Evidence brief
AO Principles of Fracture Management
Anatomic reduction (especially articular)
Stable internal fixation
Preservation of blood supply
Early, safe mobilization
Evolved to include biological fixation
AO principles revolutionized fracture care by providing a systematic approach to internal fixation. Modern adaptation emphasizes biology alongside mechanics.
Original 4 principles evolved with biological understanding. Modern emphasis: anatomic articular reduction, relative stability acceptable for metaphyseal/diaphyseal. Know lag screw principle, plate functions (compression, neutralization, buttress, bridge). Understand locking vs conventional screws.
Müller ME, Allgöwer M, Schneider R, Willenegger H. Manual of Internal Fixation: Techniques Recommended by the AO-ASIF Group. Berlin: Springer; 1969.
Level V
Expert opinion or mechanism-based reasoning