Surgical education requires the combination of declarative knowledge with spatial, procedural, and sensorimotor skills, yet most training materials rely predominantly on two-dimensional media and passive instruction. This paper presents a mixed reality (MR) training system that enables learners to physically manipulate real surgical instruments while receiving spatially registered, context-aware digital guidance. The system is designed to support embodied learning and to improve the transition between training and clinical practice. In a controlled study (N = 42), MR-based training was compared to conventional text- and image-based instruction. Results show that MR significantly improved recall of spatially embedded instrument knowledge, such as component names, while no overall advantage was observed for purely symbolic information. Both groups reported comparable gains in perceived learning success. User experience measures indicate high engagement, immersion, and minimal discomfort in the MR condition. These findings suggest that MR is particularly effective for learning tasks involving spatial relations and interaction, and may serve as a complementary modality to existing instructional approaches in early-stage surgical training.