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Dive into the research topics where Gokhan Demirkiran is active.

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Featured researches published by Gokhan Demirkiran.


Spine | 2014

Local intrawound vancomycin powder decreases the risk of surgical site infections in complex adult deformity reconstruction: a cost analysis.

Alexander A. Theologis; Gokhan Demirkiran; Matt Callahan; Murat Pekmezci; Christopher P. Ames; Vedat Deviren

Study Design. Retrospective cohort analysis. Objective. To evaluate the rate of surgical site infections (SSIs) and cost-effectiveness of the use of intraoperative vancomycin powder in thoracolumbar adult deformity procedures. Summary of Background Data. The rates of SSI remain unacceptably high in adult spinal deformity surgery despite routine intravenous antibiotics. Vancomycin powder applied directly to the wound intraoperatively has shown promise for decreasing SSI in spine surgery. Methods. Adults who underwent adult deformity reconstruction by 2 surgeons between 2008 and 2012 with a minimum of 3 months of clinical follow-up were retrospectively reviewed. The patients were subdivided into those who had received only routine perioperative intravenous antibiotics (control) and those who received intravenous antibiotics and 2 g of vancomycin powder applied into the surgical wound. The primary outcome was SSI within 90 days. Secondary outcomes included surgical/clinical parameters and SSI-related medical costs based on hospital billing records. Results. Two hundred fifteen patients were evaluated—controls (n = 64) and vancomycin powder group (n = 151). The average number of levels fused was 10 (5–17, control) and 12 (5–19, vancomycin). The mean follow-up was 34 months (3–68 mo, control) and 18 months (3–35 mo, vancomycin) (P < 0.05). There were significantly fewer hospital readmissions within 90 days for SSI in patients who received vancomycin powder (2.6%; 4/151) compared with controls (10.9%; 7/64) (P = 0.01). There were no reported adverse events related to the intrawound vancomycin use. The average cost per patient of treating a postoperative SSI was higher in the control group (


Spine | 2016

Magnetically controlled Growing Rods for Early-onset Scoliosis: A Multicenter Study of 23 Cases With Minimum 2 years Follow-up.

Pooria Hosseini; Jeff Pawelek; Gregory M. Mundis; Burt Yaszay; John Ferguson; Ilkka Helenius; Kenneth M.C. Cheung; Gokhan Demirkiran; Ahmet Alanay; Alpaslan Senkoylu; Hazem Elsebaie; Behrooz A. Akbarnia

34,388) than in the study group (


Journal of Pediatric Orthopaedics B | 2013

Evaluation of acetabular development after Dega acetabuloplasty in developmental dysplasia of the hip.

Cemalettin Aksoy; Caglar Yilgor; Gokhan Demirkiran; Omur Caglar

28,169). With the use of vancomycin powder, there was a cost saving of


Spine | 2012

The Effect of Pedicle Screw Insertion at a Young Age on Pedicle and Canal Development

Zeynep Deniz Olgun; Gokhan Demirkiran; Mehmet Ayvaz; Emre Karadeniz; Muharrem Yazici

244,402 per 100 complex spinal procedures. Conclusion. Local application of vancomycin powder significantly decreased SSI for adults undergoing spinal reconstructive surgery. This resulted in cost savings of


Journal of Pediatric Orthopaedics | 2017

Implant Complications After Magnetically Controlled Growing Rods for Early Onset Scoliosis: A Multicenter Retrospective Review

Edmund Choi; Burt Yaszay; Gregory M. Mundis; Pooria Hosseini; Jeff Pawelek; Ahmet Alanay; Haluk Berk; Kenneth M.C. Cheung; Gokhan Demirkiran; John Ferguson; Tiziana Greggi; Ilkka Helenius; Guido La Rosa; Alpaslan Senkoylu; Behrooz A. Akbarnia

244,402 per 100 thoracolumbar adult deformity procedures. Level of Evidence: 3


Scoliosis | 2011

Is decreased bone mineral density associated with development of scoliosis?A bipedal osteopenic rat model

Ozgur Dede; Ibrahim Akel; Gokhan Demirkiran; Nadir Yalcin; Ralph S. Marcucio; Emre Acaroglu

Study Design. Retrospective study. Objective. To report 2-year clinical and radiographic results of patients treated with magnetically controlled growing rods (MCGR). Summary of Background Data. MCGR for early-onset scoliosis has been reported to provide adequate spinal growth and curve correction by eliminating surgical lengthening procedures. This study was designed to report the results of MCGR patients with 2-year follow-up. Methods. A retrospective study of MCGR patients with the following inclusion criteria: (i) major curve size ≥30°, (ii) T1-T12 height <22 cm, (iii) <11-years old; all at the time of index surgery was performed. Of 54 patients enrolled, 23 had 2-year follow-up. Both primary and conversion patients were evaluated at baseline 6, 12, and 24 months. Results. Mean preoperative age in the primary group was 6.6 ± 2.6 years versus 8.3 ± 2.2 years for the conversion group. A total of 41 adverse events occurred in 11 patients, of which 14 events were implant related. Major coronal curve magnitude improved from 61.3° to 34.3° from baseline to postoperation in primary cases and from 49.4° to 43.8° in conversion cases. Curve correction was maintained for 2 years in both groups. T1-S1 height improved from 252.7 to 288.9 mm in primary cases and was maintained for 2 years. However, conversion cases had some decline in T1- S1 height (270.3 at baseline to 294.4 mm post-MCGR and 290.2 mm at 2-year follow-up; mean loss of 4.2 mm (1.5%) from postoperation to 2 years, P > 0.05). Conclusion. This study showed satisfactory curve correction and growth is achieved among primary cases. T1-S1 height in conversion cases had a slight decline in 2 years. However, this decline was not statistically significant. Level of Evidence: 3


Journal of Pediatric Orthopaedics | 2014

Safety and efficacy of instrumented convex growth arrest in treatment of congenital scoliosis.

Gokhan Demirkiran; Guney Yilmaz; Burak Kaymaz; Ibrahim Akel; Mehmet Ayvaz; Emre Acaroglu; Ahmet Alanay; Muharrem Yazici

The Dega acetabuloplasty is considered to be safe and effective in the treatment of hip pathologies, but the number of clinical follow-up series in the literature is not sufficient. The aim of our study was to identify the alterations in acetabular development in 35 patients (43 hips) with developmental dysplasia of the hip who were treated with Dega acetabuloplasty. This study is a retrospective review of 7 years of one surgeon’s experience with Dega acetabuloplasty performed between May 2002 and January 2010. A total of 35 patients (43 hips) were evaluated, with an average of 58 months (range 25–108 months) of follow-up. Dega acetabuloplasties that were performed for neuromuscular or other conditions and patients who had a follow-up period of less than 2 years were excluded. Open reduction was performed and femoral shortening or varus osteotomy was added whenever the surgeon considered it necessary. The preoperative mean acetabular index (AI) was 35° (range 27–53°), and the mean age of operation was 35 months (range 18–65 months). The mean AI in the early postoperative period was 20° (range 10–34°). At the last follow-up, all patients were pain-free and had unlimited physical activity with no limp, with an improvement in AI to 13° (range 5–23°). An improvement of 7° was observed in AI within the follow-up period. The maximum improvement was 17° and occurred within an 83-month period. In 42 of 43 (98%) of the hips, the AI improved; in one of 43 (2%) of the hips, it remained unchanged and in none of hips did the AI worsen over time. This study is one of the largest series in the English-language orthopedic literature to report that Dega osteotomy is effective in improving the AI and femoral coverage, and that the index further improves over the course of the follow-up period.


Current Opinion in Pediatrics | 2014

2014 Update on the 'growing spine surgery' for young children with scoliosis.

Ozgur Dede; Gokhan Demirkiran; Muharrem Yazici

Study Design. A longitudinal case study. Objective. To determine whether pedicle screws placed in an immature spine exert effect on the continued growth of the vertebral body. Summary of Background Data. Pedicle screws have revolutionized surgical treatment of spinal deformities by allowing a mode of secure fixation that provides consistently better correction rates in adults and adolescents. In the young child, however, the trajectory of pedicle screws takes them through an open physis: the neurocentral cartilage. There exists little information regarding the possible effect of pedicle screws inserted at a young age on further development of the spine and the spinal canal. Methods. Patients undergoing pedicle screw instrumentation of at least 2 levels before the age of 5 years (60 mo) for the first time for any diagnosis and who had been followed for at least 24 months were included. Measurements were performed in instrumented and adjacent noninstrumented levels without visible deformity in pre- and postoperative cross-sectional images and compared using statistical methods. Results. Ninety segments in 15 patients met the inclusion criteria (average age at instrumentation 46.3 mo [range, 29–60 mo]). Forty segments had no screws and 50 had at least 1 screw. Pedicle length and vertebral body diameter had significantly increased in both groups, whereas spinal canal parameters did not change significantly. No significant difference was observed between the growth rates in levels with or without screws in pedicle length, vertebral body diameter, or spinal canal parameters (anterior-posterior and interpedicular diameters, and area). Conclusion. Pedicle screw instrumentation performed before the age of 5 years does not cause a negative effect on the growth of pedicles, the transverse plane of the vertebral body, or the spinal canal. It can be safely performed in the treatment of deformity in this age group.


Journal of Pediatric Orthopaedics | 2014

The effect of dual growing rod instrumentation on the apical vertebral rotation in early-onset idiopathic scoliosis.

Saygin Kamaci; Gokhan Demirkiran; Ismayilov; Zeynep Deniz Olgun; Muharrem Yazici

Background: Traditional growing rods have a reported wound and implant complication rate as high as 58%. It is unclear whether the use of magnetically controlled growing rods (MCGR) will affect this rate. This study was performed to characterize surgical complications following MCGR in early onset scoliosis. Methods: A multicenter retrospective review of MCGR cases was performed. Inclusion criteria were: (1) diagnosis of early onset scoliosis of any etiology; (2) 10 years and younger at time of index surgery; (3) preoperative major curve size >30 degrees; (4) preoperative thoracic spine height <22 cm. Complications were categorized as wound related and instrumentation related. Complications were also classified as early (<6 mo from index surgery) versus late (>6 mo). Distraction technique and interval of distraction was surgeon preference without standardization across sites. Results: Fifty-four MCGR patients met inclusion criteria. There were 30 primary and 24 conversion procedures. Mean age at initial surgery was 7.3 years (range, 2.4 to 11 y), and mean duration of follow-up 19.4 months. Twenty-one (38.8%) of 54 patients had at least 1 complication. Fifteen (27.8%) had at least 1 revision surgery. Six (11.1%) had broken rods (2 to 4.5 and 4 to 5.5 mm rods); two 5.5 mm rods failed early (4 mo) and 4 late (mean=14.5 mo). Six (11.1%) patients experienced 1 episode of lack or loss of lengthening, of which 4 patients subsequently lengthened. Seven patients (13.0%) had either proximal or distal fixation-related complication at average of 8.4 months. Two patients (3.7%) had infections requiring incision and drainage; 1 early (2 wk) with wound drainage and 1 late (8 mo). The late case required removal of one of the dual rods. Conclusions: This study shows that compared with traditional growing rods, MCGR has a lower infection rate (3.7% vs. 11.1%). MCGR does not appear to prevent common implant-related complications such as rod or foundation failure. The long-term implication remains to be determined. Level of Evidence: Level IV.


Journal of Spinal Disorders & Techniques | 2015

Anterior and Posterior Vertebral Column Resection Versus Posterior-only Technique: A Comparison of Clinical Outcomes and Complications in Congenital Kyphoscoliosis.

Gokhan Demirkiran; Ozgur Dede; Emre Karadeniz; Deniz Olgun; Mehmet Ayvaz; Muharrem Yazici

BackgroundAn association between adolescent idiopathic scoliosis and osteopenia has been proposed to exist. It is still not clear whether there is such an association and if so, whether osteopenia is a causative factor or a consequence. Our previous pilot studies have suggested the presence of osteopenia in scoliotic animals. The aim of this study was to investigate the development of scoliosis in an unpinealectomized bipedal osteopenic rat model, implementing osteoporosis as a causative factor.MethodsFifty Sprague-Dawley rats were rendered bipedal at the 3rd postnatal week and separated into control (25 rats) and heparin (25 rats receiving 1 IU/gr body weight/day) groups. DEXA scans after 4 weeks of heparin administration showed low bone mass in the heparin group. Anteroposterior and lateral x-rays of the surviving 42 animals (19 in heparin and 23 in control groups) were taken under anesthesia at the 40th week to evaluate for spinal deformity. Additional histomorphometric analysis was done on spine specimens to confirm the low bone mass in heparin receiving animals. Results of the DEXA scans, histomorphometric analysis and radiological data were compared between the groups.ResultsBone mineral densities of rats in the heparin group were significantly lower than the control group as evidenced by both the DEXA scans and histomorphometric analyses. However, the incidence of scoliosis (82% in heparin and 65% in control; p > 0.05) as well as the curve magnitudes (12.1 ± 3.8 in heparin versus 10.1 ± 4.3 degrees in control; p > 0.05) were not significantly different. Osteopenic rats were significantly less kyphotic compared to control specimens (p = 0.001).ConclusionsThis study has revealed two important findings. One is that bipedality (in the absence of pinealectomy) by itself may be a cause of scoliosis in this animal model. Further studies on animal models need to consider bipedality as an independent factor. Secondly, relative hypokyphosis in osteopenic animals may have important implications. The absence of sagittal plane analyses in previous studies makes comparison impossible, but nonetheless these findings suggest that osteopenia may be important in the development of 3D deformity in adolescent idiopathic scoliosis.

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Ozgur Dede

University of Pittsburgh

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Ilkka Helenius

Turku University Hospital

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