Browsing by Author "Kaya, Ibrahim"

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A Novel 3D Printed Custom Antibiotic Spacer Mold for Osteomyelitis Cases which are Prone to Instability
(GAZI UNIV, FAC MED, 2018-01-01) Gemalmaz, Halil Can; Sariyilmaz, Kerim; Ozkunt, Okan; Sungur, Mustafa; Kaya, Ibrahim; Dikici, Fatih
Presence of complex bone defects in osteomyelitis treatment may be challenging for the surgeon. Antibiotic cement spacers take a role in managing these defects. The available techniques and systems of antibiotic cement spacers have their pros and cons. There are cases in which these standard options may fail, mainly due to stability related issues. In this report, we present an antibiotic spacer technique in a very complex bone defect that is prone to failure if managed by routine spacer applications. Anticipating that any standard spacer application methodology will fail, we decided to make our own custom antibiotic cement spacer. We used the patient's uninjured side's tomography data to create a custom 3D spacer mold model with the help of a computer software. Later this 3D spacer mold model was printed with a 3D printer. The print out was sterilized and used to cast a custom antibiotic cement spacer resulting in a perfect fit in the defect.
Brain region-specific amyloid plaque-associated myelin lipid loss, APOE deposition and disruption of the myelin sheath in familial Alzheimer's disease mice
(WILEY, 2020-01-01) Kaya, Ibrahim; Jennische, Eva; Lange, Stefan; Baykal, Ahmet Tarik; Malmberg, Per; Fletcher, John S.
There is emerging evidence that amyloid beta (A beta) aggregates forming neuritic plaques lead to impairment of the lipid-rich myelin sheath and glia. In this study, we examined focal myelin lipid alterations and the disruption of the myelin sheath associated with amyloid plaques in a widely used familial Alzheimer's disease (AD) mouse model
Comparison of fixation techniques in Vancouver type AG periprosthetic femoral fracture: a biomechanical study
(TURKISH ASSOC ORTHOPAEDICS TRAUMATOLOGY, 2016-01-01) Sariyilmaz, Kerim; Korkmaz, Murat; Ozkunt, Okan; Gemalmaz, Hall Can; Sunguill, Mustafa; Baydogan, Murat; Kaya, Ibrahim; Okla, Fatih
Objective: The purpose of this study was to biomechanically compare cable, trochanteric grip plate, and locking plate techniques in Vancouver type AG fracture model in an in vitro test environment. Methods: Fifteen pieces of fourth-generation synthetic femora were separated into 3 groups of 5 models each. A greater trochanteric fracture model was created after femoral stem implantation. Group 1 was fixated with only cable, Group 2 with trochanteric grip plate, and Group 3 with locking plate. Horizontal stiffness, axial stiffness, and failure loads were compared between the groups. Results: In horizontal compression tests, Group 3 had the highest values, but the only statistically significant difference was between the locking plate group and cable group. Axial distraction test results showed that mean stiffness of Group 1 was 94.6 +/- 9.44 N/mm, that of Group 2 was 174.8 +/- 28.64 N/mm, and that of Group 3 was 185.6 +/- 71.64 N/mm. While locking plate versus cable fixation and grip plate fixation versus cable fixation showed statistically significant differences (p<0.05), comparison of locking plate versus grip plate fixation showed no statistically significant difference (p>0.05). In axial failure load test, Group 3 had the highest results. The only significant difference was between the locking plate and cable groups (p<0.05). Conclusion: In Vancouver type AG fractures stable fixation may be achieved with grip plate fixation and locking plates, with the former ensuring more stable osteosynthesis.
Postoperative mechanical alignment analysis of total knee replacement patients operated with 3D printed patient specific instruments: A Prospective Cohort Study
(TURKISH ASSOC ORTHOPAEDICS TRAUMATOLOGY, 2019-01-01) Gemalmaz, Halil Can; Sariyilmaz, Kerim; Ozkunt, Okan; Sungur, Mustafa; Kaya, Ibrahim; Dikici, Fatih
Objective: Total knee replacement (TKR) is a surgical treatment for final stage gonarthrosis. The lifespan of the prosthetic implants used in TKR surgery is a major interest for the orthopaedic research community. Previously, proper implant alignment of the implants has been advocated for longevity of the TKR surgery. Recently, patient-specific (PSI) instruments have been proposed to improve the mechanical alignment of the TKR by permitting better implant positioning over conventional TKR surgery. The aim of this study is to compare the mechanical alignment results of patients operated with PSIs and conventional instruments. Methods: Two groups of 20 patients chosen in a quasi-random manner have been compared in this study. In the first group femoral distal and tibial osteotomies were made by a PSI which was produced by the patients' computed tomography scans. All osteotomies in the control group were made with the TKR set's routine instruments by conventional means. Patients' preoperative and postoperative mechanical femorotibal angles (mFTA), femoral coronal angles (FCA), tibial coronal angles (TCA) were measured and the number of outliers which showed more than 3 degrees of malalignment were counted in both groups for comparison. Results: The average postoperative mFTA was found to be 2.09 degrees for the PSI group and in was found to be 2.84 degrees for the control which was not statistically significant. The comparison of postoperative FCA and TCA also did not show significant difference between the groups. The number of outliers showing more than 3 degrees of malalignment per group were found to be 1 out of 20 (5\%) for the PSI group and 7 out of 20 (35\%) for the control which was statistically significant. Conclusion: In this study patient-specific instrumentation provided significantly better mechanical alignment compared to conventional TKR for the frequency of outlier cases with malalignment beyond 3 degrees. PSI proved no significant difference when the groups were compared for mFTA, FCA and TCA. Our findings support that PSI may improve TKR alignment by improving the ratio of the outlier patients with marked malalignment. (C) 2019 Turkish Association of Orthopaedics and Traumatology. Publishing services by Elsevier B.V.