Kompozit İnterferans Vidaların Geliştirilmesi

Abstract

The anterior cruciate ligament is one of the structures that connect the femur and tibia bones in the knee joint. This ligament, which is very important for the normal functioning of the knee, is the most important structure that prevents the tibia bone from displacing abnormally forward. Anterior cruciate ligament rupture is a very common sports injury. Reconstruction surgery is widely used in this type of injury. The purpose of treatment in individuals with anterior cruciate ligament injury is to eliminate the feeling of space and insecurity in the knee and to obtain a knee that the person can press safely during sports or challenging activities. Another goal of surgery is to return people with anterior cruciate ligament injury to their level of health prior to injury and prevent new injuries to the knee. For ligament repair, the joists of the muscles around the knee are usually used. The most commonly used tissues for this are; patellar tendons located at the front of the knee and hamstring tendons at the back of the knee. In these surgeries, tunnels are opened to the bones in the knee joint to prepare the path through which this new ligament, called the graft, is taken from the person himself. In order to implant these tendons in surgeries, bioabsorbable interference screws holding the ligament in place are widely preferred.

In this thesis we realized the chemical, physical and biological testing of resorbable composite interference screw implants of different lengths and diameters, composed of 70/30% by weight of Poly(Lactic Acid-co-Glycolic Acid) (PLGA) and β-Tricalcium Phosphate (β-TCP) for use in anterior cruciate ligament repair. In this thesis, in addition to trialing composite ratios, the analysis of the chemical changes in the polymeric phase during and after processing, the optimization of processing parameters such as temperature, pressure and drying, analysis of the effects of gamma sterilization on the polymeric phase, assessment of the mechanical properties of the composite and biocompatibility studies were conducted. To summarize the analysis results performed on the composite interference screw, which is the final output of the thesis study; As a result of TGA analysis, 71.08% PLGA amount and 28.90% β-TCP amount by weight were determined. As a result of DSC analysis; The Tg value was determined as 60.40 (ºC) and the Tm value as 162.16 (ºC). As a result of FT-IR analysis; PO43- (phosphate) group peaks were observed in 543 cm-1, 604 cm-1, 945 cm-1, 970 cm-1 bands. The carbonyl peak (-C=O-) was observed in the 1748 cm-1 band. Also the presence of Ca3(PO4)2 groups was determined by XRD analysis. The crystal size in the sample was calculated as 26 nanometers with the help of Scherrer formula. With the help of the ICP-MS analysis applied to the raw material, the amount of Pb (Lead) in the material was determined as 0.58 ± 0.03 mg / kg (ppm) and the amount of Cd (Cadmium) as 0.19 ± 0.01 mg / kg (ppm). As (Arsenic) and Hg (Mercury) levels were below the detection limit. With the help of µ-CT analysis, it was determined that the density of the substance was 99.99% by volume. 557 closed pores were identified. During the six-month degradation study, at T0 Inherent Viscosity value was calculated as 1.56 dl / g. The roughness value was calculated as approximately 25 µm. According to the results of the static torsion analysis at T0, the torsional yield strength was determined as 6.2 (Nm), the maximum torque 6.6 (Nm) and the fracture angle 43 (°).