A novel patella fracture fixation technique: finite element analysis

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Finite element analysis

Background:

• Patella fractures represent about 1% of all bone fractures.
• Tension band wiring is a common surgical treatment, but K-wire placement details are unclear.
• Transverse patella fractures require effective fixation to ensure optimal healing.

Purpose of the Study:

• To evaluate a novel fixation technique for transverse patella fractures using K-wires and cerclage.
• To compare the biomechanical performance of different K-wire configurations against standard tension band methods.
• To analyze fracture line opening, surface pressure, and implant stress using finite element analysis.

Main Methods:

• Created 10 finite element models for AO/OTA 34-C1 patella fractures.
• Tested classical tension band wiring (circumferential and 8-shaped cerclage) as reference models.
• Evaluated K-wires at 45° and 60°, alone and with cerclage, under varying forces (200-800 N) at a 45° knee angle.

Main Results:

• K-wires placed at 60° with cerclage demonstrated superior performance over other models.
• Diagonal K-wire placement (45° or 60°) combined with cerclage outperformed standard tension band techniques.
• Analysis revealed reduced fracture line opening and implant stress with the proposed method.

Conclusions:

• The proposed K-wire fixation method at 60° with cerclage is a viable alternative for transverse patella fractures.
• This technique may lead to lower complication rates compared to traditional methods.
• Further clinical studies are warranted to confirm the efficacy of this novel fixation approach.