An alternative patellar fracture fixation: a biomechanical study

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Trauma care

Background:

• Patellar fractures are common injuries.
• Current fixation methods include screw fixation (SF).
• Novel fixation techniques are being explored.

Purpose of the Study:

• To compare the biomechanical performance of locking plate and tension-band (PF) fixation versus cannulated screw and tension-band (SF) fixation for transverse patellar fractures.
• To test the hypothesis that both constructs have similar failure loads under simulated extension loading.

Main Methods:

• Transverse patellar fractures were created in 10 cadaveric leg pairs.
• Fixation was performed using either PF or SF constructs.
• Bone mineral density (BMD) was measured using DXA scans.
• Constructs underwent cyclic loading to failure using a servohydraulic testing machine.

Main Results:

• No significant difference in BMD between PF and SF groups.
• No significant difference in load at clinical failure between the two groups.
• Stiffness was significantly higher in the SF group.
• Ultimate strength of fixation was significantly higher in the PF group.
• BMD correlated with ultimate strength for PF fixation but not for SF fixation.

Conclusions:

• The locking plate and tension-band (PF) construct offers comparable strength to cannulated screw and tension-band (SF) fixation for patellar fractures.
• PF fixation is a safe and effective alternative to current standards of care.
• Further research may explore the long-term clinical outcomes of PF fixation.