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Dive into the research topics where Önder Baran is active.

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Featured researches published by Önder Baran.


Archives of Orthopaedic and Trauma Surgery | 2001

Primary intramuscular hydatidosis of supraspinatus muscle.

Hasan Tatari; Önder Baran; T. S¸anlıdağ; O. Göre; D. Ak; Metin Manisali; Hasan Havitcioglu

Abstract Hydatid disease of the muscle is very rare and represents approximately 3% of all patients with hydatidosis. Since the infection closely resembles a soft-tissue tumor on clinical examination, the preoperative radiologic diagnosis is very important to avoid biopsy. We report an unusual case of primary intramuscular hydatidosis with its magnetic resonance imaging appearance, clinical and pathological findings.


Archives of Orthopaedic and Trauma Surgery | 2001

Deleterious effects of local corticosteroid injections on the Achilles tendon of rats.

Hasan Tatari; Can Kosay; Önder Baran; Özal Özcan; Erdener Özer

Abstract The purpose of this study was to examine the pathological changes in the Achilles tendon and its paratenon after intratendinous corticosteroid injections and to reveal the effects of this drug on healthy tendon. We also sought for the effects of these injections compared with compression with a clamp on the Achilles tendons of the rats. Fifty-two Achilles tendons in 26 male Wistar rats were included in the study. Betamethasone injections were applied to the left tendons at different intervals, while the right tendons served for compression with mosquito clamps for varied periods. At the end of 30 days, all of the tendons were excised and examined histopathologically according to a semiquantitative scoring system. Histopathologic evaluation demonstrated some degree of degeneration in both groups. Statistical analysis showed no significant difference among the two groups, but in macroscopic evaluation, the tendons in the betamethasone group demonstrated enlargement and strong adhesion to the subcutaneous tissue. We conclude that intratendinous betamethasone injections are as harmful as compression with a clamp and can be used as a degeneration-producing model in further studies. Enlargement of the tendon mass and strong adhesion to the subcutaneous tissue can be due to injection of the betamethasone partly outside the tendon.


International Orthopaedics | 2009

Anatomical and biomechanical evaluation of the tension band technique in patellar fractures

Önder Baran; Metin Manisali; Berivan Cecen

Tension band wiring for patellar fractures is common, but some recent reports refer to disadvantages of this approach. Our anatomical and biomechanical study focused on use of tension band techniques in patellar fractures. The anatomy of the patella and tendon insertion was examined with knee magnetic resonance imaging (MRI) and correlated with the technical requirements of the tension band. Tension band wiring over tendinous tissue was simulated and calculated with a cyclic biomechanical test on cow patellae. According to tension band templating on the MRI section, Kirschner wire insertion was needed for the tension band to turn over the tendinous tissue. The tension band became more stable while turning over less tendinous tissue and more adjacent bone surface. Nevertheless, cyclic loading tests indicate that all tension band applications in this study lose their initial stability. Excessive initial compression by the tension band resulted in bending of the Kirschner wire and thus reduction failure. For optimum stabilisation, tension force transfer should be done directly on bone or at least material that protects the tendon would be useful.RésuméLa tension des fils métalliques lors de l’ostéosynthèse par hauban des fractures de rotules est habituellement utilisée, mais certains travaux en montrent les désavantages. Cette étude anatomique et biomécanique a été centrée sur cette pratique du hauban dans les fractures de la rotule. L’anatomie de la rotule et des insertions tendineuses ont été étudiées et corrélées avec les nécessités de tension. La tension de ce hauban mis en place au dessus des structures tendineuses a été évaluée par des tests biomécaniques sur des rotules de vaches. Selon l’insertion des broches de Kirschner, après étude IRM, il est nécessaire de serrer les fils du hauban sur les structures tendineuses mais, ce hauban est beaucoup plus stable que les tissus tendineux adjacents à l’os. Cependant, les tests de mise en charge nous montrent que ces haubans perdent leur stabilité initiale dès qu’une tension importante entraîne une plicature des broches de Kirschner et un échec de la réduction. Pour une stabilisation optimum, les forces de serrage du hauban doivent être directement appliquées sur l’os ou, tout au plus, au niveau de l’insertion tendineuse au plus près du matériel.


Journal of Biomechanics | 2008

The stiffness characteristics of hybrid Ilizarov fixators

Önder Baran; Hasan Havitcioglu; Hasan Tatari; Berivan Cecen

The use of hybrid Ilizarov models around femoral area is gaining clinical popularity lately. Hybrid systems show different mechanical properties. The purpose of this report is to examine the stiffness characteristics of the C-arch and half-pins on the hybrid Ilizarov fixators. Eight models that included standard Ilizarov and hybrid models were applied to six femoral sawbones. The distal part of fixation was composed of a two-ring frame applied identically to all bones. The difference of the configuration was at the proximal part, where half-pins with or without C-arches were either added to the proximal two-ring frame or replaced the proximal one- or two-ring frame. Osteotomy was performed in the femoral diaphysis and the bone was distracted 2cm. The stability of the system was tested with the axial compression testing machine. Displacements between the adjacent fracture sides were measured with the video extensometer in three dimensions. We found that proximal half-pin applications alone had less stiffness, but half-pins with C-arch had more stiffness than the model including only half-pins. Additional half-pins onto one- or two-ring frames had more longitudinal stiffness, but this system showed weak resistance against transverse displacement.


Journal of Bone and Joint Surgery-british Volume | 2000

Lengthening of congenital below-elbow amputation stumps by the Ilizarov technique.

C. Alekberov; Vasfi Karatosun; Önder Baran; Izge Gunal

Patients with short congenital amputations below the elbow often function as if they have had a disarticulation of the elbow. We have reviewed the results in six patients who had lengthening of such stumps by the Ilizarov technique to improve the fitting of prostheses. The mean lengthening was 5.6 cm (3.4 to 8.4), and in two patients flexion contractures of the elbows were corrected simultaneously. Additional lateral distraction was used in one patient to provide a better surface on the stump. There were no major complications. All six patients were able to use their prosthesis at the latest follow-up after 39 to 78 months.


Knee Surgery, Sports Traumatology, Arthroscopy | 2003

Calcium pyrophosphate dihydrate crystal deposition disease mimicking malignant soft tissue tumor

Hasan Havitcioglu; Hasan Tatari; Önder Baran; Metin Manisali; Sermin Özkal; Mustafa Secil; Dinç Özaksoy; Kutsal Yorukoglu

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease has multiple clinical features with variable courses creating several pitfalls in clinical diagnosis. There are number of reported cases mimicking malignant skeletal tumors such as chondrosarcoma. However, no case of CPPD disease with radiographic noncalcified soft tissue mass has been reported in the literature. Here we report a case of CPPD disease clinically mimicking soft tissue tumor with its magnetic resonance imaging appearance and histopathology.


Acta Orthopaedica Scandinavica | 2002

Open fractures of the proximal humerus treated with the Ilizarov method: 12 patients followed 3-8 years

Vasfi Karatosun; C. Alekberov; Önder Baran; Erhan Serin; Emin Alici; Ceyhun Balci

We followed 12 patients who had been treated with the Ilizarov method for open proximal humeral fractures for more than 3 years. No wound infection occurred. Avascular necrosis and nonunion were each detected in 1 patient. According to Neers criteria, the outcome was excellent or satisfactory in 8 patients.


national biomedical engineering meeting | 2009

Extendable intramedullary nail with mechanical loading

Bora Uzun; Önder Baran; Hasan Havitcioglu

There are various extremity lengthening methods in the literature. Lentghening with intramedullary nails is also important method which is emphasized recent years. In this study, in the light of previous studies, it is aimed to develop a new expandable intramedullary system providing lengthening in order to remove previous problems and complications and to annihilate leg length discrepancies at present and future without second surgical intervention as far as possibble by lenghtening the intramedullary nail.


Journal of Bone and Joint Surgery, American Volume | 2000

Lengthening of congenital below-elbow amputation stumps by the Ilizarov technique

C. Alekberov; Vasfi Karatosun; Önder Baran; Izge Gunal

We performed an audit of 71 children with consecutive displaced, extension-type supracondylar fractures of the humerus over a period of 30 months. The fractures were classified according to the Wilkins modification of the Gartland system. There were 29 type IIA, 22 type IIB and 20 type III. We assessed the effectiveness of guidelines proposed after a previous four-year review of 83 supracondylar fractures. These recommended that: 1) an experienced surgeon should be responsible for the initial management; 2) closed or open reduction of type-IIB and type-III fractures must be supplemented by stabilisation with Kirschner (K-) wires; and 3) K-wires of adequate thickness (1.6 mm) must be used in a crossed configuration. The guidelines were followed in 52 of the 71 cases. When they were observed there were no reoperations and no malunion. In 19 children in whom they had not been observed more than one-third required further operation and six had a varus deformity. Failure to institute treatment according to the guidelines led to an unsatisfactory result in 11 patients. When they were followed the result of treatment was much better. We have devised a protocol for the management of these difficult injuries.Accurate quantitative measurements of micromovement immediately after operation would be a reliable indicator of the stability of an individual component. We have therefore developed a system for measuring micromovement of the tibial component using three non-contact displacement transducers attached to the tibial cortex during total knee arthroplasty (TKA). Using this system we measured the initial stability in 31 uncemented TKAs. All the tibial components were fixed by a stem and four screws. The initial stability was defined as the amount of displacement when a load of 20 kg was applied. The mean subsidence was 60.7 μm and the mean lift-off was 103.3 μm. We also studied the migration of the tibial component using roentgen stereophotogrammetric analysis (RSA) for up to two years after operation. Most migration occurred during the first six months, after which all prostheses remained stable. We defined migration as the maximum total point motion (MTPM) at two years after operation. The mean migration was 1.29 mm at two years. Our results show that there was a significant correlation between the initial stability and migration (pWe enrolled 34 normal volunteers to test the hypothesis that there were two types of movement of the wrist. On lateral radiographs two distinct patterns of movement emerged. Some volunteers showed extensive rotation of the lunate with a mean range of dorsiflexion of 65°, while others had a mean range of 50°. The extensive rotators were associated with a greater excursion of the centre of articulation of the wrist. It is suggested that dynamic external fixation of a fracture of the distal radius carries with it the risk of stretching the ligaments or causing volar displacement at the site of the fracture.We have reviewed 202 consecutive primary hip replacements using a Freeman cemented femoral component after a mean period of follow-up of 64 months (23 to 113). There was only one revision for aseptic loosening. Retention of the femoral neck may act to reduce the torsional and shear forces at the implant-cement interface and may provide a seal against the migration of polyethylene-laden joint fluid in the potential joint space. The cemented Freeman femoral component with retention of the femoral neck was successful for up to nine years.: Acute compartment syndrome is a serious complication of injury. It occurs when raised pressure within a closed osteofascial compartment compromises the circulation and function of tissues within the compartment. Most cases are caused by fracture. The largest group are tibial diaphyseal fractures, followed by soft tissue injury, crush syndrome, distal radial fractures and forearm diaphyseal fractures. Those at risk of developing acute compartment syndrome are young males, patients with bleeding disorders or on anticoagulant therapy and in the upper limb, high energy injury. The clinical symptoms and signs of acute compartment syndrome are pain, stretch pain and neurological abnormality, none of which are constantly present. Since early diagnosis of this condition is of paramount importance compartment monitoring is recommended. The recommended tissue pressure threshold for decompression has been variable through the years but should be related to the patients blood pressure. A difference of less than 30 mmHg between the diastolic and tissue pressures has been validated clinically and it is recommended that at this level serious consideration should be given to decompression of the affected compartments. Use of this pressure threshold with compartment monitoring has been shown to half the delay to fasciotomy and significantly reduces the late complications of acute compartment syndrome.After cemented total hip arthroplasty (THA) there may be failure at either the cement-stem or the cement-bone interface. This results from the occurrence of abnormally high shear and compressive stresses within the cement and excessive relative micromovement. We therefore evaluated micromovement and stress at the cement-bone and cement-stem interfaces for a titanium and a chromium-cobalt stem. The behaviour of both implants was similar and no substantial differences were found in the size and distribution of micromovement on either interface with respect to the stiffness of the stem. Micromovement was minimal with a cement mantle 3 to 4 mm thick but then increased with greater thickness of the cement. Abnormally high micromovement occurred when the cement was thinner than 2 mm and the stem was made of titanium. The relative decrease in surface roughness augmented slipping but decreased debonding at the cement-bone interface. Shear stress at this site did not vary significantly for the different coefficients of cement-bone friction while compressive and hoop stresses within the cement increased slightly.We reviewed 120 consecutive primary total hip replacements in 109 patients in whom a Freeman uncemented metal-backed component had been used. Acetabular components were used with a Freeman neck-retaining stem in one of three configurations: cemented smooth stem, uncemented smooth stem or uncemented ridged stem. After a mean follow up of 72 months (62 to 113) there were nine cases of aseptic loosening; a survivorship at eight years of 83%. In addition, more than one-third of the remaining surviving cups showed loosening radiologically. The Freeman acetabular component demonstrated a characteristic pattern of loosening on radiographs. The high incidence of aseptic loosening can be explained by poor design and material failure.Although the technique of autogenous acetabular bone grafting has been widely used to augment containment of the acetabulum in total hip arthroplasty (THA) for developmental dysplasia, the role of this technique in improving long-term results remains controversial. We present the long-term results of cemented THA with acetabular bone grafting in 112 patients (133 hips) in order to clarify the factors which affect the outcome. The mean follow-up was for 12.3 years (8 to 24). Kaplan-Meier survivorship analysis predicted a rate of survival of the acetabular component at 15 years of 96% (95% confidence interval (CI) 92 to 99) with revision for aseptic loosening as the endpoint, and of 75% (95% CI 65 to 85) when radiological loosening was used. Parametric survivorship analysis using the Cox proportional-hazards model indicated that trochanteric nonunion, lateral placement of the socket, and delayed trabecular reorientation of the bone graft were risk factors for loosening of the acetabular component. Our findings have shown that autologous acetabular bone grafting is of value for long-term success provided that the risk factors are reduced.


European Radiology | 2003

Bone mineral density reference values in the normal female and male population of Izmir, Turkey.

Metin Manisali; Dinç Özaksoy; Erkan Yilmaz; Özlem Şenocak; Hasan Tatari; Önder Baran; Hasan Havitcioglu

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Hasan Tatari

Dokuz Eylül University

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Özal Özcan

Dokuz Eylül University

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Bora Uzun

Dokuz Eylül University

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C. Alekberov

Dokuz Eylül University

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Hakan Oflaz

Dokuz Eylül University

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