Preparation and characterization of composite interference screws

The Anterior Cruciate Ligament (ACL) is an important connector between the thigh bone and shinbone in the knee joint. In sport activities, ACL tears commonly occur hence they need surgery to be rebuilt. These are patellar tendons located in front of the knee and hamstring tendons found on its posterior side that are mostly used for reconstruction of the anterior cruciate ligament. These grafts can be secured by using bioabsorbable interference screws by surgery. Here we report development of composite interference screws consisting of 70% (w/w) Poly (Lactic Acid- co -Glycolic Acid) (PLGA) and 30% (w/w) β-Tricalcium Phosphate (β-TCP) with different sizes using plastic injection molding. A series of characterization techniques was used to validate the final product including Thermal Gravimetric Analysis, Fourier Transform Infrared Spectroscopy, Inductively Coupled Plasma Mass Spectrometry, Scanning Electron Microscopy. Interference screws were tested mechanically and finally biocompatibility was investigated. The studies carried out here are thought to contribute to a better understanding of the screws used in the treatment of cruciate ligament injury and new biomaterials that can be developed for treatment.