Proksimal Fibular Osteotomisi ile Kombine Tek Kompartmanlı Diz Artroplastisinin Sonlu Eleman Analizi ile İncelenmesi

Özet:&nbsp;Konservatif yöntemlerin yanı sıra, medial gonartroz tedavisi için yüksek tibial osteotomi (HTO), unikondiler diz artroplastisi (UKA) ve total diz artroplastisi (TKA) gibi çeşitli cerrahi tedavi yöntemleri uygulanmaktadır. UKA ve PFO’nun birlikte uygulanması, implant üzerindeki yükü ve ardından implant aşınmasını azaltarak daha uzun implant ömrü sağlayabilir. UKA implantı üzerinde fibulektominin uygulanması implant üzerindeki temas stresini azaltıp azaltmayacağını sonlu elemanlar (FE) modeli üzerinde araştırmayı amaçladık. Çalışmada kullanılmak üzere UKA implantasyonu ve fibula osteotomisinden kaynaklanan biyomekanik ortamdaki değişiklikleri değerlendirmek için Sonlu Elemanlar modeli geliştirildi. Menisküs, kemik ve implantlar lineer elastik izotropik malzeme olarak modellendi. UKA implantı ile 3B diz eklemi modeli oluşturulup bu model üzerinde PFO uygulanmıştır. Anatomik olarak femur başına 800N luk dikey yük uygulandı. Fibulektomi yapılmadan önce ve sonra tibial komponent üzerindeki stres değerleri değerlendirildi. Temas stresi, UKA için ortalama (10,2 MPa ± 6,8) ve UKA + Fibulektomi için (9,44 MPa ± 6,5) olarak raporlandı.PFO ve UKA’nın birlikte uygulanması, Sonlu Elemanlar Modelinde implant üzerindeki temas gerilimlerini azaltmıştır. Gözlemlerimizin bulguları ayrıca UKA’nın etkilenen hasta memnuniyetini, tıbbi etkileri ve implant ömrünü artırabilecek ek bir öneri sunmaktadır.Anahtar Kelimeler:&nbsp;unikondiler diz artroplastisi, proksimal fibular osteotomi, sonlu eleman analiziAbstract:&nbsp;Besides conservative methods, various surgical treatment modalities including high tibial osteotomy (HTO), unicondylar knee arthroplasty (UKA) and total knee arthroplasty (TKA) have been applied for the treatment of medial gonarthrosis. Combined application of UKA and PFO may enable longer implant survival by reducing the load over the implant and subsequent implant wear. We aimed to investigate on a finite element (FE) model, whether integrating a fibulectomy would reduce the contact stresses on the UKA implant. Finite Elements model developed to evaluate changes in the biomechanical environment resulting from UKA implantation and fibula osteotomy for use in the study. Menisci, bone and implants modeled as linear elastic isotropic material. We developed a 3D knee joint model with UKA implant and performed PFO on this model. A vertical load of 800N was applied anatomically to the femoral head. Stress on the tibial component was assessed before and after fibulectomy was performed. The contact stress was evaluated for UKA the mean stress (10,2 MPa ± 6,8) and for UKA + Fibulectomy (9,44 MPa ± 6,5). Combined application of PFO and UKA reduced contact stresses over the implant on a Finite Element Model. The findings of our observe additionally offer which might also additionally enhance the affected patient satisfaction, medical effects and implant survivorship of UKA.Keywords:&nbsp;unicondylar knee arthroplasty, proximal fibular osteotomy, finite element analysis</div

Radiological Evaluation of the Effects of Printing Parameters on 3D Printed Cylindrical LW-PLA Samples: Preliminary Results

Purpose: In this study, it is aimed to evaluate the radiological tissue equivalency of different 3D printed samples obtained at different printing temperatures, flow rates and infill rates. Materials and Methods: Ultimaker 3 Extended 3D printer and LW-PLA filament were used witin the scope of this study. A total of 18 cylinders were printed by using 3 different printing temperatures of 195°C, 200oC and 205oC, 3 different flow rates of 60%, 80% and 100%, and 2 different infilling rates of 90% and 100%. Each sample is obtained 1 cm in diameter and 3 cm in height. After calculating the densities of the samples, they were imaged by a Philips Brilliance 128-slice computed tomography scanner. In the images, the average Hounsfield Unit values and the standard deviations of these values were recorded at 5 different axial positions for each sample. The mean HU and standard deviation values recorded over 5 slices were evaluated according to the printing parameters. Results: Density of the samples are obtained between 0.63 g/cm3 and 1.19 g/cm3. It was observed that the density of the samples were directly proportional to the flow rate and the infill rate. In addition, the average Hounsfield Unit values of the samples varied between -450 and +73. On the other hand, the standard deviation values were recorded between ±6 and ±25. It was observed that the mean Hounsfield Unit values increased with increasing temperature, flow rate and infill rate. The standard deviation values decreased with increasing printing temperatures. Conclusion: Considering the mean Hounsfield Unit values of different tissues imaged in routine computed tomography examinations, it is concluded that the samples obtained at different printing parameters using LW-PLA filament may have radiological properties that can represent many soft tissues.</p