A comparison between cannulated and non-cannulated cancellous screws used in the fixation of simulated femoral neck fracture

• Main Author: Tan, Daren Teng Yeow.
• Other Authors: Chou Siaw Meng
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/40444
• Institution: Nanyang Technological University

There are an increasing number of femoral neck fractures worldwide which may rise to 6.3 million cases by the year 2050. The associated healthcare costs are also expected to increase significantly to $8.7 billion. Screw fixation was considered as ideal treatment of undisplaced or minimally displaced neck fractures in terms of cost and strength. A comparison of the strength of fixation using cannulated versus non-cannulated screws was done via experiments. A jig prototype was designed and manufactured to ensure the accuracy of the screws position and the repeatability of all experimental conditions. The repeatability was confirmed by a coefficient of variations data which range from 5% to 13%. Experiments were conducted to test for differences in the maximum load to failure, maximum displacement at failure and stiffness for both types of screw fixation. A mean maximum load to failure at 2452.25 N, maximum displacement at failure at 22.39 mm and stiffness of 110.06 N/mm was observed for the non-cannulated screw fixation. A mean maximum load to failure of 2013.21 N, maximum displacement at failure at 21.29 mm and stiffness of 94.77 N/mm was observed for the cannulated screw fixation. The mean maximum load to failure as well as stiffness was higher for the non-cannulated screw fixation with statistical significance.