Reverse dynamisation: a modern perspective on Stephan Perren's strain theory

Area of Science:

• Biomedical Engineering
• Orthopedic Surgery
• Regenerative Medicine

Background:

• Stephan Perren's strain theory is foundational in understanding bone healing mechanics.
• Previous theories did not fully account for dynamic mechanical changes during healing.
• Optimizing bone regeneration requires active control over the mechanical environment.

Purpose of the Study:

• To review and extend Stephan Perren's strain theory using the concept of reverse dynamisation.
• To explore how variable mechanical conditions can accelerate and optimize bone healing.
• To provide a modern perspective on mechanical manipulation for bone regeneration.

Main Methods:

• Literature review focusing on animal studies and recent advances in bone regeneration.
• Analysis of the principles of reverse dynamisation in controlling mechanical stimuli.
• Examination of the transition from flexible to rigid mechanical conditions during healing.

Main Results:

• Reverse dynamisation involves a regimen of initially flexible, then rigid mechanical conditions.
• Flexible conditions promote early callus formation, while rigid conditions enhance conversion to hard callus.
• Animal studies provide evidence supporting the effectiveness of reverse dynamisation in bone healing.

Conclusions:

• Reverse dynamisation offers a method to actively control the mechanical environment for improved bone healing.
• This approach holds potential for accelerating union in fractures, osteotomies, and non-unions.
• Mechanically guided bone regeneration represents a significant advance in orthopedic treatment.