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Refractory pain to the fourth and fifth tarsometatarsal (TMT) joint can be a source of disability and functional impairment. While pain has been attributed to injury, post-traumatic arthritis, arthrofibrosis, the principal causes of pain in the absence of arthritis are not well elucidated. The purpose of this study is to characterize arthroscopic pathology associated with chronic refractory pain to the fourth and fifth TMT joints. We retrospectively examined 24 patients that underwent arthroscopic surgery of the fourth and fifth TMT joints for refractory pain at our academic institution between 2015 and 2019. We used the Outerbridge classification for chondral lesions, the Kellgren Lawrence radiographic classification for osteoarthritis, and described intraarticular pathologies as acute hypertrophic synovitis, chronic synovial fibrosis, hyaline bands, meniscoid bodies, loose joint bodies, arthrofibrosis. Approximately, 31 of 45 TMT joints (68.9%) presented with radiographic evidence of arthritis. Approximately, 14 of 45 TMT joints (31.11%) were absent of radiographic signs of arthritis. The frequency of soft tissue pathology seen in these patients without radiographic evidence of arthritis was arthrofibrosis (87.5%), chronic synovial fibrosis (75.0%), and acute hypertrophic synovitis (62.5%). This is the first study to report arthroscopic pathologies associated with refractory pain to the fourth and fifth TMT joints.

There are multiple factors that lead to the development of the diabetic foot ulceration (DFU). The ultimate goal when treating DFU is to prevent amputation. Initial therapy should include debridement, maintaining a healthy wound environment, and offloading. In the setting of infection or a nonhealing DFU, surgical intervention may be necessary. The goals of this article are to discuss the key aspects of the initial examination, standard nonoperative treatment, and the operative treatment options for patients with DFU.

Severe diabetic foot infections (DFI) are both limb threatening and life threatening and associated with negative impact on health-related quality of life. Most severe DFIs require surgical intervention, and the goal of treatment should be preservation of limb function in addition to eradication of infection. Minor amputations are required in approximately 40% and major amputations in approximately 20% of patients. Significant risk factors for lower extremity amputation included male gender, smoking, previous amputation, osteomyelitis, peripheral artery disease, retinopathy, severe infections, gangrene, neuroischemic diabetic foot infections, leukocytosis, positive wound cultures, and isolation of gram-negative bacteria.

Diabetic foot infections (DFI) are an increasingly common cause of hospitalizations. Once hospitalized with DFI, many patients require some level of amputation, often undergoing multiple operations. With increasing importance on patient-centered metrics, self-reported health-related quality of life (HRQOL) tools have been developed. This prospective cohort study aimed assessed the impact of DFI on HRQOL. Two hundred twenty-four patients completed the 29-item Patient-Reported Outcome Measurement Information System (PROMIS) and 12-Item Short Form (SF-12) survey. Secondary outcomes using the Foot and Ankle Ability Measures survey were obtained and included in the analysis. The study group was comprised of hospitalized patients with DFIs (n = 120), and the control group was comprised of patients with diabetes who were evaluated for routine outpatient foot care (n = 104); diabetic foot screening, wound care, onychomycosis, and/or callosities. Using this cohort, a propensity score-matched sample of hospitalized patients with DFI (n = 35) and control group patients (n = 35) was created for comparative analysis. The 2-independent sample t test was used to test for group differences on each of the PROMIS subscale outcomes. Using PROMIS, we found that hospitalized patients with DFI reported significantly worse HRQOL in 6 of 7 subscales (physical function, anxiety, depression, fatigue, social role, pain intensity; p value range: .0001-.02) compared to outpatients with diabetes evaluated for routine foot care. There was no significant difference between the 2 groups on sleep disturbance (p = .22). Patients hospitalized for DFI report lower HRQOL compared to patients with diabetes receiving routine outpatient foot care.

Homologous recombination (HR), the error-free mechanism for double-strand break (DSB) repair, relies on DNA end resection by nucleolytic degradation of the 5′-terminated ends. However, the role of long-range resection mediated by Exo1 and/or Sgs1-Dna2 in HR is not fully understood. Here, we show that Exo1 and Sgs1 are dispensable for recombination between closely-linked repeats but are required for interchromosomal repeat recombination inSaccharomyces cerevisiae. This requirement for long-range resection is coupled to DNA damage checkpoint activation and the need for checkpoint proteins. Furthermore, artificial activation of the checkpoint partially restores interchromosomal recombination toexo1Δ sgs1Δcells. However, cell cycle delay is insufficient to rescue the interchromosomal recombination defect ofexo1Δ sgs1Δcells, suggesting an additional role for the checkpoint. Given that the checkpoint is necessary for DNA damage-induced chromosome mobility, we propose that the importance of the checkpoint, and therefore long-range resection, in interchromosomal recombination is due to a need to increase chromosome mobility to facilitate pairing of distant sites. The need for long-range resection is circumvented when the DSB and its repair template are in close proximity.

Automatic differentiation (AD) is conventionally understood as a family of distinct algorithms, rooted in two “modes”—forward and reverse—which are typically presented (and implemented) separately. Can there be only one? Following up on the AD systems developed in the JAX and Dex projects, we formalize a decomposition of reverse-mode AD into (i) forward-mode AD followed by (ii) unzipping the linear and non-linear parts and then (iii) transposition of the linear part. To that end, we define a (substructurally) linear type system that can prove a class of functions are (algebraically) linear. Our main results are that forward-mode AD produces such linear functions, and that we can unzip and transpose any such linear function, conserving cost, size, and linearity. Composing these three transformations recovers reverse-mode AD. This decomposition also sheds light on checkpointing, which emerges naturally from a free choice in unzipping let expressions. As a corollary, checkpointing techniques are applicable to general-purpose partial evaluation, not just AD. We hope that our formalization will lead to a deeper understanding of automatic differentiation and that it will simplify implementations, by separating the concerns of differentiation proper from the concerns of gaining efficiency (namely, separating the derivative computation from the act of running it backward).

Invasive plants threaten biodiversity worldwide, but control of non-native species may affect native species in complex ways. Non-native tamarisk (Tamarix spp.) is widespread in western U.S. riparian environments, and tamarisk beetles (Diorhabda spp.), a tamarisk-specific herbivore, were subsequently introduced as biocontrol. The primary effect of biocontrol is defoliation and branch dieback, with repeated defoliation killing the plant. We investigated the initial stages of site recovery after biocontrol and how tamarisk decline affected birds, their arthropod prey, and microclimate. We compared avian community diversity and composition, arthropod abundance, humidity, and temperature at sites along the Virgin River in Nevada and Arizona, USA characterized as either mixed native vegetation, tamarisk-dominated, or tamarisk-dominated where the majority of tamarisk died from biocontrol. We compared avian communities sampled after biocontrol to counts at the same locations before biocontrol. Prior to biocontrol, community compositions of all but one site grouped together using unbiased clustering algorithms. Following biocontrol, tamarisk-dominated sites grouped separately, and mixed sites grouped with the pre-biocontrol cluster. Comparison of pre- and post-biocontrol communities showed 7 common species declined by ≥30% in dead tamarisk sites, while one species did so at mixed sites and 3 at tamarisk-dominated sites. Individual census points in dead tamarisk had significantly lower Simpson diversity than the same points censused before biocontrol, unless native vegetation was present, suggesting tamarisk death was the cause of dominant species abundance changes. Tamarisk-dominated sites were hotter and drier than sites with native vegetation and supported fewer non-tamarisk-obligate arthropods, consistent with the hypothesis that bird reductions were driven by changes in microclimate and prey abundance. How long these effects last will depend upon the rate of native vegetation recovery after biocontrol, therefore we recommend monitoring sites to determine the trajectory of vegetative recovery and considering the need and feasibility of active restoration in those sites with slow or no native regeneration.

Understanding how genes, drugs and neural circuits influence behavior requires the ability to effectively organize information about similarities and differences within complex behavioral datasets. Motion Sequencing (MoSeq) is an ethologically inspired behavioral analysis method that identifies modular components of three-dimensional mouse body language called ‘syllables’. Here, we show that MoSeq effectively parses behavioral differences and captures similarities elicited by a panel of neuroactive and psychoactive drugs administered to a cohort of nearly 700 mice. MoSeq identifies syllables that are characteristic of individual drugs, a finding we leverage to reveal specific on- and off-target effects of both established and candidate therapeutics in a mouse model of autism spectrum disorder. These results demonstrate that MoSeq can meaningfully organize large-scale behavioral data, illustrate the power of a fundamentally modular description of behavior and suggest that behavioral syllables represent a new class of druggable target. By analyzing hundreds of mice treated with a library of neuro- and psychoactive drugs, Wiltschko et al. show that Motion Sequencing can effectively discriminate and categorize drug effects and link molecular targets to behavioral syllables.

Background: Maternal nutrition influences fetal development and may permanently alter ("program") offspring body composition and metabolism, thereby influencing later risk of diabetes and cardiovascular (cardiometabolic) disease. The prevalence of cardiometabolic disease is rising rapidly in India. Objectives: To test the hypothesis that supplementing low-income Indian women with micronutrient-rich foods preconceptionally and during pregnancy has a beneficial impact on the children's body composition and cardiometabolic risk marker profiles. Methods: Follow-up of 1255 children aged 5-10 y whose mothers took part in the Mumbai Maternal Nutrition Project [Project "SARAS"; International Standard Randomised Controlled Trial Number (ISRCTN)62811278]. Mothers were randomly assigned to receive a daily micronutrient-rich snack or a control snack of lower micronutrient content, both made from local foods, in addition to normal diet, from before pregnancy until delivery. Children's body composition was assessed using anthropometry and DXA. Their blood pressure, plasma glucose, insulin, and lipid concentrations were measured. Outcomes were compared between allocation groups with and without adjustment for confounding factors. Results: Overall, 15% of children were stunted, 34% were wasted, and 3% were overweight. In the intention-To-Treat analysis, there were no differences in body composition or risk markers between children in the intervention and control groups. Among children whose mothers started supplementation ≥3 mo before conception (the "per protocol"sample) the intervention increased adiposity among girls, but not boys. BMI in girls was increased relative to controls by 2% (95% CI: 1, 4; P = 0.01); fat mass index by 10% (95% CI: 3, 18; P = 0.004); and percent fat by 7% (95% CI: 1, 13; P = 0.01) unadjusted, with similar results in adjusted models. Conclusions: Overall, supplementing women with micronutrient-rich foods from before pregnancy until delivery did not alter body composition or cardiometabolic risk markers in the children. Subgroup analyses showed that, if started ≥3 mo before conception, supplementation may increase adiposity among female children.

Adoptive transfer of tumor-infiltrating lymphocytes (TIL) fails to consistently elicit tumor rejection. Manipulation of intrinsic factors that inhibit T cell effector function and neoantigen recognition may therefore improve TIL therapy outcomes. We previously identified the cytokine-induced SH2 protein (CISH) as a key regulator of T cell functional avidity in mice. Here, we investigate the mechanistic role of CISH in regulating human T cell effector function in solid tumors and demonstrate that CRISPR/Cas9 disruption of CISH enhances TIL neoantigen recognition and response to checkpoint blockade.Single-cell gene expression profiling was used to identify a negative correlation between high CISH expression and TIL activation in patient-derived TIL. A GMP-compliant CRISPR/Cas9 gene editing process was developed to assess the impact of CISH disruption on the molecular and functional phenotype of human peripheral blood T cells and TIL. Tumor-specific T cells with disrupted Cish function were adoptively transferred into tumor-bearing mice and evaluated for efficacy with or without checkpoint blockade.CISH expression was associated with T cell dysfunction. CISH deletion using CRISPR/Cas9 resulted in hyper-activation and improved functional avidity against tumor-derived neoantigens without perturbing T cell maturation. Cish knockout resulted in increased susceptibility to checkpoint blockade in vivo.CISH negatively regulates human T cell effector function, and its genetic disruption offers a novel avenue to improve the therapeutic efficacy of adoptive TIL therapy.This study was funded by Intima Bioscience, U.S. and in part through the Intramural program CCR at the National Cancer Institute.

We develop automatic differentiation (AD) procedures for reductions and scans—parameterized by arbitrary differentiable monoids—in a way that preserves parallelism, by rewriting them as other reductions and scans. This is in contrast with the literature and with existing AD systems, which are either general, but force sequential execution of the derivative program, or only include hand-crafted rules for a select few monoids (usually (0, +), (1, ×), (−∞, max) and (∞, min)) and thus lack the general flexibility of second-order languages.

There is a paucity of literature characterizing risk factors for nonunion associated with the modified Lapidus procedure for correction of hallux valgus. The purpose of this study was to evaluate risk factors associated with nonunion for Lapidus bunionectomies. Patients who underwent modified Lapidus procedure from 2009 to 2018 were retrospectively reviewed. Patient's age, sex, body mass index, prior bunionectomy, history of tobacco use, presence of diabetes mellitus or hypothyroidism, and fixation method were recorded along with pre- and postoperative radiographic parameters. A multiple logistic regression analysis was implemented to estimate the odds of nonunion. Of the 222 patients who met inclusion criteria, nonunion with modified Lapidus procedure was observed in 20 patients (9.01%). Odds of nonunion with modified Lapidus procedure were greater for patients who had undergone previous bunionectomy (odds ratio [OR] = 3.957, 95% confidence interval [CI]: 1.021-15.338), as body mass index increased (OR = 1.091, 95% CI: 1.018-1.170), and as preoperative HV angle increased (OR = 1.108, 95% CI: 1.020-1.203). Odds of nonunion were lower for patients as preoperative intermetatarsal angle increased (OR = 0.739, 95% CI: 0.580-0.941). No significant increased odds of nonunion were found between fixation methods.

The objective of the study was to evaluate the effect of the erbium:yttrium aluminum garnet (YAG) laser on diabetic foot ulcers (DFUs) that had not responded to standard care. We retrospectively evaluated 22 nonhealing DFUs that received at least 4 weeks of standard wound care, demonstrated poor healing response, and subsequently were treated with an erbium:YAG laser. We measured the percent wound area reduction (PWAR) for the 4 weeks before initiating laser therapy and the PWAR for 4 weeks after the initiation of laser therapy. Erbium:YAG laser treatment consisted of 2 components: debridement and resurfacing. The laser settings were the same for all treatments. We used the paired t test to compare pretreatment with posttreatment wound area reduction. During the 4-week period before the initiation of laser therapy, the average PWAR was –33.6%. Four weeks after initiating treatment with the erbium:YAG laser, the average PWAR was 63.4% (p = .002) and 72.7% of wounds had ≥50% PWAR. By 12 weeks, 50% of wounds had healed. Erbium:YAG laser therapy accelerated DFU healing in a cohort of patients with ulcers that had been unresponsive to standard of care therapy.

To determine the degree patients with diabetic foot ulcers, Charcot neuroarthropathy and neuropathic fractures and dislocations fear complications (death, dialysis, heart attack, stroke, blindness, diabetic foot infection, minor and major lower extremity amputation [LEA]) that can occur and to assess if there is a difference between fears of patients with diabetic foot ulcers, Charcot neuroarthropathy and neuropathic fractures and dislocations and diabetic patients without these complications.478 patients completed an eight question Likert scale survey. The study group was defined as non-infected foot ulcers, neuropathic fractures and Charcot neuroarthropathy.Of the 478 patients, 121 (25.3 %) had diabetic foot ulcers, Charcot neuroarthropathy or neuropathic fractures and dislocations and 357 (74.7 %) did not. The study group had significantly higher odds of reporting extreme fear of foot infection (OR 2.8, 95 % CI 1.8-4.5), major LEA (OR 2.8, 95 % CI 1.8-4.4), minor LEA (OR 2.3, 95 % CI 1.5-3.5), blindness (OR 2.0, 95 % CI 1.3-3.2), dialysis (OR 2.0, 95 % CI 1.1-3.3), and death (OR 2.4, 95 % CI 1.4-4.2). In the study group highest rated fear measures were foot infection (3.71, SD 1.23), minor amputation (3.67, SD 1.45) and major amputation (3.63, SD 1.52). There were no significant differences in the mean fear of infection, minor amputation or major amputation.Patients with diabetic foot ulcers, Charcot neuroarthropathy or neuropathic fractures and dislocations reported higher fear ratings of diabetes-related complications compared to those without these complications.

We present a novel programming language design that attempts to combine the clarity and safety of high-level functional languages with the efficiency and parallelism of low-level numerical languages. We treat arrays as eagerly-memoized functions on typed index sets, allowing abstract function manipulations, such as currying, to work on arrays. In contrast to composing primitive bulk-array operations, we argue for an explicit nested indexing style that mirrors application of functions to arguments. We also introduce a fine-grained typed effects system which affords concise and automatically-parallelized in-place updates. Specifically, an associative accumulation effect allows reverse-mode automatic differentiation of in-place updates in a way that preserves parallelism. Empirically, we benchmark against the Futhark array programming language, and demonstrate that aggressive inlining and type-driven compilation allows array programs to be written in an expressive, "pointful" style with little performance penalty., Comment: 31 pages with appendix, 11 figures. A conference submission is still under review

Our aim was to evaluate the effect of antibiotic exposure on bacterial pathogen yield in patients with diabetic foot osteomyelitis. In a retrospective cohort study, we evaluated 142 patients admitted to the hospital with diabetic foot osteomyelitis which confirmed by histologic evaluation. Histologic criteria for osteomyelitis included the presence of an inflammatory response, bone necrosis, and/or bone fragmentation. We compared bacterial pathogens in patients that received antibiotics before bone culture (n=114) and patients that did not receive antibiotics (n=28), as well as bacterial yield based on the duration of antibiotic exposure. We used the chi square test to compare antibiotic exposure and culture yield. There was not a significant difference in culture yield in patients that received antibiotics (77.9%) and patients that did not (85.7%, p=0.58). There was no difference in patients that received antibiotics for ≥4 days (n=56, 71.4%), 1-3 days (n=58, 84.5%) and no antibiotics (85.7%, p=0.15). In conclusion, the results of bacterial recovery were similar in patients regardless of the length of antibiotic treatment. Antibiotic exposure did not change the bacterial yield, the type of bacteria or the number of bacteria. In patients with suspected diabetic foot osteomyelitis, there is no evidence to support withholding antibiotics prior to obtaining a bone biopsy. Disclosure L.A. Lavery: Advisory Panel; Self; Acelity, Bayer AG. Consultant; Self; Boehringer Ingelheim International GmbH. Research Support; Self; AstraZeneca, Cardinal Health, EO2 Concepts, Integra LifeSciences, MedImmune, Smith & Nephew. E.C. Ryan: None. D.H. Truong: None. M.J. Johnson: None. J. La Fontaine: None. P.A. Crisologo: None.

Charcot neuroarthropathy can cause severe deformity of the midfoot, and intramedullary use of beams and bolts has been utilized as a method of definitive stabilization. This systematic review evaluated the outcomes of intramedullary beaming in patients with Charcot neuroarthropathy and determined the methodological quality of the studies. Four online databases were searched: PubMed, MEDLINE (Clarivate Analytics), CINAHL (Cumulative Index to Nursing and Allied Health) and Web of Science (Clarivate Analytics). To assess the methodological quality of the studies, the Coleman Methodology Score was used. The data was pooled into 2 outcomes groups for comparison: (1) Studies that reported on the outcomes of Charcot specific implants (study group). (2) Studies that reported on the outcomes using non-Charcot specific implants (control group). After screening, 16 studies were included. Compared to our control group, our study group had significantly higher rates of overall hardware complications, hardware migration, surgical site infection, reoperation, and nonunion. The study group had significantly lower rates of limb salvage compared to the control group. Our study and control groups did not differ in the rates of hardware breakage, wound healing complications, or mortality. The limb salvage rate was 92% and 97% of patients were still alive at a mean follow-up of 25 months. The mean Coleman Methodology Score indicated the quality of the studies was poor and consistent with methodologic limitations. The quality of published studies on intramedullary implants for Charcot reconstruction is low. Complications when utilizing intramedullary fixation for Charcot reconstruction are high, whether or not Charcot specific implants are used.

The CRISPR/Cas9 system allows for site-specific gene editing and genome engineering of primary human cells. Here we describe methods for gene editing and genome engineering of B cells isolated from human peripheral blood mononuclear cells using CRISPR/Cas9. Editing frequencies of up to 90% and integration rates greater than 60% can be achieved with this method.

Timing and spatial dynamics of tamarisk (Tamarix spp. L.) defoliation by the biological control agent Diorhabda carinulata (Desbrochers) were evaluated. Relative abundance of D. carinulata and the phenology of tamarisk along the San Juan and Colorado rivers were recorded in 2011–2012. D. carinulata began reproducing in the spring when temperatures were >15°C. Variation in spring temperature-rise affected the timing of development of larvae of the first summer generation and initial defoliation of tamarisk at each site. Shortening day lengths in mid- to late-summer cued D. carinulata to enter reproductive diapause resulting in cessation of defoliation. The critical day length for inducing reproductive diapause was 33–47 minutes shorter than that of populations of D. carinulata released into North America in 2001. Variation in spring temperature-rise combined with timing of shortening day length resulted in differences in D. carinulata voltinism per site. During the active season, larvae were less likely to establish in areas where defoliation was >70%. Lack of reestablishment of larvae led to temporary loss of D. carinulata from the locations and allowed tamarisks to sprout new canopies. Defoliation of tamarisk was dictated by environmental cues and abundance of D. carinulata, and in turn large amounts of defoliation negatively affected abundance of D. carinulata.

Native species can have a range of responses to nonnative introductions, from negative to positive, and understanding how and why native species respond differently to nonnatives remains an important management challenge. Based on differences and similarities in ecology and behavior, we predicted how abundance and diet of two native warblers, Lucy’s warbler (Oreothlypis luciae) and yellow warbler (Setophaga petechia), would differ in habitats with different amounts of nonnative tamarisk trees and the three nonnative insects obligately dependent on tamarisk (Tamarix spp.). Specifically, we predicted that Lucy’s warblers would have similar densities across sites, yellow warbler densities would be inversely related to tamarisk cover, and both warblers, being generalist insectivores, would incorporate tamarisk biocontrol insects in their diet. Based on point counts and fecal samples at six sites along the Virgin River in the southwestern United States, we found that yellow warblers decreased in abundance with increasing tamarisk cover, while Lucy’s warbler abundance did not and that diet of the two warblers did not differ, with both species exhibiting strong selection for the nonnative tamarisk weevil (Coniatus splendidulus) and weak to no selection for the nonnative tamarisk leafhopper (Opsius stactogalus). Both warblers showed negative selection for the tamarisk beetle (Diorhabda carinulata) and its larvae, even when those insects were 10–100 times more abundant during outbreaks. Although both warblers exploited the novel food resources offered by tamarisk, with those insects contributing half or more of total prey biomass, Lucy’s warblers were better able to maintain densities in tamarisk habitats. We hypothesize this was due to the Lucy’s warbler’s ability to exploit a broader array of habitats surrounding tamarisk sites and its cavity nesting habit that buffers its nests from the higher temperatures and lower humidity of tamarisk-dominated habitat. Our results suggest that predictions based on detailed knowledge of the form and function of native and nonnative species can be used to predict native bird response to nonnatives.

The western population of the yellow-billed cuckoo (Coccyzus americanus) was recently listed as threatened under the federal Endangered Species Act. Yellow-billed cuckoo conservation efforts require the identification of features and area requirements associated with high quality, riparian forest habitat at spatial scales that range from nest microhabitat to landscape, as well as lower-suitability areas that can be enhanced or restored. Spatially explicit models inform conservation efforts by increasing ecological understanding of a target species, especially at landscape scales. Previous yellow-billed cuckoo modelling efforts derived plant-community maps from aerial photography, an expensive and oftentimes inconsistent approach. Satellite models can remotely map vegetation features (e.g., vegetation density, heterogeneity in vegetation density or structure) across large areas with near perfect repeatability, but they usually cannot identify plant communities. We used aerial photos and satellite imagery, and a hierarchical spatial scale approach, to identify yellow-billed cuckoo breeding habitat along the Lower Colorado River and its tributaries. Aerial-photo and satellite models identified several key features associated with yellow-billed cuckoo breeding locations: (1) a 4.5 ha core area of dense cottonwood-willow vegetation, (2) a large native, heterogeneously dense forest (72 ha) around the core area, and (3) moderately rough topography. The odds of yellow-billed cuckoo occurrence decreased rapidly as the amount of tamarisk cover increased or when cottonwood-willow vegetation was limited. We achieved model accuracies of 75–80% in the project area the following year after updating the imagery and location data. The two model types had very similar probability maps, largely predicting the same areas as high quality habitat. While each model provided unique information, a dual-modelling approach provided a more complete picture of yellow-billed cuckoo habitat requirements and will be useful for management and conservation activities.

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.