• Geomechanics and Engineering
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• v.35 no.4
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• pp.411-424
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• 2023

Reasonable estimates of tunnel lining dislocations in the operation stage, especially under longitudinal differential settlement, are important for the design of waterproof gaskets. In this paper, a modified shell-joint model is proposed to calculate shield tunnel dislocations under longitudinal differential settlement, with the ability to consider the nonlinear shear stiffness of the joint. In the case of shell elements in the model, an elastoplastic damage constitutive model was adopted to describe the nonlinear stress-strain relationship of concrete. After verifying its applicability and correctness against a full-scale tunnel test and a joint shear test, the proposed model was used to analyze the dislocation behaviors of a shield tunnel in Shanghai Metro Line 2 under longitudinal differential settlement. Based on the results, when the tunnel structure is solely subjected to water-earth load, circumferential and longitudinal joint dislocations are all less than 0.1 mm. When the tunnel suffers longitudinal differential settlement and the curvature radius of the differential settlement is less than 300 m, although maximum longitudinal joint dislocation is still less than 0.1 mm, the maximum circumferential joint dislocation is approximately 10.3 mm, which leads to leakage and damage of the tunnel structure. However, with concavo-convex tenons applied to circumferential joints, the maximum dislocation value reduces to 4.5 mm.

• Imaging Science in Dentistry
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• v.42 no.1
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• pp.13-18
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• 2012

Purpose : The aim of this study was to investigate the effect of the autologous blood injection (ABI) for chronic recurrent temporomandibular joint (TMJ) dislocation using magnetic resonance imaging (MRI). Materials and Methods : ABI was applied to 14 patients who had chronic recurrent TMJ dislocation. MRIs of the patients were taken and compared before and one month after the injection. Results : All of the patients had no dislocations of their TMJs on clinical examination one month after the injection. In the pre-injection, unilateral or bilateral TMJ dislocations were observed on MRIs in all patients. One month after the injection, TMJ dislocations were not observed in MRI evaluation of any patients. A significant structural change that caused by ABI was not observed. Conclusion : The procedure was easy to perform and it caused no foreign body reaction. However, it was unclear how the procedure prevented the dislocation.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.394-397
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• 2014

Background Proximal interphalangeal joint (PIPJ) dislocations represent a significant proportion of hand clinic visits and typically require frequent follow-ups for clinical assessment, orthotic adjustments, and physiotherapy. There are a large number of treatment options available for PIPJ dislocations, yet no prospective or controlled studies have been carried out, largely due to the diversity of the various types of injuries. Methods We retrospectively reviewed all the PIPJ dislocations in our institution over a five-year period and directly compared the different splinting techniques that we have used over this time frame. Results There were a total of 77 dislocations of the PIPJ (57 men and 20 women) that were included in our study. We found that our management has shifted gradually from complete immobilisation to controlled early mobilisation with figure-of-eight splints. Following treatment, the range of motion of the PIPJ in the figure-of-eight group was significantly greater than that in the other three methods (P<0.05) used. There were significantly fewer hospital visits in the figure-of-eight splint group than in the other treatment groups. Conclusions The treatment of PIPJ dislocations has undergone a significant evolution in our experience. Early controlled mobilisation has become increasingly important, and therefore, splints have had to be adapted to allow for this. The figure-of-eight splint has yielded excellent results in our experience. It should be considered for all PIPJ dislocations, but careful patient selection is required to achieve optimum results.

• Journal of Trauma and Injury
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• v.31 no.1
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• pp.43-50
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• 2018

Traumatic hip joint dislocations account for 2-5% of total joint dislocations. Bilateral asymmetric hip joint dislocation with anteriorly and posteriorly dislocation is an even more rare case because it was according to G. Loupasis reported in 11 cases only since 1879. We want to report 2 cases of bilateral asymmetric hip joint dislocation with unilateral acatabulum fracture which happened in our hospital. Bilateral asymmetric dislocation of hip joint accompanied by unilateral fracture of acetabulum is a very rare case so statistical verification cannot be done. However, close examinations are required at early treatment and follow-up because the patterns of dislocation and fracture of hip joint are variable and an orthopedic emergent condition and several complications may occur at both hip joints.

• Clinics in Shoulder and Elbow
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• v.17 no.4
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• pp.205-208
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• 2014

Sternoclavicular joint posterior dislocations are considered a very uncommon, and type of injury where if esophagus or airway injury occurs behind the clavicle, it poses a high risk to the patient. In addition, if epiphyseal fracture occurs as a result of the sternoclavicular joint posterior dislocation, surgical treatment is often required. However, in the absence of a complete ossification of the clavicle, it is difficult to differentiate between a simple dislocation and epiphyseal fracture-dislocation solely based on simple radiographs or computed tomography scans. In this case report, the authors present a case in which a sternoclavicular joint posterior dislocation was diagnosed in a 14-year-old male athlete. The case report discusses how the posterior dislocation without epiphyseal fracture was diagnosed using an ultrasound and subsequently treated with successful outcomes using manual reduction. The case report presents our findings along with discussion that includes a literature review of relevant research.

• Journal of Korean Foot and Ankle Society
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• v.6 no.2
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• pp.265-270
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• 2002

Metatarsophalangeal joint dislocations are unusual, and especially most dorsal metatarsophalangeal joint dislocations can be easily reduced with closed manipuations. But we are reporting a case of irreducible traumatic dislocation of the fourth, fifth metatarsophalangeal joint with closed manipulation. So open reduction was performed. Fixation with Kirschner wire was necessary because of joint instability. This report demonstrates the phathology and the reason why closed manipulation failed.

• Journal of Korean Orthopaedic Sports Medicine
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• v.1 no.2
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• pp.143-148
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• 2002

Purpose: We examined patients to evaluate the clinical results of traumatic metacarpophalangeal(M-P) dislocations of the thumb, uncommon and irreducible. Materials and Methods: In 11 traumatic M-P dislocations of the thumb, the types of dislocations were 10 dorsal and 1 volar dislocations resulted from the impacted and hyperextended forces on thumb. Authors evaluated the possibility of closed reduction, the anatomical structures interfering with closed reduction, and the surgical approaches. Results: Eight cases were treated with open reduction through volar approach and two cases were treated with closed reduction. Joint fusion was done with a plate in a chronic case. Initial closed reduction was attempted in all cases, but succeeded in only 2 cases because the interposed ruptured volar plate, the flexor pollicis brevis tendon and ulnar sesamoid bone at the volar side of the M-Pjoint were the obstacles to reduce. The metacarpal head was caught in button-hole slit between theflexor pollicis brevis and the ruptured volar joint capsule in all cases. Conclusion: Similar with the M-P joint dislocations of other fingers, the dorsal complex M-P dislocations of the thumb due to hyper extension are unusual and can't easily be reduced by closed manipulation. It is necessary to pay attention to the ruptured volar plate, capsule, the subluxated portion ofthe sesamoid and flexor pollicis brevis as interfering structures.

• Journal of Trauma and Injury
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• v.36 no.1
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• pp.70-73
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• 2023

The hip is a stable ball-and-socket joint. Bilateral anterior dislocations of the native hip joints account for fewer than 1% of all dislocations. We present a unique case of a bilateral anterior dislocation in a patient who presented to our institution within 6 hours of trauma. The dislocations were promptly reduced under propofol anesthesia in the operating room. The patient did not suffer a concurrent fracture. After the procedure, we performed regular X-ray examinations for 2 years to rule out the development of avascular necrosis of the head of the femur. The course of the patient was unremarkable.

• Clinics in Shoulder and Elbow
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• v.21 no.2
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• pp.95-100
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• 2018

Background: The purpose of this study was to evaluate the clinical outcomes and complications of hook plate fixation in acromioclavicular (AC) joint dislocations and distal clavicle fractures. Methods: We retrospectively reviewed a series of 60 consecutive patients with hook plate fixation for AC joint dislocation (group I) and distal clavicle fracture (group II). Groups I and II had 39 and 21 patients, respectively. Clinical results were evaluated using the pain visual analogue scale (VAS), simple shoulder test, and Constant-Murley scores. In addition, subacromial erosion and stiffness were evaluated as complications. Results: At the removal, the pain VAS was $2.69{\pm}1.30$ and $4.10{\pm}2.14$ in groups I and II, respectively, which were significantly different (p=0.003). The simple shoulder test score was $9.59{\pm}1.60$ and $7.81{\pm}2.67$ in groups I and II, respectively, which were also significantly different (p=0.002). Subacromial erosion was significantly more frequent in group II (14/21 patients, 66.7%) than in group I (15/39 patients, 38.5%) (p=0.037), and stiffness was also higher in group II (17/21 patients, 81.0%) than in group I (22/39 patients, 56.4%), but it was not significant. Conclusions: Hook plate fixation showed good clinical and functional results for the treatment of acute unstable AC joint dislocation and distal clavicle fracture. But, in distal clavicle fractures, there are more subacromial erosion and stiffness compare with acute unstable AC joint dislocation.

• Earthquakes and Structures
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• v.17 no.4
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• pp.411-424
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• 2019

In this study, a numerical model of a shield tunnel with an assembled segmental lining was built. The seismic response of the segmental lining of the section of the shield tunnel in Line 1 of the Chengdu Metro is analyzed as it passes through the interface of sand-cobble and mudstone layers. To do so, the node-stress seismic-motion input method was used to input the seismic motion measured during the 2008 Wenchuan earthquake, and the joint openings and dislocations associated with the earthquake action were obtained. With reference to the Ethylene-Propylene-Diene Monomer (EPDM) sealing gaskets used in the shield tunnels in the Chengdu Metro, numerical simulation was applied to analyze the contact pressure along the seepage paths and the waterproof property under different joint openings and dislocations. A laboratory test on the elastic sealing gasket was also conducted to study its waterproof property. The test results accord well with the numerical results and the occurrence of water seepage in the section of the shield tunnel in Line 1 of the Chengdu Metro during the 2008 Wenchuan earthquake was verified. These research results demonstrate the deformation of segmental joint under earthquake, also demonstrate the relationship between segmental joint deformation and waterproof property.