Larger stem to bone diameter ratio predicts lower cemented endoprosthesis failure

BACKGROUND AND OBJECTIVES

With continued advances in treatment options, patients with endoprosthetic reconstruction are living longer and consequently relying upon their devices for a longer duration. Major causes of endoprosthesis failure include aseptic loosening and mechanical failure. In the setting of tumor resection, loss of bone stock and use of radiation therapy increase the risk for these complications. As such, considerations of remaining native bone and stem length and diameter may be increasingly important. We asked the following questions: (1) What was the overall rate of endoprosthesis failure at a minimum of 5-year follow-up? (2) Does resection length increase implant failure rates? (3) Does implant size and its ratio to cortical width of bone alter implant failure rates?

METHODS

We retrospectively analyzed patient outcomes at a single institution between the years of 1999-2022 who underwent cemented endoprosthetic reconstruction at the hip or knee and identified 150 patients. Of these 150, 55 had a follow-up of greater than 5 years and were used for analysis. Radiographs of these patients at time of surgery were assessed and measured for resection length, bone diameter, stem diameter, and remaining bone length. Resection percentage, and stem to bone diameter ratios were then calculated and their relationship to endoprosthesis failure were analyzed.

RESULTS

Patients in this cohort had a mean age of 55.8, and mean follow-up of 59.96 months. There were 78 distal femoral replacements (52%), 16 proximal femoral replacements (10.7%), and 56 proximal tibial replacements (37.3%). There were five patients who experienced aseptic loosening and six patients who experienced mechanical failure. Patients with implant failure had a smaller mean stem to bone diameter (36% vs. 44%; p = 0.002). A stem to bone diameter of 40% appeared to be a breaking point between success and failure in this series, with 90% of patients with implant failure having a stem: bone ratio less than 40%. Stem to bone ratio less than 40% increased risk for failure versus stems that were at least 40% the diameter of bone (6/19 [31.6%] vs. 0/36 [0%]; odds ratio 0.68; p < 0.001). Resection length did not appear to have an impact on the rates of aseptic loosening and mechanical failure in this series.

CONCLUSIONS

Data from this series suggests a benefit to using stems with a larger diameter when implanting cemented endoprostheses at the hip or knee. Stems which were less than 40% the diameter of bone were substantially more likely to undergo implant failure.

Exploring novel HIV-1 reverse transcriptase inhibitors with drug-resistant mutants: A double mutant surprise

HIV-1 reverse transcriptase (RT) remains a key target for HIV drug development. As successful management of the disease requires lifelong treatment, the emergence of resistance mutations is inevitable, making development of new RT inhibitors, which remain effective against resistant variants crucial. To this end, previous computationally guided drug design efforts have resulted in catechol diether compounds, which inhibit wildtype RT with picomolar affinities and appear to be promising preclinical candidates. To confirm that these compounds remain potent against Y181C, a widespread mutation conferring resistance to first generation inhibitors, they were screened against the HIV-1 N119 clinical isolate, reported as a Y181C single mutant. In comparison to a molecular clone with the same mutation, N119 appears less susceptible to inhibition by our preclinical candidate compounds. A more detailed sequencing effort determined that N119 was misidentified and carries V106A in combination with Y181C. While both indolizine and naphthalene substituted catechol diethers are potent against the classical Y181C single mutant, the addition of V106A confers more resistance against the indolizine derivatives than the naphthalene derivatives. Crystal structures presented in this study highlight key features of the naphthyl group, which allow these compounds to remain potent in the double mutant, including stronger interactions with F227 and less reliance on V106 for stabilization of the ethoxy-uracil ring, which makes critical hydrogen bonds with other residues in the binding pocket.

The Effects of Long-term Molybdenum Exposure in Drinking Water on Molybdenum Metabolism and Production Performance of Beef Cattle Consuming a High Forage Diet

Fifty-four multiparous beef cows with calves were used to evaluate the effects of Mo source (feed or water) on reproduction, mineral status, and performance over two cow-calf production cycles (553 days). Cows were stratified by age, body weight, liver Cu, and Mo status and were then randomly assigned to one of six treatment groups. Treatments were (1) negative control (NC; basal diet with no supplemental Mo or Cu), (2) positive control (NC + Cu; 3 mg of supplemental Cu/kg DM), (3) NC + 500 µg Mo/L from Na2MoO4·2H2O supplied in drinking water, (4) NC + 1000 µg Mo/L of Na2MoO4·2H2O supplied in drinking water, (5) NC + Mo 1000-water + 3 mg of supplemental Cu/kg DM, and (6) NC + 3.0 mg of supplemental Mo/kg diet DM from Na2MoO4·2H2O. Animals were allowed ad libitum access to both harvested grass hay (DM basis: 6.6% crude protein; 0.15% S, 6.7 mg Cu/kg, 2.4 mg Mo/kg) and water throughout the experiment. Calves were weaned at approximately 6 months of age each year. Dietary Cu concentration below 10.0 mg Cu/kg DM total diet reduced liver and plasma Cu concentrations to values indicative of a marginal Cu deficiency in beef cows. However, no production parameters measured in this experiment were affected by treatment. Results suggest that Mo supplemented in water or feed at the concentrations used in this experiment had minimal impact on Cu status and overall performance.

Identifying Patients at Risk for Venous Thromboembolic Events After Isolated Upper Extremity Trauma: A Predictive Scale

Previous studies have defined risk factors for development of venous thromboembolisms (VTEs) among patients with lower extremity orthopedic trauma. Limited data exist on this risk after upper extremity orthopedic trauma. A total of 269,137 incidents of upper extremity orthopedic trauma (fractures of the clavicle, scapula, humerus, elbow, or lower arm) were identified in the State Inpatient Database for 4 states included in the analysis (California, Florida, New York, and Washington) from 2006 to 2014. These patients were split into 2 cohorts, a derivation cohort (California and New York) and a validation cohort (Florida and Washington). Univariate and multivariate logistic regression analyses of risk factors for VTE within 90 days of discharge in the derivation group were used to develop the Thromboembolic Risk after Upper Extremity Trauma (TRUE-T) scale. Linear regression was used to determine fit of the TRUE-T scale to the 2 cohorts. We found that 2.61% of patients in the derivation cohort and 2.72% of patients in the validation cohort had a VTE within 90 days of discharge. Risk factors associated with increased rates of VTE were age older than 40 years, Medicare payer, anemia, chronic lung disease, coagulopathy, heart failure, malignancy, obesity, renal failure, head injury, chest injury, abdominal injury, rib fracture, humerus fracture, elbow fracture, and closed reduction. Application of the TRUE-T scale to the validation cohort showed an R² value of 0.88. The patient factors, concomitant injuries, and fracture treatment modalities included in the TRUE-T scale can be used to identify patients at increased risk for VTE after upper extremity orthopedic trauma. [Orthopedics. 2022;45(6):345-352.].

The relative citation ratio (RCR) as a novel bibliometric among 2511 academic orthopedic surgeons

Objectively measuring research output is important for grant awards, promotion, and tenure, or self-evaluation of productivity. However, certain shortcomings limit common bibliometric indicators. The time- and field-independent relative citation ratio (RCR) was proposed to overcome these limitations. The objective of this study was to determine whether the RCR correlates with academic rank, gender, and PhD degree status among US academic orthopedic surgeons. Full-time faculty surgeons at Accreditation Council for Graduate Medical Education-accredited orthopedic surgery residency programs were included in this study. Mean (mRCR) and weighted (wRCR) RCR scores were collected from the National Institutes of Health iCite database to quantify scholarly "impact" and "production," respectively, and were compared by academic rank, gender, and PhD status. All information was collected from publicly available faculty listings on departmental websites. A total of 2511 orthopedic surgeons from 132 residency programs were assessed. Overall, the median (interquartile range) mRCR score was 1.56 (1.05-2.12) and the median wRCR score was 27.6 (6.97-88.44). Both metrics increased with each successive academic rank, except for department chairs. There was no difference in mRCR between male and female surgeons. Among assistant professors, males had higher wRCR scores. Both metrics were higher among surgeons with a PhD degree. The RCR offers key advantages over other indices, which are reflected in differences in score distributions compared with the widely used h-index. Nevertheless, implementation of the RCR should be preceded with careful consideration of its own limitations.

Covalent Modification of the JH2 Domain of Janus Kinase 2

Probe molecules that covalently modify the JAK2 pseudokinase domain (JH2) are reported. Selective targeting of JH2 domains over the kinase (JH1) domains is a necessary feature for ligands intended to evaluate JH2 domains as therapeutic targets. The JH2 domains of three Janus kinases (JAK1, JAK2, and TYK2) possess a cysteine residue in the catalytic loop that does not occur in their JH1 domains. Starting from a non-selective kinase binding molecule, computer-aided design directed attachment of substituents terminating in acrylamide warheads to modify Cys675 of JAK2 JH2. Successful covalent attachment was demonstrated first through observation of enhanced binding with increasing incubation time in fluorescence polarization experiments. Covalent binding also increased selectivity to as much as ca. 30-fold for binding the JAK2 JH2 domain over the JH1 domain after a 20-h incubation. Covalency was confirmed through HPLC electrospray quadrupole time-of-flight HRMS experiments, which revealed the expected mass shifts.

Synergistic effects of robotic surgery and IPACK nerve block on reduction of opioid consumption in total knee arthroplasty

Background

There are numerous strategies to combat postoperative analgesia and expedite recovery after total knee arthroplasty (TKA). The purpose of this study was to determine opioid consumption, length of stay, and functional outcomes after robotic versus standard TKA in the setting of various regional pain modalities.

Methods

A consecutive series of patients treated with unilateral primary robotic or standard TKA from January 2018-February 2021 were retrospectively identified. Regional pain modalities included peri-articular injection (PAI), adductor canal block (ACB), and infiltration between popliteal artery and capsule of knee (IPACK). Patient demographics, operative/perioperative variables, and postoperative function were recorded. Daily opiate consumption was calculated as morphine milligram equivalents (MME). Multivariate regression was performed to control for age, sex, and race.

Results

After review, 283 patients (177 Females; 106 Males) were included. Robotic TKA patients received IPACK + ACB (36), while standard TKA patients received either ACB (45), IPACK + ACB (167), or PAI (35). Daily inpatient opioid consumption in the standard IPACK + ACB (p = 0.02) and robotic IPACK + ACB groups (p = 0.0001) was significantly lower compared to standard ACB. When combined with IPACK block, robotic procedures synergistically lowered opiate consumption (p = 0.004) compared to standard procedures and led to earlier discharge (p = 0.003). The robotic IPACK + ACB cohort also demonstrated improved early ambulation compared to standard ACB, (p = 0.05), whereas the same benefit was not seen for patients who received IPACK during standard TKA.

Conclusions

The utilization of IPACK block decreases inpatient postoperative opioid requirements following TKA. Robotic TKA and IPACK block appeared to have a synergistic effect on opioid consumption and postoperative recovery.

Insights on JAK2 Modulation by Potent, Selective, and Cell-Permeable Pseudokinase-Domain Ligands

JAK2 is a non-receptor tyrosine kinase that regulates hematopoiesis through the JAK-STAT pathway. The pseudokinase domain (JH2) is an important regulator of the activity of the kinase domain (JH1). V617F mutation in JH2 has been associated with the pathogenesis of various myeloproliferative neoplasms, but JAK2 JH2 has been poorly explored as a pharmacological target. In light of this, we aimed to develop JAK2 JH2 binders that could selectively target JH2 over JH1 and test their capacity to modulate JAK2 activity in cells. Toward this goal, we optimized a diaminotriazole lead compound into potent, selective, and cell-permeable JH2 binders leveraging computational design, synthesis, binding affinity measurements for the JH1, JH2 WT, and JH2 V617F domains, permeability measurements, crystallography, and cell assays. Optimized diaminotriazoles are capable of inhibiting STAT5 phosphorylation in both WT and V617F JAK2 in cells.

Conversion of a False Virtual Screen Hit into Selective JAK2 JH2 Domain Binders Using Convergent Design Strategies

The Janus kinase 2 (JAK2) pseudokinase domain (JH2) is an ATP-binding domain that regulates the activity of the catalytic tyrosine kinase domain (JH1). Dysregulation of JAK2 JH1 signaling caused by the V617F mutation in JH2 is implicated in various myeloproliferative neoplasms. To explore if JAK2 activity can be modulated by a small molecule binding to the ATP site in JH2, we have developed several ligand series aimed at selectively targeting the JAK2 JH2 domain. We report here the evolution of a false virtual screen hit into a new JAK2 JH2 series. Optimization guided by computational modeling has yielded analogues with nanomolar affinity for the JAK2 JH2 domain and >100-fold selectivity for the JH2 domain over the JH1 domain. A crystal structure for one of the potent compounds bound to JAK2 JH2 clarifies the origins of the strong binding and selectivity. The compounds expand the platform for seeking molecules to regulate JAK2 signaling, including V617F JAK2 hyperactivation.

Cemented-augmented fixation of metastatic humeral lesions without segmental bone loss results in reliable outcomes

Background

Treatment of metastatic lesions to the humerus is dependent on patient's pain, lesion size and location, and post-operative functional goals. Surgical options include plate or nail fixation [open reduction internal fixation (ORIF)], or endoprosthetic replacement (EPR), with cement augmentation. The objective of this study was to perform a single institution retrospective analysis of outcomes by method of reconstruction, tumor volume, and pathologic diagnosis.

Methods

The records of 229 consecutive patients treated surgically for appendicular metastatic disease from 2005-2018 at our musculoskeletal oncology center were retrospectively reviewed following institutional review board (IRB) approval. Indications for surgical treatment at the humerus included patients who presented with impending and displaced pathologic fractures.

Results

Sixty patients (34 male, 26 female) with a mean age of 62.9±12.2 were identified who were treated surgically at the proximal (n=21), diaphyseal (n=29), or distal (n=10) humerus. Forty-nine (82%) patients presented with displaced pathologic fractures. The remaining eleven patients had a mean Mirels score of 9.5. There was no difference in overall complication rate between EPR or ORIF [4/36 (11%) versus 2/24 (8%); P=0.725]. Mean Musculoskeletal Tumor Society (MSTS) scores were 83% for both EPR and ORIF, with no differences in subgroup analyses at the proximal, diaphyseal, or distal humerus. Patients with cortical destruction on anterior posterior (AP) and lateral imaging were at increased risk for mechanical failure [2/6 (33%) versus 0/18 (0%), P=0.015].

Conclusions

In conclusion, when pathologic pattern permits, cement-augmented fixation allows for stabilization of pathologic bone, while minimizing risk of soft-tissue detachment, while EPR resulted in similar outcomes in patients with more extensive bone destruction. Increased tumor volume was associated with lower MSTS scores.

Structural Studies and Structure Activity Relationships for Novel Computationally Designed Non-nucleoside Inhibitors and Their Interactions With HIV-1 Reverse Transcriptase

Reverse transcriptase (RT) from the human immunodeficiency virus continues to be an attractive drug target for antiretroviral therapy. June 2022 will commemorate the 30th anniversary of the first Human Immunodeficiency Virus (HIV) RT crystal structure complex that was solved with non-nucleoside reverse transcriptase inhibitor nevirapine. The release of this structure opened opportunities for designing many families of non-nucleoside reverse transcriptase inhibitors (NNRTIs). In paying tribute to the first RT-nevirapine structure, we have developed several compound classes targeting the non-nucleoside inhibitor binding pocket of HIV RT. Extensive analysis of crystal structures of RT in complex with the compounds informed iterations of structure-based drug design. Structures of seven additional complexes were determined and analyzed to summarize key interactions with residues in the non-nucleoside inhibitor binding pocket (NNIBP) of RT. Additional insights comparing structures with antiviral data and results from molecular dynamics simulations elucidate key interactions and dynamics between the nucleotide and non-nucleoside binding sites.

Detection of Elder Abuse Among Orthopedic Patients

Approximately 10% of US adults experience elder abuse, which often manifests as musculoskeletal and soft tissue injuries. The goal of our study was to determine the rate of elder abuse among orthopedic surgery patients and characterize which patients may be at an increased risk. National Inpatient Sample Healthcare Cost and Utilization Project data from 2001 to 2015 were parsed with the Clinical Classifications Software tool. Patients 60 years and older were identified by International Classification of Diseases, Ninth Revision (ICD-9), code for elder abuse. Primary orthopedic procedures and subsequent inpatient diagnoses and comorbidities were used to develop a binary logistic regression model to predict an elder's risk of abuse. Of a total of 20,532,211 admissions for an orthopedic procedure, 0.010% (2084) were classified as elder abuse. Patients with a classification of abuse more commonly were women (74.8% vs 60.6%) and from the lowest socioeconomic quartile by income (28.5% vs 21.7%). In addition, these patients had hospital stays that were twice as long (10.2 vs 5.3 days) and had higher admission mortality rates (4.4% vs 1.2%). No primary orthopedic procedures were associated with a higher risk of elder abuse. Nonorthopedic diagnoses made during admission that were associated with increased risk of abuse included superficial injury or contusion (odds ratio [OR], 3.252), chronic skin ulcer (OR, 3.119), nutritional deficiency (OR, 3.418), fluid and electrolyte disturbances (OR, 1.729), and delirium or dementia (OR, 2.210). The incidence of elder abuse among orthopedic surgery patients is significantly lower than national estimates. This finding warrants further investigation to determine whether it is a function of underreporting or differences in patient populations, given the 4-fold increase in mortality risk. [Orthopedics. 2022;45(1):50-56.].

Optimization of Triarylpyridinone Inhibitors of the Main Protease of SARS-CoV-2 to Low-Nanomolar Antiviral Potency

Non-covalent inhibitors of the main protease (Mpro) of SARS-CoV-2 having a pyridinone core were previously reported with IC50 values as low as 0.018 μM for inhibition of enzymatic activity and EC50 values as low as 0.8 μM for inhibition of viral replication in Vero E6 cells. The series has now been further advanced by consideration of placement of substituted five-membered-ring heterocycles in the S4 pocket of Mpro and N-methylation of a uracil ring. Free energy perturbation calculations provided guidance on the choice of the heterocycles, and protein crystallography confirmed the desired S4 placement. Here we report inhibitors with EC50 values as low as 0.080 μM, while remdesivir yields values of 0.5-2 μM in side-by-side testing with infectious SARS-CoV-2. A key factor in the improvement is enhanced cell permeability, as reflected in PAMPA measurements. Compounds 19 and 21 are particularly promising as potential therapies for COVID-19, featuring IC50 values of 0.044-0.061 μM, EC50 values of ca. 0.1 μM, good aqueous solubility, and no cytotoxicity.

Structure-guided design of a perampanel-derived pharmacophore targeting the SARS-CoV-2 main protease

There is a clinical need for direct-acting antivirals targeting SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic, to complement current therapeutic strategies. The main protease (Mpro) is an attractive target for antiviral therapy. However, the vast majority of protease inhibitors described thus far are peptidomimetic and bind to the active-site cysteine via a covalent adduct, which is generally pharmacokinetically unfavorable. We have reported the optimization of an existing FDA-approved chemical scaffold, perampanel, to bind to and inhibit Mpro noncovalently with IC50s in the low-nanomolar range and EC50s in the low-micromolar range. Here, we present nine crystal structures of Mpro bound to a series of perampanel analogs, providing detailed structural insights into their mechanism of action and structure-activity relationship. These insights further reveal strategies for pursuing rational inhibitor design efforts in the context of considerable active-site flexibility and potential resistance mechanisms.

Potent Noncovalent Inhibitors of the Main Protease of SARS-CoV-2 from Molecular Sculpting of the Drug Perampanel Guided by Free Energy Perturbation Calculations

Starting from our previous finding of 14 known drugs as inhibitors of the main protease (Mpro) of SARS-CoV-2, the virus responsible for COVID-19, we have redesigned the weak hit perampanel to yield multiple noncovalent, nonpeptidic inhibitors with ca. 20 nM IC50 values in a kinetic assay. Free-energy perturbation (FEP) calculations for Mpro-ligand complexes provided valuable guidance on beneficial modifications that rapidly delivered the potent analogues. The design efforts were confirmed and augmented by determination of high-resolution X-ray crystal structures for five analogues bound to Mpro. Results of cell-based antiviral assays further demonstrated the potential of the compounds for treatment of COVID-19. In addition to the possible therapeutic significance, the work clearly demonstrates the power of computational chemistry for drug discovery, especially FEP-guided lead optimization.

Covalent Inhibition of Wild-Type HIV-1 Reverse Transcriptase Using a Fluorosulfate Warhead

Covalent inhibitors of wild-type HIV-1 reverse transcriptase (CRTIs) are reported. Three compounds derived from catechol diether non-nucleoside inhibitors (NNRTIs) with addition of a fluorosulfate warhead are demonstrated to covalently modify Tyr181 of HIV-RT. X-ray crystal structures for complexes of the CRTIs with the enzyme are provided, which fully demonstrate the covalent attachment, and confirmation is provided by appropriate mass shifts in ESI-TOF mass spectra. The three CRTIs and six noncovalent analogues are found to be potent inhibitors with both IC₅₀ values for in vitro inhibition of WT RT and EC₅₀ values for cytopathic protection of HIV-1-infected human T-cells in the 5-320 nM range.

Evaluating the Readability of Online Patient Education Materials Related to Orthopedic Oncology

The internet is increasingly used to access patient education materials. The average American reading level has been found to be that of a 7th- to 8th-grade student, prompting the National Institutes of Health (NIH) and the American Medical Association (AMA) to advise that patient education materials be written between the 4th- to 6th-grade reading level. The purpose of this study was to evaluate the reading level of current patient education materials for the most common musculoskeletal oncological tumors. A Google search was performed with all location filters off to account for geographic variability for patient education materials related to 28 orthopedic primary or secondary tumors. All patient education articles from the first 10 website hits for each tumor type were analyzed. Patient education materials from these websites were evaluated using 8 validated readability scales. Patient resources were found to be written at an average grade level nearly double the NIH and AMA recommendation. Patient education materials for soft tissue chondromas were written at the highest level (14.8±1.9), whereas education materials for chordomas (10.1±1.0) most closely approached national recommendations, despite still being written at a readability level nearly 4 grade levels higher than has been recommended. The Flesch Reading Ease assessment provided a mean score of 46.5±7.7, corresponding with a "difficult to read" result. Current patient education materials regarding oncological musculoskeletal-related patient education materials are written significantly above the recommended reading level. Further modification of these resources is warranted to ensure adequate comprehension and informed decision making in the clinical setting. [Orthopedics. 2021;44(1):38-42.].

Identification of 14 Known Drugs as Inhibitors of the Main Protease of SARS-CoV-2

A consensus virtual screening protocol has been applied to ca. 2000 approved drugs to seek inhibitors of the main protease (M^pro) of SARS-CoV-2, the virus responsible for COVID-19. 42 drugs emerged as top candidates, and after visual analyses of the predicted structures of their complexes with M^pro, 17 were chosen for evaluation in a kinetic assay for M^pro inhibition. Remarkably 14 of the compounds at 100-μM concentration were found to reduce the enzymatic activity and 5 provided IC₅₀ values below 40 μM: manidipine (4.8 μM), boceprevir (5.4 μM), lercanidipine (16.2 μM), bedaquiline (18.7 μM), and efonidipine (38.5 μM). Structural analyses reveal a common cloverleaf pattern for the binding of the active compounds to the P1, P1′, and P2 pockets of M^pro. Further study of the most active compounds in the context of COVID-19 therapy is warranted, while all of the active compounds may provide a foundation for lead optimization to deliver valuable chemotherapeutics to combat the pandemic.

An Analysis of Trends in National Residency Matching Program Match Data for Orthopedic Surgery

Due to electronic residency applications, US Medical Licensing Examination Step 1 scores are frequently used by orthopedic surgery program directors to screen applicants. Prospective applicants therefore often use Step 1 scores as a proxy for specialty competitiveness. The goal of this investigation was two-fold: (1) to determine whether trends in Step 1 scores are indicative of trends in competitiveness of orthopedic surgery and (2) to report the characteristics that optimize a US medical student's match success. A retrospective review of published National Resident Matching Program data from 2009 to 2018 was performed for orthopedic surgery residency applicants. Additional data from the Charting Outcomes reports were used for specific analyses of applicant characteristics. From 2009 to 2018, the number of orthopedic surgery residency positions grew at an annual rate of 1.51% (95% confidence interval [CI], 1.37% to 1.64%; P<.001), accommodating the 1.26% (95% CI, 0.63% to 1.90%; P=.006) annual increase in the number of applicants who ranked orthopedic surgery as their preferred specialty choice (only choice or first choice). There were no significant changes in the applicant-to-position ratio (95% CI, -0.85% to 0.37%; P=.483) or the match rate for US seniors who ranked orthopedic surgery as their preferred choice (95% CI, -0.23% to 0.87%; P=.313). Increases in mean Step 1 scores of matched orthopedic surgery applicants parallel national Step 1 growth trends (0.49% vs 0.44%, respectively). Although orthopedic surgery is currently a competitive specialty to match into, this has been the case since 2009. Increasing Step 1 scores of matched applicants is not unique to orthopedic surgery and should not be misinterpreted as a proxy for increasing competitiveness of the specialty. [Orthopedics. 2020;43(6):e616-e622.].

Identification of 14 Known Drugs as Inhibitors of the Main Protease of SARS-CoV-2

A consensus virtual screening protocol has been applied to ca. 2000 approved drugs to seek inhibitors of the main protease (M ^pro ) of SARS-CoV-2, the virus responsible for COVID-19. 42 drugs emerged as top candidates, and after visual analyses of the predicted structures of their complexes with M ^pro , 17 were chosen for evaluation in a kinetic assay for M ^pro inhibition. Remarkably 14 of the compounds at 100-μM concentration were found to reduce the enzymatic activity and 5 provided IC ₅₀ values below 40 μM: manidipine (4.8 μM), boceprevir (5.4 μM), lercanidipine (16.2 μM), bedaquiline (18.7 μM), and efonidipine (38.5 μM). Structural analyses reveal a common cloverleaf pattern for the binding of the active compounds to the P1, P1', and P2 pockets of M ^pro . Further study of the most active compounds in the context of COVID-19 therapy is warranted, while all of the active compounds may provide a foundation for lead optimization to deliver valuable chemotherapeutics to combat the pandemic.

Structural investigation of 2-naphthyl phenyl ether inhibitors bound to WT and Y181C reverse transcriptase highlights key features of the NNRTI binding site

Human immunodeficiency virus (HIV)-1 remains as a global health issue that is primarily treated with highly active antiretroviral therapy, a combination of drugs that target the viral life cycle. One class of these drugs are non-nucleoside reverse transcriptase inhibitors (NNRTIs) that target the viral reverse transcriptase (RT). First generation NNRTIs were troubled with poor pharmacological properties and drug resistance, incentivizing the development of improved compounds. One class of developed compounds are the 2-naphthyl phenyl ethers, showing promising efficacy against the Y181C RT mutation. Further biochemical and structural work demonstrated differences in potency against the Y181C mutation and binding mode of the compounds. This work aims to understand the relationship between the binding mode and ability to overcome drug resistance using macromolecular x-ray crystallography. Comparison of 2-naphthyl phenyl ethers bound to Y181C RT reveal that compounds that interact with the invariant W229 are more capable of retaining efficacy against the resistance mutation. Additional modifications to these compounds at the 4-position, computationally designed to compensate for the Y181C mutation, do not demonstrate improved potency. Ultimately, we highlight important considerations for the development of future HIV-1 drugs that are able to combat drug resistance.

Reconstruction with Custom Unicondylar Hemiarthroplasty following Tumor Resection: A Case Series and Review of the Literature

For patients with tumors of the distal femur, options for limb salvage include tumor resection followed by reconstruction. While reconstruction commonly involves a distal femoral replacement, careful selection of patients with tumor involvement limited to a single condyle may be candidates for reconstruction with distal femur hemiarthroplasty. In these procedures, resection spares considerably more native anatomy. Three consecutive patients who underwent resection and reconstruction at the distal femur with custom unicondylar hemiarthroplasty are presented in this case series at a mean follow-up of 45 months (range, 26-78). In two cases, prostheses were utilized as a secondary procedure after failure of initial reconstruction. In one case, the custom prosthesis was utilized as the primary method of reconstruction. Mean Musculoskeletal Tumor Society disease-specific scores were 26.7 (range, 25-28). All patients achieved a return to full weight bearing, activities of daily living, and functional range of motion. In appropriately selected patients with tumors of the distal femur, reconstruction with custom unicondylar hemiarthroplasty provides benefits including optimal function postoperatively via preservation of tumor-free bone and ligamentous structures. Additionally, maintenance of greater bone stock may confer benefits to patients with pathology at a high likelihood for recurrence and need for subsequent procedures.

Nonsurgical Treatment of De Quervain Tenosynovitis: A Prospective Randomized Trial

Background: De Quervain tenosynovitis is commonly seen in patients who perform repetitive wrist ulnar deviation with thumb abduction and extension. Previous studies comparing nonsurgical options have contributed to a lack of consensus about ideal management. This study's purpose was to analyze results in prospectively randomized patients treated with either corticosteroid injection (CSI) alone versus CSI with immobilization. Methods: Radial sided wrist pain, first dorsal compartment tenderness, and positive Finkelstein test were used to define De Quervain. Pain score of 4 or higher on a visual analog scale (VAS) was utilized for inclusion. Following exclusion criteria, patients underwent randomization into groups: (1) CSI alone; or (2) CSI with 3 weeks of immobilization. We followed at 3 weeks and 6 months for further evaluation, where resolution of symptoms and improvements in VAS and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were assessed to evaluate treatment success. Results: Nine patients with CSI alone and 11 patients with CSI and immobilization were followed. At 6 months in both groups, patients experienced significant improvement in VAS and DASH scores, while 88% of patients with CSI alone and 73% of patients with CSI and immobilization experienced complete resolution of at least 2 out of 3 of their pretreatment symptoms. Between groups, outcomes were comparable except for resolution of radial-sided wrist pain, which was superior in patients with CSI alone (100% vs 64%). Conclusions: Immobilization following injection increases costs, may hinder activities of daily living, and did not contribute to improved patient outcomes in this study. Further prospective studies are warranted.

Physiologic widening of the medial clear space: What's normal?

BACKGROUND

Literature has validated the use of stress radiographs for evaluation of ankle stability. However, to our knowledge no study has reported the amount of physiological widening that occurs with manual external rotation stress test in uninjured ankles. The purpose of this study was to assess the amount of medial clear space widening that occurs with a manual external rotation stress test in uninjured ankles.

METHODS

A cohort of adult patients undergoing operative fixation of unstable ankle fractures were prospectively enrolled to have their contralateral ankle undergo manual external rotation stress examination. Fluoroscopic images of the unaffected ankle were performed in the OR. A non-stressed mortise view and manual external rotation stress view were obtained with a standardized marker to correct for magnification differences. The images were de-identified, presented in a randomized order and reviewers who were blinded. Each reviewer measured the medial clear space.

RESULTS

Thirty fluoroscopic images on fifteen patients were obtained. The mean medial clear space on the non-stressed mortise view was 3.1 mm (SD-0.69; Range 1.9 to 4.2, 95% CI [2.75, 3.45]) versus a mean of 3.2 mm (SD-0.71; Range 2.0 to 4.7, 95% CI [2.94, 3.66]) in the stressed mortise view group. Inter-rater reliability was excellent between all observers for medial clear space (ICC-0.88; CI [0.78, 0.94]).

CONCLUSIONS

Our results support the previous literature and allow us to advocate for ankle fractures with >5 mm medial clear space after external rotational stress to be considered unstable. Additionally, ankles with a medial clear space between 4 and 5 mm, instability should be considered only if lateral shift is > 2 mm on stress examination. Our data shows that no physiologically healthy ankles widened beyond these established cut-offs before or after the manual external rotation stress.

The Effect of Sex on Orthopaedic Surgeon Income

BACKGROUND

Several studies have identified discrepancies in salary between male and female surgeons. Our aim was to investigate the impact of sex on an orthopaedic surgeon's yearly earnings by evaluating stratified income and specialty data from a large sample survey of orthopaedic surgeons.

METHODS

Self-reported data were obtained from the 2014 and 2008 American Academy of Orthopaedic Surgeons (AAOS) biennial censuses. Responses were received from 6,805 (24.26%) of those who were surveyed. The census form is a 19-question survey that includes information regarding work status (full time versus part time), sex, years in practice, practice type (private versus academic), specialty, hours worked, case volume, and income. The main outcome evaluated was self-reported income, and a multivariate regression model was used to control for confounding variables.

RESULTS

Male surgeons reported higher incomes than female colleagues working equivalent hours ($802,474 versus $560,618; p = 0.016); however, male surgeons reported a greater case volume for the same number of hours. Among surgeons who performed ≥26 procedures per month, male and female surgeons reported comparable incomes ($949,508 versus $872,903; p = 0.649). Incomes of those in practice for >20 years also were comparable. Regression analysis controlling for subspecialty choice, hours worked, work status, case volume, years in practice, and practice setting revealed that income was $62,032.51 less for women than men (p < 0.001).

CONCLUSIONS

Income disparity between male and female orthopaedic surgeons remains significant, and the gap increased from 2008 to 2014. Although subspecialty choice, practice setting, years in practice, and amount and distribution of procedures performed can partially explain salary differences, our regression analysis suggests persistence of an income gap based on sex in orthopaedic surgery.

Biochar reduces the efficiency of nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) mitigating N2O emissions

Among strategies suggested to decrease agricultural soil N₂O losses, the use of nitrification inhibitors such as DMPP (3,4-dimethylpyrazole phosphate) has been proposed. However, the efficiency of DMPP might be affected by soil amendments, such as biochar, which has been shown to reduce N₂O emissions. This study evaluated the synergic effect of a woody biochar applied with DMPP on soil N₂O emissions. A incubation study was conducted with a silt loam soil and a biochar obtained from Pinus taeda at 500 °C. Two biochar rates (0 and 2% (w/w)) and three different nitrogen treatments (unfertilized, fertilized and fertilized + DMPP) were assayed under two contrasting soil water content levels (40% and 80% of water filled pore space (WFPS)) over a 163 day incubation period. Results showed that DMPP reduced N₂O emissions by reducing ammonia-oxidizing bacteria (AOB) populations and promoting the last step of denitrification (measured by the ratio nosZI + nosZII/nirS + nirK genes). Biochar mitigated N₂O emissions only at 40% WFPS due to a reduction in AOB population. However, when DMPP was applied to the biochar amended soil, a counteracting effect was observed, since the N₂O mitigation induced by DMPP was lower than in control soil, demonstrating that this biochar diminishes the efficiency of the DMPP both at low and high soil water contents.

Dealing with the loss of a resident: An analysis of burnout rates in a reduced complement training program

BACKGROUND

Residents in all fields of medicine experience high levels of burnout and less job-related satisfaction due to the stress experienced during training. Reduced complement residency classes often experience increased workloads due to the need to compensate for the fewer number of classmates.

OBJECTIVE

The goal of this study was to examine whether residency classes of reduced size experience higher levels of burnout.

METHODS

The Maslach Burnout Inventory Survey was distributed to all orthopaedic residents at our institution for four consecutive years. Emotional exhaustion≥27 and depersonalization≥10 correlate with high levels of burnout. At our institution, two residents were lost during their second year of training. Group 1 (n = 56) consisted of residents with reduced-size classes, while group 2 (n = 60) consisted of residents with full complement classes.

RESULTS

Mean emotional exhaustion (29 vs. 30) and depersonalization (17 vs. 17) scores were comparable between reduced and full complement classes. The Maslach data from our study showed no statistical difference in burnout levels between classes of full complement and reduced complement.

CONCLUSIONS

When compared to a previous study on burnout conducted in large orthopaedic residency programs, our entire residency program did demonstrate similar levels of emotional exhaustion and depersonalization.

Surgical Reconstruction of the Acetabulum and Pelvis in Metastatic Bone Disease

Management of a painful metastatic acetabular lesion is complex and requires the assessment of tumor size and location, remaining integrity of the acetabulum, analgesic requirements, ability to use postoperative radiation, and projected patient survival. Patients presenting with suspected periacetabular metastasis frequently have groin pain aggravated by weight bearing. After a complete physical examination, advanced imaging and a complete laboratory workup should be performed to assess the extent of local and systemic disease. If a patient has a previously identified metastatic lesion, it is beneficial to communicate with the patient's medical oncologist to gather information on responses to chemotherapeutic agents, hormonal agents, and radiation therapy. Management may be nonsurgical, interventional, or surgical. Despite the limited life expectancy of patients with periacetabular metastasis, when performed in the appropriate setting, reconstruction by using anti-protrusio cages, screws, and cemented hip arthroplasty can improve quality of life by aiding independent ambulation and decreasing pain.

Complications following allograft reconstruction for primary bone tumors: Considerations for management

Introduction

The aim of this study was to investigate complication rates and types following allograft reconstruction and discuss unique considerations for management.

Methods

Seventy-four consecutive patients underwent large segment allograft reconstruction following resection of primary musculoskeletal tumors from 1991 to 2016. Mean patient age was 32 ± 20 years (range, 5-71 years). Minimum follow-up was 2 years unless patients were lost to disease prior. Mean follow-up was 105 months.

Results

Thirty-five patients had complications requiring subsequent surgery at a mean of 30 months (range, 1-146 months) post-operatively. Individual complication rates were 29%, 50%, and 42% for Allograft Prosthetic Composite, Intercalary, and Osteoarticular allograft reconstruction, respectively. Risk factors for complication included age less than 30 (OR 4.5; p = 0.002), male gender (OR 2.8; p = 0.031), chemotherapy (OR 4.4; p = 0.003), lower extremity disease (OR 3.4; p = 0.025). In patients with complications, limb-retention rate was 91% and mean MSTS scores were 23.6.

Conclusion

Despite considerable complication rates, management with a systematic approach results in successful outcomes with limb-retention greater than 90% and mean MSTS scores of 79%. In carefully selected patients, allografts provide a reliable method of reconstruction with treatable complications occurring at a mean of 30 months.

Evaluation of the Content and Accessibility of Web Sites for Accredited Orthopaedic Trauma Surgery Fellowships

BACKGROUND

Orthopaedic trauma fellowship applicants use online-based resources when researching information on potential U.S. fellowship programs. The 2 primary sources for identifying programs are the Orthopaedic Trauma Association (OTA) database and the San Francisco Match (SF Match) database. Previous studies in other orthopaedic subspecialty areas have demonstrated considerable discrepancies among fellowship programs. The purpose of this study was to analyze content and availability of information on orthopaedic trauma surgery fellowship web sites.

METHODS

The online databases of the OTA and SF Match were reviewed to determine the availability of embedded program links or external links for the included programs. Thereafter, a Google search was performed for each program individually by typing the program's name, followed by the term "orthopaedic trauma fellowship." All identified fellowship web sites were analyzed for accessibility and content. Web sites were evaluated for comprehensiveness in mentioning key components of the orthopaedic trauma surgery curriculum. By consensus, we refined the final list of variables utilizing the methodology of previous studies on the topic.

RESULTS

We identified 54 OTA-accredited fellowship programs, offering 87 positions. The majority (94%) of programs had web sites accessible through a Google search. Of the 51 web sites found, all (100%) described their program. Most commonly, hospital affiliation (88%), operative experiences (76%), and rotation overview (65%) were listed, and, least commonly, interview dates (6%), selection criteria (16%), on-call requirements (20%), and fellow evaluation criteria (20%) were listed. Programs with ≥2 fellows provided more information with regard to education content (p = 0.0001) and recruitment content (p = 0.013). Programs with Accreditation Council for Graduate Medical Education (ACGME) accreditation status also provided greater information with regard to education content (odds ratio, 4.0; p = 0.0001). Otherwise, no differences were seen by region, residency affiliation, medical school affiliation, or hospital affiliation.

CONCLUSIONS

The SF Match and OTA databases provide few direct links to fellowship web sites. Individual program web sites do not effectively and completely convey information about the programs. The Internet is an underused resource for fellow recruitment. The lack of information on these sites allows for future opportunity to optimize this resource.

A Preoperative Scale for Determining Surgical Readmission Risk After Total Knee Arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) is one of the most common orthopaedic procedures performed in the U.S. The purpose of this study was to develop and verify a scale to preoperatively stratify a patient's risk of being readmitted to the hospital following a TKA.

METHODS

Discharge data on 433,638 patients from New York and California (derivation cohort) and 269,934 patients from Florida and Washington (validation cohort) who underwent TKA were collected from the State Inpatient Database, a part of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality (2006 to 2011). Demographic and clinical characteristics of patients were abstracted and analyzed to develop the Readmission After Total Knee Arthroplasty (RATKA) Scale.

RESULTS

Overall 30-day readmission rates in the derivation and validation cohorts were 5.11% and 4.98%, respectively. The following factors were significantly associated with increased 30-day readmission rates in the derivation cohort: age of 41 to 50 years (odds ratio [OR] = 1.13), age of 71 to 80 years (OR = 1.21), age of 81 to 90 years (OR = 1.70), male sex (OR = 1.19), African-American race (OR = 1.37), "other" race/ethnicity (OR = 1.08), Medicaid payer (OR = 1.43), Medicare payer (OR = 1.27), anemia (OR = 1.19), chronic obstructive pulmonary disease (OR = 1.29), coagulopathy (OR = 1.22), congestive heart failure (OR = 1.64), diabetes (OR = 1.19), fluid and electrolyte disorder (OR = 1.25), hypertension (OR = 1.10), liver disease (OR = 1.27), renal failure (OR = 1.33), and rheumatoid arthritis (OR = 1.14). These factors were used to create the RATKA Scale. The RATKA score was then used to define 3 levels of risk for readmission: low (RATKA score of <13; 3.7% readmission rate), moderate (RATKA score of 13 to 16; 5.4% readmission rate), and high (RATKA score of >16; 7.6% readmission rate). The relative risk of readmission was 2.06 for the high-risk group compared with the low-risk group.

CONCLUSIONS

The RATKA Scale derived from patient data from the derivation cohort was reliably able to explain readmission variability after TKA for patients in the validation cohort at a rate of >95%. Models such as the RATKA Scale will enable identification of the risk of readmission following TKA based on a patient's risk profile prior to surgery.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effects of local vanadium delivery on diabetic fracture healing

This study evaluated the effect of local vanadyl acetylacetonate (VAC), an insulin mimetic agent, upon the early and late parameters of fracture healing in rats using a standard femur fracture model. Mechanical testing, and radiographic scoring were performed, as well as histomorphometry, including percent bone, percent cartilage, and osteoclast numbers. Fractures treated with local 1.5 mg/kg VAC possessed significantly increased mechanical properties compared to controls at 6 weeks post-fracture, including increased torque to failure (15%; p = 0.046), shear modulus (89%; p = 0.043), and shear stress (81%; p = 0.009). The radiographic scoring analysis showed increased cortical bridging at 4 weeks and 6 weeks (119%; p = 0.036 and 209%; p = 0.002) in 1.5 mg/kg VAC treated groups. Histomorphometry of the fracture callus at days 10 and 14 showed increased percent cartilage (121%; p = 0.009 and 45%; p = 0.035) and percent mineralized tissue (66%; p = 0.035 and 58%; p = 0.006) with local VAC treated groups compared to control. Additionally, fewer osteoclasts were observed in the local VAC treated animals as compared to controls at day 14 (0.45% ± 0.29% vs. 0.83% ± 0.36% of callus area; p = 0.032). The results suggest local administration of VAC acts to modulate osteoclast activity and increase percentage of early callus cartilage, ultimately enhancing mechanical properties comparably to non-diabetic animals treated with local VAC. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2174-2180, 2017.

Hoverboards: A new cause of pediatric morbidity

INTRODUCTION

The hoverboard, a self-balancing powered scooter, was introduced to the market in 2015 and quickly became one of the most popular purchases of the year. As with similar products, this scooter brought a host of concerns surrounding injuries. The purpose of this study is to determine the incidence of injuries that coincided with the popularity of hoverboard.

METHODS

The National Electronic Injury Surveillance System (NEISS) was queried from 2011 through 2015 for injuries related to scooters/skateboards, powered (product number, 5042), which includes the hoverboard. Patient data on sex, age, race, diagnosis, most severely injured body part, location where the injury occurred, and narrative of the injury were collected. The estimated injury incidence was calculated and compared on a yearly and monthly basis. Google Trends was used to determine the popularity of the hoverboard over the same time period.

RESULTS

During the 5-year study period, there were an estimated 47,277 injuries associated with the hoverboard. In 2015, there was an average 208% (range, 167-278%; standard deviation (SD), 51.8%) increase in the number of injuries compared to any of the previous 4 years. Further analysis of these injuries revealed a significant increase in the number of forearm (475%; range, 310-662%; SD, 159%), leg (178%; range, 133-206%; SD, 34%), and head and neck (187%; range, 179-197%; SD, 7.6%) injuries in 2015 compared to the previous 4 years. The most common type of injury in 2015 was a fracture (38.9%). Analysis of the sites of these fractures between 2014 and 2015 revealed a 752% increase in forearm fractures, which included over a 4000% increase in the number of wrist fractures.

CONCLUSIONS

Given the number of injuries caused by these products, safety equipment, such as wrist guards and helmets, should be worn in an attempt to reduce the number of injuries. Additionally, this study highlights the importance of physicians keeping up to date with current trends to best advise their patients on safe practices.

Supplemental Bone Grafting in Giant Cell Tumor of the Extremity Reduces Nononcologic Complications

BACKGROUND

Giant cell tumors (GCTs) are treated with resection curettage and adjuvants followed by stabilization. Complications include recurrence, fracture, and joint degeneration. Studies have shown treatment with polymethylmethacrylate (PMMA) may increase the risk of joint degeneration and fracture. Other studies have suggested that subchondral bone grafting may reduce these risks.

QUESTIONS/PURPOSES

Following standard intralesional resection-curettage and adjuvant treatment, is the use of bone graft, with or without supplemental PMMA, (1) associated with fewer nononcologic complications; (2) associated with differences in tumor recurrence between patients treated with versus those treated without bone grafting for GCT; and (3) associated with differences in Musculoskeletal Tumor Society (MSTS) scores?

METHODS

Between 1996 and 2014, 49 patients presented with GCT in the epiphysis of a long bone. Six patients were excluded, four who were lost to followup before 12 months and two because they presented with displaced, comminuted, intraarticular pathologic fractures with a nonreconstructable joint surface. The remaining 43 patients were included in our study at a mean followup of 59 months (range, 12-234 months). After resection-curettage, 21 patients were reconstructed using femoral head allograft with or without PMMA (JB) and 22 patients were reconstructed using PMMA alone (FRP, KSB); each surgeon used the same approach (that is, bone graft or no bone graft) throughout the period of study. The primary study comparison was between patients treated with bone graft (with or without PMMA) and those treated without bone graft.

RESULTS

Nononcologic complications occurred less frequently in patients treated with bone graft than those treated without (10% [two of 21] versus 55% [12 of 22]; odds ratio, 0.088; 95% confidence interval [CI], 0.02-0.47; p = 0.002). Patients with bone graft had increased nononcologic complication-free survival (hazard ratio, 4.59; 95% CI, 1.39-15.12; p = 0.012). With the numbers available, there was no difference in tumor recurrence between patients treated with bone graft versus without (29% [six of 21] versus 32% [seven of 22]; odds ratio, 0.70; 95% CI, 0.1936-2.531; p = 0.586) or in recurrence-free survival among patients with bone graft versus without (hazard ratio, 0.94; 95% CI, 0.30-2.98; p = 0.920). With the numbers available, there was no difference in mean MSTS scores between patients treated with bone graft versus without (92% ± 2% versus 93% ± 1.4%; mean difference 1.0%; 95% CI, -3.9% to 6.0%; p = 0.675).

CONCLUSIONS

Compared with PMMA alone, the use of periarticular bone graft constructs reduces postoperative complications apparently without increasing the likelihood of tumor recurrence.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Radial Shaft Reconstruction With an Intercalary Endoprosthesis Following Resection of Metastatic Tumor

Improvements in imaging and treatment of musculoskeletal tumors have increased the variety of options for reconstruction following joint-sparing diaphyseal resection. The purpose of this case series was to show that reconstruction of malignant tumors of the radial shaft with an intercalary prosthesis may be an option for patients with segmental bone loss. Three consecutive patients underwent wide resection of the radial diaphysis followed by reconstruction with a custom intercalary prosthesis. A custom intercalary prosthesis with lap joint design was used in all 3 cases. Mean follow-up was 18 months (range, 9-25 months). All patients were weight bearing as tolerated 1 week postoperatively. At the most recent follow-up, patients' mean elbow flexion and extension arc was 137° (range, 130°-140°). At the forearm, mean supination was 60° (range, 30°-90°) and mean pronation was 70° (range, 60°-90°). At the wrist, mean palmar flexion was 80° (range, 70°-90°) and mean dorsiflexion was 80° (range, 70°-90°). All patients reported minimal to no pain and no significant functional limitations. Mean Musculoskeletal Tumor Society score was 26/30 (87%). Reconstruction with an intercalary prosthesis is a viable option for patients with metastatic disease of the radial shaft. All patients had satisfactory results and early return to function; none required return to the operating room. Possible advantages of reconstruction with an intercalary prosthesis compared with reconstruction with a bone graft or polymethylmethacrylate osteosynthesis include early return to function and minimal weight-bearing restrictions postoperatively. [Orthopedics. 2017; 40(2):e242-e247.].

Biochars Reduce Mine Land Soil Bioavailable Metals

Biochar has been proposed as an amendment to remediate mine land soils; however, it could be advantageous and novel if feedstocks local to mine land sites were used for biochar production. Two different feedstocks (pine beetle-killed lodgepole pine [] and tamarisk [ spp.]), within close proximity to mine land-affected soils, were used to create biochars to determine if they have the potential to reduce metal bioavailability. Four different mine land soils, contaminated with various amounts of Cd, Cu, Pb, and Zn, received increasing amounts of biochar (0, 5, 10, and 15% by wt). Soil pH and metal bioavailability were determined, and the European Community Bureau of Reference (BCR) sequential extraction procedure was used to identify pools responsible for potential shifts in bioavailability. Increasing biochar application rates caused increases in soil pH (initial, 3.97; final, 7.49) and 55 to 100% (i.e., no longer detectable) decreases in metal bioavailability. The BCR procedure supported the association of Cd with carbonates, Cu and Zn with oxyhydroxides and carbonates, and Pb with oxyhydroxides; these phases were likely responsible for the reduction in heavy metal bioavailability. This study proved that both of these feedstocks local to abandoned mining operations could be used to create biochars and reduce heavy metal bioavailability in mine land soils.

The Use of the h-Index in Academic Orthopaedic Surgery

BACKGROUND

The Hirsch index (h-index), widely considered a valuable measure of assessing academic productivity, has been studied in various medical and surgical specialties and has shown strong associations between higher h-indices and academic promotion, as well as with National Institutes of Health (NIH) awards. Additionally, the m-index and e-index may complement the h-index in this assessment of merit. The purpose of this study was to investigate the relationship between the h, m, and e-indices and academic rank for 2,061 academic orthopaedic surgeons in the United States.

METHODS

The h-indices of faculty members from 120 academic orthopaedic surgery residency programs were organized and calculated using the Scopus and Google Scholar databases. Additionally, m-index and e-index scores were calculated from Google Scholar. After application of exclusion criteria, 2,061 academic orthopaedic surgeons were included.

RESULTS

Academic rank (assistant professor, associate professor, professor, and chair) increases as mean h-index, m-index, and e-index scores increase. Among 976 assistant professors, 504 associate professors, 461 professors, and 120 chairs, mean h, m, and e-indices increased with each academic rank. In the comparison of male and female surgeons, there was no significant difference in h, m, or e-index scores, with the exception of increased h-index scores among male assistant professors.

CONCLUSIONS

Scholarly impact, as defined by academic productivity and scientific relevance, can be classified by the h-index and supplemented by the m and e-indices. This study has revealed well-defined differences in h, m, and e-indices with regard to academic rank among orthopaedic surgeons. Although the h, m, and e-indices may be of value as adjunct assessment devices for scholarly merit, careful consideration of their limitations must be maintained.

Customizable orthopaedic oncology implants: one institution's experience with meeting current IRB and FDA requirements

Background

Customizable orthopaedic implants are often needed for patients with primary malignant bone tumors due to unique anatomy or complex mechanical problems. Currently, obtaining customizable orthopaedic implants for orthopaedic oncology patients can be an arduous task involving submitting approval requests to the Institutional Review Board (IRB) and the Food and Drug Administration (FDA). There is great potential for the delay of a patient’s surgery and unnecessary paperwork if the submission pathways are misunderstood or a streamlined protocol is not in place.

Purpose

The objective of this study was to review the existing FDA custom implant approval pathways and to determine whether this process was improved with an institutional protocol.

Methods

An institutional protocol for obtaining IRB and FDA approval for customizable orthopaedic implants was established with the IRB at our institution in 2013. This protocol was approved by the IRB, such that new patients only require submission of a modification to the existing protocol with individualized patient information. During the two-year period of 2013–2014, eight patients were retrospectively identified as having required customizable implants for various orthopaedic oncology surgeries. The dates of request for IRB approval, request for FDA approval, and total time to surgery were recorded, along with the specific pathway utilized for FDA approval.

Results

The average patient age was 12 years old (7–21 years old). The average time to IRB approval of a modification to the pre-approved protocol was 14 days (7–21 days). Average time to FDA approval after submission of the IRB approval to the manufacturer was 12.5 days (7–19 days). FDA approval was obtained for all implants as compassionate use requests in accordance with Section 561 of the Federal Food Drug and Cosmetic Act’s expanded access provisions.

Conclusions

Establishment of an institutional protocol with pre-approval by the IRB can expedite the otherwise time-consuming and complicated process of obtaining customizable orthopaedic implants for orthopaedic oncology patients.

Level of evidence

Retrospective case series, Level IV. See the Guidelines for authors for a complete description of levels of evidence.

Designer, acidic biochar influences calcareous soil characteristics

In a proof-of-concept study, an acidic (pH 5.8) biochar was created using a low pyrolysis temperature (350 °C) and steam activation (800 °C) to potentially improve the soil physicochemical status of an eroded calcareous soil. Biochar was added at 0%, 1%, 2%, and 10% (by wt.) and soils were destructively sampled at 1, 2, 3, 4, 5, and 6 month intervals. Soil was analyzed for gravimetric water content, pH, NO3-N, plant-available Fe, Zn, Mn, Cu, and P, organic C, CO2 respiration, and microbial enumeration via extractable DNA and 16S rRNA gene copies. Gravimetric soil water content increased with biochar application regardless of rate, as compared to the control. Soil pH decreased between 0.2 and 0.4 units, while plant-available Zn, Mn, and P increased with increasing biochar application rate. Micronutrient availability decreased over time likely due to insoluble mineral species precipitation. Increasing biochar application raised the soil organic C content and remained elevated over time. Increasing biochar application rate also increased respired CO2, yet the CO2 released decreased over time. Soil NO3-N concentrations significantly decreased with increasing biochar application rate likely due to microbial immobilization or denitrification. Depending on application rate, biochar produced a 1.4 to 2.1-fold increase in soil DNA extracted and 1.4- to 2.4-fold increase in 16S rRNA gene abundance over control soils, suggesting microbial stimulation and a subsequent burst of activity upon biochar addition. Our results showed that there is promise in designing a biochar to improve the quality and water relations of eroded calcareous soils.

Hardwood biochar and manure co-application to a calcareous soil

Biochar may affect the mineralization rate of labile organic C sources such as manures via microbial community shifts, and subsequently affect nutrient release. In order to ascertain the positive or negative priming effect of biochar on manure, dairy manure (2% by wt.) and a hardwood-based, fast pyrolysis biochar were applied (0%, 1%, 2%, and 10% by wt.) to a calcareous soil. Destructive sampling occurred at 1, 2, 3, 4, 6 and 12 months to monitor for changes in soil chemistry, water content, microbial respiration, bacterial populations, and microbial community structure. Overall results showed that increasing biochar application rate improved the soil water content, which may be beneficial in limited irrigation or rainfall areas. Biochar application increased soil organic C content and plant-available Fe and Mn, while a synergistic biochar-manure effect increased plant-available Zn. Compared to the other rates, the 10% biochar application lowered concentrations of NO3-N; effects appeared masked at lower biochar rates due to manure application. Over time, soil NO3-N increased likely due to manure N mineralization, yet soil NO3-N in the 10% biochar rate remained lower as compared to other treatments. In the presence of manure, only the 10% biochar application caused subtle microbial community structure shifts by increasing the relative amounts of two fatty acids associated with Gram-negative bacteria and decreasing Gram-positive bacterial fatty acids, each by ∼1%. Our previous findings with biochar alone suggested an overall negative priming effect with increasing biochar application rates, yet when co-applied with manure the negative priming effect was eliminated.

Desmoplastic fibroma of the distal radius: an interesting case and a review of the literature and therapeutic implications

Desmoplastic fibromas are rare, benign, locally aggressive bone tumors, which arise primarily in patients younger than 30 years old. Historically, even with greater functional loss, en bloc or wide resection of the tumors to prevent local recurrence has been the method of choice in treatment. This article discusses the presentation of a 10-year-old male who presented with a mass in the distal forearm, after reporting difficulty in pronation and supination. The patient was ultimately treated with wide resection and allo-arthrodesis with allograft. Post-operatively, the patient has exhibited excellent recovery, including normal range of motion at the shoulder and elbow, and ability to perform all activities of daily livings despite reduced grip strength compared with the contralateral side.

Copper and zinc speciation in a biosolids-amended, semiarid grassland soil

Predicting trace-metal solid-phase speciation changes associated with long-term biosolids land application is important for understanding and improving environmental quality. Biosolids were surface-applied (no incorporation; 0, 2.5, 5, 10, 21, and 30 Mg ha) to a semiarid grassland in 1991 (single application) and 2002 (repeated application). In July 2003, soils were obtained from the 0- to 8-, 8- to15-, and 15- to 30-cm depths in all plots. Using soil pH, soluble anion and cation concentrations from 0.01 mol L CaCl extractions, dissolved organic C (DOC) content, and an estimate of solid phase humic and fulvic acids present, Cu and Zn associated with minerals, hydrous ferric oxides (HFO), organically complexed, electrostatically bound to organic matter (OM), or DOC phases was modeled using Visual Minteq. Scanning electron microscopy and energy-dispersive X-ray analysis (SEM-EDXRA) was also used to identify solid-phase metal associations present in single and repeated biosolids-amended soils. Based on soil solution chemistry in all depths, as modeled using Visual Minteq, >90% of the Cu and >95% of the Zn from the single or repeated biosolids-applied soils were sorbed electrostatically or as mono- or bidentate solid-phase OM complexes. Up to 10 and 5% of the Cu and Zn, respectively, was associated with HFO, with negligible amounts associated with DOC. The SEM-EDXRA of clay-sized separates from all soil depths led to direct observation of Fe-Cu and Fe-Zn associations. Results implied that after surface-applying biosolids either once or twice with up to 30 Mg ha, some shifts occurred in phases controlling Cu and Zn solubility, but solution concentrations remained below drinking water standards.

Hardwood biochar influences calcareous soil physicochemical and microbiological status

The effects of biochar application to calcareous soils are not well documented. In a laboratory incubation study, a hardwood-based, fast pyrolysis biochar was applied (0, 1, 2, and 10% by weight) to a calcareous soil. Changes in soil chemistry, water content, microbial respiration, and microbial community structure were monitored over a 12-mo period. Increasing the biochar application rate increased the water-holding capacity of the soil-biochar blend, a trait that could be beneficial under water-limited situations. Biochar application also caused an increase in plant-available Fe and Mn, soil C content, soil respiration rates, and bacterial populations and a decrease in soil NO-N concentration. Biochar rates of 2 and 10% altered the relative proportions of bacterial and fungal fatty acids and shifted the microbial community toward greater relative amounts of bacteria and fewer fungi. The ratio of fatty acid 19:0 cy to its precursor, 18:1ω7c, was higher in the 10% biochar rate soil than in all other soils, potentially indicating an environmental stress response. The 10% application rate of this particular biochar was extreme, causing the greatest change in microbial community structure, a physiological response to stress in Gram-negative bacteria, and a drastic reduction in soil NO-N (85-97% reduction compared with the control), all of which were sustained over time.

Investigation of copper sorption by sugar beet processing lime waste

In the western United States, sugar beet processing for sugar recovery generates a lime-based waste product (∼250,000 Mg yr) that has little liming value in the region's calcareous soils. This area has recently experienced an increase in dairy production, with dairies using copper (Cu)-based hoof baths to prevent hoof diseases. A concern exists regarding soil Cu accumulation because spent hoof baths may be disposed of in waste ponds, with pond waters being used for irrigation. The objective of this preliminary study was to evaluate the ability of lime waste to sorb Cu. Lime waste was mixed with increasing Cu-containing solutions (up to 100,000 mg Cu kg lime waste) at various buffered pH values (pH 6, 7, 8, and 9) and shaken over various time periods (up to 30 d). Copper sorption phenomenon was quantified using sorption maximum fitting, and the sorption mechanism was investigated using X-ray absorption spectroscopy. Results showed that sorption onto lime waste increased with decreasing pH and that the maximum Cu sorption of ∼45,000 mg kg occurred at pH 6. X-ray absorption spectroscopy indicated that Cu(OH) was the probable species present, although the precipitate existed as small multinuclear precipitates on the surface of the lime waste. Such structures may be precursors for larger surface precipitates that develop over longer incubation times. Findings suggest that sugar beet processing lime waste can viably sorb Cu from liquid waste streams, and thus it may have the ability to remove Cu from spent hoof baths.

Macroscopic and molecular investigations of copper sorption by a steam-activated biochar

Excessive Cu concentrations in water systems can negatively affect biological systems. Because Cu can form strong associations with organic functional groups, we examined the ability of biochar (an O-C-enriched organic bioenergy by-product) to sorb Cu from solution. In a batch experiment, KOH steam-activated pecan shell biochar was shaken for 24 h in pH 6, 7, 8, or 9 buffered solutions containing various Cu concentrations to identify the effect of pH on biochar Cu sorption. Afterward, all biochar solids from the 24-h shaking period were air-dried and analyzed using X-ray absorption fine structure (XAFS) spectroscopy to determine solid-phase Cu speciation. In a separate batch experiment, biochar was shaken for 30 d in pH 6 buffered solution containing increasing Cu concentrations; the Cu sorption maximum was calculated based on the exponential rise to a maximum equation. Biochar sorbed increasing amounts of Cu as the solution pH decreased from 9 to 6. The XAFS spectroscopy revealed that Cu was predominantly sorbed onto a biochar organic phase at pH 6 in a molecular structure similar to Cu adsorbed on model humic acid (Cu-humic acid [HA]). The XAFS spectra at pH 7, 8, and 9 suggested that Cu was associated with the biochar as three phases: (i) a complex adsorbed on organic ligands similar to Cu-HA, (ii) carbonate phases similar to azurite (Cu(CO)(OH)), and (iii) a Cu oxide phase like tenorite (CuO). The exponential rise equation fit to the incubated samples predicted a Cu sorption maximum of 42,300 mg Cu kg. The results showed that KOH steam-activated pecan shell biochar could be used as a material for sorbing excess Cu from water systems, potentially reducing the negative effects of Cu in the environment.

Switchgrass biochar affects two aridisols

The use of biochar has received growing attention because of its ability to improve the physicochemical properties of highly weathered Ultisols and Oxisols, yet very little research has focused on its effects in Aridisols. We investigated the effect of low or high temperature (250 or 500°C) pyrolyzed switchgrass () biochar on two Aridisols. In a pot study, biochar was added at 2% w/w to a Declo loam (Xeric Haplocalcids) or to a Warden very fine sandy loam (Xeric Haplocambids) and incubated at 15% moisture content (by weight) for 127 d; a control (no biochar) was also included. Soils were leached with 1.2 to 1.3 pore volumes of deionized HO on Days 34, 62, 92, and 127, and cumulative leachate Ca, K, Mg, Na, P, Cu, Fe, Mn, Ni, Zn, NO-N, NO-N, and NH-N concentrations were quantified. On termination of the incubation, soils were destructively sampled for extractable Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Zn, NO-N, and NH-N, total C, inorganic C, organic C, and pH. Compared with 250°C, the 500°C pyrolysis temperature resulted in greater biochar surface area, elevated pH, higher ash content, and minimal total surface charge. For both soils, leachate Ca and Mg decreased with the 250°C switchgrass biochar, likely due to binding by biochar's functional group sites. Both biochars caused an increase in leachate K, whereas the 500°C biochar increased leachate P. Both biochars reduced leachate NO-N concentrations compared with the control; however, the 250°C biochar reduced NO-N concentrations to the greatest extent. Easily degradable C, associated with the 250°C biochar's structural make-up, likely stimulated microbial growth, which caused NO-N immobilization. Soil-extractable K, P, and NO-N followed a pattern similar to the leachate observations. Total soil C content increases were linked to an increase in organic C from the biochars. Cumulative results suggest that the use of switchgrass biochar prepared at 250°C could improve environmental quality in calcareous soil systems by reducing nutrient leaching potential.

Biochar and manure affect calcareous soil and corn silage nutrient concentrations and uptake

Carbon-rich biochar derived from the pyrolysis of biomass can sequester atmospheric CO, mitigate climate change, and potentially increase crop productivity. However, research is needed to confirm the suitability and sustainability of biochar application to different soils. To an irrigated calcareous soil, we applied stockpiled dairy manure (42 Mg ha dry wt) and hardwood-derived biochar (22.4 Mg ha), singly and in combination with manure, along with a control, yielding four treatments. Nitrogen fertilizer was applied when needed (based on preseason soil test N and crop requirements) in all plots and years, with N mineralized from added manure included in this determination. Available soil nutrients (NH-N; NO-N; Olsen P; and diethylenetriaminepentaacetic acid-extractable K, Mg, Na, Cu, Mn, Zn, and Fe), total C (TC), total N (TN), total organic C (TOC), and pH were evaluated annually, and silage corn nutrient concentration, yield, and uptake were measured over two growing seasons. Biochar treatment resulted in a 1.5-fold increase in available soil Mn and a 1.4-fold increase in TC and TOC, whereas manure produced a 1.2- to 1.7-fold increase in available nutrients (except Fe), compared with controls. In 2009 biochar increased corn silage B concentration but produced no yield increase; in 2010 biochar decreased corn silage TN (33%), S (7%) concentrations, and yield (36%) relative to controls. Manure produced a 1.3-fold increase in corn silage Cu, Mn, S, Mg, K, and TN concentrations and yield compared with the control in 2010. The combined biochar-manure effects were not synergistic except in the case of available soil Mn. In these calcareous soils, biochar did not alter pH or availability of P and cations, as is typically observed for acidic soils. If the second year results are representative, they suggest that biochar applications to calcareous soils may lead to reduced N availability, requiring additional soil N inputs to maintain yield targets.