The Effect of Greater Area Deprivation and Medicaid Insurance Status on Timing of Care and Rate of Reinjury After Anterior Cruciate Ligament Reconstruction.

Background: Lower socioeconomic status and public insurance lead to a longer delay to surgery and a higher likelihood of concomitant pathology before undergoing anterior cruciate ligament reconstruction (ACLR). However, few studies have examined the influence of community deprivation on ACLR timing and outcomes. Purpose/Hypothesis: The primary aim of this study was to define the effect of the area deprivation index (ADI) and insurance classification on access to orthopaedic care after an ACL rupture, and the secondary aim was to determine whether these variables were associated with a second ACL injury after primary ACLR. It was hypothesized that patients with a greater national ADI percentile and Medicaid insurance would experience longer delays to care and an increased risk of reinjury after ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective study was performed to evaluate patients undergoing primary ACLR between 2016 and 2019. The national ADI percentile was obtained utilizing the Neighborhood Atlas website. The relationship between national ADI percentile and care characteristics (eg, time to specialized care) was investigated using the Spearman rho correlation coefficient (r). The association between patient and care characteristics and second ACL injury after the index procedure (ie, graft rerupture or contralateral ACL rupture) was investigated using binary logistic regression. Results: A total of 197 patients met the inclusion criteria. Longer times from injury to surgery (r = 0.238; P < .001) and from specialized care to surgery (r = 0.217; P = .002) were associated with a greater national ADI percentile. The second injury group reported significantly greater national ADI (P = .026) and included a greater percentage of patients with Medicaid insurance (31.3%) compared with the no second injury group. Patients experienced 5.1% greater odds of a second ACL injury for each additional month between evaluation and surgery. Conclusion: Greater national ADI percentile and Medicaid insurance status were associated with adverse ACLR timing and outcomes. Patients with a greater national ADI percentile took significantly longer to obtain surgery after ACL injury. Those who sustained a second ACL injury after ACLR had an overall higher mean national ADI percentile and included a greater proportion of patients with Medicaid compared with those who did not sustain a second ACL injury. Future studies should critically investigate the underlying factors of these associations to reach equity in orthopaedic care.

Intraoperative Intra-articular Antibiotic Injection Reduces Infection in Shoulder Arthroplasty.

Deep infection is a debilitating complication after shoulder arthroplasty. The authors hypothesized that an intra-articular, intraoperative injection of antibiotics would result in a lower infection rate compared with intravenous antibiotics alone. Before 2007, 164 patients (group A) did not receive intra-articular antibiotics. From 2007 to 2018, 1324 patients (group B) received intra-articular antibiotics. Patients received intra-articular gentamicin at the end of surgery with the addition of 1 g of cefazolin in January 2014. Records were retrospectively reviewed for comorbidities, type of surgery, and infection. The cohort that received intra-articular antibiotics was compared with the cohort that did not to determine the effect of prophylactic intra-articular antibiotic administration in preventing infection. There was 1 deep infection in the antibiotic group compared with 5 in the non-antibiotic group (P<.001). Superficial infections developed in 2 cases of patients treated with antibiotics; there were no superficial infections in patients treated without antibiotics (P=.62). One previous study evaluated intra-articular injection of antibiotics for shoulder arthroplasty and found significantly lower rates of infection with the injection of intra-articular gentamicin. In this retrospective follow-up study, the injection of intra-articular gentamicin or gentamicin and cefazolin effectively decreased rates of postoperative infection. At mean follow-up of 399 days, intra-articular antibiotics at the time of surgery resulted in significantly fewer deep infections. Given the minimal risk of adverse events and minimal cost, this is a valid method of reducing infections in total shoulder arthroplasty. [Orthopedics. 2023;46(5):310-314.].

Multiple Opioid Prescribers During the Perioperative Period Increases Opioid Consumption Following Upper Extremity Surgery: A Multicenter Analysis.

Background Opioid prescribing practices have been an area of interest for orthopedic surgeons in the wake of the opioid epidemic. Previous studies have investigated the effects of a multitude of patient-specific risk factors on prolonged opioid use postoperatively. However, to date, there is a lack of studies examining the effects of multiple prescribers during the perioperative period and their potential contribution to prolonged opioid use postoperatively. This study aimed to investigate if multiple unique opioid prescribers perioperatively predispose patients to prolonged opioid use following upper extremity surgery. Second, we compared opioid prescribing patterns among different medical specialties. Methodology This retrospective study was conducted at three academic institutions. Between April 30, 2018, and August 30, 2019, 634 consecutive patients who underwent one of three upper extremity procedures  were included in the analysis: carpal tunnel release (CTR), basal joint arthroplasty (BJA), or distal radius fracture open reduction and  internal fixation (DRF ORIF). Prescription information was collected using the state Prescription Drug Monitoring Program (PDMP) online database  from a period of three months preoperatively to six months postoperatively. A Google search was performed to group prescriptions by medical specialty.  Dependent outcomes included whether patients filled an additional opioid prescription postoperatively and prolonged opioid use (defined as opioid use three to six months postoperatively). Results In total, 634 patients were identified, including 276 CTRs, 217 DRF ORIFs, and 141 BJAs. This consisted of 196 males (30.9%) and 438 females (69.1%) with an average age of 59.4 years (SD: 14.7 years). By six months postoperatively, 191 (30.1%) patients filled an additional opioid prescription, and 89 (14.0%) experienced prolonged opioid use. In total, 235 (37.1%) patients had more than one unique opioid prescriber during the study period (average 2.5 prescribers). Patients with more than one unique opioid prescriber were significantly more likely to have received overlapping opioid prescriptions (15.7% vs. 0.8%, p<.001), to have filled an additional opioid prescription postoperatively (63.8% vs 10.3%, p<.001), and to have experienced prolonged opioid use postoperatively (35.3% vs 1.5%, p<.001) compared to patients with only one opioid prescriber. Patients with multiple unique prescribers filled more opioid prescriptions compared to those with a single prescriber (2.8 refills vs 1.8 refills, p=.035). Within six months postoperatively, 71.4% of opioid refills were written by non-orthopedic providers. Opioid refills written by non-orthopedic prescribers were written for a significantly greater number of pills (68.4 vs. 27.9, p<.001), for a longer duration (22.2 vs. 6.2 days, p<.001), and for larger total morphine milligram equivalents per prescription (831.4 vs. 169.8, p<.001) compared to those written by orthopedic prescribers. Conclusions Patients with multiple unique opioid prescribers during the perioperative period are at a higher risk for prolonged opioid use postoperatively. Non-orthopedic providers were the highest prescribers of opioids postoperatively, and they prescribed significantly larger and longer prescriptions. Our findings highlight the value of utilizing PDMP databases to help curtail opioid overprescription and potential adverse opioid-related outcomes following upper extremity surgery.

No Difference in Complications Between Elbow Ulnar Collateral Ligament Reconstruction With the Docking and Modified Jobe Techniques: A Systematic Review and Meta-analysis.

BACKGROUND: The most commonly used techniques for elbow ulnar collateral ligament reconstruction (UCLR) are the docking and modified Jobe figure-of-8 techniques. Previous literature has suggested that UCLR with the docking technique is associated with fewer complications; however, these studies included results from the original classic Jobe technique without controlling for the effects of flexor pronator mass (FPM) detachment and routine submuscular ulnar nerve transposition (UNT). PURPOSE/HYPOTHESIS: This study sought to compare the rates of complications and subsequent unplanned surgical procedures between the docking and figure-of-8 techniques. We hypothesized that there would be no significant difference in the rates of complications or subsequent unplanned surgical procedures between the techniques when the FPM was preserved and no routine submuscular UNT was performed. STUDY DESIGN: Systematic review and meta-analysis; Level of evidence, 4. METHODS: This study was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A series of mixed-effects multivariate metaregression models were implemented using the restricted maximum likelihood method. Complications and subsequent unplanned surgical procedures were modeled as Freeman-Tukey transformed incidence rates for variance stabilization, and nerve-specific complications were assessed as the Freeman-Tukey transformed proportion of cases, with back-transformation to estimate summary effects. RESULTS: There were 19 studies eligible for qualitative analysis, consisting of 1788 cases of UCLR (303 docking, 1485 figure-of-8), 18 of which were suitable for quantitative analysis (1769 cases; 291 docking, 1478 figure-of-8). A total of 338 complications were reported (17 for docking, 321 for figure-of-8), the majority of which were nerve related. Additionally, a total of 75 subsequent unplanned surgical procedures were related to the index UCLR procedure. There was no significant difference in the rate of complications (P = .146) or proportion of cases with nerve-specific complications (P = .127) between the docking and figure-of-8 techniques when controlling for FPM preservation versus detachment with submuscular UNT. FPM detachment with submuscular UNT was independently associated with a significantly higher proportion of postoperative nerve-related complications (P = .004). There was also no significant difference in the rates of subsequent unplanned surgical procedures between the docking and figure-of-8 techniques (P = .961), although FPM detachment with routine submuscular UNT was independently associated with a significantly higher incidence of subsequent unplanned surgical procedures. CONCLUSION: The results of this study demonstrate no significant difference in the rates of complications or subsequent unplanned surgical procedures between the figure-of-8 and docking techniques for UCLR when controlling for FPM preservation versus detachment with submuscular UNT. With modern muscle-sparing approaches and avoiding submuscular UNT, the modified Jobe technique does not differ significantly from the docking technique in terms of complication rates, proportions of cases with nerve-specific complications, or rates of subsequent unplanned surgical procedures.

Larger Perioperative Opioid Prescriptions Lead to Prolonged Opioid Use After Hand and Upper Extremity Surgery: A Multicenter Analysis.

INTRODUCTION: The opioid epidemic remains an ongoing public health crisis. The purpose of this study was to investigate whether surgeons' prescribing patterns of the initial postoperative opioid prescription predispose patients to prolonged opioid use after upper extremity surgery. METHODS: This multicenter retrospective study was done at three academic institutions. Patients who underwent carpal tunnel release, basal joint arthroplasty, and distal radius fracture open reduction and internal fixation over a 1.5-year period were included. Opioid prescription data were obtained from the Pennsylvania Prescription Drug Monitoring Program website. RESULTS: Postoperatively, 30.1% of the patients (191/634) filled ≥1 additional opioid prescription, and 14.0% (89/634) experienced prolonged opioid use 3 to 6 months postoperatively. Patients who filled an additional prescription postoperatively were initially prescribed significantly more pills (P = 0.001), a significantly longer duration prescription (P = 0.009), and a significantly larger prescription in total milligram morphine equivalents (P = 0.002) than patients who did not fill additional prescriptions. Patients who had prolonged opioid use were prescribed a significantly longer duration prescription (P = 0.026) than those without prolonged use. CONCLUSION: Larger and longer duration of initial opioid prescriptions predisposed patients to continued postoperative opioid use. These findings emphasize the importance of safe and evidence-based prescribing practices to prevent the detrimental effects of opioid use after orthopaedic surgery.

Postoperative Use of Blood Flow Restriction in Orthopedics.

Blood flow restriction (BFR) therapy is being used more frequently for rehabilitation from orthopedic injuries. Several physiologic mechanisms of action, at local and systemic levels, have been proposed. Numerous studies have investigated the effects of BFR training in healthy athletes; however, limited clinical data exist supporting the use of BFR after surgery. Given that BFR training may facilitate muscle development using low-load resistance exercises, it offers a unique advantage for the post-surgical patient who cannot tolerate traditional high resistance training. [Orthopedics. 2021;44(6):e694-e698.].

Modified Jobe Versus Docking Technique for Elbow Ulnar Collateral Ligament Reconstruction: A Systematic Review and Meta-analysis of Clinical Outcomes.

BACKGROUND: The modified Jobe and docking techniques are the most common techniques used for elbow ulnar collateral ligament (UCL) reconstruction. Previous systematic reviews have suggested that the docking technique results in superior outcomes as compared with the Jobe (figure-of-8) technique. However, these included results from earlier studies in which the flexor-pronator mass (FPM) was detached and an obligatory submuscular ulnar nerve transposition was performed. PURPOSE/HYPOTHESIS: The purpose was to compare the outcomes and return-to-play (RTP) time between the docking and figure-of-8 techniques for UCL reconstruction. We hypothesized that there would be no significant difference in the proportion of excellent outcomes between techniques when the FPM was preserved and no obligatory submuscular ulnar nerve transposition was performed. We also hypothesized that there would be no significant difference in RTP time between techniques. STUDY DESIGN: Systematic review and meta-analysis. METHODS: This study was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. In the primary analysis, techniques were compared in random effects models by using the restricted maximum likelihood method, with weighted effect sizes calculated as the Freeman-Tukey double-arcsine transformed proportion of excellent outcomes for variance stabilization and with summary effects estimated from the inverse double-arcsine transformation per the harmonic mean of the sample sizes. Mean RTP times for techniques were compared in a separate model. RESULTS: There were 21 eligible articles identified, with results for 1842 UCL reconstructions (n = 320, docking; n = 1466, figure-of-8). Without controlling for the effects of flexor-pronator detachment and submuscular ulnar nerve transposition, a significantly larger proportion of excellent outcomes was observed with docking reconstruction (86.58%; 95% CI, 80.42%-91.85%) than with figure-of-8 reconstruction (76.76%; 95% CI, 69.65%-83.25%; P = .031); however, there was no significant difference between techniques when controlling for FPM preservation or detachment with submuscular nerve transposition (P = .139). There was no significant difference between techniques in time to return to sports (P = .729), although no reconstructions with FPM detachment and submuscular ulnar nerve transposition were available for RTP time analysis. CONCLUSION: There was no significant difference in the proportion of excellent Conway Scale outcomes or RTP time between the docking and modified Jobe techniques for UCL reconstruction when the FPM was preserved and routine submuscular ulnar nerve transposition was not performed.

Treatment of Pectoralis Major Tendon Tears: A Systematic Review and Meta-analysis of Repair Timing and Fixation Methods.

BACKGROUND: Repair of torn pectoralis major tendons is generally considered superior to nonoperative management, but there is a paucity of comparative data to demonstrate ideal repair timing and fixation methods. PURPOSE/HYPOTHESIS: The purpose was to compare the outcomes between acute and chronic repair and among the various methods of fixation (transosseous tunnels, cortical buttons, suture anchors, screws with washers, and direct repair). It was hypothesized that acute repair would have superior outcomes and there would be similar outcomes among the various methods of fixation. STUDY DESIGN: Meta-analysis. METHODS: In accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review of the literature was completed through MEDLINE, SPORTDiscus, CINAHL, Cochrane, Embase, and Web of Science databases. English-language studies were included with a minimum of 6 months' mean follow-up and 5 cases per study. MINORS (Methodological Index for Nonrandomized Studies) was utilized to assess the quality of the existing literature. Analysis of mechanisms of injury and meta-analysis of pooled outcomes were completed. Pooled effect sizes were calculated from random effects models. Continuous variables were assessed via mixed model analysis, with the individual study designated as a random effect and the desired treatment for comparison as a fixed effect. Bivariate frequency data were transformed through Freeman-Tukey log-linear transformation for variance stabilization and then assessed through a mixed model with a study-level random effect and subsequently back-transformed. Significance was set at P < .05. RESULTS: Twenty articles with 384 injuries met the inclusion criteria for comparison. All patients were male, with 61.9% of injuries occurring during weight training, at a mean age of 31.53 years, and with a mean follow-up of 30.12 months. Included studies scored a mean (SD) 15.53 ± 4.26 (range, 7.0-23.3) by MINORS criteria. Acute repair was significantly superior to chronic repair, with a relative improvement of functional outcome by 0.85 (P = .004) and satisfaction with cosmesis by 20.50% (P = .003). There was a trend toward acute repair having a higher proportion of patients who were pain-free (34.47%, P = .064). There were no significant differences among the methods of fixation for repair. CONCLUSION: Acute repair of pectoralis major tendon tears resulted in significantly superior functional outcomes and cosmesis satisfaction with a trend toward a higher proportion of patients who were pain-free. There were no significant differences among the methods of fixation for repair.

Treatment of Pectoralis Major Tendon Tears: A Systematic Review and Meta-analysis of Operative and Nonoperative Treatment.

BACKGROUND: The incidence of pectoralis major tendon tears is increasing, and repair is generally considered; however, a paucity of comparative data are available to demonstrate the superiority of operative treatment. PURPOSE/HYPOTHESIS: The purpose of this study is to compare the outcomes of operative and nonoperative treatment of pectoralis major tendon tears. We hypothesized that repair would result in superior outcomes compared with nonoperative treatment. METHODS: In accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review of the literature was completed by use of MEDLINE, SPORTDiscus, CINAHL, Cochrane, EMBASE, and Web of Science databases. We included English-language studies that had a minimum of 6 months of average follow-up and 5 cases per study. The MINORS (Methodological Index for Non-Randomized Studies) was used to assess the quality of the existing literature. Meta-analysis of pooled mechanisms of injury and outcomes was completed. Pooled effect sizes were calculated from random-effects models. Continuous variables were assessed by use of mixed-model analysis, with the individual study designated as a random effect and the desired treatment for comparison as a fixed effect. Bivariate frequency data were transformed via the Freeman-Tukey log-linear transformation for variance stabilization and then assessed through use of a mixed model with a study level random effect and subsequently back-transformed. Significance was set at P < .05. RESULTS: A total of 23 articles with 664 injuries met the inclusion criteria for comparison. All patients were male, with an average age of 31.48 years; 63.2% of injuries occurred during weight training, and the average follow-up was 37.02 months. Included studies had moderately high methodological quality. Operative treatment was significantly superior to nonoperative treatment, with relative improvements of functional outcome by 23.33% (0.70 improvement by Bak criteria which is scored 1-4; P = .027), full isometric strength 77.07% (P < .001), isokinetic strength 28.86% (P < .001) compared with the uninjured arm, cosmesis satisfaction 13.79% (P = .037), and resting deformity 98.85% (P < .001). The overall complication rate for operative treatment was 14.21%, including a 3.08% rate of rerupture. CONCLUSION: Pectoralis major tendon repair resulted in significantly superior outcomes compared with nonoperative treatment, with an associated 14.21% complication rate. Statistically significant improvements were noted in functional outcome, isokinetic strength, isometric strength, cosmesis, and resting deformity.

Transformation of an Online Multidisciplinary Course into a Live Interprofessional Experience.

Objective. To design, implement, and assess an interprofessional education (IPE) course in the first professional year of students enrolled in eight different health professions programs. Design. An interprofessional faculty committee created a 1-credit hour required IPE course to not only teach students about the roles and responsibilities of each discipline and how they may contribute to an interprofessional team, but to also improve collaboration and team-based communication skills among health care professions students. Students were placed in interprofessional groups and met weekly to participate in didactic lectures, discussion sessions, and a standardized patient encounter. Assessment. Seven hundred and eighty-three health professions students were enrolled in the course, of which 130 students completed questionnaires at all three time points. Students were neutral about the course and found it moderately valuable (Mean 6.23 [on a scale from 1 to 10], interesting (Mean 5.61), and enjoyable (Mean 5.57). Written feedback from the course indicated that the majority of students enjoyed the standardized patient encounter and thought the course provided a valuable opportunity to interact with other students in other health professions programs. Conclusion. This required course served as an introductory interprofessional approach in preparing health professions students to learn from each other about their various roles and responsibilities and how each can contribute to the health care team.

Augmentation of Distal Biceps Repair With an Acellular Dermal Graft Restores Native Biomechanical Properties in a Tendon-Deficient Model.

BACKGROUND: The majority of distal biceps tendon injuries can be repaired in a single procedure. In contrast, complete chronic tears with severe tendon substance deficiency and retraction often require tendon graft augmentation. In cases with extensive partial tears of the distal biceps, a human dermal allograft may be used as an alternative to restore tendon thickness and biomechanical integrity. HYPOTHESIS: Dermal graft augmentation will improve load to failure compared with nonaugmented repair in a tendon-deficient model. STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-six matched specimens were organized into 1 of 4 groups: native tendon, native tendon with dermal graft augmentation, tendon with an attritional defect, and tendon with an attritional defect repaired with a graft. To mimic a chronic attritional biceps lesion, a defect was created by a complete tear, leaving 30% of the tendon's width intact. The repair technique in all groups consisted of cortical button and interference screw fixation. All specimens underwent cyclical loading for 3000 cycles and were then tested to failure; gap formation and peak load at failure were documented. RESULTS: The mean (±SD) load to failure (320.9 ± 49.1 N vs 348.8 ± 77.6 N, respectively; P = .38) and gap formation (displacement) (1.8 ± 1.4 mm vs 1.6 ± 1.1 mm, respectively; P = .38) did not differ between the native tendon groups with and without graft augmentation. In the tendon-deficient model, the mean load to failure was significantly improved with graft augmentation compared with no graft augmentation (282.1 ± 83.8 N vs 199.7 ± 45.5 N, respectively; P = .04), while the mean gap formation was significantly reduced (1.2 ± 1.0 mm vs 2.7 ± 1.4 mm, respectively; P = .04). The mean load to failure of the deficient tendon with graft augmentation (282.1 N) compared with the native tendon (348.8 N) was not significantly different ( P = .12). This indicates that the native tendon did not perform differently from the grafted deficient tendon. CONCLUSION: In a tendon-deficient, complete distal biceps rupture model, acellular dermal allograft augmentation restored the native tendon's biomechanical properties at time zero. The grafted tissue-deficient model demonstrated no significant differences in the load to failure and gap formation compared with the native tendon. As expected, dermal augmentation of attritional tendon repair increased the load to failure and stiffness as well as decreased displacement compared with the ungrafted tissue-deficient model. Tendons with their native width showed no statistical difference or negative biomechanical consequences of dermal augmentation. CLINICAL RELEVANCE: Dermal augmentation of the distal biceps is a biomechanically feasible option for patients with an attritionally thinned-out tendon.

A comprehensive experimental and detailed chemical kinetic modelling study of 2,5-dimethylfuran pyrolysis and oxidation.

The pyrolytic and oxidative behaviour of the biofuel 2,5-dimethylfuran (25DMF) has been studied in a range of experimental facilities in order to investigate the relatively unexplored combustion chemistry of the title species and to provide combustor relevant experimental data. The pyrolysis of 25DMF has been re-investigated in a shock tube using the single-pulse method for mixtures of 3% 25DMF in argon, at temperatures from 1200-1350 K, pressures from 2-2.5 atm and residence times of approximately 2 ms. Ignition delay times for mixtures of 0.75% 25DMF in argon have been measured at atmospheric pressure, temperatures of 1350-1800 K at equivalence ratios (ϕ) of 0.5, 1.0 and 2.0 along with auto-ignition measurements for stoichiometric fuel in air mixtures of 25DMF at 20 and 80 bar, from 820-1210 K. This is supplemented with an oxidative speciation study of 25DMF in a jet-stirred reactor (JSR) from 770-1220 K, at 10.0 atm, residence times of 0.7 s and at ϕ = 0.5, 1.0 and 2.0. Laminar burning velocities for 25DMF-air mixtures have been measured using the heat-flux method at unburnt gas temperatures of 298 and 358 K, at atmospheric pressure from ϕ = 0.6-1.6. These laminar burning velocity measurements highlight inconsistencies in the current literature data and provide a validation target for kinetic mechanisms. A detailed chemical kinetic mechanism containing 2768 reactions and 545 species has been simultaneously developed to describe the combustion of 25DMF under the experimental conditions described above. Numerical modelling results based on the mechanism can accurately reproduce the majority of experimental data. At high temperatures, a hydrogen atom transfer reaction is found to be the dominant unimolecular decomposition pathway of 25DMF. The reactions of hydrogen atom with the fuel are also found to be important in predicting pyrolysis and ignition delay time experiments. Numerous proposals are made on the mechanism and kinetics of the previously unexplored intermediate temperature combustion pathways of 25DMF. Hydroxyl radical addition to the furan ring is highlighted as an important fuel consuming reaction, leading to the formation of methyl vinyl ketone and acetyl radical. The chemically activated recombination of HȮ2 or CH3Ȯ2 with the 5-methyl-2-furanylmethyl radical, forming a 5-methyl-2-furylmethanoxy radical and ȮH or CH3Ȯ radical is also found to exhibit significant control over ignition delay times, as well as being important reactions in the prediction of species profiles in a JSR. Kinetics for the abstraction of a hydrogen atom from the alkyl side-chain of the fuel by molecular oxygen and HȮ2 radical are found to be sensitive in the estimation of ignition delay times for fuel-air mixtures from temperatures of 820-1200 K. At intermediate temperatures, the resonantly stabilised 5-methyl-2-furanylmethyl radical is found to predominantly undergo bimolecular reactions, and as a result sub-mechanisms for 5-methyl-2-formylfuran and 5-methyl-2-ethylfuran, and their derivatives, have also been developed with consumption pathways proposed. This study is the first to attempt to simulate the combustion of these species in any detail, although future refinements are likely necessary. The current study illustrates both quantitatively and qualitatively the complex chemical behavior of what is a high potential biofuel. Whilst the current work is the most comprehensive study on the oxidation of 25DMF in the literature to date, the mechanism cannot accurately reproduce laminar burning velocity measurements over a suitable range of unburnt gas temperatures, pressures and equivalence ratios, although discrepancies in the experimental literature data are highlighted. Resolving this issue should remain a focus of future work.