Epidemiological Trends and Outcomes of Unicompartmental Knee Arthroplasty Among 104 Million Patients in the United States.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty (TKA) for localized osteoarthritis. Recent advancements in UKA implant design and expanding patient criteria may have increased its utilization. However, few studies have examined the use of UKA in the United States. Thus, this study assessed the current and projected future trends of UKA and robotic UKA in the United States through 2035, along with postoperative outcomes. METHODS: A collaborative healthcare research network was queried to identify patients who had undergone UKA. Primary outcomes measured included prevalence (P), incidence proportion (IP), and incidence rate (IR) from 2012 to 2022. Chi-squared analyses were done to compare outcomes across categorical data. Regression modeling was performed to project UKA to the year 2035. Statistical significance was held at P < .05 for all analyses. RESULTS: In 2022, 1,662 UKAs were performed within the network, a 590% increase from 2012 (241 performed). The IP increased on an average annual basis by 41.8%, the IR by 50%, and the P by 51.3%. A year following UKA, conversion to TKA was the most common orthopaedic complication (39.9%). As of 2022, there were 68 robotic UKAs performed, a 518% increase from the 11 performed in 2012. Regression analysis for UKA through 2035 showed that IP will be 0.04%, IR will be 1.75 × 10-6 cases/person-day, and P will be 0.3%. CONCLUSIONS: These findings are consistent with prior studies indicating a higher utilization of UKA over the past decade. Reported complications were not uncommon, as nearly 40% of patients required a conversion to a TKA. Further research is needed to optimally identify criteria for appropriate patients and determine the benefits robotic UKA may provide, specifically reducing the risk of conversion to a TKA.

Emergency Department Visits Within Thirty Days of Discharge After Primary Total Hip Arthroplasty: A Hidden Quality Measure.

BACKGROUND: Thirty-day hospital readmissions following total hip arthroplasty (THA) have received increasing scrutiny by policy makers and hospitals. Emergency department (ED) visits may not necessarily result in an inpatient readmission but can be a measure of performance and can incur costs to the health system. The purpose of this study is to describe the following: (1) the frequency and subsequent disposition; (2) patient characteristics; (3) reasons; and (4) potential risk factors for ED visits that did not result in a readmission within 30 days of discharge after THA. METHODS: All primary THAs performed at a large healthcare system between 2013 and 2015 were identified. Patients who received unplanned hospital services for complications within 30 days following surgery were identified and analyzed. A multiple regression analysis was utilized to identify risk factors predisposing for returning to the ED without readmission. RESULTS: From a total of 6270 primary THAs, 440 patients (7%) had an unplanned return to the hospital within 30 days. Of those, 227 (3.6%) patients presented to the ED and were not readmitted. Higher percentage of African Americans was noted among patients who returned to the ED versus those who did not (20.2% vs 9.8%, P < .01). The most common medical diagnoses were nonspecific medical symptoms (24.8%) followed by minor gastrointestinal problems (10.5%). The most common surgery-related diagnoses were pain and swelling (35%), followed by wound complications (12%) and hip dislocations (7.3%). Nearly 50% of wound complications and 40% of hip dislocations were managed and discharged from the ED without a readmission. Both African Americans (odds ratio 2.28, 95% confidence interval 1.55-3.36) and home discharge (odds ratio 1.90, 95% confidence interval 1.28-2.82) were independent risk factors for return to the ED without readmission. CONCLUSION: ED visits that do not result in hospital readmissions, many of which may be due to serious complications, are more frequent than inpatient readmission. This is extremely relevant to policy makers and quality metrics, especially as comprehensive and bundled payment initiatives become more prevalent.

The Quality of Diagnostic Studies in Periprosthetic Joint Infections: Can We Do Better?

BACKGROUND: The diagnosis of periprosthetic joint infections (PJIs) continues to be a subject of extensive debate. This is in part due to the lack of a single "gold standard" test, and the marked heterogeneity in the design of studies evaluating the accuracy of different diagnostic modalities. The goal of this review is to critically analyze the evidence cited by the proceedings of the 2013 International Consensus Meeting (ICM) on PJI with regards to the diagnosis of PJI. METHODS: References from the Proceedings of the ICM on PJI related to PJI minor criteria were retrieved and manually reviewed. A total of 25 studies were analyzed using a Validated Quality Assessment of Diagnostic Accuracy Studies tool. RESULTS: A large number of studies were determined to have a high risk of bias for flow and timing domains due to the large numbers of exclusions. Studies of synovial white blood cells count and polymorphonuclear neutrophils percentage suffered from threshold optimization and lack of internal validity. Furthermore, due to the lack of homogeneity across studies, index test and reference standard domains showed high risk of bias for white blood cell/polymorphonuclear neutrophil percentage and the utility histological analysis, respectively. Leukocyte esterase testing lacked standardization with regard to the strip reagent used, and the exclusion of bloody samples limited sample sizes. CONCLUSION: The 2013 ICM minor criteria were based on studies with a low quality of evidence. As the committee continues to adjust these guidelines, they should encourage future studies with sound clinical design, patient selection, and testing procedures.

Neer Award 2015: Analysis of cytokine profiles in the diagnosis of periprosthetic joint infections of the shoulder.

BACKGROUND: Periprosthetic joint infection (PJI) after shoulder arthroplasty can present a diagnostic and therapeutic challenge. This study evaluated the diagnostic utility of broader synovial fluid cytokine analysis for identifying PJI in patients undergoing revision shoulder arthroplasty. METHODS: Synovial fluid levels of 9 cytokines (interleukin [IL] 6, granulocyte-macrophage colony-stimulating factor, IL-1ß, IL-12, IL-2, IL-8, interferon-γ, IL-10, and tumor necrosis factor-α) were measured in 75 cases of revision shoulder arthroplasty with a multiplex immunoassay. Cases were classified into infection categories and groups based on objective perioperative findings. Differences in cytokine levels among infection groups were evaluated. Receiver operating characteristic curves were used to assess the diagnostic utility of the individual synovial fluid cytokines and combinations of cytokines in determining infection status. RESULTS: Synovial IL-6, granulocyte-macrophage colony-stimulating factor, interferon-γ, IL-1ß, IL-2, IL-8, and IL-10 were significantly elevated in cases of revision shoulder arthroplasty classified as infected. Individually, IL-6, IL-1ß, IL-8, and IL-10 showed the best combination of sensitivity and specificity for predicting infection, and a combined cytokine model consisting of IL-6, tumor necrosis factor-α, and IL-2 showed better diagnostic test characteristics than any cytokine alone, with sensitivity of 0.80, specificity of 0.93,, positive and negative predictive values of 0.87 and 0.89, and positive and negative likelihood ratios of 12.0 and 0.21. CONCLUSIONS: Individual and combined synovial fluid cytokine analysis were both more effective than routine perioperative testing, such as serum erythrocyte sedimentation rate and C-reactive protein, in the diagnosis of PJI of the shoulder. Once validated, combined synovial fluid cytokine analysis could be used as a predictive tool to determine the probability of PJI in patients undergoing revision shoulder arthroplasty and better guide treatment.

The Use of Transcutaneous Electrical Nerve Stimulation After Total Knee Arthroplasty: A Prospective Randomized Controlled Trial.

INTRODUCTION: Multimodal pain management is used after total knee arthroplasty (TKA) to reduce opioid intake. Transcutaneous electrical nerve stimulation (TENS) has generated much interest as a non-pharmacologic, patient-controlled therapy. The aims of this study were to evaluate the efficacy of TENS in reducing opioid intake and improving recovery after TKA. MATERIALS AND METHODS: This was a prospective, parallel-group, double-blinded, randomized trial of patients receiving femoral nerve catheter block with allocation to either active or placebo TENS device groups. All participants were 18-85 years and underwent unilateral, primary TKA at two academic hospitals. Device usage was monitored during inpatient and outpatient phases. Participants were requested to return at second, fourth, and sixth postoperative weeks for follow-up. The primary endpoint was opioid usage, as indicated by medication intake in equianalgesic equivalents to morphine. Secondary measures included: visual analogue scale (VAS) pain scores; functional assessments as measured from knee joint range of motion (ROM) and Timed Up and Go (TUG) test; and clinical outcomes as defined by modified Knee injury and Osteoarthritis Outcome Scores (KOOS) and the 12-item Short Form Survey Instrument (SF-12). RESULTS: Among 116 participants, overall withdrawal was 37.9% (44 patients) at similar rates in both study arms. After excluding for non-femoral nerve catheter (FNC) blocks (i.e., protocol deviations), there were 35 patients in the active group and 31 patients in the placebo group whose complete records were analyzed. There were no significant differences between groups in any of the clinical endpoints.

Synovial Cytokines and the MSIS Criteria Are Not Useful for Determining Infection Resolution After Periprosthetic Joint Infection Explantation.

BACKGROUND: Diagnosing periprosthetic joint infection (PJI) requires a combination of clinical and laboratory parameters, which may be expensive and difficult to interpret. Synovial fluid cytokines have been shown to accurately differentiate septic from aseptic failed total knee (TKA) and hip (THA) arthroplasties. However, after first-stage explantation, there is still no reliable test to rule out PJI before a second-stage reimplantation procedure. QUESTIONS/PURPOSES: (1) Which synovial fluid cytokines have the highest diagnostic accuracy for PJI? (2) Which cytokine shows the greatest decrease associated with the resolution of infection in the same patient between explantation and subsequent reimplantation of an infected arthroplasty? (3) What is the accuracy of synovial fluid cytokines and the Musculoskeletal Infection Society (MSIS) criteria to rule out PJI after first-stage explantation? (4) What are the most studied synovial fluid cytokines for diagnosing PJI as reported in the literature and what are their cumulative diagnostic accuracy? METHODS: Between May 2013 and March 2014, 104 patients with painful THA and TKA evaluated for possible PJI were included in our study. Of these, 90 (87%) had cytokine levels measured from synovial fluid samples collected as part of this prospective study (n = 33 hips, n = 57 knees). A second group of 35 patients (n = 36 samples) who presented during the same time period with an antibiotic spacer also had synovial cytokines measured before second-stage reimplantation. For the first group of 90 patients, the MSIS definition classified each joint at the time of surgery as infected (n = 31) or not infected (n = 59) and was used as the standard to test the accuracy in diagnosing PJI. Of the 35 patients with synovial marker data before second-stage surgery, 15 patients had cytokine measurements both at explantation and reimplantation and were used to quantify the change between stages. The reimplantation group had a minimum 1-year followup (with four [11%] patients lost to followup) and was classified into successful or failed treatment based on Delphi-based consensus data and was used to test the accuracy in detecting infection resolution at reimplantation. RESULTS: Interleukin (IL)-1ß and interferon-γ demonstrated the highest diagnostic utility (area under the curve 0.92, 0.91, respectively); IL-1ß and IL-6 had the highest sensitivities (0.90 [95% confidence interval {CI}, 0.74-0.98] and 0.81 [0.63-0.93]). As a measure of infection resolution, IL-1ß had the greatest decrease (12.4-fold; level at explantation: 232.4 [range, 23.1-1545.7]; level at reimplantation: 18.8 (range 1.2-298.9); mean difference: 325.5 [95% CI, 65.0-596.0]; p = 0.0001), and IL-6 had a nearly similar decrease (11.2-fold; level at explantation: 228.1 [range, 10,158.4-182,725.0]; level at reimplantation: 2518.2 [range, 10.4-41,319.3]; mean difference: 33,176.0 [95% CI, 7543.6-58,808.3]; p < 0.0001). Cytokines and MSIS criteria had low sensitivity to rule out infection in a joint treated for PJI. CONCLUSIONS: IL-6 and IL-1ß demonstrated high sensitivities to diagnose PJI and showed the greatest decrease between first and second stages, which may potentially be used to monitor treatment response to PJI. However, cytokines and MSIS criteria had low sensitivity to rule out infection before reimplantation. LEVEL OF EVIDENCE: Level III, diagnostic study.

α-Defensin Accuracy to Diagnose Periprosthetic Joint Infection-Best Available Test?

BACKGROUND: The purpose of this study was to test the accuracy of a single synovial fluid biomarker, α-defensin, in diagnosing periprosthetic joint infection in revision total hip and revision total knee arthroplasty. METHODS: A total of 102 patients comprising 116 revision total hip arthroplasty and revision total knee arthroplasty procedures performed between May 2013 and March 2014 were prospectively evaluated. Cases were categorized as infected or notinfected using Musculoskeletal Infection Society criteria. Synovial fluid was obtained and tested for α-defensin using a commercially available kit (Synovasure [CD Diagnostics, Baltimore, Maryland]). RESULTS: For first-stage and single-stage revisions, the α-defensin test had a sensitivity of 100% (95% confidence interval [CI], 86%-100%) and a specificity of 98% (95% CI, 90%-100%) with a positive predictive value of 96% (95% CI, 80%-99%) and negative predictive value of 100% (95% CI, 93%-100%). CONCLUSION: A positive α-defensin test result was significantly more sensitive and specific for predicting infection than current diagnostic testing and should be considered when managing periprosthetic joint infection. LEVEL OF EVIDENCE: Level III, Study of Diagnostic Test.

The Reamer-Irrigator-Aspirator System: A Review.

The reamer-irrigator-aspirator (RIA) system has been recently developed to decrease the incidence of osseous thermal necrosis and fat embolism associated with intramedullary reaming of long bones in trauma cases. This is achieved by continuous irrigation and suction. Recently, the use of RIA has been expanded to harvest bone graft and debride the medullary canal of long bones in cases of osteomyelitis and intramedullary tumors. Additionally, the collection system of this device has been utilized for its ability to capture bone graft and marrow aspirate. The purpose of this study is to report a comprehensive literature review on the: 1) use of RIA for canal reaming prior to intramedullary nailing; 2) use of RIA for the treatment of intramedullary osteomyelitis of long bones; 3) use of RIA for bone graft harvesting; 4) osteogenic potential of the RIA aspirate; and 5) future applications of the RIA system.

Glycopeptides versus ß-lactams for the prevention of surgical site infections in cardiovascular and orthopedic surgery: a meta-analysis.

OBJECTIVE: To compare the efficacy of glycopeptides and ß-lactams in preventing surgical site infections (SSIs) in cardiac, vascular, and orthopedic surgery. BACKGROUND: The cost-effectiveness of switching from ß-lactams to glycopeptides for preoperative antibiotic prophylaxis has been controversial. ß-Lactams are generally recommended in clean surgical procedures, but they are ineffective against resistant gram-positive bacteria. METHODS: PubMed, International Pharmaceuticals Abstracts, Scopus, and Cochrane were searched for randomized clinical trials comparing glycopeptides and ß-lactams for prophylaxis in adults undergoing cardiac, vascular, or orthopedic surgery. Abstracts and conference proceedings were included. Two independent reviewers performed study selection, data extraction, and assessment of risk of bias. RESULTS: Fourteen studies with a total of 8952 patients were analyzed. No difference was detected in overall SSIs between antibiotic types. However, compared with ß-lactams, glycopeptides reduced the risk of resistant staphylococcal SSIs by 48% (relative risk, 0.52; 95% confidence interval, 0.29-0.93; P = 0.03) and enterococcal SSIs by 64% (relative risk, 0.36; 95% confidence interval, 0.16-0.80; P = 0.01), but increased respiratory tract infections by 54% (relative risk, 1.54; 95% confidence interval, 1.19-2.01; P ≤ 0.01). Subgroup analysis of cardiac procedures showed superiority of ß-lactams in preventing superficial and deep chest SSIs, susceptible staphylococcal SSIs, and respiratory tract infections. CONCLUSIONS: Glycopeptides reduce the risk of resistant staphylococcal SSIs and enterococcal SSIs, but increase the risk of respiratory tract infections. Additional high-quality randomized clinical trials are needed as these results are limited by high risk of bias.

α-Defensin as a predictor of periprosthetic shoulder infection.

BACKGROUND: Diagnosis of periprosthetic joint infection (PJI) in revision shoulder arthroplasty can be challenging because of the indolent nature of the common offending organisms. The purpose of this study was to evaluate the diagnostic utility of synovial fluid α-defensin levels in identifying PJI of the shoulder. METHODS: Thirty patients evaluated for painful shoulder arthroplasty were prospectively enrolled and underwent revision surgery (n = 33 cases). Cases were categorized into infection (n = 11) and no-infection (n = 22) groups on the basis of preoperative and intraoperative findings. Synovial fluid was obtained from preoperative aspirations or intraoperative aspiration before arthrotomy. α-Defensin was tested by the Synovasure (CD Diagnostics, Wynnewood, PA, USA) test for joint infection. Synovial fluid was also obtained intraoperatively from a control group undergoing arthroscopic rotator cuff repair (n = 16) for baseline data on normal α-defensin levels in the shoulder. A receiver operating characteristic curve was used to determine the diagnostic utility of synovial fluid α-defensin. RESULTS: Synovial α-defensin had an area under the curve, sensitivity, specificity, and positive and negative likelihood ratios of 0.78, 63%, 95%, 12.1, and 0.38, respectively. There was a significant difference in α-defensin levels between the infection (median, 3.2 S/CO [signal to cutoff ratio]) and no-infection groups (median, 0.21 S/CO; P = .006). Synovial α-defensin was elevated in the presence of a culture positive for Propionibacterium acnes (median, 1.33 S/CO; P = .03) and showed moderate correlation with the number of positive cultures. CONCLUSION: Synovial fluid α-defensin was more effective than current diagnostic testing in predicting positive cultures and may be an effective adjunct in the workup of shoulder PJI.

Poor utility of serum interleukin-6 levels to predict indolent periprosthetic shoulder infections.

BACKGROUND: Infection after shoulder arthroplasty can present a diagnostic challenge. The purpose of this study was to evaluate the utility of serum interleukin-6 (IL-6) levels in diagnosis of periprosthetic infection in patients undergoing revision shoulder arthroplasty. METHODS: We prospectively enrolled 69 patients who underwent revision shoulder arthroplasty at one institution. All patients underwent a standard preoperative and intraoperative workup for infection, which included shoulder aspirate culture, erythrocyte sedimentation rate, C-reactive protein level, tissue culture, and frozen section analysis. In addition, serum levels of IL-6 were measured preoperatively in all patients. Infection classification was divided into 4 groups, (1) definite, (2) probable, (3) possible, and (4) no infection, on the basis of previously reported criteria using intraoperative cultures and preoperative and intraoperative findings of infections. RESULTS: Of the 69 patients, 24 were classified as having a definite or probable infection. Propionibacterium acnes was the offending organism for the majority of these cases (20 of 24, 83%). IL-6 was not a sensitive marker of infection for these patients (sensitivity: 3 of 24, 12%; specificity: 3 of 45, 93%). The sensitivity of serum IL-6 was lower compared with erythrocyte sedimentation rate (sensitivity: 10 of 24, 42%; specificity: 37 of 45, 82%) and C-reactive protein level (sensitivity: 11 of 24, 46%; specificity: 42 of 45, 93%). For the non-P. acnes cases (1 Staphylococcus aureus, 1 Enterobacter cloacae, 2 coagulase-negative Staphylococcus species), the sensitivity of IL-6 was 25% (1 of 4). CONCLUSION: Serum IL-6 is not an effective marker for diagnosis of infection in shoulder arthroplasty. On the basis of this large prospective study, we do not recommend its use as a preoperative diagnostic test in patients undergoing revision shoulder arthroplasty.

Unexpected positive intraoperative cultures in aseptic revision arthroplasty.

Unexpected positive intraoperative cultures (UPIC) in presumed aseptic revision arthroplasty can be difficult to interpret. The purpose of this retrospective study was to compare the incidence of subsequent periprosthetic joint infection (PJI) in patients who received antibiotic therapy according to an institutional protocol with those who did not and whether they meet Musculoskeletal Infection Society (MSIS) criteria for PJI. In patients who were treated with antibiotic according to institutional criteria, the incidence of PJI after revision was higher in those who did not meet MSIS criteria (22%) than in those that met MSIS criteria (14%; P > 0.71). UPIC in aseptic revision arthroplasty are not uncommon. PJI cannot be excluded in patients that do not meet MSIS definition.

Serum inflammatory markers for periprosthetic knee infection in obese versus non-obese patients.

Accurate diagnosis of periprosthetic joint infection (PJI) is challenging. Most infection diagnosis criteria define elevated serum C-reactive protein (CRP) as >1.0mg/dL and erythrocyte sedimentation rate (ESR) as >30mm/hour. Obesity has been reported as a pro-inflammatory state with elevated baseline CRP values. We hypothesized that higher cut-off values would be more accurate to diagnose PJI in obese patients due to their elevated baseline CRP. BMI, serum inflammatory markers, and synovial fluid were collected for 102 revision total knee arthroplasty patients, and analyzed for the highest area under the curve. We found a CRP of 3.6mg/dL was more accurate to diagnose PJI in obese patients versus traditional values. Clinicians should be judicious and use additional criteria when diagnosing PJI in obese patients.

Primary total knee arthroplasty allogenic transfusion trends, length of stay, and complications: nationwide inpatient sample 2000-2009.

Perioperative blood loss leading to blood transfusion continues to be an issue for total knee arthroplasty (TKA) patients. The US Nationwide Inpatient Sample (NIS) was used to determine annual trends in allogenic blood transfusion rates, and effects of transfusion on in-hospital mortality, length of stay (LOS), costs, discharge disposition, and complications of primary TKA patients. TKA patients between 2000 and 2009 were included (n = 4,544,999) and categorized as: (1) those who received a transfusion of allogenic blood, and (2) those who did not. Transfusion rates increased from 7.7% to 12.2%. For both transfused and not transfused groups, mortality rates and mean LOS declined, while total costs increased. Transfused patients were associated with adjusted odds ratios of in-hospital mortality (AOR 1.16; P = 0.184), 0.71 ± 0.01 days longer LOS (P < 0.0001), and incurred ($1777 ± 36; P < 0.0001) higher total costs per admission.

Acetabular imprinting device (AID) improves acetabular component positioning: a Sawbones® study.

The purpose of this study was to define the ability of a novel acetabular positioning device with 3D preoperative planning (AID) to improve acetabular component placement in total hip arthroplasty. Four surgeons placed the acetabular component in two Sawbones® models using three different methods: standard method, 3D planning method, and the AID method. The AID significantly decreased the mean deviation of actual acetabular component inclination from the preoperative plan when compared with standard and 3D planning methods (p = 0.003). Overall, AID reduced the number of malpositioned implants to 12.5%, compared with 87.5% in the standard method and 75% in the 3D planning method without use of the AID (p = 0.005). A clinical trial is needed to compare AID to standard surgical techniques.

Engineering tumor-colonizing E. coli Nissle 1917 for detection and treatment of colorectal neoplasia.

Bioengineered probiotics enable new opportunities to improve colorectal cancer (CRC) screening, prevention and treatment. Here, first, we demonstrate selective colonization of colorectal adenomas after oral delivery of probiotic E. coli Nissle 1917 (EcN) to a genetically-engineered murine model of CRC predisposition and orthotopic models of CRC. We next undertake an interventional, double-blind, dual-centre, prospective clinical trial, in which CRC patients take either placebo or EcN for two weeks prior to resection of neoplastic and adjacent normal colorectal tissue (ACTRN12619000210178). We detect enrichment of EcN in tumor samples over normal tissue from probiotic-treated patients (primary outcome of the trial). Next, we develop early CRC intervention strategies. To detect lesions, we engineer EcN to produce a small molecule, salicylate. Oral delivery of this strain results in increased levels of salicylate in the urine of adenoma-bearing mice, in comparison to healthy controls. To assess therapeutic potential, we engineer EcN to locally release a cytokine, GM-CSF, and blocking nanobodies against PD-L1 and CTLA-4 at the neoplastic site, and demonstrate that oral delivery of this strain reduces adenoma burden by ~50%. Together, these results support the use of EcN as an orally-deliverable platform to detect disease and treat CRC through the production of screening and therapeutic molecules.

Low vitamin D status does not adversely affect short-term functional outcome after total hip arthroplasty.

We prospectively measured functional performances (Western Ontario and McMaster Universities Osteoarthritis Index, Short Form-36, 2-minute walk test, and timed get-up-and-go test) of patients who underwent total hip arthroplasty (THA) and had serum vitamin D levels tested during the preoperative evaluation. Of 219 patients, 102 (46.6%) had low vitamin D levels (25-hydroxyvitamin D<30 ng/mL). Low vitamin D status did not adversely affect short-term function at 6 weeks after THA. In addition, there was no association between serum vitamin D levels and the within-patient changes of scores of each outcome measurement. Because this 6-week period is generally adequate to correct vitamin D deficiency, orthopedic surgeons can safely perform THA without delay. Nevertheless, because vitamin D deficiency impairs bone quality, patients with low vitamin D levels should be treated once identified.

Colorectal cancer detection and treatment with engineered probiotics.

Bioengineered probiotics enable new opportunities to improve colorectal cancer (CRC) screening, prevention and treatment strategies. Here, we demonstrate the phenomenon of selective, long-term colonization of colorectal adenomas after oral delivery of probiotic E. coli Nissle 1917 (EcN) to a genetically-engineered murine model of CRC predisposition. We show that, after oral administration, adenomas can be monitored over time by recovering EcN from stool. We also demonstrate specific colonization of EcN to solitary neoplastic lesions in an orthotopic murine model of CRC. We then exploit this neoplasia-homing property of EcN to develop early CRC intervention strategies. To detect lesions, we engineer EcN to produce a small molecule, salicylate, and demonstrate that oral delivery of this strain results in significantly increased levels of salicylate in the urine of adenoma-bearing mice, in comparison to healthy controls. We also assess EcN engineered to locally release immunotherapeutics at the neoplastic site. Oral delivery to mice bearing adenomas, reduced adenoma burden by ∻50%, with notable differences in the spatial distribution of T cell populations within diseased and healthy intestinal tissue, suggesting local induction of robust anti-tumor immunity. Together, these results support the use of EcN as an orally-delivered platform to detect disease and treat CRC through its production of screening and therapeutic molecules.