Are extra locking bolts or fibular plating more important in extreme nailing of distal tibia fractures? A cadaveric biomechanical analysis.

OBJECTIVES: In far-distal extra-articular tibia fracture "extreme" nailing, debate surrounds the relative biomechanical performance of plating the fibula compared with extra distal interlocks. This study aimed to evaluate several constructs for extreme nailing including one interlock (one medial-lateral interlock), one interlock + plate (one medial-lateral interlock with lateral fibula compression plating), and two interlocks (one medial-lateral interlock and one anterior-posterior interlock). METHODS: Fifteen pairs of fresh cadaver legs were instrumented with a tibial nail to the physeal scar. A 1 cm segment of bone was resected from the distal tibia 3.5 cm from the joint and an oblique osteotomy was made in the distal fibula. We loaded specimens with three different distal fixation constructs (one interlock, one interlock + plate, and two interlocks) through 10,000 cycles form 100N-700 N of axial loading. Load to failure (Newtons), angulation and displacement were also measured. RESULTS: Mean load to failure was 2092 N (one interlock), 1917 N (one interlock + plate), and 2545 N (two interlocks). Linear mixed effects modeling demonstrated that two interlocks had a load to failure 578 N higher than one interlock alone (95 % CI, 74N-1082 N; P = 0.02), but demonstrated no significant difference between one interlock and one interlock + plate. No statistically significant difference in rates or timing of displacement >2 mm or angulation >10° were demonstrated. CONCLUSIONS: When nailing far-distal extra-articular tibia and fibula fractures, adding a second interlock provides more stability than adding a fibular plate. Distal fibula plating may have minimal biomechanical effect in extreme nailing.

Membrane modification with carbon nanomaterials for fouling mitigation: A review.

This paper provides a comprehensive overview of recent advancements in membrane modification for fouling mitigation in various water treatment processes, employing carbon nanomaterials such as fullerenes, nanodiamonds, carbon quantum dots, carbon nanotubes, and graphene oxide. Currently, using different carbon nanomaterials for polymeric membrane fouling mitigation is at various stages: CNT-modified membranes have been studied for more than ten years and have already been tested in pilot-scale setups; tremendous attention has been paid to utilizing graphene oxide as a modifying agent, while the research on carbon quantum dots' influence on the membrane antifouling properties is in the early stages. Given the intricate nature of fouling as a colloidal phenomenon, the review initially delves into the factors influencing the fouling process and explores strategies to address it. The diverse chemistry and antibacterial properties of carbon nanomaterials make them valuable for mitigating scaling, colloidal, and biofouling. This review covers surface modification of existing membranes using different carbon materials, which can be implemented as a post-treatment procedure during membrane fabrication. Creating mixed-matrix membranes by incorporating carbon nanomaterials into the polymer matrix requires the development of new synthetic procedures. Additionally, it discusses promising strategies to actively suppress fouling through external influences on modified membranes. In the concluding section, the review compares the effectiveness of carbon materials of varying dimensions and identifies key characteristics influencing the antifouling properties of membranes modified with carbon nanomaterials.

Latitudinal patterns in stabilizing density dependence of forest communities.

Numerous studies have shown reduced performance in plants that are surrounded by neighbours of the same species1,2, a phenomenon known as conspecific negative density dependence (CNDD)3. A long-held ecological hypothesis posits that CNDD is more pronounced in tropical than in temperate forests4,5, which increases community stabilization, species coexistence and the diversity of local tree species6,7. Previous analyses supporting such a latitudinal gradient in CNDD8,9 have suffered from methodological limitations related to the use of static data10-12. Here we present a comprehensive assessment of latitudinal CNDD patterns using dynamic mortality data to estimate species-site-specific CNDD across 23 sites. Averaged across species, we found that stabilizing CNDD was present at all except one site, but that average stabilizing CNDD was not stronger toward the tropics. However, in tropical tree communities, rare and intermediate abundant species experienced stronger stabilizing CNDD than did common species. This pattern was absent in temperate forests, which suggests that CNDD influences species abundances more strongly in tropical forests than it does in temperate ones13. We also found that interspecific variation in CNDD, which might attenuate its stabilizing effect on species diversity14,15, was high but not significantly different across latitudes. Although the consequences of these patterns for latitudinal diversity gradients are difficult to evaluate, we speculate that a more effective regulation of population abundances could translate into greater stabilization of tropical tree communities and thus contribute to the high local diversity of tropical forests.

Climate change determines the sign of productivity trends in US forests.

Forests are integral to the global land carbon sink, which has sequestered ~30% of anthropogenic carbon emissions over recent decades. The persistence of this sink depends on the balance of positive drivers that increase ecosystem carbon storage-e.g., CO2 fertilization-and negative drivers that decrease it-e.g., intensifying disturbances. The net response of forest productivity to these drivers is uncertain due to the challenge of separating their effects from background disturbance-regrowth dynamics. We fit non-linear models to US forest inventory data (113,806 plot remeasurements in non-plantation forests from ~1999 to 2020) to quantify productivity trends while accounting for stand age, tree mortality, and harvest. Productivity trends were generally positive in the eastern United States, where climate change has been mild, and negative in the western United States, where climate change has been more severe. Productivity declines in the western United States cannot be explained by increased mortality or harvest; these declines likely reflect adverse climate-change impacts on tree growth. In the eastern United States, where data were available to partition biomass change into age-dependent and age-independent components, forest maturation and increasing productivity (likely due, at least in part, to CO2 fertilization) contributed roughly equally to biomass carbon sinks. Thus, adverse effects of climate change appear to overwhelm any positive drivers in the water-limited forests of the western United States, whereas forest maturation and positive responses to age-independent drivers contribute to eastern US carbon sinks. The future land carbon balance of forests will likely depend on the geographic extent of drought and heat stress.

Mycorrhizal feedbacks influence global forest structure and diversity.

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal type, with ectomycorrhizal tree species exhibiting higher sapling densities with increasing adult densities than arbuscular mycorrhizal tree species. Moreover, we found evidence of positive CMDD for tree species of both mycorrhizal types. Collectively, these findings indicate that mycorrhizal interactions likely play a foundational role in global forest diversity patterns and structure.

Effects of drought, disturbance, and biotic neighborhood on experimental tree seedling performance.

Forest biodiversity is likely maintained by a complex suite of interacting drivers that vary in importance across both space and time. Contributing factors include disturbance, interannual variation in abiotic variables, and biotic neighborhood effects. To probe ongoing uncertainties and potential interactions, we investigated tree seedling performance in a temperate mid-Atlantic forest ecosystem. We planted seedlings of five native tree species in mapped study plots, half of which were subjected to disturbance, and then monitored seedling survival, height growth, and foliar condition. The final year of data collection encompassed a drought, enabling comparison between intervals varying in water availability. Seedling performance was analyzed as a function of canopy cover and biotic neighborhood (conspecific and heterospecific abundance), including interactions, with separate generalized linear mixed models fit for each interval. All species exhibited: (a) pronounced declines in height growth during the drought year, (b) detrimental effects of adult conspecifics, and (c) beneficial effects of canopy openness. However, despite these consistencies, there was considerable variation across species in terms of the relevant predictors for each response variable in each interval. Our results suggest that drought may strengthen or reveal conspecific inhibition in some instances while weakening it or obscuring it in others, and that some forms of conspecific inhibition may manifest only under particular canopy conditions (although given the inconsistency of our findings, we are not convinced that conspecific inhibition is critical for diversity maintenance in our study system). Overall, our work reveals a complex forest ecosystem that appears simultaneously and interactively governed by biotic neighborhood structure (e.g., conspecific and/or heterospecific abundance), local habitat conditions (e.g., canopy cover), and interannual variability (e.g., drought).

Synthesis and characterisation of new antimalarial fluorinated triazolopyrazine compounds.

Nine new fluorinated analogues were synthesised by late-stage functionalisation using Diversinate™ chemistry on the Open Source Malaria (OSM) triazolopyrazine scaffold (Series 4). The structures of all analogues were fully characterised by NMR, UV and MS data analysis; three triazolopyrazines were confirmed by X-ray crystal structure analysis. The inhibitory activity of all compounds against the growth of the malaria parasite Plasmodium falciparum (3D7 and Dd2 strains) and the cytotoxicity against a human embryonic kidney (HEK293) cell line were tested. Some of the compounds demonstrated moderate antimalarial activity with IC50 values ranging from 0.2 to >80 µM; none of the compounds displayed any cytotoxicity against HEK293 cells at 80 µM. Antimalarial activity was significantly reduced when C-8 of the triazolopyrazine scaffold was substituted with CF3 and CF2H moieties, whereas incorporation of a CF2Me group at the same position completely abolished antiplasmodial effects.

Functional Interaction of the Cruciate Ligaments, Posteromedial and Posterolateral Capsule, Oblique Popliteal Ligament, and Other Structures in Preventing Abnormal Knee Hyperextension.

BACKGROUND: The ligaments and soft tissue capsular structures of the knee joint that provide a resisting force to prevent abnormal knee hyperextension have not been determined. This knowledge is required for the diagnosis and treatment of knee hyperextension abnormalities. PURPOSE: To determine the resisting moment of knee ligament and capsular structures that resist knee hyperextension. HYPOTHESIS: The combined posteromedial and posterolateral capsular structures function to provide a major restraint to prevent abnormal knee hyperextension. The anterior and posterior cruciate ligaments resist knee hyperextension but function as secondary restraints. STUDY DESIGN: Descriptive laboratory study. METHODS: A 6 degrees of freedom robotic system determined intact laxity limits in 24 cadaveric knees from 0° to 100° of knee flexion for anteroposterior limits at ±135 N, abduction-adduction limits at ±7 N·m, and external-internal limits at ±5 N·m. One loading method (n = 14 knees) used a static loading sequence with knee hyperextension to 27-N·m torque while maintaining all other degrees of freedom at zero load during sequential soft tissue cutting. The second method (n = 10 knees) used a cyclic loading sequence to decrease viscoelastic effects with soft tissue cutting at 0° of extension, followed by knee hyperextension to 27-N·m torque and cycled back to 0°. Selective soft tissue cuttings were performed of the following: oblique popliteal ligament, fabellofibular ligament, posterolateral capsule, posteromedial capsule with posterior oblique ligament, cruciate ligaments, lateral collateral ligament, popliteus, anterolateral ligament and iliotibial band, and superficial plus deep medial collateral ligaments. The sequential loss in the restraining moment with sectioning provides the function of that structure in resisting knee hyperextension. RESULTS: The median resisting force to knee hyperextension, in descending order, was the posteromedial capsule and posterior oblique ligament (21.7%), posterorolateral ligament and fabellofibular ligament (17.1%), anterior and posterior cruciate ligaments (13% and 12.9%, respectively), superior and deep medial collateral ligament (9.6%), oblique popliteal ligament (7.7%), and lateral collateral ligament (5.4%). The combined posterior capsular structures provided 54.7% and the anterior and posterior cruciate ligaments 25.3% of the total resisting moment to prevent knee hyperextension. CONCLUSION: Diagnosis of abnormal knee hyperextension involves a combination of multiple ligament and soft tissue structures without 1 primary restraint. The posteromedial and posterolateral capsular structures provided the major resisting moment to prevent knee hyperextension. The cruciate ligaments produced a lesser resisting moment to knee hyperextension. CLINICAL RELEVANCE: This is the first study to comprehensively measure all of the knee ligaments and capsular structures providing a resisting moment to abnormal knee hyperextension. These data are required for diagnostic and treatment strategies on the pathomechanics of abnormal knee hyperextension in patients after injury or developmental cases.

Social Media Posts Pertaining to Anterior Cervical Discectomy and Fusion (ACDF) Surgery: A Cross-sectional Analysis of Patient and Surgeon Perceptions.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To analyze publicly available content on a major social media outlet related to anterior cervical discectomy and fusion (ACDF) surgery based on perspective, location, timing, content, tone, and patient satisfaction. SUMMARY OF BACKGROUND DATA: Social media offers a powerful platform for sharing the patient experience with the public through an unfiltered perspective. Social media content may influence future perceptions around surgical care and postings around ACDF have not been previously reported. METHODS: A query of content from a major social media outlet was performed for the study period January 1, 2018, to January 1, 2020, and returned 6500 publicly available posts. Content was identified by the hashtags "#acdf" or "#acdfsurgery." Content was ranked by number of "likes." Of the 1500 most popular posts, 1136 related to ACDF surgery and were included. Post content was characterized and classified. RESULTS: Patients created 85% of ACDF-related content and spine surgeons created 11.8%. Most posts portrayed the patient experience in the postoperative period and depicted patients performing activities of daily living, participating in sports, or completing work activities (54.4%). The connotation of posts was deemed to be positive in 79.2% of cases. In regard to their care or state of health as it related to ACDF surgery, 59.8% of patients expressed satisfaction, whereas 14.1% expressed dissatisfaction. Female patients were >4 times as likely to express dissatisfaction (odds ratio=4.16, P =<0.0001), with their clinical course compared with their male counterparts. CONCLUSIONS: Patients were the source of most posts on a major social media outlet that pertained to ACDF surgery with a majority reporting positive tone and satisfaction. These mechanisms of communication offer surgeons unique insights into patient experience and may provide an opportunity for surgeons to assess patient feedback, influence patient perceptions, and enhance delivery of cervical spine care.

Outcomes of Iliac Wing Fractures: A Systematic Review of the Literature.

To review the literature on iliac wing fractures to assess outcomes of operative and nonoperative treatment. A search of PubMed, MEDLINE, and Cochrane Database of Systematic Reviews was performed. Articles reporting on iliac wing fractures without pelvic ring destabilization or intraarticular extension were included. Study information and patient data were collected, and a Methodological Index for Non-randomized Studies (MINORS) score was assigned to each article. In total, 19,363 articles were identified with 32 qualifying for inclusion. The articles included 131 patients with 133 fractures. The mean age was 43.6, and mean follow-up time was 41.9 months. Forty-eight (36%) fractures were treated operatively, and 85 (64%) were treated nonoperatively. Associated injuries included bowel injuries, other pelvic fractures, gunshot wounds, and arterial injuries. There is an absence of comparative studies between operative and nonoperative management of iliac wing fractures. Indications for operative management appear to depend on comminution, open fractures, and associated injuries. (Journal of Surgical Orthopaedic Advances 32(3):139-147, 2023).

Soil water content and nitrogen differentially correlate with multidimensional leaf traits of two temperate broadleaf species.

The variation and correlation of leaf economics and vein traits are crucial for predicting plant ecological strategies under different environmental changes. However, correlations between these two suites of traits and abiotic factors such as soil water and nitrogen content remain ambiguous. We measured leaf economics and vein traits as well as soil water and nitrogen content for two different shade-tolerant species (Betula platyphylla and Acer mono) in four mixed broadleaved-Korean pine (Pinus koraiensis) forests along a latitudinal gradient in Northeast China. We found that leaf economics traits and vein traits were decoupled in shade-intolerant species, Betula platphylla, but significantly coupled in a shade-tolerant species, A. mono. We found stronger correlations among leaf traits in the shade tolerant species than in the shade intolerant species. Furthermore, leaf economic traits were positively correlated with the soil water gradient for both species, whereas vein traits were positively correlated with soil water gradient for the shade intolerant species but negatively correlated in the shade tolerant species. Although economic traits were positively correlated with soil nitrogen gradient in shade intolerant species but not correlated in shade tolerant species, vein traits were negatively correlated with soil nitrogen gradient in shade tolerant species but not correlated in shade intolerant species. Our study provides evidence for distinct correlations between leaf economics and vein traits and local abiotic factors of species differing in light demands. We recommend that the ecological significance of shade tolerance be considered for species when evaluating ecosystem functions and predicting plant responses to environmental changes.

Risk factors for loss to follow up of pelvis and acetabular fractures.

INTRODUCTION: Pelvic and acetabular fracture incidence is increasing worldwide for more than four decades. There is currently no evidence examining risk factors for loss to follow up in patients with these injuries. METHODS: Patients presenting with pelvic and/or acetabular fractures at our institution between 2015 and 2020 were included. Demographic, injury, treatment, and follow up information was included. Excluded patients were those who sustained a pathologic fracture, has a course of treatment prior to transfer to our centre, or expired prior to discharge. RESULTS: 446 patients, 263 with a pelvic ring injury, 172 with an acetabular fracture, and 11 with combined injuries were identified. 271 (61%) of patients in our cohort followed up in Orthopaedic clinic (p = 0.016). With an odds ratio of 2.134, gunshot wound mechanism of injury was the largest risk factor for loss to follow up (p = 0.031) followed by male sex (OR= 1.859) and surgery with general trauma surgery (OR=1.841). The most protective risk factors for follow up with Orthopaedic surgery were operatively treated pelvic and acetabular fractures (OR=0.239) and Orthopaedic Surgery as the discharging service (OR=0.372). DISCUSSION: Numerous risk factors exist for loss to follow up including male sex, ballistic mechanism, and discharging service. Investigation into interventions to improve follow up in these patients are warranted.

Differential impacts of adult trees on offspring and non-offspring recruits in a subtropical forest.

An important mechanism promoting species coexistence is conspecific negative density dependence (CNDD), which inhibits conspecific neighbors by accumulating host-specific enemies near adult trees. Natural enemies may be genotype-specific and regulate offspring dynamics more strongly than non-offspring, which is often neglected due to the difficulty in ascertaining genetic relatedness. Here, we investigated whether offspring and non-offspring of a dominant species, Castanopsis eyrei, suffered from different strength of CNDD based on parentage assignment in a subtropical forest. We found decreased recruitment efficiency (proxy of survival probability) of offspring compared with non-offspring near adult trees during the seedling-sapling transition, suggesting genotype-dependent interactions drive tree demographic dynamics. Furthermore, the genetic similarity between individuals of same cohort decreased in late life history stages, indicating genetic-relatedness-dependent tree mortality throughout ontogeny. Our results demonstrate that within-species genetic relatedness significantly affects the strength of CNDD, implying genotype-specific natural enemies may contribute to population dynamics in natural forests.

Determining the Impact of the COVID-19 Pandemic on Hand Surgery Fellowship Education.

The purpose of this study is to report the impact of COVID-19 on hand surgery fellow learning and preparedness for practice. A multi-dimensional questionnaire was distributed to current hand fellows and fellowship directors across the United States. Survey questions included fellowship location, institutional response, impact on practice, education and job search. Thirty-two hand surgery fellows and 14 fellowship directors completed the survey. Of fellows, 59% reported a greater than 75% decrease in case volume. Mean hours worked per week per fellow decreased by 52%. All fellowship directors and 94% of fellows did not expect COVID-19 to impact their ability to graduate, and nearly all fellows felt prepared to start practice after fellowship training. However, many fellows expressed concern about job opportunities. The work hours and exposure of hand surgery fellows to elective surgical cases have been adversely impacted by COVID-19. Nevertheless, current hand fellows feel prepared to enter practice. (Journal of Surgical Orthopaedic Advances 31(1):048-052, 2022).

Interannual climate variability has predominant effects on seedling survival in a temperate forest.

Mechanisms such as conspecific negative density dependence (CNDD) and niche partitioning have been proposed to explain species coexistence and community diversity. However, as a potentially important axis of niche partitioning, the role of interannual climate variability in driving local community dynamics remains largely unknown. Here we used a 15-year monitoring data set of more than 53,000 seedlings in a temperate forest to examine (1) what are the relative effects of interannual climate variability, biotic interactions, and habitat conditions on seedling survival; (2) how the effects of biotic interactions change with interannual climate variability, and habitat conditions; and (3) whether the impacts of interannual climate variability, biotic interactions, and habitat conditions differ with plant traits. Interannual climate variability accounted for the most variation in seedling survival at the community level, followed by biotic interactions, and habitat conditions. Increased snowpack and decreased minimum temperature during the non-growing season had positive effects on seedling survival. Effects of conspecific neighbor density were weakened in higher snowpack, effective accumulated temperature, elevation, and soil-resource gradient, but were intensified with increased ultraviolet radiation, maximum precipitation, minimum temperature, and soil moisture. In addition, the relative importance of interannual climate variability versus biotic interactions differed depending on species-trait groups. Specifically, biotic interactions for gravity-dispersed species had a larger effect size in affecting seedling survival than other trait groups. Also, gravity-dispersed species experienced a stronger CNDD than wind-dispersed, probably because wind-dispersed seedlings rarely had adult conspecifics nearby. We found that interannual climate variability was most strongly associated with seedling survival, but the magnitude of climatic effects varied among species-trait groups. Interannual climate variability may act as an inhibitor or accelerator to density-dependent interactions and should be accounted for in future studies, as both a potential direct and indirect factor in understanding the diversity of forest communities.

Demographic composition, not demographic diversity, predicts biomass and turnover across temperate and tropical forests.

The growth and survival of individual trees determine the physical structure of a forest with important consequences for forest function. However, given the diversity of tree species and forest biomes, quantifying the multitude of demographic strategies within and across forests and the way that they translate into forest structure and function remains a significant challenge. Here, we quantify the demographic rates of 1961 tree species from temperate and tropical forests and evaluate how demographic diversity (DD) and demographic composition (DC) differ across forests, and how these differences in demography relate to species richness, aboveground biomass (AGB), and carbon residence time. We find wide variation in DD and DC across forest plots, patterns that are not explained by species richness or climate variables alone. There is no evidence that DD has an effect on either AGB or carbon residence time. Rather, the DC of forests, specifically the relative abundance of large statured species, predicted both biomass and carbon residence time. Our results demonstrate the distinct DCs of globally distributed forests, reflecting biogeography, recent history, and current plot conditions. Linking the DC of forests to resilience or vulnerability to climate change, will improve the precision and accuracy of predictions of future forest composition, structure, and function.

Spine Surgery and COVID-19: The Influence of Practice Type on Preparedness, Response, and Economic Impact.

STUDY DESIGN: Cross-sectional observational cohort study. OBJECTIVE: To investigate preparation, response, and economic impact of COVID-19 on private, public, academic, and privademic spine surgeons. METHODS: AO Spine COVID-19 and Spine Surgeon Global Impact Survey includes domains on surgeon demographics, location of practice, type of practice, COVID-19 perceptions, institutional preparedness and response, personal and practice impact, and future perceptions. The survey was distributed by AO Spine via email to members (n = 3805). Univariate and multivariate analyses were performed to identify differences between practice settings. RESULTS: A total of 902 surgeons completed the survey. In all, 45.4% of respondents worked in an academic setting, 22.9% in privademics, 16.1% in private practice, and 15.6% in public hospitals. Academic practice setting was independently associated with performing elective and emergent spine surgeries at the time of survey distribution. A majority of surgeons reported a >75% decrease in case volume. Private practice and privademic surgeons reported losing income at a higher rate compared with academic or public surgeons. Practice setting was associated with personal protective equipment availability and economic issues as a source of stress. CONCLUSIONS: The current study indicates that practice setting affected both preparedness and response to COVID-19. Surgeons in private and privademic practices reported increased worry about the economic implications of the current crisis compared with surgeons in academic and public hospitals. COVID-19 decreased overall clinical productivity, revenue, and income. Government response to the current pandemic and preparation for future pandemics needs to be adaptable to surgeons in all practice settings.

Preoperative PROMIS Scores Predict Postoperative Outcomes in Lumbar Spine Surgery Patients.

STUDY DESIGN: Retrospective case series. OBJECTIVE: Our objective was to examine the ability of preoperative Patient-reported Outcomes Measurement Information System (PROMIS) scores to predict postoperative achievement of a minimum clinically important difference (MCID) in outcome scores following lumbar spine surgery. SUMMARY OF BACKGROUND DATA: PROMIS is a computer adaptive testing system that has been validated in spine surgery patients. PROMIS allows for more efficient and personalized data collection compared to legacy assessment tools. METHODS: A total of 138 patients who underwent lumbar spine surgery at a single institution completed PROMIS Physical Function (PF) and Pain Interference (PI) scores preoperatively and at 3, 12, and 24 months postoperatively. Univariate and multivariate analyses of PROMIS scores and clinical factors were performed. Receiver-operating characteristic curves were calculated to determine the ability of preoperative scores to predict postoperative achievement of an MCID of 8. PF and PI t score MCID achievement threshold values with 90% specificity were calculated. RESULTS: Preoperative PROMIS PF and PI scores were significantly correlated to achievement of postoperative MCID after multivariate analysis. Patients with worse preoperative scores were more likely to achieve MCID. Preoperative PF and PI scores showed strong predictive value in determining ability to achieve postoperative MCID with respective area under the curve of 0.85 and 0.82. A preoperative PF threshold T-score of 31.6 had a 64% chance of achieving postoperative MCID, while a preoperative PI threshold t score of 67.8 had an 86% chance of achieving postoperative MCID. CONCLUSION: Preoperative PROMIS PF and PI scores predicted improvement in postoperative PROMIS scores in lumbar spine surgery patients as worse preoperative scores correlated to improved PROMIS scores postoperatively. The calculated threshold t scores showed the ability to predict improvement in postoperative PROMIS scores. Preoperative PROMIS data may be useful in surgical decision-making and improved patient education regarding postoperative outcomes.Level of Evidence: 4.

Rate of USMLE Step 2 CK Scores Included on Orthopedic Surgery Applications and Associations With Step 1 Score.

Background At present, orthopedic surgery applicants do not universally include Step 2 Clinical Knowledge (Step 2 CK) scores on their applications and current inclusion rates are not yet reported. As Step 1 transitions to pass/fail scoring, we suspect more applicants will include Step 2 CK scores. We sought to identify what percentage of applications currently include Step 2 CK, if applicants who include Step 2 CK (Step 1+CK) score lower on Step 1 than those not including Step 2 CK (Step 1-CK), and what correlations exist between Step 1 and Step 2 CK scores among those who include the scores on their applications. Methodology Applicants to one residency program over two application cycles (2019-2020) were analyzed. The percentage including Step 1 and Step 2 scores was recorded. Step 1 scores were compared between Step 1+CK and Step 1-CK applicants. Differences between Step 2 CK and Step 1 scores were stratified by Step 1 score. Results A total of 1,688 applicants applied to our institution from 2019 to 2020. Of those reporting United States Medical Licensing Examination scores, 1,316/1,660 (79%) reported a Step 2 CK score. Step 1-CK applicants scored higher on Step 1 (250.7 ± 10.9) versus Step 1+CK applicants (244.3 ± 13.1) (p < 0.0001). More applicants who scored lower on Step 1 improved upon their percentile rank between Step 1 and Step 2 CK than those who scored higher on Step 1 (χ2 (8,1316) = 79.1, p < 0.0001). Conclusions From 2019 to 2020, 79% of applicants included Step 2 CK. Lower Step 1 scores were more likely to include Step 2 CK and improve upon their percentile score. It is unclear how Step 1 scoring change will affect current practice.