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Knee ; 26(2): 339-346, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30709642


BACKGROUND: Injuries of the anterolateral ligament (ALL) are fairly common in patients with ruptures of the anterior cruciate ligament (ACL). Before considering repair or reconstruction of the ALL, the lack of knowledge with regard to the biomechanical behavior of this ligament must be considered. The purpose of this study was to analyze the strain of the ALL induced by tibial internal rotation at different flexion angles and find out the strain distribution features. METHODS: The ALLs of ten fresh-frozen cadaver knees were dissected. All specimens underwent tibial internal rotation from 0° to 25° at 30°, 60°, 90°, and 120° of knee flexion. Strain distribution of the ALL during internal rotation was recorded by digital image correlation (DIC). The overall strain and sub-regional strain were measured. RESULTS: The strain of the ALL increased with increasing tibial internal rotation. With 25° of internal rotation, the overall strain at each flexion angle was 12.89 ±â€¯2.73% (30°), 15.32 ±â€¯2.50% (60°), 18.94 ±â€¯2.34% (90°), and 20.10 ±â€¯3.27% (120°). The sub-regional strain was significantly different at all flexion angles. The strain of the distal 1/3 of the ALL was the greatest, followed by the middle 1/3, while the proximal 1/3 was the smallest (all P < 0.001). CONCLUSION: The ALL resisted internal rotation of the tibia by becoming more tense with increasing rotation. A significantly high strain was observed in the distal portion near the tibial insertion site of the ALL, which may suggest that this region is prone to injury with excessive internal rotation.

Lesões do Ligamento Cruzado Anterior/fisiopatologia , Ligamento Cruzado Anterior/fisiopatologia , Articulação do Joelho/fisiopatologia , Amplitude de Movimento Articular/fisiologia , Adulto , Idoso , Ligamento Cruzado Anterior/cirurgia , Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/métodos , Fenômenos Biomecânicos , Cadáver , Feminino , Humanos , Articulação do Joelho/cirurgia , Masculino , Pessoa de Meia-Idade , Tíbia/cirurgia
Foot Ankle Int ; 39(5): 618-628, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29533732


BACKGROUND: Ligament repair and augmentation techniques can stabilize syndesmosis injuries. However, little is known about the mechanical behavior of syndesmotic ligaments. The aim of this study was to analyze full-field strain, strain trend under foot rotation, and subregional strain differences of the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), and interosseous membrane (IOM). METHODS: Eleven fresh-frozen lower limbs were dissected to expose the AITFL, PITFL, and IOM. The foot underwent rotation from 0° to 25° internal and 35° external, with 3 ankle positions (neutral, 15° dorsiflexion, and 25° plantarflexion) and a vertical load of 430 N. Ligament strain was recorded using digital image correlation. RESULTS: The mean strain on the AITFL with 35° external rotation was greater in the proximal portion compared with distal portion in the neutral position ( P = .009) and dorsiflexion ( P = .003). The mean strain in the tibial insertion and midsubstance near tibial insertion were greater when compared with other regions ( P = .018 and P = .009). The subregions of mean strain in the PITFL and IOM groups were not significantly different. The strain trend of AITFL, PITFL, and IOM showed common transformation, just when the foot was externally rotated. CONCLUSION: The findings of this study show that a significantly high strain was observed on the proximal part and the midsubstance near the Chaput tubercle of the AITFL when the ankle was externally rotated. All 3 ligaments resisted the torque in the syndesmosis by external rotation of the foot. CLINICAL RELEVANCE: This study allows for better understanding of the mechanical behavior of the syndesmosis ligaments, which could influence the repair technique and AITFL augmentation techniques.

Surg Endosc ; 30(10): 4553-61, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26873748


BACKGROUND: Suture skills are essential to laparoscopic liver resection. The current suture training models are not ideal enough. The aim of this study is to develop and verify a highly simulated-bleeding continuously perfused training model (CPTM) and to evaluate its training efficacy. METHODS: CPTM was constructed using fresh lamb liver whose portal veins were perfused with red-dyed liquid gelatin. Construct validity of CPTMs was tested in 33 participants with three levels of laparoscopic experience (experts, intermediates, and novices) who were demanded to finish one superficial stitch and one deep stitch for suture hemostasis on CPTMs. The CPTMs were also evaluated by the experts. CPTMs were compared with dry box training models (DBTMs) regarding training efficacy among the novices who were assigned to DBTM and CPTM groups to, respectively, complete a 10-day training on CPTMs or DBTMs. Before and after their assignments, their superficial stitches were assessed by completion time, suture accuracy, and suture knot performance while their deep stitches by completion time and bleeding control. RESULTS: CPTM proved to be construct valid by both superficial and deep stitches. Significant differences were found regarding completion time (763, 271, 174 s), suture accuracy (4.4, 1.8, 0.2 mm), and suturing knot performance (12.1, 21.5, 22.0) for superficial stitches (p < 0.001), as well as regarding completion time (807, 423, 277 s) for deep stitches (p < 0.001). Positive comments were given by all experts. CPTMs helped novices to acquire laparoscopic suture skills. Their training efficacy was significantly better than that of DBTMs (p < 0.05). Learning curves of CPTM group plateaued at the sixth round for superficial stitches and at the seventh round for deep stitches. CONCLUSION: CPTM offers trainees a highly simulated-bleeding means to acquire advanced laparoscopic suture skills. The suture skills learned on CPTMs may improve significantly at the seventh round.

Competência Clínica , Laparoscopia/educação , Curva de Aprendizado , Fígado/cirurgia , Treinamento por Simulação , Técnicas de Sutura/educação , Animais , Perda Sanguínea Cirúrgica , Humanos , Masculino , Modelos Anatômicos , Reprodutibilidade dos Testes , Ovinos
Nan Fang Yi Ke Da Xue Xue Bao ; 35(9): 1362-5, 2015 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-26403757


OBJECTIVE: To construct a three-dimensional (3D) liver model of Wuzhishan mini-pig for virtual liver surgeries. METHODS: The biliary tree and hepatic arteries of Wuzhishan mini-pig were perfused with perchloroethylene and ethyl acetate along mixed with lead oxide, and the hepatic vein and portal vein were perfused with a mixture of dental base acrylic resin and lead oxide. The sectional images were acquired using a 64-slice spiral CT, and the 3D models of the portal vein, hepatic vein, biliary tree, hepatic arteries, and liver parenchyma were reconstructed using Mimics software; the resection image of the liver was also designed. The intrahepatic vascular cast was prepared by corroding the soft tissue with hydrochloric acid. RESULTS AND CONCLUSION: The intrahepatic vascular cast obtained fully retained the vascular architecture and displayed the fifth- and sixth-level branches of the hepatic vein and portal vein and the third- and fourth-level branches of the artery and bile duct. The 3D model of liver allowed stereoscopic and accurate display of the third- and fourth-level branches of the hepatic vein and portal vein and the second- and third-level branches of the artery and bile duct. The 3D model showed fewer branches but represented the structural distribution identical to the cast. The 3D model could clearly display the spatial relationship between the vasculature and the soft tissue in virtual resection of the liver tissues, and thus provides a useful model for training of laparoscopic liver resection.

Imagem Tridimensional , Fígado/anatomia & histologia , Modelos Anatômicos , Animais , Ductos Biliares , Artéria Hepática , Veias Hepáticas , Veia Porta , Suínos , Porco Miniatura , Tomografia Computadorizada Espiral
PLoS One ; 8(1): e53580, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23326461


BACKGROUND: With the properties of three-column fixation and anterior-approach-only procedure, anterior transpedicular screw (ATPS) is ideal for severe multilevel traumatic cervical instabilities. However, the accurate insertion of ATPS remains challenging. Here we constructed a patient-specific biocompatible drill template and evaluated its accuracy in assisting ATPS insertion. METHODS: After ethical approval, 24 formalin-preserved cervical vertebrae (C2-C7) were CT scanned. 3D reconstruction models of cervical vertebra were obtained with 2-mm-diameter virtual pin tracts at the central pedicles. The 3D models were used for rapid prototyping (RP) printing. A 2-mm-diameter Kirschner wire was then inserted into the pin tract of the RP model before polymethylmethacrylate was used to construct the patient-specific biocompatible drill template. After removal of the anterior soft tissue, a 2-mm-diameter Kirschner wire was inserted into the cervical pedicle with the assistance of drill template. Cadaveric cervical spines with pin tracts were subsequently scanned using the same CT scanner. A 3D reconstruction was performed of the scanned spines to get 3D models of the vertebrae containing the actual pin tracts. The deviations were calculated between 3D models with virtual and actual pin tracts at the middle point of the cervical pedicle. 3D models of 3.5 mm-diameter screws were used in simulated insertion to grade the screw positions. FINDINGS: The patient-specific biocompatible drill template was constructed to assist ATPS insertion successfully. There were no significant differences between medial/lateral deviations (P = 0.797) or between superior/inferior deviations (P = 0.741). The absolute deviation values were 0.82±0.75 mm and 1.10±0.96 mm in axial and sagittal planes, respectively. In the simulated insertion, the screws in non-critical position were 44/48 (91.7%). CONCLUSIONS: The patient-specific drill template is biocompatible, easy-to-apply and accurate in assisting ATPS insertion. Its clinical applications should be further researched.

Materiais Biocompatíveis/farmacologia , Parafusos Ósseos , Vértebras Cervicais/efeitos dos fármacos , Teste de Materiais/métodos , Procedimentos Ortopédicos/métodos , Idoso , Feminino , Humanos , Imagem Tridimensional , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Modelos Anatômicos