Researcher:
Özben, Hakan

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Hakan

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Özben

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Özben, Hakan

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2014 - 202010

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    Dynamic ultrasound imaging for the assessment of extensor tendon adhesion after fifth metacarpal intraarticular head fracture: a case report
    (Hanley & Belfus-Elsevier Inc, 2019) N/A; N/A; Mısırlıoğlu, Tuğçe Özekli; Özben, Hakan; Doctor; Faculty Member; N/A; School of Medicine; Koç University Hospital; N/A; 175999; N/A
    Study Design: Case report. Introduction: Development of extensor tendon adhesions is a common complication after intra-articular metacarpal head fracture. Whenever these adhesions cannot be mobilized by rehabilitation, tenolysis should be considered. However, the decision for tenolysis is often delayed. When the rehabilitation program comes to a plateau and clinical examination may not be sufficient to find out the cause, dynamic ultrasound (US) can show where the gliding mechanism is disrupted and help clinicians to give an accurate decision for determining the next steps. Purpose of the Study: To determine the role of dynamic US during hand rehabilitation. Methods: A 22-year-old woman presented with a fifth metacarpal intra-articular head fracture. Ten days after the surgery (open reduction and internal fixation) the hand rehabilitation program was commenced. After the third week, the metacarpophalangeal (MP) joint range of motion (ROM) gradually diminished. Dynamic US near the level of fifth MP joint revealed diminished extensor tendon excursion and capsular thickening. Results: Considering physical and sonographic findings, surgical tenolysis and capsular release was planned. After surgery, the DIP, PIP and MP joints reached full passive ROM. Conclusion(s): Ultrasound is a quick and practical way to diagnose tendon adhesions. With this report, the authors suggest that clinicians may use dynamic US, especially in times when the patient comes to plateau during hand rehabilitation.
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    Treatment of scaphotrapezial trapezoidal osteoarthritis with resection of the distal pole of the scaphoid
    (Turkish Assoc Orthopaedics Traumatology, 2014) Marcuzzi, Augusto; Russomando, Antonio; N/A; Özben, Hakan; Faculty Member; School of Medicine; N/A
    Objective: The aim of this study was to describe the surgical technique for resection of the distal quarter of the scaphoid and compare the results of patients treated by resection with patients treated by resection with insertion of a pyrocarbon implant. Methods: The study included 9 wrists treated by resection-only and 8 wrists treated by resection with implant. Average follow-up period was 77 (range: 24 to 130) months. Wrist motion and pinch strength were measured and pain was evaluated using the visual analog scale (VAS). Radiographic classification was performed according to Crosby's classification system and the radiolunate (RL) angle was measured pre- and postoperatively. Results: Postoperative VAS pain scores were 2.1 and 2.6 in the in the resection-only and implant group, respectively. Pain scores decreased significantly in both groups (p=0.007 and p=0.01, respectively). The mean RL angle increased from 14 degrees to 30 degrees in the resection-only group (p=0.008). In the STPI implant group, there was an increase in the mean RL angle from 21 degrees to 23 degrees; however, this difference was not significant (p=0.75). Conclusion: Application of a pyrocarbon implant appears to be useful for pain relief and may help prevent secondary deformities in the treatment of scaphotrapezial trapezoidal arthritis.
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    Hybrid compounds & oxidative stress induced apoptosis in cancer therapy
    (Bentham Science Publ Ltd, 2020) Hanikoğlu, Ayşegül; Hanikoğlu, Ferhat; Özben, Tomris; N/A; Özben, Hakan; Faculty Member; School of Medicine; N/A
    Elevated Reactive Oxygen Species (ROS) generated by the conventional cancer therapies and the endogenous production of ROS have been observed in various types of cancers. In contrast to the harmful effects of oxidative stress in different pathologies other than cancer, ROS can speed anti-tumorigenic signaling and cause apoptosis of tumor cells via oxidative stress as demonstrated in several studies. The primary actions of antioxidants in cells are to provide a redox balance between reduction-oxidation reactions. Antioxidants in tumor cells can scavenge excess ROS, causing resistance to ROS induced apoptosis. Various chemotherapeutic drugs, in their clinical use, have evoked drug resistance and serious side effects. Consequently, drugs having single-targets are not able to provide an effective cancer therapy. Recently, developed hybrid anticancer drugs promise great therapeutic advantages due to their capacity to overcome the limitations encountered with conventional chemotherapeutic agents. Hybrid compounds have advantages in comparison to the single cancer drugs which have usually low solubility, adverse side effects, and drug resistance. This review addresses two important treatments strategies in cancer therapy: oxidative stress induced apoptosis and hybrid anticancer drugs.
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    Latarjet procedure using subscapularis split approach offers better rotational endurance than partial tenotomy for anterior shoulder instability
    (Springer, 2018) Ersen, Ali; Birisik, Fevzi; Atalar, Ata Can; Sahinkaya, Turker; N/A; N/A; N/A; Özben, Hakan; Seyahi, Aksel; Demirhan, Mehmet; Faculty Member; Faculty Member; School of Medicine; School of Medicine; School of Medicine; Koç University Hospital; N/A; 52082; 9882
    Latarjet, which is a coracoid bone block procedure, is an effective treatment for anterior shoulder instability with glenoid bone loss. During this reconstructive procedure the subscapularis may be tenotomized or be split to expose the glenoid neck. The aim of this study was to assess the effect of subscapularis management on functional outcomes and internal and external rotation durability and strength. Hypothesis is that the subscapularis split approach will result in better functional results and superior internal rotation strength and endurance. The study included 48 patients [median age 30 (range 16-69); 42 males, 6 females], who underwent a modified Latarjet procedure for anterior shoulder instability. There were 20 patients in the subscapularis tenotomy group and 28 patients in the subscapularis split group. The groups were compared isokinetically using a computerized dynamometer for internal and external rotation durability and strength. At the latest follow-up, the patients were evaluated with the American Shoulder and Elbow Surgeons (ASES) and ROWE scores for functional outcomes. At a median follow-up period of 25 (range 12-73) months after the Latarjet procedure, the internal rotation durability was significantly higher in the split group (p = 0.045). However, a statistically significant difference could not be found for internal and external rotational strengths (n.s.). There was also no significant difference between the final ASES and ROWE scores (n.s.). Although both approaches offer promising results, the subscapularis split approach appears to provide better internal rotation durability compared to subscapularis tenotomy. Therefore, the subscapularis split approach may be more preferable for the management of the subscapularis muscle during Latarjet procedure. Retrospective cohort study, Level III.
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    Rotator cuff tear characteristics: how comparable are the pre-operative mri findings with intra-operative measurements following debridement during arthroscopic repair?
    (Springer, 2019) Aydıngöz, Üstün; Koyuncu, Özgür; N/A; Eren, İlker; Özben, Hakan; Günerbüyük, Caner; Aygün, Murat Serhat; Hatipoğlu, Edip; Demirhan, Mehmet; Faculty Member; Faculty Member; Teaching Faculty; Teaching Faculty; Doctor; Faculty Member; School of Medicine; School of Medicine; School of Medicine; School of Medicine; N/A; School of Medicine; Koç University Hospital; 168021; N/A; 380939; 291692; N/A; 9882
    Purpose Magnetic resonance (MRI) is a valuable imaging method which can detect pre-operative rotator cuff tear characteristics accurately. However, tendon degeneration almost always necessitates a certain amount of debridement during arthroscopic repair, which alters tear size and shape. The aim of this study is to question the accuracy of the pre-operative tear size and classification in MRI and its relation to the tear size and type of the debrided tendon during arthroscopic repair.MethodsA retrospective survey was performed to identify shoulders that underwent arthroscopic rotator cuff repair. Rotator cuff tears with an adequate history, a standard pre-operative MRI, and available surgical video records with appropriate measurements were included. Traumatic tears, calcifying tendonitis, isolated subscapularis tears, and revisions were excluded. In total, 60 shoulders' (30 males, 27 females; age 55.2 [35-73]) preoperative MRIs and intra-operative measurements were analyzed by orthopaedic surgeons and radiologists. Tear width and type were recorded. Interdisciplinary and intradisciplinary consistency of measurements and classifications were analyzed. Tear width measured on pre-operative MRI and after debridement were compared.ResultsAverage measured tear width was 95.3mm on MRI. Surgeons (9.98 +/- 4.6mm) measured tears significantly wider than radiologists (7.71 +/- 6.6mm). Radiologists (ICC, 0.930; CI, 0.883-0.959) showed superior consistency on MRI than surgeons (CI, 0.502; CI, 0.105-0.726). Average tear width measured after debridement (29.3 +/- 9.6mm) was significantly higher than tear width measured on pre-operative MRI (p<0.0001). None of the researchers assessing tear type on pre-operative MRI showed agreement with surgeons assessing intra-operative data.Conclusionsp id=ParThere were significant differences between the pre-operative tear characteristics on MRI and the debrided tendon characteristics during surgery, which were extensive enough to classify the tear in a different category.
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    An arthroscopic-assisted minimal invasive method for the reconstruction of the scapho-lunate ligament using a bone-ligament-bone graft
    (2016) Dellarosa, N.; Abate, M.; Russomando, A.; Petrella, G.; Landi, A.; N/A; Özben, Hakan; Faculty Member; School of Medicine; N/A
    We report the outcomes of an arthroscopic-assisted minimally invasive technique to reconstruct the scapho-lunate ligament using a bone-ligament-bone graft in 11 patients (11 wrists). The mean follow-up time was 29 months (range 20 to 38). The preoperative mean wrist flexion, extension, grip strength and patient-rated wrist evaluation score values were 61 degrees, 54 degrees, 115N and 54, respectively. The postoperative mean values were 64 degrees, 58 degrees, 142 N and 15, respectively. There were no statistical differences between the pre- and postoperative wrist flexion and extension, whereas changes in grip strength and patient-rated wrist evaluation score were significant. Scapho-lunate angles decreased significantly from 69 degrees to 60 degrees. Based on our clinical outcomes, this method provides a reliable alterative for the reconstruction of the scapho-lunate ligament in patients with persistent Geissler type 3 and 4 lesions in the short-term.
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    Time-dependent changes after latissimus dorsi transfer: Tenodesis or tendon transfer?
    (Springer, 2014) Ersen, Ali; Atalar, Ata Can; Kapicioglu, Mehmet; N/A; Demirhan, Mehmet; Özben, Hakan; Faculty Member; Faculty Member; School of Medicine; School of Medicine; Koç University Hospital; 9882; N/A
    Background Transfer of the latissimus dorsi tendon to the posterosuperior part of the rotator cuff is an option in active patients with massive rotator cuff tears to restore shoulder elevation and external rotation. However, it is unknown whether this treatment prevents progression of cuff tear arthropathy. Questions/purposes The purpose of this study was to determine whether the observed improvement in shoulder function in the early postoperative period with latissimus dorsi tendon transfer for irreparable rotator cuff tears will be permanent or will deteriorate in the midterm period (at 1-5 years after surgery). Methods During a 6-year period, we performed 11 latissimus dorsi tendon transfers in 11 patients for patients with massive, irreparable, chronic tears of the posterosuperior part of the rotator cuff (defined as [5 cm supraspinatus and infraspinatus tendon tears with Goutallier Grade 3 to 4 fatty infiltration on MRI), for patients who were younger than 65 years of age, and had high functional demands and intact subscapularis function. No patients were lost to followup; minimum followup was 12 months (median, 33 months; range, 12-62 months). The mean patient age was 55 years (median, 53 years; range, 47-65 years). Shoulder forward elevation, external rotation, and Constant-Murley and American Shoulder and Elbow Surgeons scores were assessed. Pain was assessed by a 0- to 10-point visual analog scale. Acromiohumeral distance and cuff tear arthropathy (staged according to the Hamada classification) were evaluated on radiographs. Results Shoulder forward elevation, external rotation, Constant-Murley scores, and American Shoulder and Elbow Surgeons scores improved at 6 months. However, although shoulder motion values and Constant-Murley scores remained unchanged between the 6-month and latest evaluations, American Shoulder and Elbow Surgeons scores decreased in this period (median, 71; range, 33-88 versus median, 68; range, 33-85; p = 0.009). Visual analog scale scores improved between the preoperative and 6-month evaluations but then worsened (representing worse pain) between the 6-month and latest evaluations (median, 2; range, 0-5 versus median, 2; range, 1-6; p = 0.034), but scores at latest followup were still lower than preoperative values (median, 7; range, 4-8; p = 0.003). Although acromiohumeral distance values were increased at 6 months (median, 8 mm; range, 6-10 mm; p = 0.023), the values at latest followup (median, 8 mm; range, 5-10 mm) were no different from the preoperative ones (mean, 7 mm; range, 6-9 mm; p > 0.05). According to Hamada classification, all patients were Grade 1 both pre- and postoperatively, except one who was Grade 3 at latest followup. Conclusions The latissimus dorsi tendon transfer may improve shoulder function in irreparable massive rotator cuff tears. However, because the tenodesis effect loses its strength with time, progression of the arthropathy should be expected over time. Nevertheless, latissimus dorsi tendon transfer may help to delay the need for reverse shoulder arthroplasty for these patients.
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    Epoxomicin sensitizes resistant osteosarcoma cells to TRAIL induced apoptosis
    (Bentham Science, 2015) Hanikoglu, Ferhat; Cort, Aysegul; Hanikoglu, Aysegul; Ozben, Tomris; N/A; Özben, Hakan; Faculty Member; School of Medicine; N/A
    Osteosarcoma (OS) is the second most common primary malign bone neoplasm after multiple myeloma. Despite systemic chemotherapy, OS may give rise to local recurrences and metastases. Resistance to chemotherapy is not rare and is likely to occur in a high number of patients. Novel therapeutic approaches are required in order to efficiently treat osteosarcoma. Tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL) and proteasome inhibitors (epoxomicin, MG132, bortezomib) represent new promising approaches in cancer treatment. The aim of our study is to elucidate the effects of epoxomicin alone or in combination with TRAIL in two TRAIL-resistant OS cell lines, Saos-2 and MG-63 namely. We determined the cytotoxic effects of epoxomicin and/or TRAIL on these two types of OS cells using dimethylthiazolyl 2,5 diphenyltetrazolium bromide (MTT) test and measured apoptosis markers such as pro-apoptotic Bax levels and caspase-3, -8, -9 activities. We used TUNEL assay to demonstrate apoptosis. We investigated dose and time dependent survival rates of OS cells and determined LD50 doses of epoxomicin and TRAIL on OS cell viability after 24, 48, and 72 hour incubations. Concurrent incubation with TRAIL and epoxomicin for 24 hour significantly increased caspase-3, caspase-8, caspase-9 activities and Bax protein levels. Our study demonstrated that the combination of TRAIL with epoxomicin enhances apoptosis, and overcomes TRAIL resistance, denoting promising results for OS therapy in the future.
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    PublicationOpen Access
    Clinical and radiological outcomes in arthroscopic repair of shoulder rotator interval lesions
    (Galenos Yayınevi, 2019) Eren, Şule Meral; Uçak, Ayla; Akpek, Sergin; N/A; N/A; Eren, İlker; Özben, Hakan; Demirhan, Mehmet; Canbulat, Nazan; Faculty Member; Faculty Member; School of Medicine; N/A; N/A; 9882; 58534
    Objective: rotator interval lesion (RIL) is a distinct rotator cuff (RC) injury patern consisting of subscapularis and supraspinatus tear with biceps problem. This pathology is an underdiagnosed RC entitiy and not studied in-depth. Aim of this study is to report the functional and radiological results of RIL surgeries performed. Methods: surgeries performed in a single center, in a 7-year-period were retrospectively reviewed. Sixteen cases (n=16) who underwent ar throscopic RC repair including subscapularis with biceps tenodesis or tenotomy were called for an up-to-date assessment. Fourteen shoulders of 13 patients (3 females, 10 males) were included. Constant, disabilities of the arm shoulder and hand (DASH), standardized shoulder assessment form (ASES) scores, and RC thickness measurements with magnetic resonance imaging (MR1) were recorded. Preoperative and postoperative results were compared. Results: average age of the patients were 60.6 (47-74), and follow-up period was 3.2 +/- 1.9 years. Average preoperative Constant, DASH and AS ES scores were 44.43 +/- 15.4, 22.11 +/- 17.21 and 51.37 +/- 27.6, respectively. Postoperative values improved to 90.45 +/- 6.44, 6 +/- 13.68 and 95.82 +/- 7.82, respectively (p<0.05). Average subscapularis and supraspinatus thicknesses measured with MRI were 3.85 +/- 0.87 and 4.60 +/- 0.65 mm respectively. MRI revealed subscapularis tendinitis in 1 patient. Re-tear was not observed in any patients. Conclusion: arthroscopic subscapularis and supraspinatus repair with biceps tenodesis or tenotomy is an effective treatment method in RIL. No retear was observed with MRI. Clinical results arc similar with other RC pathologies.
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    PublicationOpen Access
    A rabbit model of avascular necrosis of femoral head using surgical trauma and systemic steroids
    (Galenos Yayınevi, 2020) Özben, Hakan; School of Medicine
    Objective: avascular necrosis of the femoral head (ANFH) is a disease caused by the diminished circulation of the femoral head. The incidence of the disease is increasing and it has heavy socioeconomical burden. Animal models are indispensable for the development of new treatments for bone avascular necrosis. There is not any reliable animal model for simulating the early stages of femoral head osteonecrosis. The aim of this study is to present an animal model of femoral head osteonecrosis induced by systemic steroid use combined with surgery. Methods: six New Zealand White rabbits were divided into 3 groups. Each group contained 4 femoral heads. For the induction of osteonecrosis, every hip underwent surgical dislocation followed by cauterization of extraperiosteal vessels around the femoral head and ligamentum teres resection. A single dose intramuscular steroid was administered to each rabbit. Rabbits were sacrificed at 2nd, 4th and 6th weeks and femoral heads were sent to histological evaluation. Results: the femoral heads showed typical signs of avascular necrosis at the end of 2nd week. In addition to osteocyte loss and marrow necrosis, there was also new osteoblast formation at the end of 4th week. At the end of 6th week, epiphyseal new bone formation next to large necrotic areas were visible. Conclusion: these results suggest that the single steroid administration combined with hip luxation and cauterization of neck vessels may create femoral head osteonecrosis in rabbits in a repeatable and reliable manner. This model can be presented as an alternative model for the new studies on the treatment of femoral head avascular necrosis in the early stage. / Amaç: femur başı avasküler nekrozu (FBAN), femur başının kanlanmasındaki azalmadan kaynaklanan, görülme sıklığı giderek artan ve ağır sosyo-ekonomik etkileri olan bir hastalıktır. Hayvan modelleri, kemiklerdeki avasküler nekrozlar için yeni tedavi yöntemlerinin oluşturulmasında vazgeçilmezdir. Halen, erken dönem FBAN’yi simüle edebilen güvenilir bir hayvan modeli yoktur. Bu çalışmanın amacı, cerrahi ve sistemik steroid kombinasyonu ile tavşanda FBAN modeli oluşturmaktır. Yöntemler: altı Yeni Zelanda beyaz tavşanı 3 gruba ayrıldı. Her grup 4 femur başı içermekteydi. FBAN oluşturmak için her kalçaya cerrahi olarak dislokasyon, femur boynu periosteal damarların koterizasyonu ve ligamentum teres eksizyonu yapıldı. Sonrasında her tavşana tek doz intramusküler steroid uygulandı. Gruplardaki hayvanlar sırasıyla 2., 4. ve 6. haftalarda sakrifiye edildi ve tüm femur başları rezeke edildi. Femur başları histolojik olarak avasküler nekroz bulguları açısından değerlendirildi. Bulgular: ikinci haftanın sonunda incelenen femur başlarında tipik histolojik avasküler nekroz bulguları mevcut idi. Dördüncü hafta sonunda alınan örneklerin yapılan histolojik değerlendirmelerinde osteosit kaybı ve kemik iliği nekrozuna ek olarak osteoblast oluşumları görüldü. Altıncı hafta sonunda yapılan incelemelerde epifizyel alanlarda geniş kemik iliği nekrozlarına ek olarak yeni kemik oluşumları görüldü. Sonuç: bu sonuçlar, femur başı luksasyonu ve koterizasyonu ile tek doz steroid uygulamasının tavşanlarda güvenilir ve tekrarlanabilir şekilde femur başı nekrozu oluşturduğunu göstermektedir. Bu model, femur başı osteonekrozlarının erken dönem tedavisi araştırmalarında kullanılabilecek bir seçenek olarak sunulabilir.