The Key and the Door: Universal Concepts of Reduction in Fracture Surgery.

Anatomic reduction is fundamental to successful osteosynthesis, yet it remains one of the most challenging surgical skills to teach and master. Although no framework can encompass the full complexity of fracture surgery, this article distills some aspects of the "art" of reduction into foundational concepts to guide surgical strategy. We review these principles through intuitive metaphors: the "key" (distract, reorient, compress), the "door" (establish a hinge and close), and the "puzzle" (reduce the easiest piece first). These concepts are integrated with the biomechanical distinction between tension-sided failures, which are often amenable to direct reduction, and compression-sided failures, sometimes better suited for indirect reduction through ligamentotaxis. The practical application of this conceptual framework is demonstrated across a spectrum of common fractures, including those of the proximal and distal humerus, acetabulum, femoral neck, and tibial plateau. By providing a systematic toolkit, these principles aim to transform fracture reduction from an abstract challenge into a more logical, approachable problem for surgeons at all levels of training.