Interlocking Nailing Versus Interlocking Plating in Intra-articular Calcaneal Fractures: A Biomechanical Study

Area of Science:

• Orthopedic surgery
• Biomechanics
• Trauma surgery

Background:

• Open reduction and internal fixation with plates is the standard for calcaneal fractures, but carries high risks of wound complications.
• Minimally invasive techniques offer potential benefits but may compromise construct stability.
• Two novel interlocking nail systems were developed for minimally invasive treatment with enhanced stability.

Purpose of the Study:

• To compare the primary stability of two minimally invasive calcaneal interlocking nail systems against a variable-angle interlocking plate.
• To evaluate biomechanical performance under dynamic and load-to-failure conditions.

Main Methods:

• A standardized Sanders type IIB calcaneal fracture model was created in 21 cadavers.
• Osteosynthesis was performed using two interlocking nail systems (C-Nail, Calcanail) and one interlocking plate (Rimbus).
• Biomechanical testing included dynamic load sequences and load-to-failure tests, with interfragmentary movement and Boehler angle measurements.

Main Results:

• No significant differences in load to failure, stiffness, or Boehler angle were observed between fixation systems.
• The C-Nail exhibited the highest load to failure.
• Dynamic failure testing revealed significantly higher failure rates for Calcanail (87.5%) and Rimbus plate (66%) compared to C-Nail (14%).

Conclusions:

• Both minimally invasive interlocking nail systems demonstrate high primary stability, comparable to interlocking plates.
• Interlocking nails are a viable alternative for treating displaced intra-articular calcaneal fractures, with C-Nail showing promising results in dynamic stability.