Safe zones for chevron osteotomy and lateral capsular release. Medial view shows that sites of cortical osteotomy must remain in interval between pericapsular perforators distally and nutrient artery proximally. Safe zone for lateral capsular release spares all perforators into metatarsal head proximally and all perforators into proximal phalanx distally, as long as capsulotomy is performed in line with metatarsophalangeal joint in coronal plane. Dorsal view shows relationship between osteotomy and nutrient artery and distal pericapsular perforators. First dorsal metatarsal artery and its branches are especially vulnerable to overpenetration of lateral cortex by oscillating saw.