Knotless Tensionable Anchors: Versatility, Tips, and Tricks.

Arthroscopic surgery, including implants and advanced techniques, continues to advance in the field of orthopaedics. The evolution of suture anchors has undergone design changes, passing from first-generation metal anchors, biodegradable materials, different plastic polymers, to all-suture constructs. Knotless technology also has been found to be a more reproducible method and have comparable outcomes with those found using knotted anchors. This Technical Note describes the advantages and different ways this tensionable anchor can be used in arthroscopic procedures. This implant and its understanding will be useful in the sports medicine area by simplifying procedures and making them more reproducible. The aim of the present Technical Note is to detail the simplicity and versatility of the anchor and discuss different scenarios in which this technology can be used to address common hip pathologies.

Pneumothorax and Timing to Safe Air Travel.

INTRODUCTION: Current guidelines regarding the time to flight after an acquired pneumothorax have been generally accepted and in place for years. The majority of these typically advise holding off on air travel until the complete resolution of a pneumothorax. Over the past decade, however, there has been an increase in the amount of literature focusing on this subject and challenging this well-held dogma. A review of these studies has shown that recent evidence contradicts the historical guidelines that many practitioners follow about the safety and timing of flying after pneumothoraces. Based on these studies, air travel with a known pneumothorax is likely safe and can be undertaken much sooner than current guidelines advise.Kashtan HW, Schulte SN, Connelly KS. Pneumothorax and timing to safe air travel. Aerosp Med Hum Perform. 2024; 95(2):113-117.

TEMPORARY REMOVAL: Favorable and Durable Outcomes at 10-Year Follow Up After Endoscopic Gluteus Medius Repair With Concomitant Hip Arthroscopy.

The publisher regrets that this article has been temporarily removed. A replacement will appear as soon as possible in which the reason for the removal of the article will be specified, or the article will be reinstated. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal.

Environment-Induced Degradation of Shape Memory Alloys: Role of Alloying and Nature of Environment.

Shape memory effects coupled with superelasticity are the distinctive characteristics of shape memory alloys (SMAs), a type of metal. When these alloys are subject to thermomechanical processing, they have the inherent ability to react to stimuli, such as heat. As a result, these alloys have established their usefulness in a variety of fields and have in recent years been chosen for use in stents, sensors, actuators, and several other forms of life-saving medical equipment. When it comes to the shape memory materials, nickel-titanium (Ni-Ti) alloys are in the forefront and have been chosen for use in a spectrum of demanding applications. As shape memory alloys (SMAs) are chosen for use in critical environments, such as blood streams (arteries and veins), orthodontic applications, orthopedic implants, and high temperature surroundings, such as actuators in aircraft engines, the phenomenon of environment-induced degradation is of both interest and concern. Hence, the environment-induced degradation behavior of the shape memory alloys (SMAs) needs to be studied to find viable ways to improve their resistance to an aggressive environment. The degradation that occurs upon exposure to an aggressive environment is often referred to as corrosion. Environment-induced degradation, or corrosion, being an unavoidable factor, certain techniques can be used for the purpose of enhancing the degradation resistance of shape memory alloys (SMAs). In this paper, we present and discuss the specific role of microstructure and contribution of environment to the degradation behavior of shape memory alloys (SMAs) while concurrently providing methods to resist both the development and growth of the degradation caused by the environment.

Timeline to dysphagia resolution after endoscopic intervention of an interarytenoid defect based on Video Fluoroscopic Swallow Study dysphagia severity.

INTRODUCTION: We previously reported that endoscopic repair of a Type 1 Laryngeal Cleft (LC1) or Deep Interarytenoid Groove (DIG) improves swallowing function postoperatively. However, caregivers often ask about the timeline to resolution of the need for thickening. This study re-examines this cohort to answer this important caregiver-centered question. METHODS: We reassessed a 3-year retrospective, single-center dataset of children with dysphagia found to have a LC-1 or DIG on endoscopic exam. The primary outcome was rate of complete resolution of dysphagia at 2, 6, and 12 months after endoscopic intervention. A sub-group analysis was made based on severity of dysphagia prior to intervention and by type of endoscopic repair. RESULTS: Thirty-nine patients with mean age 1.35 years that had a LC-1 or DIG met criteria for inclusion. Rate of complete dysphagia resolution increased over time. Those with mild dysphagia (flow-reducing nipple and/or IDDSI consistency 1 or 2) had brisker resolution than those with moderate dysphagia (IDDSI consistency 3 or 4) at 2 months (67% vs 5%, p < 0.01) and at 6 months (80% vs 18%, p < 0.01) after endoscopic repair. There was no difference in dysphagia resolution between patients grouped by type of endoscopic repair. CONCLUSION: Addressing an interarytenoid defect in patients will not result in immediate, complete dysphagia resolution in most patients. However, patients that only require a flow-reducing nipple and/or thickening to an IDDSI consistency 1 or 2 have brisker resolution of the need for thickening than those that require an IDSSI consistency 3 or 4 prior to intervention. These results inform pre-operative discussions of the timeline to resolution based upon severity of dysphagia and help manage caregiver expectations.

Metrics of student dissatisfaction and disagreement: longitudinal explorations of a national survey instrument.

This study explores dissatisfaction and neutrality metrics from 12 years of a national-level undergraduate student survey. The notion of dissatisfaction is much less prevalent in the narratives surrounding student survey outcomes, and the underpinning metrics are seldom considered. This is despite an increasingly vociferous debate about 'value for money' of higher education and the positioning of students as consumers in a marketised sector. We used machine learning methods to explore over 2.7 million national survey outcomes from 154 institutions to describe year-on-year stability in the survey items that best predicted dissatisfaction and neutrality, together with their similarity to known metric predictors of satisfaction. The widely publicised annual increases in student 'satisfaction' are shown to be the result of complex reductions in the proportions of disagreement and neutrality across different survey dimensions. Due to the widespread use of survey metrics in university league tables, we create an anonymised, illustrative table to demonstrate how UK institutional rankings would have differed if dissatisfaction metrics had been the preferred focus for reporting. We conclude by debating the tensions of balancing the provision of valuable information about dissatisfaction, with perpetuating negative impacts that derive from this important subset of the survey population.

The last days: The medical response of United States and allied military teams during the Afghanistan Exodus.

OBJECTIVES: The objective of this study is to describe the United States and allied military medical response during the withdrawal from Afghanistan. BACKGROUND: The military withdrawal from Afghanistan concluded with severe hostilities resulting in numerous civilian and military casualties. The clinical care provided by coalition forces capitalized on decades of lessons learned and enabled unprecedented accomplishments. METHODS: In this retrospective, observational analysis, casualty numbers, and operative information was collected and reported from military medical assets in Kabul, Afghanistan. The continuum of medical care and the trauma system, from the point of injury back to the United States was captured and described. RESULTS: Prior to a large suicide bombing resulting in a mass casualty event, the international medical teams managed distinct 45 trauma incidents involving nearly 200 combat and non-combat civilian and military patients over the preceding 3 months. Military medical personnel treated 63 casualties from the Kabul airport suicide attack and performed 15 trauma operations. US air transport teams evacuated 37 patients within 15 hours of the attack. CONCLUSION: Lessons learned from the last 20 years of combat casualty care were successfully implemented during the culmination of the Afghanistan conflict. Ultimately, the effort, teamwork, and system adaptability exemplify not only the attitudes and character of service members who provide modern combat casualty care but also the paramount importance of the battlefield learning health care system. A continued posture to maintain military surgical preparedness in unique environments remain crucial as the US military prepares for the future.Retrospective observational analysis. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level V.

Arthroscopic Peripheral Compartment Iliopsoas Release for Iliopsoas Impingement After Primary Total Hip Arthroplasty.

Anterior iliopsoas (IP) impingement after total hip arthroplasty is an underrecognized and continued cause for postoperative pain. There are multiple etiologies for this impingement from cup positioning and sizing to changes in the leg length, and offset must be evaluated to confirm no need for implant revision. Additionally, tension of the IP tendon can be increased in patients with diminished spinal mobility, either from prior fusion or with increasing age. Managing this surgically after failing conservative treatment options is best done arthroscopically to prevent additional large, open procedures that place the arthroplasty at unnecessary risk of infection and potential instability. In this article, we describe an arthroscopic technique using fluoroscopy to guide the release of the iliopsoas tendon from the peripheral compartment.

Low Ceiling Effects of the Forgotten Joint Score Compared With Legacy Measures After Joint-Preserving Procedures: A Systematic Review.

PURPOSE: To determine, in patients undergoing joint preservation procedures, whether the Forgotten Joint Score (FJS) compares favorably with legacy measures. METHODS: Medical databases (including PubMed/MEDLINE and Embase databases) were queried for publications with the terms "Forgotten Joint Score" and "hip," "knee," "arthroscopy," or "ACL." Fourteen studies met the inclusion criteria. Methodologic quality was assessed through the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) checklist, and psychometric data were evaluated for ceiling or floor effects, convergent validity, internal consistency, reliability, responsiveness, measurement invariance, and measurement error by 2 fellowship-trained orthopaedic surgeons (B.D.K. and W.T.H.). RESULTS: Data were collected from 14 studies using the FJS after joint-preserving procedures in 911 patients (959 joints). Four studies reported strong internal consistency with an average Cronbach α of 0.92. Two studies reported responsiveness with an effect size ranging from 0.6 to 1.16. One study reported reproducibility with an interclass correlation coefficient of 0.9 (95% confidence interval, 0.8-0.9). One study reported measurement error with an minimum detectable change (MDC)individual of 32% and MDCgroup of 4.5%. Studies reported moderate to very strong convergent validity across legacy measures for hip and knee preservation surgery. Ceiling effects were favorable compared with many legacy scores for hip and knee preservation. Three studies reported the minimal clinically important difference whereas 1 study reported the patient acceptable symptomatic state for the FJS. CONCLUSIONS: The FJS is a methodologically sound outcome measure used to evaluate patient outcomes after hip and knee preservation surgery with overall low ceiling effects compared with legacy measures. LEVEL OF EVIDENCE: Level IV, systematic review of Level III and IV studies.

Anchor Arthropathy Caused by Cartilage Penetration: An Approach to Revision Hip Arthroscopy With Removal of Problematic Anchors.

Hip arthroscopy has been proven to effectively treat labral tears in the setting of femoroacetabular impingement. Anchors used for this treatment have constantly evolved and improved to ensure safety and minimal invasion. However, acetabular drilling and anchor placement are technically challenging due to the concavity of the acetabular articular surface, limited angles for anchor insertion, and finite bone availability in the anterior and posterior column. Inadequate technique can result in protruding anchors, which may lead to full-thickness articular cartilage damage, manifesting in pain, mechanical symptoms, and impaired function. This Technical Note demonstrates arthroscopic removal of protruding anchors and management of the iatrogenic grade IV cartilage damage. In this description, the technical pearls and pitfalls of acetabular anchor placement to treat labral pathology are presented along with the aforementioned technique.

Single-molecule investigations of single-chain cellulose biosynthesis.

Cellulose biosynthesis in sessile bacterial colonies originates in the membrane-integrated bacterial cellulose synthase (Bcs) AB complex. We utilize optical tweezers to measure single-strand cellulose biosynthesis by BcsAB from Rhodobacter sphaeroides. Synthesis depends on uridine diphosphate glucose, Mg2+, and cyclic diguanosine monophosphate, with the last displaying a retention time of ∼80 min. Below a stall force of 12.7 pN, biosynthesis is relatively insensitive to force and proceeds at a rate of one glucose addition every 2.5 s at room temperature, increasing to two additions per second at 37°. At low forces, conformational hopping is observed. Single-strand cellulose stretching unveiled a persistence length of 6.2 nm, an axial stiffness of 40.7 pN, and an ability for complexes to maintain a tight grip, with forces nearing 100 pN. Stretching experiments exhibited hysteresis, suggesting that cellulose microstructure underpinning robust biofilms begins to form during synthesis. Cellohexaose spontaneously binds to nascent single cellulose strands, impacting polymer mechanical properties and increasing BcsAB activity.

X-Grab: An Arthroscopic Maneuver to Efficiently and Accurately Track the Post for Knot Tying.

Numerous studies have analyzed techniques for producing reliable and efficient arthroscopic knots. All aspects have been explored, from the biomechanics and strength to the ability to teach and replicate at all levels of training. This technique article describes an additional maneuver (X-grab) for efficiently marking the post side of the arthroscopic knot without having to do this separately outside of the joint. This is most useful for procedures such as rotator cuff repair and capsular repair or plication in hip arthroscopy in which the location of the knot (i.e., the post) is critical. The aim of this Technical Note is to describe the X-grab maneuver, which shortens this process to a single step, limiting the see-sawing of sutures and over-instrumentation of the joint seen with other techniques.

Phase 2 Assessment of a New Functional Pain Scale by Comparing It to Traditional Pain Scales.

Background Assessment of pain has always been subjective and is commonly assessed using a numeric pain scale (NPS) or Wong-Baker faces scale. The pain intensity score is not standardized and relies on individuals' past experiences. The disadvantage of using such pain assessment scales and treating the numbers can lead to overdosing on analgesics leading to unwanted side effects. The Robert Packer Hospital/Functional Pain Scale (RPH/FPS) was developed as a tool for the objective assessment of pain and its impact on a patient's function.  Aim The study aimed to validate the RPH/FPS scale against NPS and Wong-Baker faces scale in medical, surgical, and trauma patients. The patients' were also asked to rank the scales as one (1) being the most preferred to three (3) being the least preferred. Design This prospective, observational cohort study compares the two most common pain scales, the NPS and the Wong-Baker Faces, to the RPH/FPS. Methods Spearman correlation was used to test for correlation between the three scales, and Wilcoxon rank-sum test was used to compare means between the RPH/FPS and NPS. The study participants were also asked to rate their preferences for the scales by rating the most preferred of the three scales as one (1) and the least preferred number three (3).  Results The RPH/FPS had a strong correlation with both the NPS and Wong-Baker Faces scales (RPH/FPS vs. NPS R=0.69, p<0.001: RPH-FPS vs. Wong-Baker Faces R=0.69, P<0.001). As for preferences, the RPH/FPS was ranked first on 36.9% of the surveys followed by NPS on 35.9%, and the Wong-Baker Faces on 22.3%. There were 4.9% of the surveys missing the preference rankings. Conclusion The results validate the RPH/FPS scale against the NPS and Wong-Baker Faces scales. This gives the clinicians a tool for objective assessment of pain and its effect on the recovery process, thereby minimizing the observed disconnect that sometimes happens between the reported pain intensity level and the providers' observation of the patient.

Retraction: Phase 2 Assessment of a New Functional Pain Scale by Comparing It to Traditional Pain Scales.

[This retracts the article DOI: 10.7759/cureus.24522.].

Dairy cows value an open area for lying down.

As dairy cows are being housed for longer periods, with all-year-round housing growing in popularity, it is important to ensure housed environments are meeting the needs of cows. Dairy cows are motivated to access open lying areas, although previous motivation studies on this topic have confounded surface type and location (i.e. pasture outdoors vs cubicles indoors). This study measured cow motivation for lying down on an indoor open mattress (MAT; 9 m x 5 m) compared to indoor mattress-bedded cubicles, thus removing the confounding factor of surface type and location. This was repeated for an identically sized indoor deep-bedded straw yard (ST), to investigate whether surface type affected motivation for an open lying area. Thirty Holstein-Friesian dairy cows were housed in groups of 5 (n = 5 x 6) in an indoor robotic milking unit with access to six mattress-bedded cubicles. To assess motivation, cows were required to walk increasing distances via a one-way indoor raceway to access the open lying areas: Short (34.5 m), followed by Medium (80.5 m) and Long (126.5 m). Cows could choose to walk the raceway, leading to the MAT or ST, to lie down or they could lie down on the cubicles for 'free'. Overall, cows lay down for longer on the open lying areas at each distance compared to the cubicles, with cows lying down slightly longer on ST than MAT, although lying times on the open lying areas did decrease at the Long distance. However, cows were still lying for >60% of their lying time on the open lying areas at the Long distance. This study demonstrates that cows had a high motivation for an open lying area, the provision of which could better cater for the behavioural needs of housed dairy cows and improve housed dairy cow welfare.

Minimum 2-Year Outcomes and Return to Sports of Competitive Athletes Who Undergo Subspine Decompression During Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome and Subspine Impingement: A Propensity-Matched Controlled Study.

BACKGROUND: Patient-reported outcomes (PROs) and return to sports (RTS) have not been established in athletes undergoing primary hip arthroscopy and subspine decompression for femoroacetabular impingement syndrome (FAIS) and subspine impingement (SSI). PURPOSE: (1) To report minimum 2-year PROs and RTS in competitive athletes undergoing primary hip arthroscopy for treatment of FAIS with subspine decompression for treatment of SSI and (2) to compare clinical results with a matched control group of athletes without SSI. STUDY DESIGN: Cohort study, Level of evidence, 3. METHODS: Data were reviewed for professional, collegiate, and high school athletes undergoing primary hip arthroscopy for FAIS with arthroscopic subspine decompression for SSI between February 2011 and October 2018. Inclusion criteria included preoperative and minimum 2-year follow-up scores for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score-Sport Specific Subscale, and visual analog scale for pain. Rates of achieving the minimal clinically important difference (MCID) were also calculated. For comparison, athletes in the SSI group were propensity matched according to age at the time of surgery, sex, body mass index, lateral center-edge angle, alpha angle, sport level, acetabular labrum articular disruption grade, and sport type to a control group of athletes without SSI. RESULTS: A total of 30 SSI athletes were included in the study, with a mean plus or minus standard deviation follow-up of 32.1 ± 7.1 months and age of 20.9 ± 5.7 years. The SSI cohort demonstrated significant improvement in all recorded PROs (P < .001), returned to sports at high rates (88.5%), and achieved the MCID for the Hip Outcome Score-Sport Specific Subscale at a high rate (80.0%). Furthermore, these patients had a low rate of undergoing revision surgery (6.7%). When compared with a propensity-matched control group of 59 athletes, the SSI group demonstrated similar rates of RTS, revision, and achieving the MCID for all PROs. CONCLUSION: Competitive athletes with FAIS and SSI who underwent primary hip arthroscopy and subspine decompression had favorable outcomes and high RTS rates at minimum 2-year follow-up. These results were comparable with those of a control group of athletes without SSI undergoing primary hip arthroscopy.

Assessment of Functional Pain Score by Comparing to Traditional Pain Scores.

BACKGROUND: Pain assessments, such as the Numerical Pain Scale (NPS) and Wong-Baker FACEs (FACEs), offer methods to quantify pain with simplistic descriptions on a scale of 0-10 or facial expressions. These tools have limitations and deliver insufficient information to the provider developing a pain management plan. A new Functional Pain Scale (FPS) assesses other scopes of pain, including the loss of function in activities of daily living, sleep habits, and communication. Although NPS and FACEs are traditionally used in clinical practice, FPS provides a functional assessment to help patients self-report their pain to their providers.  Aim: Our study attempts to show a comparative data analysis of the FPS to NPS and FACEs. The purpose of our study is not to demonstrate FPS's superiority over NPS and FACEs but to fill the gaps of information necessary to communicate the type of pain a patient has to their provider. Due to its descriptive nature and clear scores, FPS should be implemented within electronic medical records (EMR) to help providers assess patients' pain and evaluate the efficacy of interventions selected based on that pain. DESIGN: A prospective, observational, single-center, cohort study was performed, with simultaneously administered surveys to compare pains scores on a new FPS to the common NPS and FACEs. The target sample was postoperative orthopedic patients above 18 years of age who can read and speak English. Patients were surveyed on all three pain scales: FPS, NPS, and FACEs and were asked to rate their pain perioperatively after their respective orthopedic procedures. METHODS: Spearman correlation method was used to test for correlation between the three pain scales and Wilcoxon rank-sum test was used to compare means between FPS and NPS. RESULTS: FPS has a strong correlation with FACEs (r = 0.647, p<0.05) and with NPS (r = 0.634, p<0.05). There is a significant difference in mean scores between FPS and NPS. Conclusion and study implications: The most reliable marker of pain is patient self-reporting. In routine assessment, because pain is one-dimensional, we as providers need to better define the range of 0-10. This can only be done via an algorithm regarding which functions are lost as pain intensities increase. FPS fits those requirements by offering suitable descriptions with each pain score. The implications of the study include a chance to remedy the opioid crisis that plagues healthcare. We need tools that assess and educate patients about their pain level and appropriately convey that information to providers. Furthermore, this study is a chance for innovative tools to be implemented to better change healthcare practice. If FPS gains traction, it can improve pain communication between patients and providers.

Optimal timing and technique for endoscopic management of dysphagia in pediatric aerodigestive patients.

INTRODUCTION: The best strategy to manage an interarytenoid defect [Type 1 laryngeal cleft (LC-1) or deep interarytenoid groove (DIG)] in pediatric aerodigestive patients with dysphagia remains uncertain. This study compared benefit of interarytenoid augmentation (IAA) to suture repair or clinical observation alone in pediatric patients. METHODS: A 3-year retrospective, single-center analysis of children with dysphagia undergoing endoscopic airway evaluation was performed. Physician preference guided treatment plan: suture repair with CO2 laser, IAA (carboxy methylcellulose or calcium hydroxyapatite), or observation. Primary outcome was improved post-operative diet. Significance was assumed at p < 0.05. RESULTS: 449 patients underwent diagnostic endoscopy. Mean age (±SD) at procedure was 21 ± 13 months, with nearly one fourth (28 %) of children ≤ 12 months. Eighty (18 %) had either an LC-1 (n = 55) or DIG (n = 25). Of these, 35 (42 %) underwent suture repair, 22 (28 %) IAA, and 23 (30 %) observation only. Aspiration improved overall in the interventional groups compared to observational controls (58 % vs. 9 %, p < 0.05), with no change in benefit observed by age of intervention. IAA was as effective as suture repair (59 % vs 55 %, p = 0.46). In patients with only a DIG, IAA intervention alone significantly improved swallow function (66.6 % vs. 0 %, p < 0.05). CONCLUSION: In pediatric aerodigestive patients with dysphagia, 18 % of children have an addressable lesion. IAA or suture repair similarly improves dietary advancement. IAA improves swallow function in patients with DIG. These findings support a novel protocol to intervene in dysphagia patients with LC-1 or DIG via IAA at the initial operative evaluation.

Evidence of phenotypic plasticity along an altitudinal gradient in the dung beetle Onthophagus proteus.

BACKGROUND: High altitude insects are an ecologically specialized group and possess a suite of adaptions which allow persistence in the inhospitable conditions often associated with mountain tops. Changes in body coloration and reductions or increases in body size are thought to be examples of such adaptions. Melanic individuals, or individuals containing high levels of eumelanin, possess several traits which increase resistance to ultraviolet radiation and desiccation, while aiding thermoregulation. Trait variation is often observed in dung beetles and is associated with dimorphism and sexual selection. In this study, we identified trait changes which occur across an altitudinal gradient by measuring morphological color and body size traits in a montane insect. METHODS: Using standard digital photography and Image J, we examined individuals of Afromontane dung beetle Onthophagus proteus. Individuals were classified according to sex and color morph to identify intrasexual variance. Nine morphometric traits were measured per beetle to identify patterns of morphology across discrete 500 m altitude segments. RESULTS: The results of this study provide one of the first descriptions of trait changes associated with elevation in an African dung beetle. We suggest that color polymorphism in Onthophagus proteus might be at least partly driven by environmental factors as there is significantly increased melanism with increasing elevation and significant differences in color hues between altitude bands. We also suggest changes in horn length are density dependent, as we observed an increase in cephalic horn length at high elevations where O. proteus is the most abundant species.

An investigation into the impact of nine catchment characteristics on the accuracy of two phosphorus load apportionment models.

Phosphorus (P) load apportionment models (LAMs), requiring only spatially and temporally paired P and flow (Q) measurements, provide outputs of variable accuracy using long-term monthly datasets. Using a novel approach to investigate the impact of catchment characteristics on accuracy variation, 91 watercourses' Q-P datasets were applied to two LAMs, BM and GM, and bootstrapped to ascertain standard errors (SEs). Random forest and regression analysis on data pertaining to catchments' land use, steepness, size, base flow and sinuosity were used to identify the individual relative importance of a variable on SE. For BM, increasing urban cover was influential on raising SEs, accounting for c.19% of observed variation, whilst analysis for GM found no individually important catchment characteristic. Assessment of model fit evidenced BM consistently outperformed GM, modelling P values to ±10% of actual P values in 85.7% of datasets, as opposed to 17.6% by GM. Further catchment characteristics are needed to account for SE variation within both models, whilst interaction between variables may also be present. Future research should focus on quantifying these possible interactions and should expand catchment characteristics included within the random forest. Both LAMs must also be tested on a wide range of high temporal resolution datasets to ascertain if they can adequately model storm events in catchments with diverse characteristics.