Abstract
BACKGROUND: Cannulated Cancellous Screws fixation is done either as a sliding or static configuration according to the number, thread length and orientation of the screws. This study aims to compare the biomechanical properties of 3-CCS as sliding configuration and BDSF & 4-CCS (Alpha configuration) as static configuration, by finite element analysis for Pauwels type III fracture neck of femur. METHODS: DICOM format images of saw-bone were used to build the 3-D geometric models, which were hypermeshed to create models of Pauwels type III FNF with an angle of 65°. CAD models of three configurations were created as per AO specifications and analysed for stress distribution of bone & implant, relative displacement between fracture planes & stiffness. RESULTS: The peak stress at the fracture surface was found to be low in 4-CCS, which promotes fracture healing. 4-CCS had a decreased chance of failure due to lower implant stress and fracture surface displacement, indicating improved length stability. Overall, 4-CCS had the maximum construct stiffness, indicating a stable and rigid fixation. CONCLUSION: The static configuration of 4-CCS showed superior biomechanical properties in terms of low stress of bone & implant, and lower relative displacement of the fracture surface with high construct stiffness over other configurations. So, 4-CCS (Alpha configuration) should be the preferred configuration for the Pauwels type III FNF.