Kenan Koca
Military Medical Academy
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Featured researches published by Kenan Koca.
Journal of Trauma-injury Infection and Critical Care | 2011
Kenan Koca; Yuksel Yurttas; Serkan Bilgic; Umit Kaldirim; Murat Durusu; Yavuz Cekli; Huseyin Ozkan; Vokan Hanci; Tarik Purtuloglu; Emin Ozgur Akgul; Erbil Oguz; Cemil Yildiz; Mustafa Basbozkurt
BACKGROUND The aim of this study was to investigate the effects of ischemic preconditioning (IPC) and N-acetylcysteine (NAC) on oxidative stress resulting from tourniquet-induced ischemia-reperfusion (IR) period in arthroscopic knee surgery. METHODS Forty-five patients who had arthroscopic knee surgery for meniscal and chondral lesions and for pathologic medial plica were included in this study. They were assigned to the following treatment groups: control (group C; n=15), IPC (group P; n=15), and NAC (group N; n=15). Subjects in the control group underwent routine surgical procedures. Subjects in the preconditioning group were subjected to temporary ischemia, with tourniquet performed by three compression cycles of 5 minutes followed by 5 minutes of reperfusion just before the application of tourniquet inflation. Subjects in the NAC group received 10 mg/kg NAC dissolved in 100 mL 0.9% normal saline intravenously 30 minutes before tourniquet inflation. An hour before the tourniquet was applied (preischemia) and 2 hours after tourniquet was removed (reperfusion), blood samples (to test for metabolites) were obtained. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (TAC), and total oxidant status (TOS) were measured in all serum samples. Results were compared between preischemia and reperfusion in three groups. RESULTS MDA in the control group was found to be increased significantly compared with preischemia, whereas MDA in IPC and NAC groups did not change insignificantly. SOD and GSH activities in the control group were found to be increased significantly, whereas SOD and GSH activities in IPC and NAC groups did not change significantly after reperfusion. TAC in the control group was found to be decreased and TOS was found to be increased significantly, but TAC and TOS in IPC and NAC groups were not significantly different after reperfusion. Mean serum MDA, TOS, SOD, and GSH-Px levels were lower in group P than group C at reperfusion period (p<0.05). Mean serum SOD levels were lower in group P than group N at reperfusion period (p<0.05). CONCLUSIONS Tourniquet-induced IR period in routine arthroscopic knee surgery resulted in oxidative stress by increasing MDA, SOD, GSH-Px, TOS and decreasing TAC. NAC and IPC had protective effect on occurrence of oxidative stress resulting from IR period by preventing MDA, SOD, GSH-Px, TAC, and TOS changes in routine arthroscopic knee surgery.
Acta Orthopaedica et Traumatologica Turcica | 2010
Kenan Koca; Yuksel Yurttas; Cemil Yildiz; Bulent Uysal; Ahmet Korkmaz
OBJECTIVES The aim of the study was to investigate the effect of hyperbaric oxygen-preconditioning (HBO-PC) and ozone-preconditioning (O3-PC) on oxidative/nitrosative stress induced by tourniquet ischemia/reperfusion (I/R) in rat skeletal muscle. METHODS Thirty-two Wistar-Albino-type male rats included in the study were divided into four groups of equal number: 1) sham operation, 2) I/R, 3) I/R+HBO-PC, or 4) I/R+O3-PC. One session of 3-4 L/min 100% oxygenation for 60 min at 3 absolute atmosphere (ATA) was defined as one dose of HBO; in total, 7 doses of HBO-PC were administered before ischemia. One dose of O3 comprised 0.7 mg/kg ozone/oxygen mixture, administered intraperitoneally; a total of 4 doses of O3-PC were administered before ischemia. The I/R model was performed in anesthetized rats by clipping right femoral artery to induce 2 h ischemia followed by 22 h of reperfusion. The right gastrocnemius muscle and venous blood samples were harvested. Tissue was assayed for levels of malondialdehyde (MDA), inducible nitric oxide synthase (iNOS), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). Serum was assayed to measure the level of nitrite-nitrate (NOx). RESULTS Tissue MDA level, SOD activity, and serum NOx level were increased, whereas GSHPx was decreased in the I/R group. MDA and NOx levels were decreased, whereas GSH-Px activity was increased in both the I/R+HBO-PC and I/R+O3-PC groups. SOD activity was increased in the I/R+O3-PC group, but did not change significantly in the I/R+HBO-PC group. iNOS staining score and intensity were lower in the I/R+HBO-PC and I/R+O3-PC groups than I/R group. CONCLUSION Both O3-PC and HBO-PC reduced tissue lipid peroxidation, NOx levels, and iNOS staining scores in the experimental I/R model. Our data suggest that HBO-PC and O3-PC protect against oxidative/nitrosative stress induced by I/R in rat skeletal muscle.
Skeletal Radiology | 2013
Tolga Ege; Ozkan Kose; Kenan Koca; Bahtiyar Demiralp; Mustafa Basbozkurt
ObjectiveThe purpose of this study was to compare the measurements made using a smartphone accelerometer and computerized measurements as a reference in a series of 32 hallux valgus patients.Materials and methodsTwo observers used an iPhone to measure the hallux valgus angle (HVA), intermetatarsal angle (IMA), and distal metatarsal articular angle (of anteroposterior foot radiographs in 32 patients with symptomatic hallux valgus on a computer screen. Digital angular measurements on the computer were set as the reference standard for analysis and comparison. The difference between computerized measurements and all iPhone measurements, and the difference between the first and second iPhone measurements for each observer were calculated. Inter- and intraobserver reliability of the smartphone measurement method was also tested.ResultsThe variability of all measurements was similar for the iPhone and the computer-assisted techniques. The concordance between iPhone and computer-assisted angular measurements was excellent for the HVA, IMA, and DMAA. The maximum mean difference between the two techniques was 1.25 ± 1.02° for HVA, 0.92 ± 0.92° for IMA, and 1.10 ± 0.82° for DMAA. The interobserver reliability was excellent for HVA, IMA, and DMAA. The maximum mean difference between observers was 1.31 ± 0.89° for HVA, 0.90 ± 0.92° for IMA, and 0.78 ± 0.87° for DMAA. The intraobserver reliability was excellent for HVA, IMA, and DMAA.ConclusionsWe conclude that the Hallux Angles software for the iPhone can be used for measurement of hallux valgus angles in clinical practice and even for research purposes. It is an accurate and reproducible method.
Acta Orthopaedica et Traumatologica Turcica | 2011
Ibrahim Yanmis; Huseyin Ozkan; Kenan Koca; Volkan Kilincoglu; Dogan Bek; Servet Tunay
OBJECTIVES The aim of this study was to evaluate the relation between arthroscopic findings and functional outcomes in patients with septic arthritis of the knee joint, treated with arthroscopic debridement and irrigation. METHODS Twenty patients (17 male, 3 female; mean age: 31 years [5-63 years]) with knee septic arthritis treated with arthroscopic debridement and irrigation in our clinic between 2004-2007 were included in the study. The decision for arthroscopic debridement was made based on the clinical findings, erythrocyte sedimentation rate, C-reactive protein level and the aspiration of the affected knee. During the arthroscopic debridement, the joint was staged according to Gachter criteria. Continuous irrigation system was set up for all cases following surgery. After the surgery, the Bussiere functional scale was used for clinical evaluation. The mean follow-up periodwas 29±11months (range 13-54 months). The McNemar test was used in comparing the results. The Spearman correlation coefficient was used in the correlation analysis. The level of significance was set at 0.05. RESULTS The culture was positive in 3 cases, and negative in 8 cases who exhibited gram (+) cocci in gram stains. In nine cases, cultures were negative and no microorganisms were detected in gram stains. According to the arthroscopic Gachter classification, 4 cases (20%) were Stage 1, 10 cases (50%) were Stage 2, 5 cases (25%) Stage 3 and 1 case (5%) was Stage 4. There was a statistically significant difference between the mean functional score of the knees with differing Gachter stages (McNemar test, p=0.003). There was a statistically significant and strong correlation between Gachter score and functional results (correlation coefficient: 0.780; p<0.001). CONCLUSION Advanced arthroscopic findings are associated with poor functional results in patients with septic arthritis of the knee joint. In addition, the time between the initial symptoms and the surgery directly affects the functional results.
HSS Journal | 2014
Cemil Yildiz; Kenan Koca; Necmettin Koçak; Servet Tunay; Mustafa Basbozkurt
BackgroundMany studies have investigated the effect of tourniquet release time and closed suction drainage in total knee arthroplasty (TKA). However, controversy remains as to the advisability of preclosure tourniquet release and the advisability of closed suction drain use following total knee arthroplasty.Questions/PurposesThe aim of the study was to investigate if there is a benefit of performing tourniquet release after skin closure, along with drain clamping, for the first 6h following TKA.MethodsNinety-six patients underwent TKA between May 2009 and April 2010. Fourteen of these were excluded because of systemic diseases and simultaneous bilateral TKA. Twenty-nine of these were excluded due to use of a patellar component and posterior cruciate ligament (PCL)-sacrificing systems. Thus, 53 patients that underwent PCL-retaining cemented TKA were reviewed retrospectively. In the control group (group C), the tourniquet was released before skin closure, an attempt at hemostasis was made, and a compressive bandage was applied. The drain was not clamped in these patients. The test group of 23 patients (group T) had tourniquet release after skin closure and after the compressive bandage was applied. The drain was clamped for the first 6h after surgery. The two groups were compared as to the amount of drained blood, postoperative change in hemoglobin, postoperative complications, and knee function.ResultsWe found that drained blood and hemoglobin drop were significantly lower in group T compared with group C. There was no difference regarding postoperative complications and knee function.ConclusionWe conclude that tourniquet release after skin closure and compressive dressing followed by 6h of drain clamping reduces postoperative blood loss in TKR surgery.
Journal of Surgical Research | 2010
Kenan Koca; Yuksel Yurttas; Serkan Bilgic; Turgut Topal; Murat Durusu; Umit Kaldirim; Emin Ozgur Akgul; Huseyin Ozkan; Ibrahim Yanmis; Erbil Oguz; Servet Tunay; Ahmet Korkmaz; Mustafa Basbozkurt
BACKGROUND The aim of the study was to investigate effect of I/R injury on bone tissue and protective role of hyperbaric oxygen precondition (HBO-PC) and ozone precondition (O(3)-PC) on I/R injury by using biochemical analysis. MATERIALS AND METHODS Thirty-two rats were included in study. The animals were divided into four equal groups: sham operation, I/R, I/R+HBO and I/R+O(3). One session of 60 min, 3 ATA, 3-4 L/min, 100% oxygenation was defined as one dose of HBO. First dose of HBO was administrated 72 h before ischemia. Subsequent, one-dose of HBO administrated per 12 hours until ischemia time (total seven doses); 0.7 mg/kg ozone/oxygen mixture intraperitoneally was defined as one dose of ozone. First dose of O(3) was administered 72 h before ischemia (total four doses). I/R model was induced in anesthetized rats by unilateral (right) femoral artery clipping for 2 h followed by 22 h of reperfusion. The right tibia and were harvested. Tissue was assayed for levels of malondialdehyde (MDA) and protein carbonyl (PCO), activities of superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). RESULTS MDA and PCO levels were increased in I/R group. SOD activity was increased; GSH-Px activity was decreased in I/R group. MDA and PCO levels were decreased, SOD and GSH-Px activities were increased in both HBO+I/R and O(3)+I/R groups. CONCLUSION It has been shown that levels of MDA and PCO in bone were increased followed by 2 h of ischemia and 22 h of reperfusion period. Ozone-PC and HBO-PC has protective effect against skeletal bone I/R injury by decreasing levels of MDA and PCO, increasing activities of SOD and GSH-Px in rats.
Journal of Surgical Research | 2011
Erbil Oguz; Safak Ekinci; Murat Eroglu; Serkan Bilgic; Kenan Koca; Murat Durusu; Umit Kaldirim; Serdar Sadir; Yuksel Yurttas; Gokhan Cakmak; Abdullah Kilic; Tarik Purtuloglu; Selahattin Ozyurek; Yavuz Cekli; Huseyin Ozkan; Ali Sehirlioglu
BACKGROUND We evaluated and compared the efficacy of ozone (O(3)) and hyperbaric oxygen (HBO) therapies in an experimental rat model of osteomyelitis. MATERIALS AND METHODS Forty-eight male Sprague-Dawley rats were divided into sham, osteomyelitis (control), vancomycin (V), vancomycin + HBO (VHB), vancomycin + O(3) (VO), and vancomycin + HBO + O(3) (VOHB) groups. Osteomyelitis was induced by a bone injection of 10(8) CFU/mL methicillin-resistant Staphylococcus aureus. HBO was administered daily at 2.8-atm pressure for 90 min; O(3) therapy was provided as intraperitoneal injections of 0.7 mg/kg O(3)/O(2) gas mixture once daily. Treatments were continued from d 7 to 21 after induction of osteomyelitis. Bone tissues and blood samples were harvested for biochemical, histopathologic, and microbiologic analyses. RESULTS Rats in the sham, VO, and VOHB groups gained weight but those in the control, V, and VHB groups did not. Levels of malondialdehyde, superoxide dismutase, and glutathione peroxidase were lower in the VHB, VO, and VOHB groups than in V and control groups. Levels of interleukin-10 and -1β and tumor necrosis factor-α were decreased in the VHB, VO, and VOHB groups; transforming growth factor-β was increased in these groups compared with V and control groups (P ≤ 0.001). Bacteria counts in VOHB were significantly lower than those in group of V (P = 0.012). Histopathologic scores in group VO were significantly lower than those in group V (P = 0.046). CONCLUSIONS O(3) was as effective as HBO in decreasing oxidative parameters and inflammatory cytokines. Rats in the VO and VOHB groups gained more weight than did the other groups. Bacteria counts were significantly decreased in group VOHB compared with the other groups. Histopathologic scores in group VO were significantly decreased compared with the other groups.
Turkish Neurosurgery | 2012
Tolga Ege; Serkan Bilgic; Kenan Koca; Erbil Oguz; Erden Kilic; Ozkan Kose; Ali Sehirlioglu; Atilla Kazanci; Omer Ersen
AIM In spinal surgery, high doses of radiation are delivered during surgical procedures that require fluoroscopic control. The aim of this study was to determine the amount of radiation delivered from the fluoroscopic unit and also the factors to reduce the amount of radiation during the surgery of adolescent idiopathic scoliosis patients. MATERIAL AND METHODS In this retrospective study 21 patients with adolescent idiopathic scoliosis treated by transpedicular screws between 2009 and 2012 were enrolled the study. Dose Area Product (DAP) values , number of views obtained during screw placement and other data were retrieved from the medical records of the patients. RESULTS The mean number of transpedicular screws used was 18. An average of 10,1 vertebrae were instrumented. The mean number of images obtained was 7.76. Mean fluoroscopy time was 7.95 seconds. The total mean DAP was 64.6 cGy.cm < sup > 2 < /sup > . CONCLUSION The amount of ionizing radiation transmitted to the patient and the surgical team can be reduced by freehand insertion, confirmation of screw position by AP and lateral fluoroscopic views including more than one segment, the use of K-wires as a guide in spinal segments with abnormal pedicular anatomy and neuromonitorization of the patient during the surgical correction of adolescent idiopathic scoliosis.
Journal of Orthopaedic Trauma | 2012
Mustafa Basbozkurt; Mustafa Kürklü; Yuksel Yurttas; Bahtiyar Demiralp; Kenan Koca; Cenk Kilic; Cemil Yildiz
Summary: Patients with hypertrophic and oligotrophic nonunion of the femoral diaphysis associated with plate failure can be treated by Ilizarov external fixation without plate removal. Advantages of this technique include a lack of damage to the blood supply and simultaneous deformity correction.
Journal of Surgical Research | 2015
Huseyin Ozkan; Safak Ekinci; Bulent Uysal; Faruk Akyildiz; Selim Turkkan; Omer Ersen; Kenan Koca; Mehmet Murat Seven
BACKGROUND Tourniquet-induced ischemia-reperfusion, which affects local and distant organs, is very common in orthopedic surgery. Hypothermia is used in traumatic tissue during ischemic period commonly. Ozone (O3) has been recommended as a novel therapeutic agent in various medical conditions. The objective of the study was to evaluate and compare the effect of hypothermia (H) and O3 on ischemia-reperfusion injury of skeletal muscle in rats by measuring oxidative parameters and inducible nitric oxide synthase (iNOS) levels. MATERIALS AND METHODS Eighteen rats (Wistar albino) were separated into five groups randomly (sham, IR, IR + H, IR + O3, IR + H + O3; n = 6). The lower right extremity of all rats was subjected to 2 h of ischemia and 22 h of reperfusion clamping the common iliac artery and using the rubber-band technique at the level of the lesser trochanter under general anesthesia. Two hours of hypothermia were applied during the first 2 h of reperfusion in two groups. O3 was applied in two groups. All rats were sacrificed after the IR period with high dose of anesthesia. The tibialis anterior muscle and blood were saved. Levels of superoxide dismutase, glutathione peroxidase, MDA, NOx, and interleukin-1β were measured in the muscle. Creatinine kinase, lactate dehydrogenase, aspartate aminotransferase, urea, creatinine, and electrolytes were measured in serum. Immunohistochemical iNOS staining was performed on muscle samples. RESULTS The levels of MDA, NOx, and interleukin-1β in muscle were raised in the IR group compared with those in the sham group. The same parameters were lower in the groups of IR + H, IR + O3, and IR + H + O3 compared with those in the IR group. Superoxide dismutase and glutathione peroxidase activities in muscle were lower in the IR group compared with those in the sham group; however, same parameters were higher in the groups of IR + H, IR + O3, and IR + H + O3 compared with those in the IR group. Score and intensity of iNOS staining in skeletal muscle in the IR group was increased compared with that in the sham group and decreased in the groups of IR + H, IR + O3, and IR + H + O3 compared with that in the IR group. Levels of creatinine kinase, aspartate aminotransferase, and K in the three treatment groups decreased compared with those in the IR group. CONCLUSIONS These findings showed that hypothermia, which has more affect, and O3 decreased the tourniquet-induced IR injury in the rats muscle-skeletal system by reducing the levels of oxidative and nitrosative stress parameters and enhancing antioxidant enzymes. Hypothermia and O3 had no synergistic effect. Hypothermic reperfusion and O3 preconditioning might be beneficial in skeletal muscle IR injury-associated tourniquet.