Biomechanical analysis of transverse patella fracture fixation techniques

• Main Author: S, Deleep
• Other Authors: Chou Siaw Meng
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/168261
• Institution: Nanyang Technological University

Patella fractures form 1% of all fractures in adults, of which the transverse fracture is the most common type. The patella is a crucial part of the extensor mechanism of the knee, playing an important role in daily movement and regular activities like bending down and walking. Current methods widely accepted for patella surgery are the Kirschner wire (K-wire) and cannulated screw constructs with cerclage wiring. While both these methods have a high union rate and good mechanical strength, there are complications involving hardware irritation of the surrounding tissues, premature fracture displacement and higher rate of implant failure. Hence, Fibre Tape Arthrex was more recently introduced due to its low profile and mechanical strength, thus reducing such post-surgery complications. The objective of this study was to compare the mechanical strength of 4 fixation groups: cannulated screws with and without cerclage wiring, K-wire and Fibre Tape Arthrex with cerclage wiring to determine the strongest construct, through a series of static tensile tests. The results obtained showed that the cannulated screw with cerclage wiring construct had the highest failure load, followed by the Fibre Tape construct. However, there was no significant difference (p > 0.05) between these 2 groups. Additionally, the Fibre Tape construct was significantly stronger (p < 0.05) than the K-wire and cannulated screw without cerclage wiring, so the Fibre Tape is a good alternative to cerclage wiring as it was able to withstand a comparable failure load to the cannulated screw with cerclage wiring construct. Generally, the tests produced consistent results with a small standard deviation. However, it is recommended that cyclical testing be performed on the same constructs, under normal human load conditions, to gain a better insight into the performance of the construct in dynamic conditions.