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ACS Omega Oct 2023Stimuli-responsive ruthenium complexes - and -[Ru(Ctpy)(Cpyqu) OH] (- and -; Ctpy = 4'-decyloxy-2,2':6',2″-terpyridine and Cpyqu =...
Stimuli-responsive ruthenium complexes - and -[Ru(Ctpy)(Cpyqu) OH] (- and -; Ctpy = 4'-decyloxy-2,2':6',2″-terpyridine and Cpyqu = 2-[2'-(6'-decyloxy)-pyridyl]quinoline) were experimentally studied for adduct formation with a model DNA base. At 303 K, - exhibited 1:1 adduct formation with 9-ethylguanine (9-EtG) to yield -[Ru(Ctpy)(Cpyqu)(9-EtG)] (-). Rotation of the guanine ligand on the ruthenium center was sterically hindered by the presence of an adjacent quinoline moiety at 303 K. Results from H NMR measurements indicated that photoirradiation of a - solution caused photoisomerization to -, whereas heating of - caused ligand substitution to -. The distal isomer of the aqua complex, -, was observed to slowly revert to - at 303 K. In the presence of 9-EtG, - underwent thermal back-isomerization to - and adduct formation to -. Kinetic analysis of H NMR measurements showed that adduct formation between - and 9-EtG was 8-fold faster than that between - and 9-EtG. This difference may be attributed to intramolecular hydrogen bonding and steric repulsion between the aqua ligand and the pendant moiety of the bidentate ligand..
PubMed: 37841177
DOI: 10.1021/acsomega.3c05343 -
Journal of Orthopaedic Science :... Oct 2023Studies have shown that the first metatarsal contributes to hallux valgus. The proximal phalanx, another factor that defines the hallux valgus angle, also contributes to...
BACKGROUND
Studies have shown that the first metatarsal contributes to hallux valgus. The proximal phalanx, another factor that defines the hallux valgus angle, also contributes to the development of hallux valgus. There have been no reports on the use of computed tomography to evaluate bone morphology of the proximal phalanx. The purpose of this study was to analyze the morphology and deformity of the proximal phalanx and its relationship to hallux valgus using computed tomography, and to consider the indications for proximal phalanx surgery in hallux valgus.
METHODS
Patients who consulted at our clinic for foot and ankle disorders and underwent both weight-bearing radiography and computed tomography between May 2019 and March 2022 were included in the study. The hallux valgus angle, sesamoid subluxation, first metatarsal length, proximal phalanx length, metatarsal-proximal phalanx ratio, proximal phalanx valgus angle, metatarsal-proximal phalanx angle, proximal phalanx rotation angle, and distal phalanx-proximal phalanx angle were measured. These parameters were compared between the hallux valgus and control groups. In the hallux valgus group, the hallux valgus and proximal phalanx valgus angles were measured and compared using weight-bearing radiographs.
RESULTS
A total of 83 feet in 65 patients were diagnosed with hallux valgus (hallux valgus group; mean age of 68.0 ± 13.8 years) and 30 feet in 22 patients without hallux valgus (control group; mean age of 67.0 ± 25.8 years) were included in the study. The proximal phalanx length, metatarsal-proximal phalanx ratio and angle, and distal phalanx-proximal phalanx angle were significantly greater in the hallux valgus group than in the control group. However, the proximal phalanx valgus and rotation angles were not significantly different between the groups.
CONCLUSION
Since there was no significant difference in the proximal phalanx morphology, except length, between the hallux valgus and control groups, the indications for osteotomy of the proximal phalanx should be carefully considered.
PubMed: 37852898
DOI: 10.1016/j.jos.2023.09.010 -
Journal of Shoulder and Elbow Surgery Feb 2024The shoulder joint complex in the overhead athlete is organized to effectively transfer the proximally generated forces distally into the arm. The organization also... (Review)
Review
The shoulder joint complex in the overhead athlete is organized to effectively transfer the proximally generated forces distally into the arm. The organization also protects the joints and anatomic structures against the repetitive high velocities, large ranges of motions, and compressive, shear, translational, and distraction loads in the overhead motion while placing the hand in the "launch window." Coupling of the movements of the scapula, clavicle, and humerus results in scapulohumeral rhythm (SHR). Effective SHR requires the clavicle and scapula-and, at times, the mechanically linked claviscapular segment-to move the arm into the task-specific position and motion and requires the humerus to move through the ranges of motion to achieve the specific task in the throwing motion. Alterations in SHR can negatively affect effective shoulder joint complex function in the overhead throwing motion and increase injury risk. There are 4 phases of clavicular, scapular, and claviscapular motion that are coupled with arm motion in SHR. The first 3 phases occur in arm elevation motions from 0°-90° and result in the claviscapula and humerus being placed in task-specific positions. The fourth phase is coupling of claviscapular motion with humeral motion to maintain ball-and-socket kinematics throughout the throwing motion. Alterations in this composite motion are termed "scapular dyskinesis." The dyskinesis is considered an impairment of the efficient mobility of the claviscapular segment of the shoulder complex. The most prevalent problem with scapular dyskinesis is the association of scapular protraction and consequent glenoid antetilt with alterations in humeral rotation and posterior humeral head translation to produce shoulder joint internal impingement. Task effectiveness in overhead throwing is also based on and determined by humeral range of motion, precision of humeral motion, and velocity of humeral motion, as well as humeral and arm position in 3-dimensional space. This activity requires maximum ball-and-socket kinematics to create the highest amount of concavity-compression that creates stability for the joint. There are bony and soft-tissue contributions to this stability. Injuries to the glenoid labrum are among the most common deficits that alter concavity-compression. Clinical evaluation of the shoulder joint complex in the injured throwing athlete should be comprehensive and systematic, following an evaluation pathway for proximal and distal causative factors and including observation of humeral motion. This type of evaluation can result in intervention protocols that address the pathoanatomic, pathophysiological, and pathomechanical deficits identified.
Topics: Humans; Shoulder Joint; Shoulder; Scapula; Humerus; Movement; Shoulder Impingement Syndrome; Dyskinesias; Biomechanical Phenomena; Range of Motion, Articular
PubMed: 37499784
DOI: 10.1016/j.jse.2023.06.031 -
Journal of Shoulder and Elbow Surgery Dec 2023Ulnar collateral ligament (UCL) tears are common in baseball players. Although magnetic resonance imaging (MRI) is the most used imaging modality for UCL injuries, the...
BACKGROUND
Ulnar collateral ligament (UCL) tears are common in baseball players. Although magnetic resonance imaging (MRI) is the most used imaging modality for UCL injuries, the inter-rater reliability of MRI analyzing specific characteristics of UCL pathology has not been defined. The purpose of this study was to define the inter-rater reliability of MRI for evaluating UCL characteristics.
METHODS
Three surgeons analyzed 45 noncontrast MRIs: 15 without UCL tears, 15 with intraoperatively confirmed partial-thickness tears, and 15 with intraoperatively confirmed full-thickness tears. Findings evaluated included ligament characteristics (periligamentous or osseous edema, ligament hypertrophy, calcifications, and partial- or full-thickness tearing) and location of the pathology (proximal, midsubstance, or distal). Fleiss' κ coefficients were used to assess interobserver reliability.
RESULTS
There were high rates of agreement for midsubstance (κ: 0.50) and distal (κ: 0.69) ligament edema and proximal osseous edema (κ: 0.48). There were low rates of agreement for proximal ligament edema (κ: 0.08), ligament thickening (κ: -0.02 to 0.20), and proximal to midsubstance calcifications (κ: -0.04 to 0.10). Midsubstance (κ: 0.55) and distal full-thickness tears (κ: 0.63) demonstrated higher agreement than proximal (κ: 0.29). Proximal partial-thickness tears (κ: 0.45) had higher agreement than midsubstance (κ: -0.02) or distal (κ: -0.02).
CONCLUSIONS
In our study, there was high inter-rater reliability regarding proximal osseous edema, midsubstance, and distal ligament edema and full-thickness tears. There was no agreement for midsubstance and distal partial-thickness UCL tears, but fair agreement for proximal tears. UCL tissue characteristics including ligament thickening and calcifications demonstrated low agreement. Challenges remain in effectively evaluating UCL tissue characteristics on noncontrast MRIs.
Topics: Humans; Collateral Ligament, Ulnar; Reproducibility of Results; Magnetic Resonance Imaging; Baseball; Edema; Collateral Ligaments
PubMed: 37481106
DOI: 10.1016/j.jse.2023.06.019 -
Journal of Stomatology, Oral and... Oct 2023The application of dental implants presents the occurrence of implant failures associated with bone proximal support. This study aims to assess implant behavior, in...
OBJECTIVES
The application of dental implants presents the occurrence of implant failures associated with bone proximal support. This study aims to assess implant behavior, in particular implant stability and strain distribution in the bone at different bone densities, and the effect of proximal bone support.
MATERIAL AND METHODS
Three bone densities (D20, D15, and D10) were considered in the experimental in vitro study, represented by solid rigid polyurethane foam and two conditions of bone support in the proximal region. A finite element model was developed and validated experimentally and a Branemark model at a 3:1 scale was implanted in the experiments; the model was loaded and extracted.
RESULTS
The results of the experimental models validate the finite element models with a correlation R equal to 0.899 and NMSE of 7%. The implant extraction tests for the effect of bone properties in the maximum load were 2832 N for D20 and 792 N for D10. The effect of proximal bone support changes the implant stability was observed experimentally; at 1 mm less bone support decreases by 20% of stability and at 2 mm by 58% for D15 density.
CONCLUSIONS
Bone properties and bone quantity are important for the initial stability of the implant. A bone volume fraction of less than 24 g/cm exhibits poor behavior and is not indicated for implantation. Proximal bone support reduces the primary stability of the implant and the effect is critical in lower bone density.
Topics: Humans; Bone Density; Finite Element Analysis; Dental Implants
PubMed: 37209971
DOI: 10.1016/j.jormas.2023.101512 -
Journal of Wrist Surgery Oct 2023The scaphotrapeziotrapezoidal (STT) joint transfers forces to the proximal carpal row from the thumb and fingers. Clinically, STT joint osteoarthritis is frequently...
The scaphotrapeziotrapezoidal (STT) joint transfers forces to the proximal carpal row from the thumb and fingers. Clinically, STT joint osteoarthritis is frequently observed on plain radiographs though its role in the mechanics of the wrist joint remains unclear. Our purpose was to use a model of normal wrist types, to predict STT motion upon load. Five normal computed tomography scans of a wrist type 1 and five wrist type 2 were used to model the wrist. A 200-N force was split and applied to the trapezoid and capitate to replicate forces during a knuckle pushup. The bony movement was predicted by the model as bony movement using finite element analysis. We found differences in force transfer through the STT joint between the two wrist types when loading the index and middle fingers. Type 1 wrists moved quantitatively more anterior-posterior, type 2 wrists moved more medially-laterally and more proximally-distally. The trapezium in type 1 wrists moved more in the coronal plane than in type 2 wrists. The trapezoid moved more from distal to proximal in a type 2 wrist, = 0.03. This study found differences in motion upon loading through the STT joint between type 1 and 2 wrists. Type 2 wrists moved more radially toward the proximal scaphoid and scapholunate ligament. This study may provide a mechanical basis for degenerative configurations. By linking observed patterns of degeneration to their mechanical causes we can aid in prevention of arthritis.
PubMed: 37841353
DOI: 10.1055/s-0043-1761287 -
International Orthopaedics Apr 2024German-speaking surgeons have left a deep imprint on the history of diagnostics and treatment of proximal femur fractures. Some of the studies published in German have... (Review)
Review
INTRODUCTION
German-speaking surgeons have left a deep imprint on the history of diagnostics and treatment of proximal femur fractures. Some of the studies published in German have fell into oblivion, others are cited until today, although sometimes quite inaccurately. The cause of such inaccuracies are citations from secondary sources due to unavailability of the original or inability to read it because of a language barrier. In the current literature, globally predominated by English articles, the "German history" of treatment of proximal femur fractures remains undervalued. The aim of the present article is to point out its contribution.
MATERIALS AND METHODS
Literature search was performed in original publications and historical sources.
RESULTS
The German-speaking surgeons have considerably contributed to the development of the treatment of proximal femur fractures. The analyzed period between 1847 and 1970 may be divided into three basic periods. In the first period (1847-1896), the German-speaking surgeons (Langenbeck, Trendelenburg, König, Heine, Dolinger) were the first worldwide to start treating the fractures of proximal femur operatively. In the second period (1897-1935), mainly in the 1930s, the initiative in Europe was taken over by surgeons publishing studies in France and in Belgium. Overseas, American surgeons were coming to the forefront. In Germany, only Pauwels developed the first biomechanical classification of femoral neck fractures. In the third period (1936-1970), mainly in the 1940s and 1950s, implants were designed (Pohl, Künstcher), based on close collaboration between German engineers and surgeons, that served as a model for a dynamic hip screw and a proximal femoral nail, which are currently the implants of choice in the treatment of trochanteric fractures.
CONCLUSION
The historical contribution of German-speaking surgeons to understanding the issue of proximal femur fractures and their operative treatment is far more significant than presented in the historical studies published in English.
Topics: Humans; Fracture Fixation, Internal; Proximal Femoral Fractures; Hip Fractures; Femoral Neck Fractures; Femur; Bone Nails
PubMed: 37980285
DOI: 10.1007/s00264-023-06039-7