Navicular and fifth metatarsal base stress fractures: An illustrated anatomical review.

The navicular bone and the proximal fifth metatarsal (M5) play a vital role in maintaining the structural integrity and biomechanical stability of the foot's medial and lateral columns, respectively. Both bones' unique anatomical configuration, intricate mechanical environment and limited vascular supply make specific locations particularly vulnerable to stress fractures. Moreover, the combination of mechanical loading patterns and restricted perfusion in the navicular and proximal M5 further contributes to delayed healing, nonunion and refracture. Therefore, finding suitable treatment options for the different damage patterns involving both bones is critical for reducing complications and improving clinical results. This paper aims to clarify the anatomical and biomechanical features underlying these fractures to improve diagnosis, prevention, and clinical management in high-risk populations. LEVEL OF EVIDENCE: N/A.