Background: Acromioclavicular dislocation is one of the most common shoulder injuries among athletes, and appropriate treatment of acromioclavicular joint dislocation is controversial. Acromioclavicular ligament (AC) and Coracoclavicular(CC) are the most important joint stabilizers. In joint dislocation the ligaments are torn, therefore the repair of these ligaments play an important role in increasing the joint stabilization after surgical treatment. The purpose of this study was to compare treatment results of Acromioclavicular dislocation with Coracoclavicular(CC) ligament repair and without it. Methods: In a descriptive analytical study, 40 patients with acute acromioclavicular dislocation required operative treatment were studied. In the target group in addition to an open reduction and fixation with Screws, Coracoclavicular(CC) ligament repair with non-absorbable suture was done. Two groups were compared in terms of clinical outcome and functional ability and complications. Results: In this study, 40 patients were studied, including 39 males (97. 1%) and 1 female (2. 6%) were studied. The mean age was 31. 6 ± 8. 1 years. Comparisons of patient’ s performance according to Constant Score showed a significant difference between two groups. So that has been in the ligament repaired was 8. 7 ± 1. 7 and in other group was 10. 1 ± 2. 1. Also according to the Constant on ligament repair was higher points score 90% excellent and 10% good, the other group rated was 70% excellent and 30% good. Coracoclavicular (CC) distance in patients undergoing CC ligament repair was significantly reduced and was equally to the healthy side While in the cases without ligament repair was not diminished coracoclavicular(CC) distance. No complications were observed in the groups. Conclusion: Coracoclavicular(CC) ligament repair lead to better functional ability in patients with acute acromioclavicular dislocation and not associated with any symptoms.

Objectives: Acromioclavicular joint (ACJ) dislocation is one of the most common shoulder injuries, especially in young and athletes, which has a significant effect on a patient’ s function. Therapeutic strategies include non-surgical and a variety of surgical methods. Each of the 2 therapies has some advantages and disadvantages and careful decision making regarding the appropriate therapeutic approach in these patients has not been achieved due to controversial results. Standard surgical treatment is not specified as well. In this regard, the present study was conducted to compare both row Screw and hook plate. Materials and Methods: In this retrospective cohort study, 68 patients were enrolled after referring to the Shohada Medical Education Center of Tabriz during 2014-2017 with the dislocation of the 4th, 5th, and 6th grade ACJ dislocation. In this study, 44 and 24 patients underwent open reduction and internal fixation with a Screw and a hook plate, respectively. The retest workers, and the shoulder range of motion (ROM), as well as pain and device failure were compared between the 2 groups. Results: According to the results, there were no significant differences between 68 patients with acute dislocation of ACJ type 4, 5, and 6 in terms of work time and pain intensity in the 2 groups (P = 0. 78 and P = 0. 29), but in the examination of ROM, abduction, forward flexion, and external rotation had significantly higher limitations in hook plate compared to the Screw (P = 0. 03, P = 0. 001, and P = 0. 02). The maximum motion limitation was observed in shoulder abduction, but the internal rotation between the 2 groups was not significantly different. Eventually, the device failure rate for the Screw was significantly higher and approximately 18. 4% whereas there was no device failure in hook plate fixation. Conclusions: Based on the present results regarding acromioclavicular dislocation, surgical treatment using a Screw showed better functional improvement in comparison to the hook plate although the probability of devise failure was higher.

Background: The acromioclavicular joint dislocation is one of the most common joint injuries that despite different methods of repair in cases of dislocation of grade 3 to 6, there are still many conflicts regarding the efficacy of these methods in previous studies. Therefore, in this study, we aimed to evaluate the patients' recovery and function after the fixation of the acromioclavicular joint with grade 3-6 using two surgical methods including pin and Screw tools. Methods: In this cross-sectional study, 34 patients with dislocation of acromioclavicular joint with grade 3 to 6 who were treated with pin (group 1) or Screw (group 2) in two groups of 17 patients were studied. Satisfaction from surgery and functional recovery were assessed using the Shoulder score questionnaire. Results: Overall satisfaction rate was 88. 2% in the group 1 and 82. 4% in the group 2 (P>0. 05). There was no significant difference in the range of motion in different motions of the joint (p>0. 05). The score for the shoulder score questionnaire was 11. 23 in the first group and 11. 70 in the second group was, which did not show significant difference (P>0. 05). Conclusion: Surgical treatment using pin and Screw tools in cases of acromioclavicular joint dislocation with grade 3-6 can achieve the same therapeutic and functional results. However, more studies are needed to confirm the efficacy of these two tools in various cases of acromioclavicular joint dislocation.

Background and Importance: Fracture-dislocation of the thoracic or lumbar spine (traumatic spondyloptosis) occurs in less than 5% of all spinal injuries mainly affecting the ventral direction. Case Presentation: A paraplegic young man was admitted to Shahid Kamyab Hospital in Mashhad City, Iran due to a motor vehicle accident. Computerized tomography (CT) showed a complete posterior dislocation of the T10 vertebral body on T9, with the superior articular processes of T9 bilaterally locked in the inferior endplate of T10 and complete fractures of the posterior elements. Conclusion: The spinal dislocation was re-aligned by a combination of Harrington fixation and pedicular Screws leading to spinal fusion. Six months after surgery, the patient was still paraplegic but the sensory symptoms in the lower extremities and clean intermittent catheterization improved.

The present study aims to investigate the elastic fields induced due to the motion of a Screw dislocation that moves along a linear path with an arbitrary direction in an infinitely extended isotropic medium. This investigation was performed based on the assumption that the dislocation moves at a constant velocity less than the speed of shear waves in the medium. In the present analysis, from the viewpoint of micromechanics, the dislocation was described using the concept of eigenstrain. The expression of such an eigenstrain field includes a constant to be determined in the sequel of the analysis by applying the jump condition of the displacement on the slip plane of the dislocation. Following the representation of the governing field equations of the problem, a two-dimensional Fourier transform was utilized and then, the closed-form solutions were obtained for the displacement and elastic strain fields of the delineated problem, for the first time. Subsequently, two special cases of the problem, the one pertinent to the motion of the dislocation along its slip plane and the other associated with its motion perpendicular to such plane were addressed. The derived expressions showed that the strain field of the problem has a singularity at the dislocation core. The obtained results demonstrated that at different velocities and in different motion directions, the displacement field of the problem suffers from constant discontinuity on the slip plane of the dislocation. Moreover, it was shown that at distances far away from the slip plane of the dislocation, the components of the strain field vanish. The presented results, in addition, exhibited the effect of the direction of the motion of the dislocation and its velocity on the induced elastic fields. Specifically, it was shown that with an increase in the velocity of the dislocation, the magnitudes of the components of the induced strain field become larger.

All materials are made up of sub-bodies, which constitute their substructure or microstructure. The size of a sub-body may vary from atomic dimensions to a macroscopic scale, such as grain size. Depending upon the nature and accuracy of the physical phenomena to be modeled, the average distance of the sub-bodies plays a central role. This distance may vary from the order of the lattice parameter (10-8 cm in perfect crystals), to a few millimeters, as in granular solids. The boundary and initial conditions bring into play another characteristic, length. Such models, entitled nonlocal theories, have been proposed for the past four decades. The solutions of various critical problems have veried our hopes and expectations in that, by means of nonlocal models, it will be possible to make accurate predictions of physical phenomena at submicroscopic scale. In the present study, the anti-plane stress field of multiple cracks is obtained using the solution of Screw dislocation in an infinite elastic plane, based on nonlocal elasticity. The distribution dislocation technique is used to model the crack problem with Screw dislocation distribution. Unlike the classical elasticity solution, a lattice parameter enters into the problem, which makes the stresses finite in the Screw dislocation solution in the infinite elastic plane in nonlocal theory, which has no singularity at the dislocation tip, and which is consistent with theoretical results. Similarly, the crack problem using the distribution dislocation theory is solved with no singularity at the crack tip. The kernel in the related equation is of the Cauchy type, and to determine the distribution of dislocations, which generates traction along the crack line, the Gauss-Chebyshev quadrature has been used. Several numerical examples to illustrate the accuracy and capability of the solution have been calculated, where the effect of crack length, lattice parameter and constant is calculated as a variable parameter, which includes all of them. Stress at the crack tip and its graphs are depicted and the results obtained are compared with classical results in this field.

Background: In intertrochanteric fractures، dynamic hip Screw (DHS) is the most frequently used tool، but several studies did not give good results for this device in reverse-oblique and transverse fractures. Current study aimed to compare fixation results of reverse-oblique intertrochanteric and short-segment subtrochanteric fractures using dynamic condylar Screw (DCS) and DHS in patients referred to Alzahra and Kashani Hospitals in Isfahan, Iran.Methods: In a cross-sectional study، medical files of the patients referred to emergency units of the two hospitals who were diagnosed with intertrochanteric or subtrochanteric fractures and underwent DHS or DCS surgery more than 6 months before were assessed; they were invited for follow-up visit and examination. Written consent forms were taken from all the patients upon their entry; and they were examined in terms of complications including nonunion and failure of device and level of fracture improvement. These cases were evaluated by simple radiography ,too. Results obtained from examination of patients in addition to demographic information were recorded in the data collection form for each patient.Findings: Perfect union was observed in 14 (of 25) patients in DHS group and 21 (of 25) patients in DCS group (56% vs. 84%) six months after the surgery. Bone union was significantly better in DCS group (P=0.031). In addition, six months after the surgery, the devices used in 14 people in DHS group and 24 people in DCS group were fixed and the difference between the two groups was significant (P=0.001). 14 and 24 patients had total recovery in DHS and DCS groups، respectively (20% vs. 44%) with a significant difference (P=0.020).Conclusion: Considering obtained results, it can be concluded that using DCS is recommended over DHS due to severity of pain, bone union and fixation of the device.

Background: Appropriate treatment of acromioclavicular joint dislocation is controversial. Acroplate fixation is one of the most common treatment methods of acromioclavicular joint (ACJ) dislocation. Based on the risk of re-dislocation after Acroplate fixation, we assumed that combined fixation with an Acroplate and a coracoclavicular Screw helps improve the outcome. Objectives: The main purpose of the current study was to compare the outcome of ACJ dislocation treated with an Acroplate alone and in combination with coracoclavicular Screw. Patients and Methods: This study was carried out on 40 patients with ACJ dislocation types III to VI who were divided randomly into two equal groups: Acroplate group (P) and Acroplate in combination with coracoclavicular Screw group (P+S). The Screws were extracted 3-6 months postoperatively. The patients were followed for 1 year and Imatani’s score was calculated. Finally, the data were compared between the groups. Results: The mean Imatani’s score was significantly higher in P+S group (83.4±14.1) than P group (81.2±10.3) (P<0.001). The mean duration of surgery was the same in the two groups (59.8±9.4 minutes in group P V.s 64.3±10.9 minutes in group P+S; P=0.169). There were no cases of re-dislocation, degenerative changes and ossification and all patients returned to their previous jobs or sporting activities. Conclusions: Using a coracoclavicular Screw combined with an Acroplate can improve the patients’ function after ACJ disruption without any significant increase in surgical duration. Authors recommend this technique in the fixation of ACJ dislocation.