 confirmations/24) biopsies, P = 0.358. No biopsy-related side effect or complication was observed for either intervention, even for patients on antiaggregation and/or anticoagulation therapy. The mean (± standard deviation) time necessary to perform the biopsy was shorter in the ultrasound-guided group (2.6 ± 3.0 versus 7.2 ± 5.8 days, respectively, P < 0.001) and wound evolution at three months was more favorable (83.3 versus 41.2 %, P = 0.005) (94.4 % versus 66.7 %, respectively, patients with new surgical procedure within six months excluded; P = 0.055). Even though not statistically significant, healing rates in terms of wound and osteitis at six months were also better in the ultrasound-guided group (wound: 40.9 % versus 36.8 %; P = 0.790, and osteitis: 81.8 vs 55.6 % P = 0.071).

CONCLUSION

In diabetic patients with suspected foot osteitis not requiring surgery, bedside ultrasound-guided bone biopsies may constitute a promising alternative to surgical biopsies. This intervention provided excellent tolerance and microbiological documentation, short lead-times, and more favorable wound prognosis.

Diagnosis of infection in the foot of patients with diabetes: A systematic review

BACKGROUND

Securing an early accurate diagnosis of diabetic foot infections and assessment of their severity are of paramount importance since these infections can cause great morbidity and potential mortality and present formidable challenges in surgical and antimicrobial treatment.

METHODS

In June 2022, we searched the literature using PubMed and EMBASE for published studies on the diagnosis of diabetic foot infection (DFI). On the basis of pre-determined criteria, we reviewed prospective controlled, as well as non-controlled, studies in English. We then developed evidence statements based on the included papers.

RESULTS

We selected a total of 64 papers that met our inclusion criteria. The certainty of the majority of the evidence statements was low because of the weak methodology of nearly all of the studies. The available data suggest that diagnosing diabetic foot infections on the basis of clinical signs and symptoms and classified according to the International Working Group of the Diabetic Foot/Infectious Diseases Society of America scheme correlates with the patient's likelihood of the need for hospitalisation, lower extremity amputation, and risk of death. Elevated levels of selected serum inflammatory markers such as erythrocyte sedimentation rate (ESR), C-reactive protein and procalcitonin are supportive, but not diagnostic, of soft tissue infection. Culturing tissue samples of soft tissues or bone, when care is taken to avoid contamination, provides more accurate microbiological information than culturing superficial (swab) samples. Although non-culture techniques, especially next-generation sequencing, are likely to identify more bacteria from tissue samples including bone than standard cultures, no studies have established a significant impact on the management of patients with DFIs. In patients with suspected diabetic foot osteomyelitis, the combination of a positive probe-to-bone test and elevated ESR supports this diagnosis. Plain X-ray remains the first-line imaging examination when there is suspicion of diabetic foot osteomyelitis (DFO), but advanced imaging methods including magnetic resonance imaging (MRI) and nuclear imaging when MRI is not feasible help in cases when either the diagnosis or the localisation of infection is uncertain. Intra-operative or non-per-wound percutaneous biopsy is the best method to accurately identify bone pathogens in case of a suspicion of a DFO. Bedside percutaneous biopsies are effective and safe and are an option to obtain bone culture data when conventional (i.e. surgical or radiological) procedures are not feasible.

CONCLUSIONS

The results of this systematic review of the diagnosis of diabetic foot infections provide some guidance for clinicians, but there is still a need for more prospective controlled studies of high quality.

IWGDF/IDSA guidelines on the diagnosis and treatment of diabetes-related foot infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Outpatient Foot-Sparing Surgery Is Safe in Selected Patients with Diabetic Foot Infections

OBJECTIVE

To determine if outpatient foot-sparing surgery for patients with diabetic foot infections (DFIs) is associated with a higher rate of treatment failure or longer healing time.

METHODS

In this prospective observational study, the authors consecutively recruited a cohort of 200 patients with moderate and severe DFIs from the Diabetic Foot Unit of Hospital San Juan de Dios, Caja Costarricense de Seguro Social, San José de Costa Rica, Costa Rica from October 15, 2020 to December 15, 2021. They compared outpatients with those admitted. Cox univariate analysis was performed, with time to treatment failure and time to healing as dependent variables and outpatient management as the independent variable.

RESULTS

Seventy-one patients underwent surgery on an outpatient basis (35.5%), and 129 (64.5%) were admitted. Sixty of 111 patients (54.1%) with moderate infections were treated as outpatients versus 11 of 89 (12.4%) of those with severe infections. Twelve (16.9%) of the outpatients and 26 (20.2%) of those admitted presented failure (P = .57). The Cox univariate analysis with time to failure of treatment associated with outpatient management reported a hazard ratio of 1.26 (95% CI, 0.64-2.50; P = .50), and the analysis regarding healing time reported a hazard ratio of 0.91 (95% CI, 0.66-1.25; P = .56).

CONCLUSIONS

Foot-sparing surgery on an outpatient basis was safe in more than half the cases of moderate DFIs, especially in patients with osteomyelitis. This approach is not associated with treatment failure or a longer healing time. Patients with severe infections, penetrating injuries, necrosis, or high inflammatory response and those with peripheral arterial disease who require revascularizations should be admitted to the hospital.

IWGDF/IDSA Guidelines on the Diagnosis and Treatment of Diabetes-related Foot Infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

The impact of the length of total and intravenous systemic antibiotic therapy for the remission of diabetic foot infections

OBJECTIVE

We investigated the impact of the total length of systemic antibiotic therapy (ABT) and its initial intravenous (IV) part on clinical failure (CF) and microbiological failure (MF) in diabetic foot infections (DFIs).

METHODS

In this single-center, retrospective, unmatched case-control study, we included DFI episodes treated with a combined surgical-antibiotic approach.

RESULTS

We included 721 DFI episodes, 537 with osteomyelitis (DFO). CF occurred in 191 (26.5%) and MF in 42 (5.8%) episodes. Multivariate Cox regression analysis showed that a short ABT of 8-21 days (hazard ratio [HR] 0.4; 95% CI 0.2-0.7) was inversely associated with CF. This was also applicable for IV ABT with relatively short durations of 2-7 days (HR 0.5; 95% CI 0.3-0.8) or 8-14 days (HR 0.6; 95% CI 0.4-0.9). We failed to detect a minimal threshold of total or IV ABT predictive for CF or MF.

CONCLUSIONS

Compared with total ABT of more than 84 days and IV therapy of more than 14 days, shorter total and IV ABT yielded no enhanced risk of CF or MF. Considering the "bias by indication" that is inherent to retrospective DFI studies, the best study design concerning the duration of ABT would be a stratified, prospective randomized trial, which is currently under way in our medical center.

Advances in pharmacotherapy for diabetic foot osteomyelitis

Introduction: The diagnosis of diabetic foot osteomyelitis (DFO) is usually clinical. Its severity is related to the location and depth of the lesion, and the presence of necrosis or gangrene. The aetiology of diabetic foot osteomyelitis (DFO) is usually polymicrobial, and DFO is often associated with chronic or recurring ulceration.Areas covered: We built on the  International Working Group on the Diabetic Foot (IWGDF) guidelines on the management of diabetic foot infection, providing an outline of the current and new concepts in pharmacotherapy in DFO. We assess future strategies in both medical, surgical and combination management of DFO.Expert opinion: Surgical removal of infected bone is considered as the standard treatment, but a medical approach of certain selected situations has now proven efficacy in selected patients. The combination of new modalities in local antibiotic delivery may provide better long-term solutions and more lasting remission and avoid the disadvantages of prolonged systemic antibiotics.

Optimal microbiological sampling for the diagnosis of osteoarticular infection

Infection is a dire complication afflicting every field of orthopaedics and traumatology. If specific clinical, laboratory and imaging parameters are present, infection is often assumed even in the absence of microbiological confirmation. However, apart from confirming infection, knowing the exact infecting pathogen(s) and their antimicrobial susceptibility patterns is paramount to help guide treatment. Every effort should therefore be undertaken with that goal in mind.Not all microbiological findings carry the same relevance, and knowing exactly how and where a sample was collected is key. Several different sampling techniques are available, and one must be aware of both advantages and limitations. Microbiological sampling alternatives in some of the most common clinical scenarios such as native and prosthetic joint infections, osteomyelitis and fracture-related infections, spinal and diabetic foot infections will be discussed.Orthopaedic surgeons should also be aware of basic laboratory sample processing techniques as they have a direct impact on the way specimens should be dealt with and transported to the laboratory. Only by knowing these basic principles will surgeons be able to participate in the multidisciplinary discussion and decision making around how to interpret microbiological findings in each specific patient. Cite this article: EFORT Open Rev 2021;6:390-398. DOI: 10.1302/2058-5241.6.210011.