Assessment of micromotion at the bone-bone interface after coracoid and scapular-spine bone-block augmentation for the reconstruction of critical anterior glenoid bone loss-a biomechanical cadaver study.

BACKGROUND: Glenoid bone loss is among the most important risk factors for recurrent anterior shoulder instability, and a bony reconstruction is recommended in cases of critical bone loss (> 15%). The commonly used surgical techniques, including coracoid transfer, are associated with considerable complications. The aim of this study was to assess the motion at the glenoid-bone-block interface after coracoid and spina-scapula bone-block reconstruction of the anterior glenoid. METHODS: Twelve cadaveric shoulders were tested. A 20% bone defect of the anterior glenoid was created, and the specimens were randomly assigned for glenoid augmentation using a coracoid bone block (n = 6) or a scapular spine bone block (n = 6). The glenoid-bone interface was cyclically loaded for 5000 cycles with a force of 170 N. The micromotion was tracked using an optical measurement system (GOM ARMIS) and was evaluated with the GOM Correlate Pro software. RESULTS: The most dominant motion component was medial irreversible displacement for the spina-scapula (1.87 mm; SD: 1.11 mm) and coracoid bone blocks (0.91 mm; SD: 0.29 mm) (n.s.). The most medial irreversible displacement took place during the first nine cycles. The inferior reversible displacement was significantly greater for spina-scapula bone blocks (0.28 mm, SD: 0.16 mm) compared to coracoid bone blocks (0.06 mm, SD: 0.10 mm) (p = 0.02). CONCLUSIONS: The medial irreversible displacement is the dominant motion component in a bone-block reconstruction after a critical bone loss of the anterior glenoid. The spina-scapula and coracoid bone blocks are comparable in terms of primary stability and extent of motion. Thus, spina-scapula bone blocks may serve as alternatives in bony glenoid reconstruction from a biomechanical point of view.

Uterine Leiomyosarcoma Associated With Leiomyoma With Bizarre Nuclei: Histology and Genomic Analysis of 2 Cases.

Leiomyoma with bizarre nuclei (LM-BN) is a rare variant of leiomyoma with overall benign clinical course. It has histologic features showing focal or diffuse nuclear atypia surrounded by usual type leiomyoma. Uterine leiomyosarcomas (LMS) are a group of rare and aggressive malignancies with limited treatment options available. The potential association between LM-BN with LMS is largely unknown. In this study, we report 2 cases of uterine smooth muscle tumor with typical histologic and molecular evidence of LM-BN, which are associated with its progression to the malignant counterpart of LMS. We summarize the detailed histologic, morphologic, and genomic characteristics of these 2 sets of cases. Our findings suggest that LMS progressing from preexisting LM-BN can be one of the tumor pathogenesis pathways in uterine leiomyosarcomas.

Anatomical versus non-anatomical configuration of double coraco-clavicular tunnel technique in acromioclavicular joint reconstruction.

PURPOSE: Horizontal instability is a common problem after acromioclavicular joint injuries. The aim of this study was to evaluate if there is a difference regarding horizontal stability between an anatomical and a non-anatomical configuration of the double tunnel coraco-clavicular ligament reconstruction of the acromioclavicular joint. METHODS: Thirteen acromioclavicular joints of human cadaveric shoulders in ethanol-glycerin fixation were included in the study and underwent cyclic anterior and posterior translational testing at a load of 70 N using an electromechanical uniaxial testing machine. The shoulders were randomly assigned to the following groups: double coraco-clavicular tunnel technique in an anatomical configuration (DCTa) and double coraco-clavicular tunnel technique in an inverse configuration of the anatomical position (DCTb). The dislocation was recorded with a 3D optical measuring system. RESULTS: The total horizontal displacement (p10 = 0.0221; p5000 = 0.082) was significantly higher for the non-anatomical reconstruction (DCTb) compared to the anatomical reconstruction (DCTa) after every measured amount of cycles. The increase in displacement for DCTb group was overall higher than the increase in displacement for DCTa group but without significance. CONCLUSION: Reconstruction of the CC ligaments in an anatomical configuration with two suture devices results in a significantly higher stability of the AC joint in the horizontal plane than reconstruction of the CC ligaments in a non-anatomical configuration. Based on the results of this biomechanical in vitro study, the use of a double coraco-clavicular reconstruction should focus on an anatomically correct position of the suture devices.

Acromioclavicular joint reconstruction: an additional acromioclavicular cerclage does not improve horizontal stability in double coraco-clavicular tunnel technique.

PURPOSE: Horizontal instability-especially in the posterior plane-is a common problem after acromioclavicular joint injuries. The purpose was to compare the stability of a single coraco-clavicular tunnel technique and a double coraco-clavicular tunnel technique for coraco-clavicular ligament reconstruction and to examine the influence of an additional acromioclavicular cerclage on the horizontal stability in the acromioclavicular joint. METHODS: 21 acromioclavicular joints of human cadaveric shoulders were randomly assigned to the following groups: single coraco-clavicular tunnel technique with horizontal augmented acromioclavicular cerclage (SCT + AC); double coraco-clavicular tunnel technique (DCT); double coraco-clavicular tunnel technique and acromioclavicular cerclage (DCT + AC). The specimens underwent cyclic horizontal testing and were recorded using a 3D optical measuring system. RESULTS: The displacement and the increase in displacement in relation to the displacement after precondition for SCT + AC were significantly higher after every measured amount of cycles than for DCT (p10 = 0.0023; p5000 = 0.0012) and DCT + AC (p10 = 0.0006; p5000 = 0.0012). There was no significant difference in the total displacement, or in the increase in total displacement between double coraco-clavicular tunnel reconstructed groups with and without additional acromioclavicular cerclage. CONCLUSION: Double coraco-clavicular tunnel technique with and without additional acromioclavicular cerclage results in a significant higher stability regarding the horizontal plane in comparison to single coraco-clavicular tunnel technique with acromioclavicular cerclage. Based on the results of this biomechanical in vitro study, the use of an additional acromioclavicular cerclage with single coraco-clavicular tunnel technique may not be indicated in most cases. The effect of an additional acromioclavicular cerclage seems to be negligible, at least in presence of a double-coraco-clavicular tunnel technique reconstruction. Techniques of AC joint reconstruction should focus on the use of double coraco-clavicular tunnel devices.

Mirror writing in 5- to 6-year-old children: The preferred hand is not the explanation.

Non-pathological, spontaneous mirror writing, whether complete or partial, has long been associated with writing with the left hand and attributed to the fact that abductive writing, which most people find easier, is from right to left when people write with their left hand. However, recent research suggests another explanation: children who do not know the orientation of the letters and digits may apply an implicit right-writing rule which causes them to invert mainly left-oriented characters (e.g., J, 3). But would left-hand writers apply such a rule? The present study examines the relationship between these two explanations of mirror writing and asks whether they coexist in children who write with their left hand. Is the abductive writing explanation specific to mirror writing by left-hand writers and the implicit right-writing rule specific to right-hand writers? A comparison of 59 children who wrote with their left hand and 59 children who wrote with their right hand (matched for age and school experience) provided clear evidence against the abductive-writing explanation and in favour of the right-writing rule for both groups. Therefore, spontaneous mirror writing in typical 5- to 6-year-olds does not seem to be a function of preferred writing hand.

Unexpected wear of an unicompartimental knee arthroplasty in oxidized zirconium.

Unicompartimental knee arthroplasty is a successful procedure for the treatment of localized osteoarthritis to one compartment of the knee with good long-term results. However, several modes of failure of unicompartimental knee arthroplasty have been described, namely aseptic or septic loosening, progression of disease, wear, and instability. Metallosis after unicompartimental knee arthroplasty is rarely reported and is most often related with polyethylene wear or break. We report on a case of rapid failure of unicompartimental knee arthroplasty in oxidized zirconium associated with metallosis secondary to the dislocation of the polyethylene.

Digit reversal in children's writing: a simple theory and its empirical validation.

This article presents a simple theory according to which the left-right reversal of single digits by 5- and 6-year-old children is mainly due to the application of an implicit right-writing or -orienting rule. A number of nontrivial predictions can be drawn from this theory. First, left-oriented digits (1, 2, 3, 7, and 9) will be reversed more frequently than the other asymmetrical digits (4, 5, and 6). Second, for some pairs of digits, the correct writing of the preceding digit will statistically predict the reversal of the current digit and vice versa. Third, writing hand will have little effect on the frequency of reversals, and the relative frequencies with which children reverse the asymmetrical digits will be similar regardless of children's preferred writing hand. Fourth, children who reverse the left-oriented digits the most are also those who reverse the other asymmetrical digits the least. An empirical study involving 367 5- and 6-year-olds confirmed these predictions.

Preventing the Development of Dyslexia: A Reply to Mather.

Because reading/writing is a fundamental tool for children's development, the main failure in its learning-developmental dyslexia-gives rise to many attempts to remediate. A recent remedy proposed by Mather (2022), published in Perceptual and Motor Skills [129(3), p. 468], is impressive through its radical nature and the extent of its consequences. It consists of delaying the teaching of writing to the age of 7-8 years, whereas, at present, most children in Western or comparable cultures learn to write even before compulsory school (generally at age six). In this article, I present a set of arguments whose addition and possible interaction lead, if not to reject, at least to restrict Mather's proposal. My arguments show both the inefficiency of Mather's proposal through two observational studies, its practical inapplicability in contemporary society, the importance of learning to write at least in the first year of elementary school, and the stinging past failure of a math reform of similar scope (i.e., learning to count). I also question the neurological theory underlying Mather's proposal, and, finally, I point out that, even if delaying learning to write were limited to students who Mather expects (at age six) to experience future dyslexia, this remedy would be inapplicable and probably ineffective.

Novel approach to assessing the primary stability of dental implants under functional cyclic loading in vitro: a biomechanical pilot study using synthetic bone.

PURPOSE: This pilot study was conducted to develop a novel test setup for the in vitro assessment of the primary stability of dental implants. This was achieved by characterising their long-term behaviour based on the continuous recording of micromotions resulting from dynamic and cyclic loading. METHODS: Twenty screw implants, each 11 mm in length and either 3.8 mm (for premolars) or 4.3 mm (for molars) in diameter, were inserted into the posterior region of 5 synthetic mandibular models. Physiological masticatory loads were simulated by superimposing cyclic buccal-lingual movement of the mandible with a vertically applied masticatory force. Using an optical 3-dimensional (3D) measuring system, the micromotions of the dental crowns relative to the alveolar bone resulting from alternating off-centre loads were concurrently determined over 10,000 test cycles. RESULTS: The buccal-lingual deflections of the dental crowns significantly increased from cycle 10 to cycle 10,000 (P<0.05). The deflections increased sharply during the first 500 cycles before approaching a plateau. Premolars exhibited greater maximum deflections than molars. The bone regions located mesially and distally adjacent to the loaded implants demonstrated deflections that occurred synchronously and in the same direction as the applied loads. The overall spatial movement of the implants over time followed an hourglass-shaped loosening pattern with a characteristic pivot point 5.5±1.1 mm from the apical end. CONCLUSIONS: In synthetic mandibular models, the cyclic reciprocal loading of dental implants with an average masticatory force produces significant loosening. The evasive movements observed in the alveolar bone suggest that its anatomy and yielding could significantly influence the force distribution and, consequently, the mechanical behaviour of dental implants. The 3D visualisation of the overall implant movement under functional cyclic loading complements known methods and can contribute to the development of implant designs and surgical techniques by providing a more profound understanding of dynamic bone-implant interactions.

Boy's math performance, compared to girls', jumps at age 6 (in the ELFE's data at least).

The mathematics achievement discrepancy between girls and boys, with its subsequent occupational consequences, is an issue that has received considerable attention in the literature. It is often referred to as the 'math-gap' and favours boys. A major component of the explanation of this gap resides in determining its age of onset. We analyse here data from more than 10,000 (cross-sectional study) and 2000 (longitudinal study) French students aged 4-7 years, tested in the framework of the Etude Longitudinale Française depuis l'Enfance (ELFE). The results allow to precisely determine the age of onset, since the gender difference, non-existent (or even slightly in favour of girls) in kindergarten (4-5 years), is clearly in favour of boys in first grade (6-7 years). They could therefore provide an important element in the controversial debate on the origin of gender-differentiated performance in mathematics.

Are differences between social classes reduced by non-symbolic numerical tasks? Evidence from the ELFE cohort.

BACKGROUND: Young children's mathematics abilities may be divided between symbolic and non-symbolic skills. Lower performance of SES disadvantaged versus advantaged children has already been established in symbolic math. AIM: This study aimed to verify the effect of children's SES category on non-symbolic mathematical (numerical) performance. SAMPLE: The main sample comprises 4,955 children from the French longitudinal study, ELFE, tested when they were in the nursery school (4- to 5-year-olds). METHOD: The distinction between symbolic and non-symbolic math skills based on the specific math assessment items used in the present study was verified on a larger sample. The SES-related difference in non-symbolic math skills was then examined in the ELFE sample only. RESULTS: The children's performance in non-symbolic maths is significantly and almost as strongly correlated with their family's income and their mother's level of education as their performances in symbolic maths. Linear regression mixed-effects modelling shows that the score in non-symbolic maths (out of 100) of children from families with below median income is 3.8 points lower than that of their peers from families with above median income. CONCLUSION: Children from disadvantaged SES backgrounds perform significantly lower than those from advantaged backgrounds in non-symbolic maths. Even if non-symbolic math skills retain an educational interest, they should not reduce the importance of symbolic math skills in young children.

Effect of Age on Bleeding on Probing (BOP) as an Indicator of Periodontal Inflammation in Patients Enrolled in Supportive Periodontal Therapy.

PURPOSE: To assess the effect of age on the mean percentage of bleeding on probing (BOP) during supportive periodontal therapy (SPT) in patients enrolled in SPT for at least 5 years. Materials and Methods: This study was performed as a retrospective analysis of data collected from SPT patients initially diagnosed with gingivitis or mild to severe periodontitis. Two groups of patients were selected: in group A, younger adults (age ≤ 35 years) were included while group B consisted of older SPT patients (age ≥ 65 years). BOP in the two groups was compared according to both disease severity and % compliance with SPT visits. Results: BOP in all patients (n = 236) was 19.2% (±â€¯12.4). Group A (n = 110) presented mean BOP levels of 19.7% (±â€¯11.8), while lower BOP levels of 18.7% (±â€¯13.0) were found in group B (n = 126; p = 0.5272). Older patients demonstrating high % compliance had lower mean BOP levels (14.2% ±â€¯9.5) than younger patients (18.0% ±â€¯ 11.7; p = 0.0841). Similarly, BOP was lower in older patients with moderate (group B: 18.4% ±â€¯12.1, group A: 19.3% ±â€¯14.6, p = 0.0541) or severe periodontitis (group B: 22.4% ±â€¯11.4, group A: 23.2% ±â€¯ 14.0; p = 0.3440). In patients with moderate or severe periodontitis and higher % compliance with SPT, the mean BOP was statistically significantly lower in older patients than in younger patients (moderate: 14.4% ±â€¯11.9 vs 19.4% ±â€¯15.1, p < 0.0001; severe: 13.2% ±â€¯11.1 vs 18.3% ±â€¯17.5, p = 0.0170). Conclusion: Older patients enrolled in SPT may present lower levels of BOP. This finding should be considered when determining SPT intervals with elderly patients.

Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study.

BACKGROUND: All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. METHODS: First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. RESULTS: A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). CONCLUSIONS: All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

Immunotherapy in endometrial cancer: rationale, practice and perspectives.

Tumor immunotherapy has attracted more and more attention nowadays, and multiple clinical trials have confirmed its effect in a variety of solid tumors. Immune checkpoint inhibitors (ICIs), cancer vaccines, adoptive cell transfer (ACT), and lymphocyte-promoting cytokines are the main immunotherapy methods. Endometrial cancer (EC) is one of the most frequent tumors in women and the prognosis of recurrent or metastatic EC is poor. Since molecular classification has been applied to EC, immunotherapy for different EC subtypes (especially POLE and MSI-H) has gradually attracted attention. In this review, we focus on the expression and molecular basis of the main biomarkers in the immunotherapy of EC firstly, as well as their clinical application significance and limitations. Blocking tumor immune checkpoints is one of the most effective strategies for cancer treatment in recent years, and has now become the focus in the field of tumor research and treatment. We summarized clinical date of planned and ongoing clinical trials and introduced other common immunotherapy methods in EC, such as cancer vaccine and ACT. Hormone aberrations, metabolic syndrome (MetS) and p53 mutant and that affect the immunotherapy of endometrial cancer will also be discussed in this review.

Successful management of stage IV epithelioid trophoblastic tumor using multimodality treatment: A case report.

Epithelioid trophoblastic tumor (ETT) is a rare variant of gestational trophoblastic neoplasia (GTN) that develops from chorionic-type intermediate trophoblast, is more resistant to chemotherapy than choriocarcinoma, and presents with metastatic disease in 25-35% of cases. We report a case of a 32-year-old who presented one week postpartum with severe abdominal pain and was found to have profound anemia and an elevated hCG level. CT scans and MRI revealed bleeding from hepatic masses, multiple hemorrhagic pulmonary nodules, a 7 cm uterine mass, and brain metastases. She underwent emergent hepatic embolization, was started on induction chemotherapy with weekly low-dose etoposide and cisplatin followed by a transition to etoposide, high-dose methotrexate, actinomycin D, etoposide, and cisplatin (HD EMA-EP), received stereotactic brain radiotherapy, and subsequently underwent minimally-invasive hysterectomy. She remains disease free over one year after the completion of treatment. An aggressive multimodal treatment approach employing etoposide/cisplatin-based chemotherapy as well as surgical procedures to control hemorrhage or excise resistant disease, and radiotherapy for brain metastases can result in successful treatment of stage IV ETT.

Accuracy of a magnetic resonance imaging-based 3D printed stereotactic brain biopsy device in dogs.

BACKGROUND: Brain biopsy of intracranial lesions is often necessary to determine specific therapy. The cost of the currently used stereotactic rigid frame and optical tracking systems for brain biopsy in dogs is often prohibitive or accuracy is not sufficient for all types of lesion. OBJECTIVES: To evaluate the application accuracy of an inexpensive magnetic resonance imaging-based personalized, 3D printed brain biopsy device. ANIMALS: Twenty-two dog heads from cadavers were separated into 2 groups according to body weight (<15 kg, >20 kg). METHODS: Experimental study. Two target points in each cadaver head were used (target point 1: caudate nucleus, target point 2: piriform lobe). Comparison between groups was performed using the independent Student's t test or the nonparametric Mann-Whitney U Test. RESULTS: The total median target point deviation was 0.83 mm (range 0.09-2.76 mm). The separate median target point deviations for target points 1 and 2 in all dogs were 0.57 mm (range: 0.09-1.25 mm) and 0.85 mm (range: 0.14-2.76 mm), respectively. CONCLUSION AND CLINICAL IMPORTANCE: This magnetic resonance imaging-based 3D printed stereotactic brain biopsy device achieved an application accuracy that was better than the accuracy of most brain biopsy systems that are currently used in veterinary medicine. The device can be applied to every size and shape of skull and allows precise positioning of brain biopsy needles in dogs.

Whole-Genome Sequencing and Target Validation Analysis of Müllerian Adenosarcoma: A Tumor With Complex but Specific Genetic Alterations.

Mullerian adenosarcoma (MAS) is a biphasic tumor with malignant stroma. It is most commonly of endometrial origin but occasionally originates in the cervix, ovary, or other pelvic/peritoneal sites. The typical MAS is low grade with an indolent clinical course; however, tumors with sarcomatous overgrowth (SO) or a high-grade sarcoma tend to be aggressive. Tumor etiology is largely unknown. To better understand the global genome alterations and gene mutations in MAS, whole-genome sequencing (WGS) and target validation analysis were performed. MAS showed remarkable chromosome (chr) copy number variation (CNV), specifically, gains in chr 1q, 5p, 12p, 12q, and 17q and losses in chr 3p, 3q, 9p, and 11q. Gain of chr 12q13-15 was present in 50% of cases. The selected gene products in gain regions were upregulated as measured by immunohistochemistry. HMGA2 overexpression was significantly correlated with SO. While the structural variation (SV) rate was relatively low overall, a disproportionally high rate of break-ends at chr 7 was noted involving 6 in-frame rearrangement fusion genes. Among 40 frequently mutated genes detected by WGS and validated in 29 MAS by next generation sequencing (NGS), KMT2C, and BCOR were frequently seen in MAS both with and without SO, while MAGEC1 and KDM6B were strongly associated with SO. Overall, a higher rate of frequently mutated genes was found in MAS with SO (33%) than MAS without (11%). This study uncovers the complex and specific genetic alterations in this malignancy. The findings provide a tool for future investigation of these molecular changes in tumorigenesis and target therapies.

Polycyclic aromatic hydrocarbons and n-alkanes in sediments of the Upper Scheldt River Basin: contamination levels and source apportionment.

The Scheldt River system is located in northern France, Belgium and the Netherlands and includes a dense network of rivers, which contributed to the urban and industrial development in this area. Three sediment cores, collected in the Upper Scheldt River (Helkijn) and two of its tributaries (the Lys River at Wervik and the Espierre Canal), were analysed for n-alkanes and polycyclic aromatic hydrocarbons (PAHs). Total n-alkane and PAH concentrations in all the sampled cores ranged from 2.8 to 29 mg kg(-1) and from 4.9 to 96 mg kg(-1), respectively. The contributions of biogenic, petrogenic and pyrolytic sources were investigated using n-alkane indexes and PAH diagnostic ratios. n-alkane chromatograms were characterized by the predominance of odd over even long chain n-alkanes (produced by terrestrial plants) and by the occurrence of a broad unresolved complex mixture (UCM) which evidenced biodegraded petroleum residues. For the three studied cores, correlations between the concentrations of UCM and n-alkanes (both expressed on an organic carbon basis) indicated a common origin or similar pathways of these allochtonous compounds to the aquatic environment. Wervik sediments were distinguished by higher n-alkane concentrations and by a major aquatic biogenic source for low molecular weight n-alkanes. The prevalence of combustion-derived PAHs was indicated by the high contribution of four, five and six rings compounds and was confirmed by isomer ratios. Higher levels of low molecular weight PAHs in Helkijn surface sediments suggested modest petrogenic inputs in this navigable canal. High PAH concentrations in Espierre sediments could be explained by a major historical contamination from urban and industrial emissions.