About

David G. Armstrong is a Distinguished Professor of Surgery and Neurological Surgery at the University of Southern California, holding tenure at the Keck School of Medicine. He earned a Master of Science in Tissue Repair and Wound Healing from the University of Wales College of Medicine and a PhD from the University of Manchester College of Medicine, where he was appointed Visiting Professor of Medicine. Dr. Armstrong is the founder and co-Director of the Southwestern Academic Limb Salvage Alliance (SALSA) and serves as Director of USC’s NSF-funded Center to Stream Healthcare in Place (C2SHiP), focusing on integrating consumer electronics, wearables, and medical devices to enhance patient outcomes and reduce hospital stays. He has produced over 720 peer-reviewed research papers and more than 120 books or book chapters, and is the founding co-Editor of the American Diabetes Association’s Clinical Care of the Diabetic Foot. Recognized internationally, Dr. Armstrong has received numerous awards, including the inaugural Georgetown Distinguished Award for Diabetic Limb Salvage, the ADA’s Roger Pecoraro Award, and the ISDF’s Karel Bakker Award. He has held leadership roles such as past Chair of Scientific Sessions for the ADA’s Foot Care Council, and is actively involved in various professional societies, including the International Working Group on the Diabetic Foot and the American Limb Preservation Society, which he founded and co-chairs.

Research topics

• Medicine
• Surgery
• Computer Science
• Intensive care medicine
• Physical therapy
• Nursing
• Internal medicine
• Endocrinology
• Biochemistry
• Physics
• Chemistry
• Pathology
• Pharmacology
• Quantum mechanics
• Gerontology
• Nuclear physics
• Medical emergency
• Family medicine
• Condensed matter physics
• Traditional medicine
• Optics
• Atomic physics

Selected publications

• Responsible AI for Personalized Patient Education and Engagement Across Medical Conditions: Leveraging Multi-Agent LLMs, Ambient Technology, and NotebookLM—A Case Study in Diabetes Education and Limb Preservation

  Journal of the American Podiatric Medical Association · 2026-05-08 · 1 citations

  articleOpen accessSenior author

  Background: Effective communication with patients is vital for improving health outcomes in chronic disease management. In this study, we investigated WoundScribeAI’s Scribe AI, also known as Ambient Technology, and its patient education and engagement app, Pingoo.AI. It employed a multi-agent AI model that leveraged Large Language Models (LLMs) and NotebookLM to enhance patient communication in clinical settings. Methods: The system comprised specialized agents that transcribed healthcare provider–patient conversations through ambient dictation. This transcription generated medical notes that followed the Subjective, Objective, Assessment, and Plan (SOAP) format—a structured document used by healthcare providers to record and communicate information about patient encounters. Simultaneously, comprehensive visit summaries were also created. In the next step, these visit summaries were used to produce conversational and educational content by leveraging NotebookLM, an AI model introduced by Google that can generate podcast-style conversations from provided information. Integrating these agents allows clinicians to deliver engaging, empathetic, and actionable information to patients. Medical experts conducted a two-phase evaluation of the system’s performance based on multiple criteria, with a particular focus on diabetes education and diabetic foot care. The first phase used pre-recorded training videos, while the second phase involved simulated consultations by clinicians using the system. To validate the AI-generated educational content, we used several established frameworks in health communication that closely align with our enhancement goals. Results: The results showed that the AI model generated accurate clinical documentation and met the criteria for accurate SOAP Notes, visit summaries, and engaging educational content for patients. Given that hallucination is a significant concern related to large language models, especially in critical fields like healthcare, we meticulously analyzed the generated outputs to identify any signs of hallucinated information. Three outcomes successfully passed the validation criteria, including accuracy, completeness, comprehensiveness, absence of potential harm, and no hallucination. Additionally, the Conversational Education content was confirmed against established patient education frameworks and met criteria such as the use of metaphors, empathetic tone, and appropriate language, providing additional detail to help manage the condition. Conclusions: By providing specific instructions and prompts to NotebookLM to transform visit summaries into educational conversations, we significantly enhanced the comprehensiveness and engagement of the content for patients. In contrast to a traditional summary of the clinical visit, the podcast-style conversation enriched the content with background information, encouraging language, an empathetic tone, and helpful metaphors. Our analysis confirmed that the system did not exhibit any hallucinations, highlighting the effectiveness of our approach in mitigating this risk. These findings support the use of multi-agent AI models, combined with ambient dictation and tools like NotebookLM, to improve patient communication that surpasses traditional paper-based brochures, which are often impersonal, minimal, and do not always adhere to recommended factors for health literacy.

  PublisherOA PDFDOI

• Real-world outcomes of cellular, acellular, and matrix-like products (CAMPs) in Stage 3 pressure injury ulcers: A matched Medicare claims analysis (2016–2024)

  International Journal of Tissue Repair · 2026-03-17

  articleOpen access

  Background: Stage 3 pressure injuries (PIs) are full-thickness wounds associated with high morbidity, frequent infection-related complications, and substantial healthcare utilization in adults with compromised mobility. Real-world outcomes of cellular, acellular, and matrix-like products (CAMPs) for Stage 3 PIs in Medicare populations have not been well characterized. Methods: We conducted a retrospective, matched-cohort study using Medicare claims data (2016–2024). Stage 3 PI ulcer treatment episodes were constructed using a 90-day clean period (defined as ≥90 days without wound-related services) and a 90-day episode definition and evaluated in a hospital outpatient department (HOPD)/inpatient-only sample. Episodes receiving CAMPs (identified by Q- and A- Healthcare Common Procedure Coding System (HCPCS) codes) were matched 1:1 to standard-of-care (SOC) episodes (which included sharp debridement without CAMPs) using a prespecified set of exact and range-based covariates including demographics, comorbidity burden, PI location markers, and timing measures. Outcomes included episode characteristics, complications (including sepsis), healthcare utilization, costs, and mortality (death within 90 days of episode end). Two minimum-duration cohorts were analyzed (90 and 120 days). Results: For the 90-day minimum cohort (n=7223 matched episodes per group), CAMP episodes had lower mean PI-associated spending ($36,397 vs $39,886; p=0.0003) and lower mean total all-cause spending ($46,905 vs $50,686; p=0.0006). Compared with SOC, CAMP episodes were associated with lower complications and healthcare resources utilization, including lower sepsis (26.1% vs 36.1%; p<0.0001), lower major amputation (2.2% vs 3.1%; p=0.0004), fewer emergency department (ED) visits (1.34 vs 2.04; p<0.0001) and inpatient visits (1.52 vs 2.24; p<0.0001), and lower mortality (17.8% vs 22.3%; p<0.0001). Episode length was longer with CAMPs (323.8 vs 302.1 days; p<0.0001). Findings were consistent in the 120-day minimum cohort (n=6139 per group), including lower mean total all-cause spending ($51,585 vs $56,865; p<0.0001), lower sepsis (28.8% vs 39.9%; p<0.0001), lower major amputation (2.4% vs 3.3%; p=0.0041), fewer ED visits (1.50 vs 2.29; p<0.0001) and inpatient visits (1.70 vs 2.49; p<0.0001), and lower mortality (18.4% vs 22.8%; p<0.0001). Episode length remained longer with CAMPs (359.6 vs 339.1 days; p<0.0001). Conclusions: In matched Medicare Stage 3 PI episodes managed in the HOPD setting, CAMP use was associated with lower rates of sepsis, acute-care utilization, major amputations, mortality, total and PI ulcer–associated spending despite longer episode duration. These results further support confirmatory work incorporating greater clinical granularity and direct healing endpoints.

  PublisherOA PDFDOI

• An Enigma Wrapped in Oedema: Rethinking Charcot Neuroarthropathy in Diabetes on <scp>JM</scp> Charcot's 200th Birthday

  International Wound Journal · 2026-01-01

  articleOpen access1st authorCorresponding

  Winston Churchill famously described Russia as ‘a riddle, wrapped in a mystery, inside an enigma’ in a 1939 broadcast [1]. Indeed, two centuries after the birth of Jean-Martin Charcot, the condition that bears his name remains, as Churchill might say, an enigma wrapped in oedema—an inflammatory mystery too often misread or misdiagnosed as mundane. Charcot neuroarthropathy (CNO) in people with diabetes is not rare. It is under-recognised, underdiagnosed and undertreated. And thanks to a growing coalition of clinicians, researchers and now national funders, that may be about to change [2, 3]. A recent position piece by Wukich, Frykberg and Kavarthapu calls for a paradigm shift in how we diagnose and manage CNO [4]. Drawing from epidemiological estimates and evolving clinical data, the authors lay bare a startling truth: the annual incidence of CNO in U.S. patients with diabetes—more than 27 000—is higher than many primary cancers, including kidney, thyroid and multiple myeloma. It exceeds the incidence of many lower extremity fractures. And yet, CNO rarely appears on research agendas, funding calls, or performance metrics (Figure 1). We treat displaced intra-articular fractures elsewhere in the body with urgency and precision. But in the foot of a neuropathic patient, we too often default to watchful waiting. This double standard has consequences: progressive deformity, ulceration, infection and ultimately amputation. As Wukich et al. note, nearly 85% of diabetes-related amputations are preceded by a foot wound, and CNO—left unchecked—is not infrequently the engine driving that sequence. The tide may finally be turning. In a historic step, the National Institutes of Health has awarded the first-ever R-series grant specifically aimed at improving the diagnosis of Charcot neuroarthropathy. It focuses on developing predictive tools and diagnostic standards to identify CNO in its earliest, most reversible stages [5]. This effort targets the elusive ‘Stage 0’ Charcot—where oedema, warmth and subtle instability exist, but radiographs remain deceptively normal. Early diagnosis and intervention in this phase may allow clinicians to stop the deformity cascade before it begins. More experience with team treatment is building scaffolding for what some have long advocated: treating CNO as a neuropathic fracture–dislocation, not as an esoteric complication relegated to specialist clinics. With modern fixation systems, improved multidisciplinary perioperative care and better understanding of perfusion dynamics, surgical intervention for those that have true deformity or dislocation during the active phase of CNO is increasingly feasible—and, for select patients, potentially transformative [4]. On a related note, the International Working Group on the Diabetic Foot has published their first ever consensus document on the disease. Creating a pathway toward diagnosis and treatment [6]. Still, data alone will not change practice. We must embed this knowledge into training programmes, electronic health record prompts and interdisciplinary care pathways. We must update ICD coding to distinguish active versus chronic CNO. And we must launch multicentre trials that compare surgical and nonsurgical strategies—not someday, but now. The ghost of Charcot doesn't need more birthday candles. He needs us to finish what he started: not just to name diseases, but to neutralise them. It's time to unwrap this enigma—and treat the oedema beneath it. This work was supported by the National Institutes of Health. The authors have nothing to report. The authors declare no conflicts of interest. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.

  PublisherOA PDFDOI

• Racial Disparities In Mobility And Prosthetic Outcomes After Lower Extremity Amputationin The United States: A Systematic Review

  Zenodo (CERN European Organization for Nuclear Research) · 2026-05-09

  articleOpen accessSenior author

  PURPOSE: Lower extremity (LE) amputation is a life-altering event that disproportionately affects racialminorities in the United States. Although disparities in amputation incidence are well established, post-amputation functional outcomes are under explored. This review aims to evaluate the nature of racial disparities in lower extremity function, and to explore potential structural and physiological contributors to these disparities. METHODS: Following PRISMA guidelines, we conducted a systematic review of PubMed, Embase, and Scopus (June 2025) to identify English-language studies reporting race-stratified functional outcomes after LE amputation. Inclusion criteria focused on mobility, prosthetic use or abandonment, and rehabilitation access. Two reviewers independently screened and extracted data. Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS), Appraisal Tool for Cross-Sectional Studies (AXIS), and Critical Appraisal Skills Programme (CASP) tools. Eight studies (n = 29,881) met inclusion criteria. RESULTS: Five reported significant racial disparities in functional recovery, including lower mid-swing gait elevation, reduced walking endurance, and a 13-fold increased risk of fall-related injury among non-White patients. Black, Native American, and Pacific Islander patients were less likely to receive a prosthesis, with rural Black veterans facing particularly high abandonment rates. One qualitative study underscored severe access barriers in underserved populations. Risk of bias was generally low across studies. CONCLUSION: Racial disparities in mobility and prosthetic outcomes after LE amputation are multi-factorial, including limited access to care, socioeconomic inequality, comorbidities, and racial differences in gait physiology. Urgent, personalized interventions are needed to close these outcome gaps and improve recovery trajectories for all amputees. *Source: https://ps-rc.org/meeting/Program/2026/EP01.cgi*

  PublisherDOI

• International BEST-CLI Collaborative: next steps to create a coordinated global initiative to improve awareness and access while reducing mortality and amputation for patients with chronic limb-threatening ischaemia

  British journal of surgery · 2025-08-01

  articleOpen access

  [No abstract]

  PublisherOA PDFDOI

• Biofilm in Diabetic Foot Ulcers: A Systematic Narrative Review

  International Wound Journal · 2025-12-01 · 7 citations

  articleOpen accessSenior author

  Biofilms are a key driver of chronicity and treatment failure in diabetic foot ulcers (DFUs), yet clinical evidence quantifying their impact and management remains fragmented. This systematic narrative review synthesised recent evidence (2015-2025) on the prevalence, diagnostics, and management of biofilm in DFUs. A Systematic Review of the Literature (SRL) was conducted following PRISMA 2020 guidelines across PubMed/MEDLINE, Scopus, Cochrane Library and ScienceDirect. Eligible studies included adults with DFUs reporting biofilm/bioburden metrics or interventions aimed at biofilm disruption. Risk of bias was assessed using RoB 2 for randomised trials and ROBINS-I for non-randomised studies. Data were narratively synthesised by evidence tier (Tier 1 = clinical; Tier 2 = preclinical/mechanistic). Of 600 records screened, 25 studies met inclusion criteria (Tier 1 n = 9; Tier 2 n = 5; reviews n = 11). Over half of bacterial isolates in DFUs were biofilm producers, with multidrug resistance exceeding 90% in several cohorts. Fungi were detected in 31% of ulcers by qPCR but only 9% by culture. Tier 1 clinical evidence supports standard care components-debridement, antiseptics, and negative-pressure wound therapy-for improved healing, though direct antibiofilm outcomes remain limited. Emerging strategies (enzymatic agents, peptides, cold plasma, smart dressings) show promise in vitro but lack clinical translation. Evidence for direct antibiofilm efficacy in DFUs remains scarce. Current data justify maintaining guideline-based care while prioritising trials that integrate validated biofilm endpoints, standardised microbiological methods, and antifungal components. Distinguishing established from experimental approaches is essential to advancing safe, evidence-based biofilm management in DFUs.

  PublisherOA PDFDOI

• SLC7 transporters at the crossroads of amino acid metabolism and diabetes pathophysiology: insights and therapeutic perspectives

  Frontiers in Nutrition · 2025-05-21 · 1 citations

  reviewOpen access

  Amino acids are fundamental components of all living cells, serving not only as the building blocks of proteins but also as crucial sources of energy and precursors to key metabolites and signaling molecules. Amino acid transporters, specialized membrane proteins, facilitate the movement of amino acids across plasma membranes and between various cells and organ compartments. The malfunction, absence, or overexpression of specific amino acid transporters is linked to several human diseases. Among the extensive family of solute carrier proteins (SLCs), which comprises 458 transporters, the SLC7 transporter family, inclusive of CATs (Cationic Amino Acid Transporters) and LATs (L-type Amino Acid Transporters), is particularly instrumental in cellular amino acid uptake. Disruptions in amino acid transport can lead to significant metabolic abnormalities in diabetes, characterized by impaired insulin signaling and altered glucose metabolism. A deeper understanding of amino acid transporters' roles in metabolic processes and insulin signaling could shed light on the pathogenesis of diabetes and unveil novel therapeutic targets for this pervasive metabolic syndrome.

  PublisherOA PDFDOI

• Safeguarding access, fiscal responsibility and innovation: a comprehensive reimbursement framework for CAMPs to preserve the Medicare Trust Fund

  Journal of Wound Care · 2025-09-03 · 2 citations

  article

  EXECUTIVE SUMMARY: This manuscript presents a unified and comprehensive policy framework addressing the flat-fee reimbursement model for skin substitutes, also referred to as cellular, acellular, and matrix-like products (CAMPs), proposed by the Centers for Medicare & Medicaid Services (CMS). These products are vital to treating hard-to-heal wounds, which disproportionately affect older patients, and those patients who are disabled and medically underserved. While CMS aims to curtail excessive spending and introduce payment consistency, the current proposal threatens access to life-saving therapies, endangers patient outcomes, and may destabilise clinical delivery infrastructures and manufacturing ecosystems critical to wound care.

  PublisherDOI

• FGFR2 identified as a NETs-associated biomarker and therapeutic target in diabetic foot ulcers

  European journal of medical research · 2025-08-13 · 2 citations

  articleOpen access

  BACKGROUND: Diabetic foot ulcer (DFU) is characterized by impaired wound healing and chronic inflammation, partly driven by the excessive formation of neutrophil extracellular traps (NETs). However, the molecular mediators linking NETs to failed tissue regeneration remain poorly understood. This study aimed to identify and validate novel NETs-associated biomarkers in DFU using an integrative bioinformatics and machine learning approach. METHODS: Differentially expressed genes (DEGs) were identified from the GEO dataset GSE134431. These DEGs were intersected with a NETs-related gene set to identify NETs-associated DEGs (NETDEGs). LASSO logistic regression and Random Forest algorithms were applied to the NETDEGs to select key feature genes. The top candidate, Fibroblast Growth Factor Receptor 2 (FGFR2), was validated in two independent datasets (GSE7014 and GSE147890). Its expression was further confirmed in human DFU tissues and diabetic mouse models using qPCR and immunohistochemistry. The effect of a high-glucose environment on FGFR2 expression in neutrophils was assessed in vitro. Finally, molecular docking technique was used to screen for existing drugs targeting FGFR2, with top candidates validated at the cellular level. RESULTS: Our analysis identified FGFR2 as a key downregulated gene at the intersection of DFU pathology and NETs-related pathways. FGFR2 expression was significantly reduced in DFU tissues across all datasets and in our experimental models, where its downregulation correlated with increased NETs accumulation. FGFR2 demonstrated strong diagnostic potential, with an AUC of 1.00 in the training set. In vitro, high glucose conditions suppressed FGFR2 expression in neutrophils. From 32 glucose-lowering drugs, Canagliflozin and Gliquidone were found to significantly upregulate FGFR2 protein expression in neutrophils, suggesting a potential modulatory effect. CONCLUSIONS: FGFR2 is a promising potential biomarker associated with NET-driven inflammation in DFU. Its downregulation in the diabetic wound microenvironment and its modulation by existing pharmacological agents suggest that targeting the FGFR2 pathway may be a viable future therapeutic strategy for improving DFU healing outcomes. Further preclinical validation is warranted.

  PublisherOA PDFDOI

• Beyond sole salvation: Prolonging life through multidisciplinary limb preservation programs

  Journal of Vascular Surgery · 2025-09-16

  article1st authorCorresponding
  PublisherDOI

Recent grants

• NIH Grant ZIAES080043

  NIH · $6.7M

• NIH Grant Z01ES080043

  NIH · $3.0M

• Infrared Eyes(iREyes)

  NIH · $1.7M · 2014–2023

• IUCRC Phase I USC: Center to Stream Healthcare In Place (C2SHIP)

  NSF · $681k · 2021–2027

Frequent coauthors

• Bharat Kotru

  King Hamad University Hospital

  820 shared

• R. Gary Sibbald

  University of Toronto

  819 shared

• Hiske Smart

  Mayo Clinic

  802 shared

• Elizabeth A. Ayello

  790 shared

• Afsáneh Alavi

  WinnMed

  790 shared

• Dieter Mayer

  University of the Philippines Manila

  789 shared

• Laurie Goodman

  788 shared

• Gregory S. Schultz

  University of Southern California

  787 shared

Awards & honors

• Inaugural Georgetown Distinguished Award for Diabetic Limb S…
• 25th and youngest-ever member elected to the Podiatric Medic…
• First surgeon to be appointed University Distinguished Outre…
• First podiatric surgeon to be selected as President of Facul…
• First podiatric surgeon to become a member of the Society of…