Javad Esmaeilzadeh; saeed hesaraki; mohammad-mehdi Hadavi; mohammad hosein Ebrahimzadeh
Abstract
Background: To study the creep behavior for a series of biodegradable nanocomposites, which are used as implantable devices in the body such as bioscrews, is a crucial factor. In the current paper, we are investigating these biomaterials -short-time creep and creep recover manners- in several classic ...
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Background: To study the creep behavior for a series of biodegradable nanocomposites, which are used as implantable devices in the body such as bioscrews, is a crucial factor. In the current paper, we are investigating these biomaterials -short-time creep and creep recover manners- in several classic models.Methods: The creep and creep recovery behaviors of nanocomposites composed of biodegradable polymer blends, poly (D/L) lactic acid (PDLLA) and polycaprolactone (PCL) reinforced with three different contents of 1, 3 and 6 percent weight percentage (Full name?)% bioactive glass nanoparticles (m-BGn) were modeled. Several theoretical models including Findley power law, Burgers and Weibull models were used to establish the relations between m-BGn dispersion and final creep and creep-recovery behaviors of nanocomposites.Results: The Findley power law model confirmed that the lowest ‘A’ and highest ‘n’ parameters ( A is the amplitude of the transient creep strain and n is the time exponent) belong to the sample with the highest young modulus and the nanocomposites compared to PDLLA/PCL blends have the lower ‘A’ and higher ‘n’ which can be related to retardation effect of m-BGn on creep strains. Besides, the burgers model results illustrated that all viscoelastic and viscoplastic parameters for nanocomposites possess higher values than those of the neat PDLLA/PCL blend. It means that the addition of glass nanoparticles leads to decrease creep strain , increasing the Burgers model prediction values which have inverse trend with . Moreover, the weibull distribution model results acknowledge that the introduction of m-BGn into PDLLA/PCL polymeric blends cause decrease in the viscoelastic strain recovery values. This is due to hindering effects of m-BGn on creep recovery behavior of nanocomposites.Conclusion: The results obtained from modeling of creep-recovery manners of PDLLA/PCL blend and its nanocomposites approved that the bioactive glass reinforcement nanoparticles play impeding role on creep and creep recovery behaviors. Level of evidence: I
Mehran razavipour; salman ghaffari; masoud shayestehazar; abolfazl kazemi; Shayan Amjadi
Abstract
Introduction: One of the factors affecting the prognosis of distal radius fracture is anatomical correction. Several studies conducted in connection with the reconstruction of anatomical and functional consequences, which have had conflicted results. This study has been designed and implemented aimed ...
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Introduction: One of the factors affecting the prognosis of distal radius fracture is anatomical correction. Several studies conducted in connection with the reconstruction of anatomical and functional consequences, which have had conflicted results. This study has been designed and implemented aimed to investigate the relationship between radiological index (anatomical) after displaced distal radius fractures with function and clinical outcomes.Methods: This is a retrospective cohort study to assess the association of radiological indices with clinical and functional outcomes of distal radius fractures. In this study, radiological indices, including the radius, volar tilt, tear drop angle, articular cavity depth and AP Distance were investigated. Pinch and grip strength were measured and Quick DASH questionnaire evaluated the performance.Results: Pain score significantly correlated with radial shortening (P=0,038), but it was not independent of treatment method. Patients’ satisfaction rate was significantly lower in patients with abnormal articular depth, independent of age and treatment method (P=0.004). Quick-DASH score significantly correlated with radial shortening and articular cavity depth, independent of treatment method and age (P=0.006). Percutaneous pinning associated significantly with less pain, less disability and more satisfaction (P<0.05).Conclusion: Radial shortening, articular cavity depth had a correlation with the clinical and functional outcomes. While Some studies suggested radiological indices in the elderly is not necessarily have a correlation with functional outcomes, in this study correlation of radiologic indices with clinical and functional outcome was independent of age.
davood asgari
Abstract
Abstract
Background: Damage in cartilage tissue is one of the global challenges and affects a large percentage of people. Trauma or age-related degenerative disease is the main cause of osteoarthritis. The aim of this study was to evaluate the effect of intra-articular injection for bone marrow mesenchymal ...
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Abstract
Background: Damage in cartilage tissue is one of the global challenges and affects a large percentage of people. Trauma or age-related degenerative disease is the main cause of osteoarthritis. The aim of this study was to evaluate the effect of intra-articular injection for bone marrow mesenchymal stem cells and the resulting secretions in repairing the damaged cartilage of the rat knee joint.
Methods: 30 male rats that weights approximately 200 to 250 g were randomly divided into five groups of 6 rats, including healthy group (receiving physiological serum), osteoarthritis group (monosodium iodoacetate injection), mesenchymal group, mesenchymal group + receiving the same volume of cell secretions + culture medium and culture medium injection group. Four weeks later, the rats have been killed and the hip joint examined by both macroscopic and microscopic methods.
Results: The results showed that the injection of 2.5*105 cells per ml had a good effect on the repairing of cartilaginous lesions caused by the monosodium iodoacetate injection. Histological studies showed that fibrillation rate, the presence of small gaps and deep gaps (P <0.05) decreased in the mesenchymal treatment group. The level of proteoglycans in mesenchymal treatment group increased significantly (P <0.05). Also, in the treatment group with mesenchymal secretions and culture medium, changes were observed in repairing the damaged cartilage, which was not significantly different from the osteoarthritis group.
Conclusion: In this study, the restorative effect has benn confirmed for bone marrow mesenchymal stem cells and their secretions in improving histopathological lesions of rat articular cartilage.
Mohammad Fakoor; Hanoon Sadoni; Payam Mohammad Hosseini; Saeed Bastan
Abstract
AbstractIntroduction: This study aimed to find a statistical relationship between clinical and functional findings based on the Lysholm scoring scale in the success rate of surgery and patient satisfaction with the arthroscopic reconstruction of the anterior cruciate ligament (ACL).Method: This prospective ...
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AbstractIntroduction: This study aimed to find a statistical relationship between clinical and functional findings based on the Lysholm scoring scale in the success rate of surgery and patient satisfaction with the arthroscopic reconstruction of the anterior cruciate ligament (ACL).Method: This prospective and cross-sectional study was performed on 38 patients (42 knees) aged 17 to 45 years who underwent anterior cruciate ligament (ACL) reconstruction during 2018-2019 due to ACL rupture at Imam Khomeini Hospital in Ahvaz.6 and 12 months after surgery, clinical trials of "anterior drawer" and "Lachman test" were performed, and the standard Lysholm questionnaire for patients was completed. Then, the compatibility of the test results with the results of the Lysholm questionnaire and MRI was assessed.Results: In the diagnosis of ACL rupture, 6 months after surgery, the highest sensitivity was related to the anterior drawer and Lysholm scale tests, and the highest specificity was related to the Lachman test. Also, the highest positive predictive value was related to the Lachman test and the highest negative predictive value was related to the anterior drawer and Lysholm scale tests. 12 months after surgery, the highest sensitivity was related to the Lysholm scale and the highest specificity was related to the Lachman test. The highest positive predictive value was for the Lachman test and the highest negative predictive value was for the Lysholm scale. In the first 6 months, graft failure was observed in 13.6% of patients, but the percentage of patients with“Fair” and “Poor”Lysholm scale was 28.95%. In the second 6 months, graft failure was observed in 7.14% of patients, but the percentage of patients with“Fair” and “Poor”Lysholm scale was 19.05%.Conclusion: Since in some cases, such as excessive knee diameter due to obesity or swelling, the examination may be limited and citation of clinical test results may be erroneous, it is recommended that in addition to mechanical tests such as the Lachman test and the anterior drawer test, standard questionnaires such as Lysholm be used to more accurately assess the success of surgery and treatment, as well as to help identify more accurate lesions.
Javad Mortazavi; mohammad ali ghasemi; Alireza Amin Javaheri
Abstract
Leg Length Discrepancy (LLD) after Total Hip Arthroplasty (THA) is a prevalent complication that affects the patient's satisfaction with joint replacement surgery. It is the most common reasons for a patient's complaint of a doctor after a joint replacement. Patients will tolerate limb shortness more ...
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Leg Length Discrepancy (LLD) after Total Hip Arthroplasty (THA) is a prevalent complication that affects the patient's satisfaction with joint replacement surgery. It is the most common reasons for a patient's complaint of a doctor after a joint replacement. Patients will tolerate limb shortness more efficiently than their longevity. The LLD will create pain and limpness for the patients that result in premature aseptic loosening and back pain. Therefore, the surgeon should try to avoid this complication with the help of preoperative templating and various other methods during the operation. The present study examined the reasons for LLD and its preventive procedures in pre/intra-operation.
