Background: The field of spinal surgery has undergone a profound transformation over the past century, driven by advances in biomechanics, imaging technologies, surgical instrumentation, and minimally invasive techniques. Central to this evolution is the concept of spinal stability, a prerequisite for both physiological function and surgical success. Objective: To provide a comprehensive review of the historical evolution and current state of spinal surgery with a particular focus on the biomechanics of spinal stability, surgical strategies for instability, and emerging technologies aimed at preserving motion while achieving mechanical balance. Methods: This narrative review synthesizes foundational biomechanical principles, historical milestones in spinal instrumentation, the role of imaging in surgical planning, and the clinical utility of stability classifications. The evolution of surgical approaches—from open discectomy to dynamic stabilization and robotic-assisted techniques—is critically evaluated through contemporary literature. Results: While minimally invasive and microsurgical techniques offer perioperative benefits, long-term outcomes remain dependent on achieving segmental stability. Fusion remains the gold standard in cases of confirmed instability; however, motion-preserving strategies such as artificial disc replacement and pedicle-based dynamic stabilization have emerged as viable alternatives. Despite promising early results, widespread adoption is limited by complications, regulatory constraints, and cost-effectiveness concerns. Conclusion: Modern spinal surgery continues to evolve toward less invasive, stability-preserving interventions. The integration of navigation, robotics, and dynamic implants represents a paradigm shift. Nonetheless, a clear understanding of spinal biomechanics and instability remains the cornerstone of surgical decision-making. Future advances should aim to reconcile mechanical stability with motion preservation through individualized, data-driven approaches.